Publications by year
In Press
Duncan E, Arrowsmith JA, Bain CE, Bowdery H, Broderick A, Chalmers T, Fuller WJ, Galloway T, Lee JH, Lindeque PK, et al (In Press). Diet-related selectivity of macroplastic ingestion in green turtles (Chelonia mydas) in the eastern Mediterranean. Scientific Reports
Godley BJ, Galloway T, Parton K (In Press). Global review of shark and ray entanglement in anthropogenic marine debris. Endangered Species Research
Godley BJ, Witt MJ, Galloway TS, Nelms SE, Coombes C, Foster LC, Lindeque PK (In Press). Marine anthropogenic litter on British beaches: a 10-year nationwide assessment using citizen science data. Science of the Total Environment
Jones J, Porter A, Muñoz-Pérez J, Alarcón-Ruales D, Galloway T, Godley B, Santillo D, Vagg J, Lewis C (In Press). Plastic contamination of the Galapagos marine food web and the relative risks to native species.
Abstract:
Plastic contamination of the Galapagos marine food web and the relative risks to native species
Abstract
. Ecuador’s Galapagos Islands and their unique biodiversity are a global conservation priority. We investigated the presence, partitioning and environmental drivers of plastic contamination across the marine ecosystem, designing a systematic risk scoring analysis to identify the most vulnerable species. Beach contamination varied by site (macroplastic 0 - 0.66 items.m-2, large microplastics 0 - 448.8 particles.m-2, small microplastics 0 – 74.6 particles.kg-1), with high plastic accumulation on east-facing beaches indicating input from the Humboldt Current. Local littering and waste management leakages accounted for 2% of macroplastic. Microplastics (including synthetic cellulosics) were prevalent in sediments (6.7 - 86.7 particles.kg-1) and surface seawater (0.04 - 0.89 particles.m-3), with elevated concentrations in the harbour suggesting local input. Microplastics were present in all seven marine invertebrate species examined, found in 52% of individuals (n = 123). Risk scoring identified 32 species in need of urgent, targeted monitoring and mitigation including pinnipeds, seabirds, turtles, sharks and corals.
Abstract.
2023
Harley-Nyang D, Memon FA, Baquero AO, Galloway T (2023). Variation in microplastic concentration, characteristics and distribution in sewage sludge & biosolids around the world.
Sci Total EnvironAbstract:
Variation in microplastic concentration, characteristics and distribution in sewage sludge & biosolids around the world.
Microplastics have been reported in wastewater treatment works across the world. The majority of microplastics are removed during the wastewater treatment process, with removal rates between 57 % and 99 %. What happens to the microplastics that are removed from the wastewater, and how they accumulate in sewage sludge and biosolids (by products of the wastewater treatment process), remains a topic of high interest. Here we systematically reviewed the current state of knowledge on the presence, concentration, and characteristics of microplastics in sewage sludge and biosolids globally to understand how biosolids may act as a pathway for microplastics pollution to soils. A systematic search was performed on the Web of Science and Science Direct data bases. Sixty-five studies reporting on microplastic pollution in sewage sludge and biosolid products were identified, spanning twenty-five countries. Reported microplastic concentrations varied considerably from 0.193 microplastics/g to 1.69 × 105 microplastics/g with a median microplastic concentration of 22.41 microplastics/g, illustrating how much microplastics are captured during the wastewater treatment process, and retained in the sewage sludge. The extent to which biosolid recycling pollutes the terrestrial environment was compared across countries. High numbers of microplastics were estimated to reach fields via biosolids with wide variation across countries (8.2 × 1010 to 1.29 × 1015 microplastics/year) although, there was no significant difference in microplastic concentration between fields with a history of biosolid applications and control fields. The comparative risk this delivery of approx. 0.4 to 6430 tonnes poses compared to the environmental benefits of nutrient and carbon recycling associated with biosolids reuse or compared to other sources of microplastics pollution remains a global research imperative. The next step in scientific research needs to focus on solutions to the biosolid and circular economy conundrum - biosolids are a valuable source of nutrients, but contain high concentrations of microplastics, which are ultimately entering the terrestrial environment.
Abstract.
Author URL.
2022
Eales J, Bethel A, Galloway T, Hopkinson P, Morrissey K, Short RE, Garside R (2022). Human health impacts of exposure to phthalate plasticizers: an overview of reviews.
Environ Int,
158Abstract:
Human health impacts of exposure to phthalate plasticizers: an overview of reviews.
In this review of reviews, we overview the current global body of available evidence from structured reviews of epidemiological studies that explore human health outcomes associated with exposure to phthalates (chemical plasticisers commonly found in plastics). We found robust evidence for an association with lower semen quality, neurodevelopment and risk of childhood asthma, and moderate to robust evidence for impact on anogenital distance in boys. We identified moderate evidence for an association between phthalates/metabolites and low birthweight, endometriosis, decreased testosterone, ADHD, Type 2 diabetes and breast/uterine cancer. There was some evidence for other outcomes including anofourchette distance, fetal sex hormones, pre-term birth, lower antral follicle count, reduced oestrodiol, autism, obesity, thyroid function and hearing disorders. We found no reviews of epidemiological human studies on the impact of phthalates from recycled plastics on human health. We recommend that future research should use urine samples as exposure measures, consider confounders in analyses and measure impacts on female reproductive systems. Our findings align with emerging research indicating that health risks can occur at exposure levels below the "safe dose" levels set out by regulators, and are of particular concern given potential additive or synergistic "cocktail effects" of chemicals. This raises important policy and regulatory issues for identifying and controlling plastics and health related impacts and highlights a need for more research into substances of concern entering plastics waste streams via recycling.
Abstract.
Author URL.
Thrift E, Porter A, Galloway TS, Coomber FG, Mathews F (2022). Ingestion of plastics by terrestrial small mammals.
Sci Total Environ,
842Abstract:
Ingestion of plastics by terrestrial small mammals.
The exposure of wildlife to waste plastic is widely recognised as an issue for aquatic ecosystems but very little is known about terrestrial systems. Here, we addressed the hypothesis that UK small mammals are ingesting plastics by examining faecal samples for the presence of plastic using micro Fourier Transform infrared microscopy. Plastic polymers were detected in four out of the seven species examined (European hedgehog (Erinaceus europaeus), wood mouse (Apodemus sylvaticus); field vole (Microtus agrestis); brown rat (Rattus norvegicus)). Ingestion occurred across species of differing dietary habits (herbivorous, insectivorous and omnivorous) and locations (urban versus non-urban). Densities excreted were comparable with those reported in human studies. The prevalence of confirmed plastics in the 261 faecal samples was 16.5 % (95 % CI 13 %, 22 %). Most (70 %) of the 60 plastic fragments were
Abstract.
Author URL.
Harley-Nyang D, Memon FA, Jones N, Galloway T (2022). Investigation and analysis of microplastics in sewage sludge and biosolids: a case study from one wastewater treatment works in the UK. Science of the Total Environment, 823, 153735-153735.
Lewis C, Jones JS, Guézou A, Medor S, Nickson C, Savage G, Alarcón-Ruales D, Galloway TS, Muñoz-Pérez JP, Nelms SE, et al (2022). Microplastic Distribution and Composition on Two Galápagos Island Beaches, Ecuador: a Spatiotemporal Assessment Using Citizen Science Derived Data.
Hobbs C (2022). Movement of plastic debris through the benthic marine ecosystem and its interactions with benthic organisms.
Abstract:
Movement of plastic debris through the benthic marine ecosystem and its interactions with benthic organisms
Plastics, including those of buoyant polymers are increasingly found in high concentrations in benthic sediments where they have the potential to be ingested and interact with a diverse range of benthic marine species. This thesis combines field work and laboratory mesocosm experiments to look at the presence and characteristics of synthetic particles found in situ within estuarine benthic habitats, and then investigates experimentally how interactions with benthic species might influence the fragmentation and movement of plastics within a test benthic ecosystem.
Firstly, a field study was undertaken to determine the abundance and particle characteristics of synthetic particles in benthic sediment and within natural populations of the benthic-dwelling polychaete, Hediste diversicolor. Sediment (10 samples per site) and worm (30 individuals per site) were collected from three locations of differing anthropogenic influence across South Devon, UK. Samples were analysed for synthetic particle content using density separation for sediments or tissue digestion, followed by particle identification using Fourier-transform infrared spectroscopy (FTIR). All sediment samples analysed contained synthetic (i.e. plastic and/or modified cellulose) particles, but with significantly higher abundance in sediment from the Plym estuary (mean 116 synthetic particles kg-1 +/- 18.09 SE) compared to Kingsbridge (mean 62 synthetic particles kg-1 +/- 13.55 SE; P < 0.001). of the H. diversicolor sampled, 48% of the worms contained synthetic particles with a mean of 0.73 synthetic particles per worm +/- 0.15 SE and no difference in particles per worm by site (P = 0.30). The dominant polymer type found within the sediment was polypropylene, accounting for 30 % of the total synthetic particles across the three sites. Semi-synthetic cellulose fibres and polystyrene particles were the most prevalent particle types found within H. diversicolor.
The potential role of benthic invertebrates in the fragmentation and movement of plastic litter within a test benthic ecosystem was investigated via a mesocosm study. Biofouled polyethylene (PE) crates (half a crate per tank) were used as the test macroplastic. Mesocosms comprising three benthic species with different functional roles; the purple sea urchin Paracentrotus lividus, the blue mussel Mytilus edulis and the sediment-dwelling polychaete, Alitta virens were maintained for 13 days under four treatment scenarios (3 tanks per treatment); 1) a no plastic control comprising all species and macroalgae but no added crate, 2) plastic crate, all organisms but macroalgae absent, 3) plastic crate, all organisms and macroalgae present and 4) plastic crate, urchins and ragworms (no mussels) with macroalgae present. In every tank containing a plastic crate and urchins, small plastic fragments were recovered from the water and from the sediment. PE fragments were present within 100 % of urchins (6.3 +/- 1.6 (SE) particles per individual), 62 % of mussels (3.5 +/- 0.6 (SE) particles per individual) and 65 % of ragworms (2.2 +/- 0.5 (SE) particles per individual), confirming urchins are effective at generating plastic fragments (size range 10.2 μm to 5816.6 μm) that are subsequently bioavailable for uptake by benthic-dwelling organisms. In this experimental system, a combination of urchin food availability and mussel presence acted to increase the bioavailability and uptake of plastic fragments into a sediment-dwelling polychaete with a ~ four-fold increase in PE fragments found within ragworms when both macroalgae and mussels were present (3.6 +/- 0.5 (SE) particles per individual) compared to mussel absence (0.9 +/- 0.2 (SE) particles per individual), and a ~ 1.6-fold increase compared to macroalgae absence (2.2 +/- 0.7 (SE) particles per individual).
Overall, this work advances the understanding of how organisms alter the distribution, accumulation and fate of microplastic in the benthic ecosystem while also highlighting the prevalence of synthetic particle contamination in benthic sediments.
Abstract.
Burrows SD, Ribeiro F, O'Brien S, Okoffo E, Toapanta T, Charlton N, Kaserzon S, Lin CY, Tang C, Rauert C, et al (2022). The message on the bottle: Rethinking plastic labelling to better encourage sustainable use.
Environmental Science and Policy,
132, 109-118.
Abstract:
The message on the bottle: Rethinking plastic labelling to better encourage sustainable use
Plastic pollution continues to worsen globally in volume and complexity. The complexity in plastic production, use and disposal is significant, highlighting the importance of clear communication to consumers. Yet despite this, poor plastic labelling is clear, evident from poor waste management metrics even in the most equipped countries. Plastic labelling must change to contribute to a holistic intervention on global plastic mismanagement. Discussion on this topic leads to three key recommendations: 1. An accurate and clear “sustainability scale” to empower consumers to make decisions informed by environmental and human health implications; 2. Directions for appropriate disposal action in the region of purchase; 3. A comprehensive list of plastic composition, including additives.
Abstract.
2021
Rowlands E, Galloway T, Manno C (2021). A Polar outlook: Potential interactions of micro- and nano-plastic with other anthropogenic stressors.
Science of the Total Environment,
754Abstract:
A Polar outlook: Potential interactions of micro- and nano-plastic with other anthropogenic stressors
Polar marine ecosystems may have higher sensitivity than other ecosystems to plastic pollution due to recurrent physical and biological features; presence of ice and high UV radiation, slow growth rates and weak genetic differentiation of resident biota, accumulation of persistent organic pollutants and heavy metals, and fast rates of warming and global ocean acidification. Here, we discuss potential sources of and exposure to micro- and nano-plastic in polar marine ecosystems and potential mixture effects of micro- and nano-plastic coupled with chemical and climate related stressors. We address the anthropogenic contaminants likely to be ‘high risk’ for interactions in Arctic and Antarctic waters for reasons such as accumulation under sea-ice, a known sink for plastic particulates. Consequently, we address the potential for localised plastic-chemical interactions and possible seasonal fluctuations in interactions associated with freeze-thaw events. The risks for keystone polar species are also considered, incorporating the behavioural and physiological traits of biota and addressing potential ‘hotspot’ areas. Finally, we discuss a possible direction for future research.
Abstract.
Coppock RL, Lindeque PK, Cole M, Galloway TS, Näkki P, Birgani H, Richards S, Queirós AM (2021). Benthic fauna contribute to microplastic sequestration in coastal sediments.
Journal of Hazardous Materials,
415Abstract:
Benthic fauna contribute to microplastic sequestration in coastal sediments
Microplastics are ubiquitous in the marine environment, however, the mechanisms governing their uptake by, and burial within, seabed habitats are poorly understood. In this study, microplastic burial and its impact on fauna-mediated sedimentary processes was quantified at three coastal sites, and the potential contribution of burrowing faunal communities to this process assessed via functional trait diversity analysis of field data. In addition, laboratory exposures were used to assess whether sediment-processing undertaken by the brittlestar Amphiura filiformis, a key species in the sampled area, could explain the burial of microplastic fibres. Field observations confirmed broad-scale burial of microplastics across the coastal seabed, consistent across sites and seasons, with microplastic sequestration linked to benthic-pelagic exchange pathways, driven by burrowing fauna. Brittlestars were observed to bury and line their burrow walls with microfibres during experiments, and their burial activity was also modified following exposure to nylon fibres, relative to controls. Collectively, these results indicate that biodiverse and functionally important seabed habitats act as microplastic sinks, with burrowing fauna contributing to this process via well-known benthic-pelagic pathways, the rates of which are modified by plastic exposure.
Abstract.
Wicaksono EA, Werorilangi S, Galloway TS, Tahir A (2021). Distribution and seasonal variation of microplastics in tallo river, makassar, eastern indonesia.
Toxics,
9(6).
Abstract:
Distribution and seasonal variation of microplastics in tallo river, makassar, eastern indonesia
Attention towards microplastic (MP) pollution in various environments is increasing, but relatively little attention has been given to the freshwater-riverine environment. As the biggest city in the eastern Indonesia region, Makassar can be a potential source of MP pollution to its riverine area. This study aimed to determine the spatial trends, seasonal variation, and characteristics of MPs in the water and sediment of Tallo River, as the main river in Makassar. Water samples were collected using a neuston net and sediment samples were collected using a sediment corer. The samples collected contained MPs with an abundance ranging from 0.74 ± 0.46 to 3.41 ± 0.13 item/m3 and 16.67 ± 20.82 to 150 ± 36.06 item/kg for water and sediment samples, respectively. The microplastic abundance in the Tallo River was higher in the dry season and tended to increase towards the lower river segment. Fragments (47.80–86.03%) and lines (12.50–47.80%) were the predominant shapes, while blue (19.49–46.15%) and transparent (14.29–38.14%) were the most dominant color. Polyethylene and polypropylene were the common MP polymers found in the Tallo river. Actions to prevent MP pollution in the Makassar riverine area are needed before MP pollution becomes more severe in the future.
Abstract.
Hird C (2021). Ecotoxicology of Active Ingredients in Changing Marine Environments.
Abstract:
Ecotoxicology of Active Ingredients in Changing Marine Environments
Active ingredients (AIs), including pesticides and pharmaceuticals, are designed to have a specific mode-of-action (MoA) in target organisms. Despite this, there is substantial evidence of their occurrence in marine environments having the potential to impact non-target species with effects both as a result of, and independent from, their MoA. Furthermore, due to a large proportion of AIs being readily ionisable, there is growing evidence that their uptake and effects are sensitive to environmental parameters such as pH, which can be driven by changes in pCO2, both in natural cycles and as a consequence of anthropogenic activities.
In this thesis I investigate the impacts of 5 common active ingredient contaminants: the selective serotonin reuptake inhibitor fluoxetine; the non-steroidal anti-inflammatory drugs ibuprofen and diclofenac; and the neonicotinoid pesticides imidacloprid and thiamethoxam; on marine invertebrates and investigate aspects such as bioconcentration, effects, and the sensitivity of these organisms to these compounds under changing pCO2-driven pH conditions.
Firstly, fluoxetine was shown to elicit a pharmacological MoA effect in the marine worm Hediste diversicolor through an increase in serotonin concentration of approximately 10 % following exposure to 10 μg L-1 fluoxetine. Fluoxetine was also shown to induce weight loss (up to 2 % at 500 μg L-1 after 72 hours); decrease feeding rates (up to 68 % at 500 μg L-1); and alter multiple metabolic biomarkers. The uptake and effects of fluoxetine here were also shown to be sensitive to feeding mode, with filter feeding worms experiencing up to 130 times greater body burdens of fluoxetine, and consequently greater effects, than deposit feeding worms – a trait-based sensitivity.
In a second series of experiments, an increase in pCO2 (1000 and 3000 μatm vs a 400 μatm control), and consequent reduction in pH from approximately pH 8.1 to pH 7.75 and 7.4 respectively, was shown to alter uptake and depuration profiles and bioconcentration of all 5 active ingredients in the marine worm Hediste diversicolor. Notably, the bioconcentration factor for fluoxetine decreased from 331 at pH 8.1 to 107 at pH 7.4, whereas the reverse trend occurred for ibuprofen, which increased from 31 at pH 8.1 to 121 at pH 7.4. Seawater pH was also shown to alter the MoA effects of some compounds, with fluoxetine only impacting its MoA endpoint, serotonin, at pH 8.1 and thiamethoxam showing a twofold greater decrease in its MoA, acetylcholinesterase activity, at pH 7.4 when compared to pH 7.75 or pH 8.1.
Finally, the neonicotinoid pesticides imidacloprid and thiamethoxam were shown to alter sperm swimming parameters, and consequently fertilisation success, in the sea urchin Paracentrotus lividus, decreasing by 15 % at 0.32 μg L-1 thiamethoxam and 28 % at 2.38 μg L-1 imidacloprid. This was further shown to be sensitive to changes in pCO2 for thiamethoxam, with a twofold greater reduction in curvilinear velocity of sperm; threefold greater reduction in motile sperm; and 64 % greater reduction in fertilisation success at pH 7.75 compared to pH 8.1.
Together these findings outline the importance of assessing the risk of active ingredients to non-target marine invertebrates and demonstrate the need for
consideration of both MoA effects and independent toxicity assays. In addition, the potential for pCO2 and pH to significantly alter the uptake and effects of active ingredients here indicate that their consideration is vital for effective assessment of current and potential future risks of active ingredients in aquatic environments.
Abstract.
Jones J (2021). Investigating the exposure and potential impacts of microplastics in the Galápagos marine food web.
Abstract:
Investigating the exposure and potential impacts of microplastics in the Galápagos marine food web
The Galápagos Marine Reserve is a global conservation priority, representing a vulnerable ecosystem experiencing growing anthropogenic pressures. The aim of this thesis is to investigate the sources of plastic contamination, to explore pathways and fates in coastal habitats at a variety of geographic scales (Archipelago, island and single beach) and to investigate potential impacts of microplastic contamination on marine species. Using San Cristóbal island as a case study, I collected field data (via seawater tows, benthic sediment grabs and beach survey) to test the hypotheses that (i) accumulation hotspots are present on the exposed eastern coast, (ii) beach plastic contamination is primarily from external sources to Galápagos and (iii) microplastic is present in the food web. Analysis of beach plastics > 5 mm showed a pattern consistent with the prevailing Humboldt Current as a possible driver for accumulation (> 2,500 particles m-2 at the most contaminated site, the east-facing Punta Pitt) with just 2% of items identified as from local sources. Evidence of microplastic uptake was observed in the digestive systems of seven marine invertebrate species including filter feeders, grazers and deposit feeders (52% of 123 individuals, mean 0.5 - 1.7 particles per individual) demonstrating entry into the food web across a range of species with different feeding modes and habitat preferences. Using comparable environmental sampling methods, sites across two biogeographic zones in the Galápagos Marine Reserve were surveyed to test the hypothesis that contamination would be greater in the populated South-Central Zone (that has greater continental connectivity), compared to the upwelling Western Zone. The most significant differences were evident in microplastic, with concentrations in seawater, benthic sediment and sand six to ten-fold higher in the South-Central Zone suggesting a differing profile of exposure risk for wildlife across the Archipelago.
As it is not ethically nor logistically possible to sample across the entire food web, a priority scoring method was developed and applied to enable the rapid assessment of potential risks from plastic interactions for 3,159 vertebrate and invertebrate species. Data on endemism, conservation status, commercial importance (for invertebrates) and literature evidence of harmful effects were incorporated into a risk ranking system. This identified 27 vertebrate and 15 invertebrate species to be at higher risk and therefore priorities for future research and mitigation action. Finally, analysis of data collected through citizen science beach surveys showed that visual identification of suspected microplastics using a standard unit quadrat method was 93% accurate, as verified by Fourier-transform infrared spectroscopy polymer analysis (synthetic vs organic particles), providing a reliable indicator to support increased spatiotemporal resolution of beach monitoring. Overall, this work contributes to our understanding of marine plastic contamination distribution and composition in this data-poor geographic area of high conservation importance, in addition to providing several tools to support management.
Abstract.
Pinheiro LM, Carvalho IV, Agostini VO, Martinez-Souza G, Galloway TS, Pinho GLL (2021). Litter contamination at a salt marsh: an ecological niche for biofouling in South Brazil.
Environmental Pollution,
285Abstract:
Litter contamination at a salt marsh: an ecological niche for biofouling in South Brazil
The presence of solid litter and its consequences for coastal ecosystems is now being investigated around the world. Different types of material can be discarded in areas such as salt marshes, and various fouling organisms can associate with such items forming the Plastisphere. This study investigated the distribution of solid litter along zones (dry, middle, flooded) of a salt marsh environment in the Patos Lagoon Estuary (South Brazil) and the association of biofouling organisms with these items. Solid litter quantities were significantly higher in the dry zone when compared to the middle and flooded zones, showing an accumulation area where the water rarely reaches. Most items were made of plastic, as shown for many other coastal areas, and originated from food packaging, fishery and shipping activities and personal use. Although not statistically significant, there was a tendency of increased biofouling towards the flooded zone. Thirteen groups were found in association with solid litter items, mainly algae, amphipods, and gastropods. The preference for salt marsh zones, types of material and items’ colour was highly variable among groups of organisms, which can be related to their varied physiological requirements. In summary, significant plastic contamination of salt marshes of the Patos Lagoon was associated with a heterogeneous distribution of fouling communities.
Abstract.
Colvin KA, Parkerton TF, Redman AD, Lewis C, Galloway TS (2021). Miniaturised marine tests as indicators of aromatic hydrocarbon toxicity: Potential applicability to oil spill assessment.
Mar Pollut Bull,
165Abstract:
Miniaturised marine tests as indicators of aromatic hydrocarbon toxicity: Potential applicability to oil spill assessment.
Assessing oil spill toxicity in real time is challenging due to dynamic field exposures and lack of simple, rapid, and sensitive tests. We investigated the relative sensitivity of two commercially available marine toxicity tests to aromatic hydrocarbons using the target lipid model (TLM). State of the art passive dosing in sealed vials was used to assess the sensitivity of brine shrimp (Artemia franciscana) and rotifer (Brachionus plicatilis). Organisms were exposed to toluene, 1-methylnaphthalene and phenanthrene for 24 h. Toxicity results were analysed using the TLM to estimate the critical target lipid body burden and support comparison to empirical data for 79 other aquatic organisms. Our findings demonstrate the applicability of passive dosing to test small volumes and indicate that the two rapid cyst-based assays are insensitive in detecting hydrocarbon exposures compared to other aquatic species. Our results highlight the limitations of applying these tests for oil pollution monitoring and decision-making.
Abstract.
Author URL.
Ribeiro F, Okoffo ED, O'Brien JW, O'Brien S, Harris JM, Samanipour S, Kaserzon S, Mueller JF, Galloway T, Thomas KV, et al (2021). Out of sight but not out of mind: Size fractionation of plastics bioaccumulated by field deployed oysters.
Journal of Hazardous Materials Letters,
2Abstract:
Out of sight but not out of mind: Size fractionation of plastics bioaccumulated by field deployed oysters
Microplastics contamination has been widely reported in filter feeders yet the < 1 μm size fraction has been largely ignored. In attempt to characterize this sub 1 μm size fraction and better understand the size distribution of microplastics contamination in filter feeders, field deployed oysters were characterised using a combination of size fractionation combined with pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) as well as Fourier Transform-Infrared Spectroscopy (μFT-IR). Sequential filtration followed by Py-GC/MS identified the 1–22 μm fraction to contain the highest total plastic mass concentration (Ʃ31 mg/g), followed by the 22 μm fraction (Ʃ0.1 mg/g). μFT-IR identified 0.2 particles/g tissue but was limited to particles >150 μm in size. Our results clearly show that an important size fraction of microplastics is being overlooked in almost all studies published to date that rely on FTIR for polymer identification.
Abstract.
Duncan EM, Broderick AC, Critchell K, Galloway TS, Hamann M, Limpus CJ, Lindeque PK, Santillo D, Tucker AD, Whiting S, et al (2021). Plastic Pollution and Small Juvenile Marine Turtles: a Potential Evolutionary Trap.
FRONTIERS IN MARINE SCIENCE,
8 Author URL.
Jones JS, Porter A, Muñoz-Pérez JP, Alarcón-Ruales D, Galloway TS, Godley BJ, Santillo D, Vagg J, Lewis C (2021). Plastic contamination of a Galapagos Island (Ecuador) and the relative risks to native marine species.
Science of the Total Environment,
789Abstract:
Plastic contamination of a Galapagos Island (Ecuador) and the relative risks to native marine species
Ecuador's Galapagos Islands and their unique biodiversity are a global conservation priority. We explored the presence, composition and environmental drivers of plastic contamination across the marine ecosystem at an island scale, investigated uptake in marine invertebrates and designed a systematic priority scoring analysis to identify the most vulnerable vertebrate species. Beach contamination varied by site (macroplastic 0–0.66 items·m−2, microplastics 0–448.8 particles·m−2 or 0–74.6 particles·kg−1), with high plastic accumulation on east-facing beaches that are influenced by the Humboldt Current. Local littering and waste management leakages accounted for just 2% of macroplastic. Microplastics (including anthropogenic cellulosics) were ubiquitous but in low concentrations in benthic sediments (6.7–86.7 particles·kg−1) and surface seawater (0.04–0.89 particles·m−3), with elevated concentrations in the harbour suggesting some local input. Microplastics were present in all seven marine invertebrate species examined, found in 52% of individuals (n = 123) confirming uptake of microplastics in the Galapagos marine food web. Priority scoring analysis combining species distribution information, IUCN Red List conservation status and literature evidence of harm from entanglement and ingestion of plastics in similar species identified 27 marine vertebrates in need of urgent, targeted monitoring and mitigation including pinnipeds, seabirds, turtles and sharks.
Abstract.
Jones-Williams K, Galloway TS, Peck VL, Manno C (2021). Remote, but Not Isolated-Microplastics in the Sub-surface Waters of the Canadian Arctic Archipelago.
FRONTIERS IN MARINE SCIENCE,
8 Author URL.
Rowlands E, Galloway T, Cole M, Lewis C, Peck V, Thorpe S, Manno C (2021). The Effects of Combined Ocean Acidification and Nanoplastic Exposures on the Embryonic Development of Antarctic Krill.
FRONTIERS IN MARINE SCIENCE,
8 Author URL.
Watson M (2021). The effects of microplastic ingestion and environmental warming on camouflage and growth in common shore crabs.
Abstract:
The effects of microplastic ingestion and environmental warming on camouflage and growth in common shore crabs
Anthropogenic stressors are becoming increasingly prevalent in the marine environment, both as direct pollutants (e.g. microplastics and noise), and indirectly through climate change (e.g. environmental warming and ocean acidification). Microplastics in particular are considered to be hazardous, due to their bioavailability through primary (diet), and secondary (respiration) means. This is owed to their small size (
Abstract.
2020
Lindeque PK, Cole M, Coppock RL, Lewis CN, Miller RZ, Watts AJR, Wilson-McNeal A, Wright SL, Galloway TS (2020). Are we underestimating microplastic abundance in the marine environment? a comparison of microplastic capture with nets of different mesh-size.
Environmental Pollution,
265Abstract:
Are we underestimating microplastic abundance in the marine environment? a comparison of microplastic capture with nets of different mesh-size
Microplastic debris is ubiquitous and yet sampling, classifying and enumerating this prolific pollutant in marine waters has proven challenging. Typically, waterborne microplastic sampling is undertaken using nets with a 333 μm mesh, which cannot account for smaller debris. In this study, we provide an estimate of the extent to which microplastic concentrations are underestimated with traditional sampling. Our efforts focus on coastal waters, where microplastics are predicted to have the greatest influence on marine life, on both sides of the North Atlantic Ocean. Microplastic debris was collected via surface trawls using 100, 333 and 500 μm nets. Our findings show that sampling using nets with a 100 μm mesh resulted in the collection of 2.5-fold and 10-fold greater microplastic concentrations compared with using 333 and 500 μm meshes respectively (P < 0.01). Based on the relationship between microplastic concentrations identified and extrapolation of our data using a power law, we estimate that microplastic concentrations could exceed 3700 microplastics m−3 if a net with a 1 μm mesh size is used. We further identified that use of finer nets resulted in the collection of significantly thinner and shorter microplastic fibres (P < 0.05). These results elucidate that estimates of marine microplastic concentrations could currently be underestimated.
Abstract.
Jones-Williams K, Galloway T, Cole M, Stowasser G, Waluda C, Manno C (2020). Close encounters - microplastic availability to pelagic amphipods in sub-antarctic and antarctic surface waters.
Environ Int,
140Abstract:
Close encounters - microplastic availability to pelagic amphipods in sub-antarctic and antarctic surface waters.
This study investigated the distribution of plastic debris from the Atlantic portion of the Sub-Antarctic to the Antarctic Peninsula. This region is home to some of the highest concentrations of zooplankton biomass but is also threatened by increasing shipping traffic from fishing and the growing tourism market. Samples were collected using a surface-towed neuston net during the Austral summer 2018, aboard the RRS James Clark Ross. Using Fourier Transform Infrared Spectrometry it was found that 45.6% of the plastic particles isolated from seawater samples were sampling contamination, originating predominantly from the ship. of the remaining particles, both low density (polyethylene, polypropylene) and high-density (phenoxy and epoxy resins) polymers were found in the surface water suggesting both long-range and local sources of origin. Whilst we found that micro and mesoplastic concentrations in seawater were significantly low (0.013 ± 0.005n/m3) compared to global averages, they were higher along the Antarctic Peninsula than the open ocean (Sub-Antarctic) stations. The potential availability of micro and mesoplastics (MP) to pelagic amphipods was explored, using an observed encounter rate (OER) and a possible encounter rate (PER). The total OER (0.8%) was higher than the PER (0.15%), suggesting that even at low concentrations, microplastics are encountered, and potentially consumed, by amphipods. This study highlights the need to prioritise regions of high zooplankton abundance and to investigate both water and biota to build up a picture of plastic pollution and its potential interaction with the Antarctic Ecosystem.
Abstract.
Author URL.
Ribeiro F, Okoffo ED, O'Brien JW, Fraissinet-Tachet S, O'Brien S, Gallen M, Samanipour S, Kaserzon S, Mueller JF, Galloway T, et al (2020). Correction to Quantitative Analysis of Selected Plastics in High-Commercial-Value Australian Seafood by Pyrolysis Gas Chromatography Mass Spectrometry.
Environ Sci Technol,
54(20).
Author URL.
Colvin KA, Lewis C, Galloway TS (2020). Current issues confounding the rapid toxicological assessment of oil spills.
Chemosphere,
245Abstract:
Current issues confounding the rapid toxicological assessment of oil spills.
Oil spills of varying magnitude occur every year, each presenting a unique challenge to the local ecosystem. The complex, changeable nature of oil makes standardised risk assessment difficult. Our review of the state of science regarding oil's unique complexity; biological impact of oil spills and use of rapid assessment tools, including commercial toxicity kits and bioassays, allows us to explore the current issues preventing effective, rapid risk assessment of oils. We found that despite the advantages to monitoring programmes of using well validated standardised tests, which investigate impacts across trophic levels at environmentally relevant concentrations, only a small percentage of the available tests are specialised for use within the marine environment, or validated for the assessment of crude oil toxicity. We discuss the use of rapid tests at low trophic levels in addition to relevant sublethal toxicity assays to allow the characterisation of oil, dispersant and oil and dispersant mixture toxicity. We identify novel, passive dosing techniques as a practical and reproducible means of improving the accuracy and maintenance of nominal concentrations. Future work should explore the possibility of linking this tiered testing system with ecosystem models to allow the prediction and risk assessment of the entire ecosystem.
Abstract.
Author URL.
Rendell-Bhatti F (2020). Developmental Toxicity of Microplastic Leachates on Marine Larvae.
Abstract:
Developmental Toxicity of Microplastic Leachates on Marine Larvae
Marine plastic pollution is now considered a diverse contaminant suite, differing in product origin, polymer composition, size, morphology, colour, additives and environmental co-contaminants. The environmental hazards associated with marine plastic pollution have been widely documented, however much of the existing research has yet to document developmental abnormalities observed when biota develop in plastic contaminated systems. The effect of microplastic leachate exposure on two marine echinoderms early developmental stages were investigated. Psammechinus milaris and Paracentrotus lividus embryonic and larval cultures were exposed to leachates derived from industrial or environmental exposed plastic pellets to investigate the effect of polymer additives and environmental contaminants. Toxicity was evaluated morphologically using images of live embryos and larvae, along with immunostaining of key developmental tissue groups to determine the extent of impact on a physiological level. This body of work suggests that leachates from pellets exposed to environmental contaminates (biobead and pre-production nurdle pellets) and highly plasticised industrial pellets (polyvinyl chloride) elicit severe, consistent and treatment-specific phenotypes in P. lividus embryonic and larval developmental stages, with impacts on morphogenic processes. Key differences in larvae morphology were documented between plastic types and environmental exposure. Industrial polyvinyl chloride pellets elicited the most pronounced abnormalities from the wild type at 24 hours post-fertilisation. However, leachates from un-plasticised industrial polyethylene pellets showed little differences from the wildtype with regards to developmental timing and abnormalities. Leachates from environmental sourced pellets elicited the most severe developmental delays and abnormalities at 48 hours post-fertilisation. Preliminary chemical analysis was also performed on industrial and beached pellet leachates, to investigate compound composition and to determine possible contributors to the developmental defects. To summarise, the findings suggest industrial and environmental microplastic leachate exposure elicits morphological malformations and specific abnormalities in neural, cilia and muscle tissues groups in both embryonic and larval stages of marine larvae of P. lividus. However, more research and investigation are needed to draw conclusive data.
Abstract.
Parton K (2020). Elasmobranch (sharks and rays) interaction with plastic pollution from global and local perspectives, via entanglement within anthropogenic debris and synthetic fibre ingestion.
Abstract:
Elasmobranch (sharks and rays) interaction with plastic pollution from global and local perspectives, via entanglement within anthropogenic debris and synthetic fibre ingestion
Plastic pollution is a known threat to a host of marine organisms across the world. Research in recent years has exposed numerous negative impacts on some of the world’s most threatened marine species, including turtles, cetaceans and pinnipeds. The impact of plastic pollution on elasmobranchs, however, has been relatively understudied. Sharks and rays are widely accepted to be two of the most threatened marine species in the oceans, most notably due to anthropogenic impacts including direct fisheries and bycatch. Their relationship with plastic pollution is only now being investigated in further detail. Previous studies have alluded to damaging effects on sharks and rays as a result of plastic pollution but have lacked in wide synthesis of existing information and empirical evidence. In this thesis, the impact of entanglement within and ingestion of plastic is highlighted for sharks and rays both globally and locally in the North-East Atlantic. Chapter one aimed to collect existing information on the occurrence and distribution of elasmobranch entanglement events, using a systematic literature review and novel data collection from social media site “Twitter”. Our results highlighted ghost fishing gear to be the most common entangling material for sharks and rays globally, consistent with previous studies on other marine species. The review also highlighted the lack of standardised reporting for elasmobranch entanglement and therefore resulted in the creation of an online entanglement report form for sharks and rays (ShaREN), allowing citizen scientists across the world to report entanglement incidents quickly and efficiently. Chapter two investigated the presence of microplastics and synthetic contaminant particles in four species of demersal shark found in the North-East Atlantic. Almost 70% of sharks analysed contained at least one contaminant particle,
2
however no significant relationship between size/weight and number of contaminants was identified, although further analysis was recommended. The study highlighted the ubiquity of synthetic fibres such as rayon and viscose, commonly found in clothing items, as contaminants in the marine environment. Chapter two presents the first empirical evidence of microplastic ingestion by UK shark species and highlights the pervasive nature of microplastic pollution off the English coast. While these two threats are unlikely to have significant population impacts on sharks and rays globally, similar to that of direct fisheries and bycatch, they are identified to be of clear animal welfare concern for these species. Entanglement within and ingestion of plastic is symptomatic of a degraded marine environment and highlights the need for policy-makers, scientists and stakeholders to work together to mitigate this issue for all marine species.
Abstract.
Burrows SD, Frustaci S, Thomas KV, Galloway T (2020). Expanding exploration of dynamic microplastic surface characteristics and interactions.
TrAC - Trends in Analytical Chemistry,
130Abstract:
Expanding exploration of dynamic microplastic surface characteristics and interactions
Microplastics have been found in all marine ecosystems, raising concern about their potential environmental impacts. Yet relatively little research has focused on surface characteristics, compared to polymer type. The aim of this review is to discuss the importance of microplastic surface properties and how expanded characterisation and more detailed quantification can aid in assessing their behaviours in aquatic environments. Concepts including surface roughness, formation of surface ecocoronae and sorptive behaviours of microplastic surfaces are discussed. To address these concepts, three exemplary methods are introduced and their application to the study of microplastic surfaces discussed with the following recommendations; atomic force microscopy should be explored for conducting physical surface characterisation and to examine surface roughness; double-shot Pyrolysis-Gas Chromatography–Mass Spectroscopy should be considered for examining microplastic sorption behaviours in multi-solute media; and finally, Whispering Gallery Mode nanosensing techniques should be explored as a potential means to generate data on microplastic sorption kinetics.
Abstract.
Scott N (2020). Investigating the environmental partitioning of microplastics in two contrasting marine ecosystems.
Abstract:
Investigating the environmental partitioning of microplastics in two contrasting marine ecosystems.
Plastic is a pervasive pollutant of marine ecosystems globally, found throughout the water column, in sediments, and biota. Small plastic particles, or microplastics, are numerous and readily ingested by marine organisms. However, these plastic particles are distributed unevenly throughout marine environments and the physical properties of the particle can influence how they are transported, and ultimately where they are found. In this thesis I review the current literature to explain how plastic particles behave in the marine environment according to their physical attributes, and how this might influence the number and types of plastic to which organisms are exposed. I then explore two cases of plastic partitioning across compartments of an Arctic fjord (Kongsfjorden, Svalbard), and in rocky shore habitats of Devon and Cornwall, UK via an extensive field sampling campaign.
Using a boat based sampling programme, seawater microplastic contamination for two different water bodies, local Arctic and Atlantic, within an Arctic fjord was assessed via sampling at two different depths of the water column. Salinity-temperature-depth (CTD) profiles were acquired, and microplastic particles collected from sea surface and 160 m depth at three different locations in Kongsfjorden, Svalbard, using surface plankton net trawls and niskin bottles. The isolated microplastic particles were counted and analysed by FTIR spectroscopy. The parameters defining Atlantic water were not detected, however the mean microplastic concentration in deep waters (2.9 (± 1.7) x 104 particles m-3) was significantly greater than surface waters (112 ± 53 particles m-3). The most common polymers identified were polyester (18%), ethylene-propylene copolymer (11.8 %), and polyacrylic acid and polyethylene (10 % each). Particles at the surface were significantly larger than particles at 160 m, fragments were on average 5430 µm larger, and fibres 850 µm longer. Significantly greater proportions of white fragments and blue fibres were found at the surface compared to 160 m, and black and blue fragments at 160 m compared to surface water.
The environmental partitioning of macro-, meso- and microplastics across surface sediment, seawater, and mussels Mytilus edulis were then analysed from 9 intertidal locations in the South West of England. Micro- and mesoplastic-like particles were found in 88.5% of the 269 mussels sampled, ranging from 1.43 to 7.64 items per mussel. of these plastic particles, 70.9% were identified as semi-synthetic (mainly modified-cellulose). Mussel microplastic abundance, but not polymer type, was correlated with that of their surrounding sediment, but not with sea-surface microplastic concentration or mussel size. Significant differences were present in the relative abundance of polymers and particle sizes between seawater, sediment, and mussels, with mussels containing a greater abundance of cellulose fibre but less polyvinyl polymer. The particle characteristics of mussel microplastic contamination are not directly proportional to that of the microplastics in their surrounding environment.
The data from these two contrasting ecosystems both add to the growing evidence that microplastics are not just a sea surface problem and partition across marine ecosystems with particle characteristics such as polymer type (density), shape, and size all likely playing a role. Although uptake of particles by organisms may be subject to processes of selection, ultimately, the distribution of plastic particles governs the particles to which organisms are exposed and might ingest. Therefore, understanding particle characteristics and dynamics will play a role in determining the biological consequences of microplastic pollution in marine biota.
Abstract.
Parton KJ, Godley BJ, Santillo D, Tausif M, Omeyer LCM, Galloway TS (2020). Investigating the presence of microplastics in demersal sharks of the North-East Atlantic.
Sci Rep,
10(1).
Abstract:
Investigating the presence of microplastics in demersal sharks of the North-East Atlantic.
Microplastic pollution is ubiquitous in the marine environment and is ingested by numerous marine species. Sharks are an understudied group regarding their susceptibility to microplastic ingestion. Here, we provide evidence of ingestion of microplastic and other anthropogenic fibres in four demersal sharks species found in the waters of the United Kingdom and investigate whether body burdens of contamination vary according to species, sex or size. Sharks were collected from the North-East Atlantic. Stomachs and digestive tracts of 46 sharks of 4 species were examined and 67% of samples contained at least one contaminant particle. Although we acknowledge modest sample size, estimated particle burden increased with body size but did not vary systematically with sex or species. A total of 379 particles were identified, leading to median estimates ranging from 2 to 7.5 ingested contaminants per animal for the 4 species. The majority were fibrous in nature (95%) and blue (88%) or black (9%) in colour. A subsample of contaminants (N = 62) were subject to FT-IR spectroscopy and polymers identified as: synthetic cellulose (33.3%), polypropylene (25%), polyacrylamides (10%) and polyester (8.3%). The level of risk posed to shark species by this level of contamination is unknown. Nevertheless, this study presents the first empirical evidence and an important baseline for ingestion of microplastics and other anthropogenic fibres in native UK shark species and highlights the pervasive nature of these pollutants.
Abstract.
Author URL.
Coppock R (2020). Microplastics in the marine environment: from top to bottom.
Abstract:
Microplastics in the marine environment: from top to bottom
The first reports of small plastic debris floating at the ocean surface were recorded in the 1970s, but it is only in the last decade that scientific and media attention has soared. Microplastics (plastic 1 µm – 5 mm) have since been acknowledged as a global marine contaminant, raising concerns about the interactions between anthropogenic debris and natural biological processes. In this thesis, I explore the hypothesis that microplastics can be transported via biotic-driven mechanisms through the water column and into coastal sediments, leading to adverse impacts on the health and functioning of marine fauna and ecosystems. In Chapter 2, I demonstrate that a key pelagic species, the copepod Calanus helgolandicus, alter their prey selection dependent upon the size or shape of the plastic in their ambient surroundings. with the capacity to reduce feeding. I also establish that C. helgolandicus faecal pellets sink slower when contaminated with low density polyethylene (PE), whereas sinking rates increase when contaminated with high density polyethylene terephthalate (PET), highlighting potential impacts to marine nutrient flux. In Chapter 3, I develop a method utilising the differential density of sediment and plastic to isolate and recover microplastics from sediments; I apply this method in Chapter 4, and latterly discuss harmonisation of microplastic estimates between studies and its use across the wider international field (Chapter 5). In Chapter 4, I employ a multi-faceted study to explore the role that benthic fauna play in the uptake of microplastics by the seabed. My environmental data demonstrate that microplastics are being permanently buried in coastal sediments, and that this process is ubiquitous across sampled sites and seasons. I further identify that benthic faunal functional groups that move sediment vertically (“conveyors”) and randomly (“biodiffusers”) influence sediment plastic loading differently, affecting ultimate burial and deep sediment loading. Furthermore, experimental data indicate that a key benthic species, the brittlestar Amphiura filiformis, buries nylon fibres along its burrow structure and that burial activity deep in the burrow is impaired when plastic is consumed. Collectively, my research contributes to our understanding of the mechanisms governing microplastic transport through the water column and into the sediment matrix, highlights risks posed to marine fauna and ecosystems and provides evidence that coastal sediments are final sinks for microplastics.
Abstract.
Cole M, Liddle C, Consolandi G, Drago C, Hird C, Lindeque PK, Galloway TS (2020). Microplastics, microfibres and nanoplastics cause variable sub-lethal responses in mussels (Mytilus spp.).
Marine Pollution Bulletin,
160Abstract:
Microplastics, microfibres and nanoplastics cause variable sub-lethal responses in mussels (Mytilus spp.)
We compare the toxicity of microplastics, microfibres and nanoplastics on mussels. Mussels (Mytilus spp.) were exposed to 500 ng mL-1 of 20 μm polystyrene microplastics, 10 × 30 μm polyamide microfibres or 50 nm polystyrene nanoplastics for 24 h or 7 days. Biomarkers of immune response, oxidative stress response, lysosomal destabilisation and genotoxic damage were measured in haemolymph, digestive gland and gills. Microplastics and microfibres were observed in the digestive glands, with significantly higher plastic concentrations after 7-days exposure (ANOVA, P < 0.05). Nanoplastics had a significant effect on hyalinocyte-granulocyte ratios (ANOVA, P < 0.05), indicative of a heightened immune response. SOD activity was significantly increased followed 24 h exposure to plastics (two-way ANOVA, P < 0.05), but returned to normal levels after 7-days exposure. No evidence of lysosomal destabilisation or genotoxic damage was observed from any form of plastic. The study highlights how particle size is a key factor in plastic particulate toxicity.
Abstract.
Alava JJ, Jones J, Calle P, Alarcón D, Muñoz-Pérez JP, Tirapé A, Muñoz-Abril L, Hobbs C, Townsend KA, Domínguez GA, et al (2020). Multiple Anthropogenic Stressors Reshape Evolutionary Processes in Galapagos: Marine Pollution and Climate Change.
Feng L-J, Sun X-D, Zhu F-P, Feng Y, Duan J-L, Xiao F, Li X-Y, Shi Y, Wang Q, Sun J-W, et al (2020). Nanoplastics Promote Microcystin Synthesis and Release from Cyanobacterial Microcystis aeruginosa.
Environ Sci Technol,
54(6), 3386-3394.
Abstract:
Nanoplastics Promote Microcystin Synthesis and Release from Cyanobacterial Microcystis aeruginosa.
Although the fate of nanoplastics (
Abstract.
Author URL.
Ribeiro F, Okoffo ED, O'Brien JW, Fraissinet-Tachet S, O'Brien S, Gallen M, Samanipour S, Kaserzon S, Mueller JF, Galloway T, et al (2020). Quantitative Analysis of Selected Plastics in High-Commercial-Value Australian Seafood by Pyrolysis Gas Chromatography Mass Spectrometry.
Environ Sci Technol,
54(15), 9408-9417.
Abstract:
Quantitative Analysis of Selected Plastics in High-Commercial-Value Australian Seafood by Pyrolysis Gas Chromatography Mass Spectrometry.
Microplastic contamination of the marine environment is widespread, but the extent to which the marine food web is contaminated is not yet known. The aims of this study were to go beyond visual identification techniques and develop and apply a simple seafood sample cleanup, extraction, and quantitative analysis method using pyrolysis gas chromatography mass spectrometry to improve the detection of plastic contamination. This method allows the identification and quantification of polystyrene, polyethylene, polyvinyl chloride, polypropylene, and poly(methyl methacrylate) in the edible portion of five different seafood organisms: oysters, prawns, squid, crabs, and sardines. Polyvinyl chloride was detected in all samples and polyethylene at the highest total concentration of between 0.04 and 2.4 mg g-1 of tissue. Sardines contained the highest total plastic mass concentration (0.3 mg g-1 tissue) and squid the lowest (0.04 mg g-1 tissue). Our findings show that the total concentration of plastics is highly variable among species and that microplastic concentration differs between organisms of the same species. The sources of microplastic exposure, such as packaging and handling with consequent transference and adherence to the tissues, are discussed. This method is a major development in the standardization of plastic quantification techniques used in seafood.
Abstract.
Author URL.
Ribeiro F, Okoffo ED, O'Brien JW, Fraissinet-Tachet S, O'Brien S, Gallen M, Samanipour S, Kaserzon S, Mueller JF, Galloway T, et al (2020). Response to Comment on "Quantitative Analysis of Selected Plastics in High-Commercial-Value Australian Seafood by Pyrolysis Gas Chromatography Mass Spectrometry".
Environ Sci Technol,
54(23), 15556-15557.
Author URL.
Galloway T, Haward M, Mason SA, Babayemi JO, Hardesty BD, Krause S, Lamb J, Hinojosa IA, Horton A (2020). Science-Based Solutions to Plastic Pollution.
ONE EARTH,
2(1), 5-7.
Author URL.
2019
Ribeiro F, O'Brien JW, Galloway T, Thomas KV (2019). Accumulation and fate of nano- and micro-plastics and associated contaminants in organisms.
TrAC - Trends in Analytical Chemistry,
111, 139-147.
Abstract:
Accumulation and fate of nano- and micro-plastics and associated contaminants in organisms
Following a decade of research on the environmental impacts of microplastics, a knowledge gap remains on the processes by which micro and nanoplastics pass across biological barriers, enter cells and are subject to biological mechanisms. Here we summarize available literature on the accumulation of microplastics and their associated contaminants in a variety of organisms including humans. Most data on the accumulation of microplastics in both field and lab studies are for marine invertebrates. Microplastics accumulation data for insects, birds, marine mammals and sea turtles are scarce due to methodological issues. There is no conclusive evidence for the mode of accumulation of microplastics in either mammals or humans. The mechanism of chemical partitioning, role of contaminants associated with plastics, and mode of action of both nano- and micro-plastics and associated chemicals in a range of organisms and associated compartments/tissues also requires further research.
Abstract.
Cole M, Coppock R, Lindeque PK, Altin D, Reed S, Pond DW, Sørensen L, Galloway TS, Booth AM (2019). Effects of Nylon Microplastic on Feeding, Lipid Accumulation, and Moulting in a Coldwater Copepod.
Environ Sci Technol,
53(12), 7075-7082.
Abstract:
Effects of Nylon Microplastic on Feeding, Lipid Accumulation, and Moulting in a Coldwater Copepod.
Microplastic debris is a pervasive environmental contaminant that has the potential to impact the health of biota, although its modes of action remain somewhat unclear. The current study tested the hypothesis that exposure to fibrous and particulate microplastics would alter feeding, impacting on lipid accumulation, and normal development (e.g. growth, moulting) in an ecologically important coldwater copepod Calanus finmarchicus. Preadult copepods were incubated in seawater containing a mixed assemblage of cultured microalgae (control), with the addition of ∼50 microplastics mL-1 of nylon microplastic granules (10-30 μm) or fibers (10 × 30 μm), which are similar in shape and size to the microalgal prey. The additive chemical profiles showed the presence of stabilizers, lubricants, monomer residues, and byproducts. Prey selectivity was significantly altered in copepods exposed to nylon fibers (ANOVA, P < 0.01) resulting in a nonsignificant 40% decrease in algal ingestion rates (ANOVA, P = 0.07), and copepods exposed to nylon granules showed nonsignificant lipid accumulation (ANOVA, P = 0.62). Both microplastics triggered premature moulting in juvenile copepods (Bernoulli GLM, P < 0.01). Our results emphasize that the shape and chemical profile of a microplastic can influence its bioavailability and toxicity, drawing attention to the importance of using environmentally relevant microplastics and chemically profiling plastics used in toxicity testing.
Abstract.
Author URL.
Nelms S (2019). Marine litter, microplastics and marine megafauna.
Abstract:
Marine litter, microplastics and marine megafauna
Over the last sixty years, the development of synthetic and durable materials, namely plastic, coupled with a growing human population, has resulted in a rapid increase in the levels of anthropogenic debris in rivers, along coastlines and in the wider marine ecosystem. Currently, an estimated 4.8 to 12.7 million tons of plastic enter the oceans every year but this is expected to increase to between 9.6 and 25.4 million tons by 2025. As such, it is one of the most widely recognised pollution issues facing the planet due to its wide-ranging ecological and socio-economic implications. The main aims of this thesis were to i) examine citizen-science beach clean data to better understand the composition of anthropogenic litter deposited on British beaches by determining the most common items, materials, sources and pathways, and exploring the data for spatial patterns and temporal trends in litter density; ii) investigate an indirect pathway (trophic transfer) of microplastic (
Abstract.
Duncan EM, Broderick AC, Fuller WJ, Galloway TS, Godfrey MH, Hamann M, Limpus CJ, Lindeque PK, Mayes AG, Omeyer LCM, et al (2019). Microplastic ingestion ubiquitous in marine turtles.
Glob Chang Biol,
25(2), 744-752.
Abstract:
Microplastic ingestion ubiquitous in marine turtles.
Despite concerns regarding the environmental impacts of microplastics, knowledge of the incidence and levels of synthetic particles in large marine vertebrates is lacking. Here, we utilize an optimized enzymatic digestion methodology, previously developed for zooplankton, to explore whether synthetic particles could be isolated from marine turtle ingesta. We report the presence of synthetic particles in every turtle subjected to investigation (n = 102) which included individuals from all seven species of marine turtle, sampled from three ocean basins (Atlantic [ATL]: n = 30, four species; Mediterranean (MED): n = 56, two species; Pacific (PAC): n = 16, five species). Most particles (n = 811) were fibres (ATL: 77.1% MED: 85.3% PAC: 64.8%) with blue and black being the dominant colours. In lesser quantities were fragments (ATL: 22.9%: MED: 14.7% PAC: 20.2%) and microbeads (4.8%; PAC only; to our knowledge the first isolation of microbeads from marine megavertebrates). Fourier transform infrared spectroscopy (FT-IR) of a subsample of particles (n = 169) showed a range of synthetic materials such as elastomers (MED: 61.2%; PAC: 3.4%), thermoplastics (ATL: 36.8%: MED: 20.7% PAC: 27.7%) and synthetic regenerated cellulosic fibres (SRCF; ATL: 63.2%: MED: 5.8% PAC: 68.9%). Synthetic particles being isolated from species occupying different trophic levels suggest the possibility of multiple ingestion pathways. These include exposure from polluted seawater and sediments and/or additional trophic transfer from contaminated prey/forage items. We assess the likelihood that microplastic ingestion presents a significant conservation problem at current levels compared to other anthropogenic threats.
Abstract.
Author URL.
Coppock RL, Galloway TS, Cole M, Fileman ES, Queirós AM, Lindeque PK (2019). Microplastics alter feeding selectivity and faecal density in the copepod, Calanus helgolandicus.
Science of the Total Environment,
687, 780-789.
Abstract:
Microplastics alter feeding selectivity and faecal density in the copepod, Calanus helgolandicus
Microplastics (1 μm–5 mm) are a ubiquitous marine contaminant of global concern, ingested by a wide range of marine taxa. Copepods are a key component of marine food webs, providing a source of food for higher trophic levels, and playing an important role in marine nutrient cycling. Microplastic ingestion has been documented in copepods, but knowledge gaps remain over how this affects feeding preference and faecal density. Here, we use exposure studies incorporating algal prey and microplastics of varying sizes and shapes at a concentration of 100 microplastics mL−1 to show: (1) prey selection by the copepod Calanus helgolandicus was affected by the size and shape of microplastics and algae they were exposed to; Exposure to nylon fibres resulted in a 6% decrease in ingestion of similar shaped chain-forming algae, whilst exposure to nylon fragments led to an 8% decrease in ingestion of a unicellular algae that were similar in shape and size. (2) Ingestion of microplastics with different densities altered the sinking rates of faecal pellets. Faeces containing low-density polyethylene sank significantly more slowly than controls, whilst sinking rates increased when faeces contained high-density polyethylene terephthalate. These results suggest that C. helgolandicus avoid ingesting algae that are similar in size and/or shape to the microplastic particles they are exposed to, potentially in a bid to avoid consuming the plastic.
Abstract.
Nelms SE, Barnett J, Brownlow A, Davison NJ, Deaville R, Galloway TS, Lindeque PK, Santillo D, Godley BJ (2019). Microplastics in marine mammals stranded around the British coast: ubiquitous but transitory?.
Scientific Reports,
9(1).
Abstract:
Microplastics in marine mammals stranded around the British coast: ubiquitous but transitory?
Plastic pollution represents a pervasive and increasing threat to marine ecosystems worldwide and there is a need to better understand the extent to which microplastics (
Abstract.
Galloway TS, Lee BP, Burić I, Steele AM, Kocur AL, Pandeth AG, Harries LW (2019). Plastics Additives and Human Health: a Case Study of Bisphenol a (BPA). In (Ed)
, 131-155.
Abstract:
Plastics Additives and Human Health: a Case Study of Bisphenol a (BPA)
Abstract.
Duncan E (2019). The Impact of Plastic Pollution on Marine Turtles.
Abstract:
The Impact of Plastic Pollution on Marine Turtles
Plastic debris is entering into the marine environment at an accelerating rate, now becoming one of the most ubiquitous and long-lasting changes in natural systems. Marine turtles are large marine vertebrates with complex life histories and highly mobile behaviour that may make them particularly vulnerable to its impacts. The main goals of this thesis were to i) evaluate the potential implications of the presence of plastic pollution in the environment to marine turtles by reviewing current literature ii) provide a global summary of the issue of entanglement in this taxon, utilising a global network of experts iii) explore the drivers of key interactions between marine turtles and plastic ingestion and develop novel additions classification methodologies to explore selective ingestion of plastics iv) develop a methodology for investigating and isolating the presence of microplastic ingestion in marine turtle gut content and v) examine plastic pollution on a key habitat for marine turtles e.g. nesting beaches. Major findings of the thesis include i) the issue of entanglement with plastic debris, the majority in ghost fishing gear, is both an under-reported and under-researched threat ii) a clear display of strong diet-related ingestion towards plastic debris that resemble natural food items, utilising a case study of green turtles in Northern Cyprus iii) a method development that allowed the identification and isolation of a suite synthetic particles in gut content residue samples, providing evidence of ingestion of synthetic debris at the microscopic size class iv) a more comprehensive viewpoint on plastic concentrations on nesting beaches, in the form of 3D sampling to investigate subsurface plastic densities, showing microplastics present down to turtle nesting depth of both loggerhead and green turtles in Northern Cyprus. In conclusion, this thesis forms the most detailed and comprehensive investigation to date on the impacts of this pollutant on the taxon of marine turtles; contributing to knowledge into macro and microplastic ingestion, entanglement and key habitats through method development and integration of marine turtle feeding ecology and developmental biology.
Abstract.
Cross RK, Tyler CR, Galloway TS (2019). The fate of cerium oxide nanoparticles in sediments and their routes of uptake in a freshwater worm.
Nanotoxicology,
13(7), 894-908.
Abstract:
The fate of cerium oxide nanoparticles in sediments and their routes of uptake in a freshwater worm
The relative importance of ingestion and transdermal uptake of nanomaterials is poorly understood, particularly in sediment dwelling organisms, where diet has the potential to contribute significantly to particle accumulation. In aquatic sediments, nanoparticles may partition to bind with the solid fraction of sediment, be freely mobile in the pore water or, for certain metal/metal oxides, undergo dissolution, each of which could influence the route of nanoparticle uptake. Here, we used the freshwater worm Lumbriculus variegatus as a model species. We took advantage of its unique feeding and non-feeding life-stages to assess the contribution of dietary and transdermal uptake in the bioaccumulation of cerium oxide nanoparticles (CeO2 NP) and soluble Ce(III)NO3. Distribution of cerium between the solid, colloidal and soluble fractions in the sediments was determined through sediment separations using micro and ultrafiltration techniques. We assessed particles of differing sizes (10, 28 and 615 nm CeO2) and stabilizing surfactants (10 nm electrostatic Citrate-CeO2 and steric stabilized PEG-CeO2). Soluble Ce(III)NO3, was found to accumulate readily across the skin of the worms whilst nanoparticles were not. Sediments reduced the uptake of CeIII by limiting the presence of dissolved species of cerium in the pore waters. Neither particle size nor the coatings studied altered the distribution of nanoparticles between solid and colloidal fractions of the sediment, with ∼99% associated to the solid phase. Any uptake of CeO2 nanoparticles into worms was only through ingestion. Stabilized 10 nm particles were retained even after gut clearance, indicating that these particles may translocate across the gut wall.
Abstract.
Porter A (2019). The movement of plastics through marine ecosystems and the influences on bioavailability and uptake into marine biota.
Abstract:
The movement of plastics through marine ecosystems and the influences on bioavailability and uptake into marine biota.
Microplastics are a diverse array of contaminants comprising a suite of sizes, shapes, and polymer types. Here I present a body of work investigating the distribution and movement of microplastics through the marine ecosystems via transportation and transformation pathways. First, I look at litter items of beaches of the Cornish coast, demonstrating that 41% of litter was plastics fragments unattributable to source and that this litter was continually re-stocked such that it was always present despite cleaning efforts. Then I took to the seas to conduct sea surface trawls in the North East Atlantic to investigate the floating proportion of marine plastic debris. Microplastics were found in every sample, yet were highly variable in concentration over geographic space ranging from 0.038 to 0.45 particles m-3. Counter to the prevailing trends, plastic fragments (84 μm – 21.8 mm) were the dominant shape (63%), with fewer fibres present. The likelihood of encounter and therefore risk of plastic to plankton was calculated and it was found that for every 1 plastic particle, there were between 500 and 1000 plankton, suggesting very low risk of biological uptake for this region. Plastics are not just found on the sea surface and are increasingly found in benthic sediments and biota. I tested whether marine snows would act as a transport mechanism of plastics from the surface to the seafloor. I demonstrate that under experimental conditions a range of plastic particle sizes, shapes, and polymer types, all readily incorporated into marine snows. This incorporation into marine snows both overcame the buoyancy of floating particles but also increased the sinking rate of dense particles. Buoyant polyethylene went from floating as a free particle to sinking at 818 m day–1
Abstract.
Maximenko N, Corradi P, Law KL, Sebille EV, Garaba SP, Lampitt RS, Galgani F, Martinez-Vicente V, Goddijn-Murphy L, Veiga JM, et al (2019). Towards the integrated marine debris observing system.
Frontiers in Marine Science,
6(JUL).
Abstract:
Towards the integrated marine debris observing system
Plastics and other artificial materials pose new risks to health of the ocean. Anthropogenic debris travels across large distances and is ubiquitous in the water and on the shorelines, yet, observations of its sources, composition, pathways and distributions in the ocean are very sparse and inaccurate. Total amounts of plastics and other man-made debris in the ocean and on the shore, temporal trends in these amounts under exponentially increasing production, as well as degradation processes, vertical fluxes and time scales are largely unknown. Present ocean circulation models are not able to accurately simulate drift of debris because of its complex hydrodynamics. In this paper we discuss the structure of the future integrated marine debris observing system (IMDOS) that is required to provide long-term monitoring of the state of the anthropogenic pollution and support operational activities to mitigate impacts on the ecosystem and safety of maritime activity. The proposed observing system integrates remote sensing and in situ observations. Also, models are used to optimize the design of the system and, in turn, they will be gradually improved using the products of the system. Remote sensing technologies will provide spatially coherent coverage and consistent surveying time series at local to global scale. Optical sensors, including high-resolution imaging, multi- and hyperspectral, fluorescence, and Raman technologies, as well as SAR will be used to measure different types of debris. They will be implemented in a variety of platforms, from hand-held tools to ship-, buoy-, aircraft-, and satellite-based sensors. A network of in situ observations, including reports from volunteers, citizen scientists and ships of opportunity, will be developed to provide data for calibration/validation of remote sensors and to monitor the spread of plastic pollution and other marine debris. IMDOS will interact with other observing systems monitoring physical, chemical, and biological processes in the ocean and on shorelines as well as state of the ecosystem, maritime activities and safety, drift of sea ice, etc. The synthesized data will support innovative multi-disciplinary research and serve diverse community of users.
Abstract.
Nelms SE, Parry HE, Bennett KA, Galloway TS, Godley BJ, Santillo D, Lindeque PK (2019). What goes in, must come out: Combining scat-based molecular diet analysis and quantification of ingested microplastics in a marine top predator.
Methods in Ecology and Evolution,
10(10), 1712-1722.
Abstract:
What goes in, must come out: Combining scat-based molecular diet analysis and quantification of ingested microplastics in a marine top predator
Microplastics (plastic particles
Abstract.
2018
Galloway T, Baglin N, Harries LW, Lee BP, Kocur AL, Shepherd M, Steele A, BPA Schools Study Consortium (2018). An engaged research study to assess the effect of a ‘real-world’ dietary intervention on urinary bisphenol a (BPA) levels in teenagers. BMJ Open, 8, e018742-e018742.
Brettell D (2018). Assessing the threat of microplastics to commercial oysters, particularly those of the genus Crassostrea.
Abstract:
Assessing the threat of microplastics to commercial oysters, particularly those of the genus Crassostrea
Current statistics show that China is the largest producer of plastics in the world, contributing to almost 30% of production worldwide (Plastics Europe, 2017). In particular, mega-cities in China connected with the Pearl River Estuary contribute to much of this production, and locations in the Estuary’s proximity are potential sites for plastic pollution. In this thesis, the hypothesis that Crassostrea hongkongensis oysters cultured in Deep Bay, Hong Kong would be susceptible to microplastic uptake was tested. Extensive sampling was conducted across the bay through the collection of oysters, water and sediment from five selected sites (rafts). Follow up analysis of samples revealed that an average of 15.1 ± 6.1 microplastics per individual were present within the oysters, and oysters situated in the outer part of the bay took up more microplastics compared to those situated in the inner part of the bay. The numbers and types of microplastics quantified in sediment and water samples across sites did not correspond to the number of microplastics quantified in Crassostrea hongkongensis specimens across sites, suggesting that there was an element of selection during the biological uptake of these particles, and this was potentially influenced by particles’ properties such as size, shape and polymer type.
Having established that wild Crassostrea hongkongensis in Deep Bay were taking up microplastics, an experiment was set up to investigate whether a genetically similar oyster species, Crassostrea gigas, would exhibit selective uptake up microplastics according to plastics’ size, shape or polymer type, and whether microplastic exposure would induce biological responses within the oysters. Eight microplastic types of various polymers, sizes and shapes were supplied in equal concentrations to Crassostrea gigas oysters at a final concentration of 100 microplastics mL-1, where they were exposed for a 24 hour period. Findings revealed that microplastic polymer type and size did indeed influence uptake (Pr (>Chi)=0.034), and oysters readily took up 0.29% of 8-30 m polyethylene beads and 0.31% of 115-156 m polyvinyl chloride fragments supplied when exposed solely to plastics; oysters exposed to a combination of algae and plastics (same microplastic concentrations) took up 0.25% of the former plastic type, and 0.32% of the latter plastic type supplied. A post-hoc Tukey test confirmed that uptake of these two plastic types were significantly higher (p
Abstract.
Noventa S, Hacker C, Rowe D, Elgy C, Galloway T (2018). Dissolution and bandgap paradigms for predicting the toxicity of metal oxide nanoparticles in the marine environment: an in vivo study with oyster embryos.
Nanotoxicology,
12(1), 63-78.
Abstract:
Dissolution and bandgap paradigms for predicting the toxicity of metal oxide nanoparticles in the marine environment: an in vivo study with oyster embryos.
Dissolution and bandgap paradigms have been proposed for predicting the ability of metal oxide nanoparticles (NPs) to induce oxidative stress in different in vitro and in vivo models. Here, we addressed the effectiveness of these paradigms in vivo and under conditions typical of the marine environment, a final sink for many NPs released through aquatic systems. We used ZnO and MnO2 NPs as models for dissolution and bandgap paradigms, respectively, and CeO2 NPs to assess reactive oxygen radical (ROS) production via Fenton-like reactions in vivo. Oyster embryos were exposed to 0.5-500 μM of each test NP over 24 h and oxidative stress was determined as a primary toxicity pathway across successive levels of biological complexity, with arrested development as the main pathological outcome. NPs were actively ingested by oyster larvae and entered cells. Dissolution was a viable paradigm for predicting the toxicity of NPs in the marine environment, whereas the surface reactivity based paradigms (i.e. bandgap and ROS generation via Fenton-like reaction) were not supported under seawater conditions. Bio-imaging identified potential cellular storage-disposal sites of solid particles that could ameliorate the toxicological behavior of non-dissolving NPs, whilst abiotic screening of surface reactivity suggested that the adsorption-complexation of surface active sites by seawater ions could provide a valuable hypothesis to explain the quenching of the intrinsic oxidation potential of MnO2 NPs in seawater.
Abstract.
Author URL.
Noventa S, Hacker C, Correia A, Drago C, Galloway T (2018). Gold nanoparticles ingested by oyster larvae are internalized by cells through an alimentary endocytic pathway.
Nanotoxicology,
12(8), 901-913.
Abstract:
Gold nanoparticles ingested by oyster larvae are internalized by cells through an alimentary endocytic pathway.
The biological fate of nanoparticles (NPs) taken up by organisms from their environment is a crucial issue for assessing ecological hazard. Despite its importance, it has scarcely been addressed due to the technical difficulties of doing so in whole organism in vivo studies. Here, by using transmission electron microscopy and energy dispersive X-ray spectroscopy (TEM-EDS), we describe the key aspects that characterize the interaction between an aquatic organism of global ecological and economic importance, the early larval stage of the Japanese oyster (Crassostrea gigas), and model gold NPs dispersed in their environment. The small size of the model organism allowed for a high-throughput visualization of the subcellular distribution of NPs, providing a comprehensive and robust picture of the route of uptake, mechanism of cellular permeation, and the pathways of clearance counterbalancing bioaccumulation. We show that NPs are ingested by larvae and penetrate cells through alimentary pinocytic/phagocytic mechanisms. They undergo intracellular digestion and storage inside residual bodies, before excretion with feces or translocation to phagocytic coelomocytes of the visceral cavity for potential extrusion or further translocation. Our mechanistically-supported findings highlight the potential of oyster larvae and other organisms which feature intracellular digestion processes to be exposed to man-made NPs and thus any risks associated with their inherent toxicity.
Abstract.
Author URL.
Nelms SE, Galloway TS, Godley BJ, Jarvis DS, Lindeque PK (2018). Investigating microplastic trophic transfer in marine top predators.
Environmental Pollution,
238, 999-1007.
Abstract:
Investigating microplastic trophic transfer in marine top predators
Microplastics are highly bioavailable to marine organisms, either through direct ingestion, or indirectly by trophic transfer from contaminated prey. The latter has been observed for low-trophic level organisms in laboratory conditions, yet empirical evidence in high trophic-level taxa is lacking. In natura studies face difficulties when dealing with contamination and differentiating between directly and indirectly ingested microplastics. The ethical constraints of subjecting large organisms, such as marine mammals, to laboratory investigations hinder the resolution of these limitations. Here, these issues were resolved by analysing sub-samples of scat from captive grey seals (Halichoerus grypus) and whole digestive tracts of the wild-caught Atlantic mackerel (Scomber scombrus) they are fed upon. An enzymatic digestion protocol was employed to remove excess organic material and facilitate visual detection of synthetic particles without damaging them. Polymer type was confirmed using Fourier-Transform Infrared (FTIR) spectroscopy. Extensive contamination control measures were implemented throughout. Approximately half of scat subsamples (48%; n = 15) and a third of fish (32%; n = 10) contained 1-4 microplastics. Particles were mainly black, clear, red and blue in colour. Mean lengths were 1.5 mm and 2 mm in scats and fish respectively. Ethylene propylene was the most frequently detected polymer type in both. Our findings suggest trophic transfer represents an indirect, yet potentially major, pathway of microplastic ingestion for any species whose feeding ecology involves the consumption of whole prey, including humans. Microplastic trophic transfer in marine top predators is poorly understood; this study using captive seals found that half of the scat sub-samples and a third of the wild caught fish they were fed on contained 1-4 microplastics, indicating transfer from prey to predator.
Abstract.
Noventa S, Rowe D, Galloway T (2018). Mitigating effect of organic matter on the in vivo toxicity of metal oxide nanoparticles in the marine environment.
Environmental Science: Nano,
5(7), 1764-1777.
Abstract:
Mitigating effect of organic matter on the in vivo toxicity of metal oxide nanoparticles in the marine environment
Major constituents of seawater, i.e. ions and natural organic matter (NOM), can influence the environmental and toxicological behaviour of nanoparticles (NPs) in aquatic systems. By adsorbing-ligating-reacting to NP surface reactive sites, they can modify the NP surface structure and overall physico-chemical proprieties. This study explored the fate and in vivo toxicity of ZnO and MnO2 NPs under artificial seawater conditions. These two nanomaterials are representative of metal oxide NPs inducing harm via dissolution and bandgap mechanisms, respectively. To gain a comprehensive understanding of the overall toxicological outcome, we traced the behaviour of NPs in the test systems (i.e. aggregation, sedimentation, dissolution, sorption), their fate in the model organism (i.e. ingestion and cellular internalization by oyster larvae), and the induction of a toxicological pathway (i.e. oxidative stress) up to pathogenesis. We found that ZnO NPs induced harm to oyster larvae under seawater conditions, but NOM mitigated its intensity. In contrast, MnO2 NPs were not toxic at the tested concentrations (up to 200 μM), and their toxicological stasis was not modified by the presence of organic matter. We propose that strong ion sorption on the MnO2 NP surface blocked redox-active sites thus preventing their bandgap mode of action.
Abstract.
Dogra Y, Scarlett AG, Rowe D, Galloway TS, Rowland SJ (2018). Predicted and measured acute toxicity and developmental abnormalities in zebrafish embryos produced by exposure to individual aromatic acids.
Chemosphere,
205, 98-107.
Abstract:
Predicted and measured acute toxicity and developmental abnormalities in zebrafish embryos produced by exposure to individual aromatic acids.
Petroleum acids, often called 'Naphthenic Acids' (NA), enter the environment in complex mixtures from numerous sources. These include from Produced and Process-Affected waters discharged from some oil industry activities, and from the environmental weathering of spilled crude oil hydrocarbons. Here, we test the hypothesis that individual NA within the complex mixtures can induce developmental abnormalities in fish, by screening a range of individual acids, with known chemical structures. Sixteen aromatic NA were tested using a Thamnocephalus platyrus (beavertail fairyshrimp) assay, to establish acute toxicity. Toxicities ranged from 568 to 8 μM, with the methylbiphenyl acid, 4-(p-tolyl)benzoic acid, most toxic. Next, five of the most toxic monoacids and for comparison, a diacid, were assayed using Danio rerio (zebrafish) embryos to test for lethality and developmental abnormalities. The toxicities were also predicted using Admet predictor™ software. Exposure to the five monoacids produced deformities in zebrafish embryos in a dose-dependent manner. Thus, exposure to 4-(p-tolyl)benzoic acid produced abnormalities in >90% of the embryos at concentrations of
Abstract.
Author URL.
Porter A, Lyons BP, Galloway TS, Lewis C (2018). Role of Marine Snows in Microplastic Fate and Bioavailability.
Environ Sci Technol,
52(12), 7111-7119.
Abstract:
Role of Marine Snows in Microplastic Fate and Bioavailability.
Microplastics contaminate global oceans and are accumulating in sediments at levels thought sufficient to leave a permanent layer in the fossil record. Despite this, the processes that vertically transport buoyant polymers from surface waters to the benthos are poorly understood. Here we demonstrate that laboratory generated marine snows can transport microplastics of different shapes, sizes, and polymers away from the water surface and enhance their bioavailability to benthic organisms. Sinking rates of all tested microplastics increased when incorporated into snows, with large changes observed for the buoyant polymer polyethylene with an increase in sinking rate of 818 m day-1 and for denser polyamide fragments of 916 m day-1. Incorporation into snows increased microplastic bioavailability for mussels, where uptake increased from zero to 340 microplastics individual-1 for free microplastics to up to 1.6 × 105 microplastics individual-1 when incorporated into snows. We therefore propose that marine snow formation and fate has the potential to play a key role in the biogeochemical processing of microplastic pollution.
Abstract.
Author URL.
Hodgson D (2018). The impacts of microplastic ingestion on marine polychaete worms.
Abstract:
The impacts of microplastic ingestion on marine polychaete worms
The benthic marine habitat is a sink for microplastics, however, our understanding of their impacts on marine organisms is still limited. This thesis investigates the ingestion and subsequent impacts of microplastics in the marine benthic dwelling polychaete worms, Hediste diversicolor and Ophryotrocha labronica. Firstly, microplastic ingestion by H. diversicolor in three estuaries across South Devon, UK, each of which were exposed to either high, medium or low levels of infrastructure and human population was assessed. The data showed 58.58% of H. diversicolor individuals ingested plastic-like particles, with fibres accounting for 86.8 % of all plastics observed. However, no significant differences in the amount of plastic-like particles ingested between sites were found. Microplastic fibres are the most commonly reported plastic shape in environmental samples, such as sediments, and during gut contents analysis of numerous phyla worldwide. However, the majority of research assessing the impacts of ingested plastics focus on microplastic spherical in shape. Therefore, the difference in toxicity between microplastic beads and fibres in H. diversicolor was investigated. The project found ingested fibres induced a greater oxidative stress response compared to that of microbeads and consequently caused cellular damage in the form of lipid peroxidation. Cellular repair and maintaining homeostasis is energetically expensive and in turn, may impact an individual’s fitness. Therefore, the impacts of microplastic exposure on the feeding and fitness of O. labronica were assessed. O. labronica exposed to plastics produced less offspring and significantly smaller eggs than unexposed mating pairs, which ultimately could lead to deleterious impacts at the population level. However, the protein content of those eggs had a similar energetic content and consequently, there was no difference in the offspring survival rate.
Abstract.
2017
Duncan EM, Botterell ZLR, Broderick AC, Galloway TS, Lindeque PK, Nuno A, Godley BJ (2017). A global review of marine turtle entanglement in anthropogenic debris: a baseline for further action.
ENDANGERED SPECIES RESEARCH,
34, 431-448.
Author URL.
Coppock RL, Cole M, Lindeque PK, Queirós AM, Galloway TS (2017). A small-scale, portable method for extracting microplastics from marine sediments.
Environmental Pollution,
230, 829-837.
Abstract:
A small-scale, portable method for extracting microplastics from marine sediments
Microplastics (plastic particles, 0.1 μm–5 mm in size) are widespread marine pollutants, accumulating in benthic sediments and shorelines the world over. To gain a clearer understanding of microplastic availability to marine life, and the risks they pose to the health of benthic communities, ecological processes and food security, it is important to obtain accurate measures of microplastic abundance in marine sediments. To date, methods for extracting microplastics from marine sediments have been disadvantaged by complexity, expense, low extraction efficiencies and incompatibility with very fine sediments. Here we present a new, portable method to separate microplastics from sediments of differing types, using the principle of density floatation. The Sediment-Microplastic Isolation (SMI) unit is a custom-built apparatus which consistently extracted microplastics from sediments in a single step, with a mean efficiency of 95.8% (±SE 1.6%; min 70%, max 100%). Zinc chloride, at a density of 1.5 g cm−3, was deemed an effective and relatively inexpensive floatation media, allowing fine sediment to settle whilst simultaneously enabling floatation of dense polymers. The method was validated by artificially spiking sediment with low and high density microplastics, and its environmental relevance was further tested by extracting plastics present in natural sediment samples from sites ranging in sediment type; fine silt/clay (mean size 10.25 ± SD 3.02 μm) to coarse sand (mean size 149.3 ± SD 49.9 μm). The method presented here is cheap, reproducible and is easily portable, lending itself for use in the laboratory and in the field, eg. on board research vessels. By employing this method, accurate estimates of microplastic type, distribution and abundance in natural sediments can be achieved, with the potential to further our understanding of the availability of microplastics to benthic organisms.
Abstract.
McNeal AW, Cole M, Galloway TS, Lewis C, Watts A, Wright S, Miller RZ, Lindeque P (2017). Are Smaller Microplastics Underestimated? Comparing Anthropogenic Debris Collected with Different Mesh Sizes. In (Ed) Fate and Impact of Microplastics in Marine Ecosystems.
Vogeler S, Galloway TS, Isupov M, Bean TP (2017). Cloning retinoid and peroxisome proliferator-activated nuclear receptors of the Pacific oyster and in silico binding to environmental chemicals.
PLoS One,
12(4).
Abstract:
Cloning retinoid and peroxisome proliferator-activated nuclear receptors of the Pacific oyster and in silico binding to environmental chemicals.
Disruption of nuclear receptors, a transcription factor superfamily regulating gene expression in animals, is one proposed mechanism through which pollution causes effects in aquatic invertebrates. Environmental pollutants have the ability to interfere with the receptor's functions through direct binding and inducing incorrect signals. Limited knowledge of invertebrate endocrinology and molecular regulatory mechanisms, however, impede the understanding of endocrine disruptive effects in many aquatic invertebrate species. Here, we isolated three nuclear receptors of the Pacific oyster, Crassostrea gigas: two isoforms of the retinoid X receptor, CgRXR-1 and CgRXR-2, a retinoic acid receptor ortholog CgRAR, and a peroxisome proliferator-activated receptor ortholog CgPPAR. Computer modelling of the receptors based on 3D crystal structures of human proteins was used to predict each receptor's ability to bind to different ligands in silico. CgRXR showed high potential to bind and be activated by 9-cis retinoic acid and the organotin tributyltin (TBT). Computer modelling of CgRAR revealed six residues in the ligand binding domain, which prevent the successful interaction with natural and synthetic retinoid ligands. This supports an existing theory of loss of retinoid binding in molluscan RARs. Modelling of CgPPAR was less reliable due to high discrepancies in sequence to its human ortholog. Yet, there are suggestions of binding to TBT, but not to rosiglitazone. The effect of potential receptor ligands on early oyster development was assessed after 24h of chemical exposure. TBT oxide (0.2μg/l), all-trans retinoic acid (ATRA) (0.06 mg/L) and perfluorooctanoic acid (20 mg/L) showed high effects on development (>74% abnormal developed D-shelled larvae), while rosiglitazone (40 mg/L) showed no effect. The results are discussed in relation to a putative direct (TBT) disruption effect on nuclear receptors. The inability of direct binding of ATRA to CgRAR suggests either a disruptive effect through a pathway excluding nuclear receptors or an indirect interaction. Our findings provide valuable information on potential mechanisms of molluscan nuclear receptors and the effects of environmental pollution on aquatic invertebrates.
Abstract.
Author URL.
Galloway TS, Dogra Y, Garrett N, Rowe D, Tyler CR, Moger J, Lammer E, Landsiedel R, Sauer UG, Scherer G, et al (2017). Ecotoxicological assessment of nanoparticle-containing acrylic copolymer dispersions in fairy shrimp and zebrafish embryos.
Environmental Science: Nano,
4(10), 1981-1997.
Abstract:
Ecotoxicological assessment of nanoparticle-containing acrylic copolymer dispersions in fairy shrimp and zebrafish embryos
Nanoparticle-containing polymer dispersions are widely used, but little is known of their environmental effects. We studied the bioavailability, uptake, tissue localisation and effects of nanoparticle-containing acrylic copolymer (ACP) dispersions (mean nanoparticle sizes: 80 nm and 110 nm) in aquatic invertebrates (Thamnocephalus platyurus; fairy shrimp) and Danio rerio zebrafish embryos after aquatic exposures. Dietary exposure tests were enabled using Casper zebrafish that lack skin pigmentation allowing for bio-imaging of uptake and internal distribution. Aqueous exposures of 1000 and 2500 mg L-1 80 nm-ACP or 110 nm-ACP showed no acute toxicity in fairy shrimp or zebrafish, constituting a non-Toxic classification according to the United Nations Globally Harmonised System of Classification and Labelling of Chemicals threshold (100 mg L-1). Similarly, dietary exposures resulted in no ecotoxicological effects. In Casper zebrafish fed with 80 nm-ACP-spiked food, hyperspectral signals derived using coherent Raman scattering (CRS) indicated that test material was present in the intestine, and possibly in the liver, but not in other organs. CRS imaging indicated that the chemical composition of the yolk sac of an 80 nm-ACP exposed zebrafish (aquatic exposure) was altered, attributed to a change in lipid metabolism, although we could not confirm with certainty that the test material was physically present in the yolk sac. These results illustrate how CRS microscopy can be used to investigate the bioaccumulation of organic nanomaterials, provided that they induce hyperspectral profiles distinct from the biological samples. In conclusion, both 80 nm-and 110 nm-ACP dispersions are internalised through dietary exposure, but are not associated with significant toxic effects.
Abstract.
Campbell AL, Ellis RP, Urbina MA, Mourabit S, Galloway TS, Lewis C (2017). Impacts of ocean acidification on sperm develop with exposure time for a polychaete with long lived sperm.
Mar Environ Res,
129, 268-276.
Abstract:
Impacts of ocean acidification on sperm develop with exposure time for a polychaete with long lived sperm.
The majority of marine invertebrate species release eggs and sperm into seawater for external fertilisation. Seawater conditions are currently changing at an unprecedented rate as a consequence of ocean acidification (OA). Sperm are thought to be particularly vulnerable to these changes and may be exposed to external environmental conditions for variable periods of time between spawning and fertilisation. Here, we undertook a mechanistic investigation of sperm swimming performance in the coastal polychaete Arenicola marina during an extended exposure to OA conditions (pHNBS 7.77, 1000 μatm pCO2). We found that key fitness-related aspects of sperm functioning declined faster under OA conditions i.e. impacts became apparent with exposure time. Sperm swimming speed (VCL), the number of motile sperm and sperm path linearity all dropped significantly after 4 h under OA conditions whilst remaining constant under ambient conditions at this time point. Our results highlight the importance of sperm exposure duration in ocean acidification experiments and may help towards explaining species specific differences in response.
Abstract.
Author URL.
Galloway TS, Cole M, lewis C (2017). Interactions of microplastics throughout the marine ecosystem. Nature Ecology and Evolution, 1
Duncan E, Broderick A, Galloway T, Lindeque P, Godley B (2017). Investigating the Presence and Effects of Microplastics in Sea Turtles. In (Ed) Fate and Impact of Microplastics in Marine Ecosystems, 33-34.
Galloway T, Lewis C (2017). Marine microplastics.
Curr Biol,
27(11), R445-R446.
Abstract:
Marine microplastics.
Galloway and Lewis discuss marine microplastics and their devastating effects on ocean ecosystems.
Abstract.
Author URL.
Miller RZ, Watts AJR, Winslow BO, Galloway TS, Barrows APW (2017). Mountains to the sea: River study of plastic and non-plastic microfiber pollution in the northeast USA.
Marine Pollution Bulletin,
124(1), 245-251.
Abstract:
Mountains to the sea: River study of plastic and non-plastic microfiber pollution in the northeast USA
Aquatic environments are sinks for anthropogenic contamination, whether chemical or solid pollutants. Microfibers shed from clothing and other textiles contribute to this problem. These can be plastic or non-plastic origin. Our aim was to investigate the presence and distribution of both types of anthropogenic microfibers along the length of the Hudson River, USA. Surface grab samples were collected and filtered through a 0.45 μm filter paper. Abundance of fibers was determined after subtraction of potential contamination. 233 microfibers were recorded in 142 samples, averaging 0.98 microfibers L− 1. Subsequent micro-FTIR showed half of the fibers were plastic while the other half were non-plastic, but of anthropogenic origin. There was no relationship between fiber abundance, wastewater treatment plant location or population density. Extrapolating from this data, and using available hydrographic data, 34.4% of the Hudson River's watershed drainage area contributes an average 300 million anthropogenic microfibers into the Atlantic Ocean per day.
Abstract.
Karami A, Golieskardi A, Keong Choo C, Larat V, Galloway TS, Salamatinia B (2017). The presence of microplastics in commercial salts from different countries.
Scientific Reports,
7Abstract:
The presence of microplastics in commercial salts from different countries
© 2017 the Author(s). In this Article, there is an error in Figure 3 where panels a and b were inverted. The correct Figure 3 appears below as Figure 1. (Figure Presented)
Abstract.
Karami A, Golieskardi A, Keong Choo C, Larat V, Galloway TS, Salamatinia B (2017). The presence of microplastics in commercial salts from different countries.
Sci Rep,
7Abstract:
The presence of microplastics in commercial salts from different countries.
The occurrence of microplastics (MPs) in saltwater bodies is relatively well studied, but nothing is known about their presence in most of the commercial salts that are widely consumed by humans across the globe. Here, we extracted MP-like particles larger than 149 μm from 17 salt brands originating from 8 different countries followed by the identification of their polymer composition using micro-Raman spectroscopy. Microplastics were absent in one brand while others contained between 1 to 10 MPs/Kg of salt. Out of the 72 extracted particles, 41.6% were plastic polymers, 23.6% were pigments, 5.50% were amorphous carbon, and 29.1% remained unidentified. The particle size (mean ± SD) was 515 ± 171 μm. The most common plastic polymers were polypropylene (40.0%) and polyethylene (33.3%). Fragments were the primary form of MPs (63.8%) followed by filaments (25.6%) and films (10.6%). According to our results, the low level of anthropogenic particles intake from the salts (maximum 37 particles per individual per annum) warrants negligible health impacts. However, to better understand the health risks associated with salt consumption, further development in extraction protocols are needed to isolate anthropogenic particles smaller than 149 μm.
Abstract.
Author URL.
Watts AJR, Porter A, Hembrow N, Sharpe J, Galloway TS, Lewis C (2017). Through the sands of time: Beach litter trends from nine cleaned north cornish beaches.
Environ Pollut,
228, 416-424.
Abstract:
Through the sands of time: Beach litter trends from nine cleaned north cornish beaches.
Marine litter and its accumulation on beaches is an issue of major current concern due to its significant environmental and economic impacts. Yet our understanding of spatio-temporal trends in beach litter and the drivers of these trends are currently limited by the availability of robust long term data sets. Here we present a unique data set collected systematically once a month, every month over a six year period for nine beaches along the North Coast of Cornwall, U.K. to investigate the key drivers of beach litter in the Bude, Padstow and Porthcothan areas. Overall, an average of 0.02 litter items m-2 per month were collected during the six year study, with Bude beaches (Summerleaze, Crooklets and Widemouth) the most impacted (0.03 ± 0.004 litter items m-2 per month). The amount of litter collected each month decreased by 18% and 71% respectively for Padstow (Polzeath, Trevone and Harlyn) and Bude areas over the 6 years, possibly related to the regular cleaning, however litter increased by 120% despite this monthly cleaning effort on the Padstow area beaches. Importantly, at all nine beaches the litter was dominated by small, fragmented plastic pieces and rope fibres, which account for 32% and 17% of all litter items collected, respectively. The weathered nature of these plastics indicates they have been in the marine environment for an extended period of time. So, whilst classifying the original source of these plastics is not possible, it can be concluded they are not the result of recent public littering. This data highlights both the extent of the marine litter problem and that current efforts to reduce littering by beach users will only tackle a fraction of this litter. Such information is vital for developing effective management strategies for beach and marine litter at both regional and global levels.
Abstract.
Author URL.
2016
Dogra Y, Arkill KP, Elgy C, Stolpe B, Lead J, Valsami-Jones E, Tyler CR, Galloway TS (2016). Cerium oxide nanoparticles induce oxidative stress in the sediment-dwelling amphipod Corophium volutator.
Nanotoxicology,
10(4), 480-487.
Abstract:
Cerium oxide nanoparticles induce oxidative stress in the sediment-dwelling amphipod Corophium volutator.
Cerium oxide nanoparticles (CeO2 NPs) exhibit fast valence exchange between Ce(IV) and Ce(III) associated with oxygen storage and both pro and antioxidant activities have been reported in laboratory models. The reactivity of CeO2 NPs once they are released into the aquatic environment is virtually unknown, but this is important to determine for assessing their environmental risk. Here, we show that amphipods (Corophium volutator) grown in marine sediments containing CeO2 NPs showed a significant increase in oxidative damage compared to those grown in sediments without NPs and those containing large-sized (bulk) CeO2 particles. There was no exposure effect on survival, but significant increases in single-strand DNA breaks, lipid peroxidation and superoxide dismutase activity were observed after a 10-day exposure to 12.5 mg L(-1) CeO2. Characterisation of the CeO2 NPs dispersed in deionised or saline exposure waters revealed that more radicals were produced by CeO2 NPs compared with bulk CeO2. Electron energy loss spectroscopy (EELS) analysis revealed that both CeO2 NPs were predominantly Ce(III) in saline waters compared to deionised waters where they were predominantly Ce(IV). In both types of medium, the bulk CeO2 consisted mainly of Ce(IV). These results support a model whereby redox cycling of CeO2 NPs between Ce(III) and Ce(IV) is enhanced in saline waters, leading to sublethal oxidative damage to tissues in our test organism.
Abstract.
Author URL.
Vogeler S, Bean TP, Lyons BP, Galloway TS (2016). Dynamics of nuclear receptor gene expression during Pacific oyster development.
BMC Dev Biol,
16(1).
Abstract:
Dynamics of nuclear receptor gene expression during Pacific oyster development.
BACKGROUND: Nuclear receptors are a highly conserved set of ligand binding transcription factors, with essential roles regulating aspects of vertebrate and invertebrate biology alike. Current understanding of nuclear receptor regulated gene expression in invertebrates remains sparse, limiting our ability to elucidate gene function and the conservation of developmental processes across phyla. Here, we studied nuclear receptor expression in the early life stages of the Pacific oyster, Crassostrea gigas, to identify at which specific key stages nuclear receptors are expressed RESULTS: We used quantitative RT-PCR to determine the expression profiles of 34 nuclear receptors, revealing three developmental key stages, during which nuclear receptor expression is dynamically regulated: embryogenesis, mid development from gastrulation to trochophore larva, and late larval development prior to metamorphosis. Clustering of nuclear receptor expression patterns demonstrated that transcriptional regulation was not directly related to gene phylogeny, suggesting closely related genes may have distinct functions. Expression of gene homologs of vertebrate retinoid receptors suggests participation in organogenesis and shell-formation, as they are highly expressed at the gastrulation and trochophore larval initial shell formation stages. The ecdysone receptor homolog showed high expression just before larval settlement, suggesting a potential role in metamorphosis. CONCLUSION: Throughout early oyster development nuclear receptors exhibited highly dynamic expression profiles, which were not confined by gene phylogeny. These results provide fundamental information on the presence of nuclear receptors during key developmental stages, which aids elucidation of their function in the developmental process. This understanding is essential as ligand sensing nuclear receptors can be disrupted by xenobiotics, a mode of action through which anthropogenic environmental pollutants have been found to mediate effects.
Abstract.
Author URL.
Watts AW, Mauricio A. Urbina MU, Goodhead RG, Moger JJ, Lewis CL, Galloway TG (2016). Effect of microplastic on the gills of the Shore Crab Carcinus maenas.
Environmental Science and Technology (Washington)Abstract:
Effect of microplastic on the gills of the Shore Crab Carcinus maenas
Microscopic plastic debris (microplastics,
Abstract.
Hird CM, Urbina MA, Lewis CN, Snape JR, Galloway TS (2016). Fluoxetine Exhibits Pharmacological Effects and Trait-Based Sensitivity in a Marine Worm.
Environ Sci Technol,
50(15), 8344-8352.
Abstract:
Fluoxetine Exhibits Pharmacological Effects and Trait-Based Sensitivity in a Marine Worm.
Global production of pharmacologically active compounds exceeds 100 000 tons annually, a proportion of which enters aquatic environments through patient use, improper medicine disposal, and production. These compounds are designed to have mode-of-action (MoA) effects on specific biological pathways, with potential to impact nontarget species. Here, we used MoA and trait-based approaches to quantify uptake and biological effects of fluoxetine, a selective serotonin reuptake inhibitor, in filter and deposit feeding marine worms (Hediste diversicolor). Worms exposed to 10 μg L(-1), accumulated fluoxetine with a body burden over 270 times greater than exposure concentrations, resulting in ∼10% increased coelomic fluid serotonin, a pharmacological effect. Observed effects included weight loss (up to 2% at 500 μg L(-1)), decreased feeding rate (68% at 500 μg L(-1)), and altered metabolism (oxygen consumption, ammonia excretion, and O/N from 10 μg L(-1)). Bioconcentration of fluoxetine was dependent on route of uptake, with filter feeding worms experiencing up to 130 times greater body burden ratios and increased magnitudes of effects than deposit feeders, a trait-based sensitivity likely as a consequence of fluoxetine partitioning to sediment. This study highlights how novel approaches such as MoA and trait-based methods can supplement environmental risk assessments of pharmaceuticals.
Abstract.
Author URL.
Clark JR, Cole M, Lindeque PK, Fileman E, Blackford J, Lewis C, Lenton TM, Galloway TS (2016). Marine microplastic debris: a targeted plan for understanding and quantifying interactions with marine life. Frontiers in Ecology and the Environment, 14, 317-324.
Galloway TS, Lewis CN (2016). Marine microplastics spell big problems for future generations.
Proc Natl Acad Sci U S A,
113(9), 2331-2333.
Author URL.
Cole M, Lindeque PK, Fileman E, Clark J, Lewis C, Halsband C, Galloway TS (2016). Microplastics Alter the Properties and Sinking Rates of Zooplankton Faecal Pellets.
Environmental science & technology,
50(6), 3239-3246.
Abstract:
Microplastics Alter the Properties and Sinking Rates of Zooplankton Faecal Pellets.
Plastic debris is a widespread contaminant, prevalent in aquatic ecosystems across the globe. Zooplankton readily ingest microscopic plastic (microplastic, < 1 mm), which are later egested within their faecal pellets. These pellets are a source of food for marine organisms, and contribute to the oceanic vertical flux of particulate organic matter as part of the biological pump. The effects of microplastics on faecal pellet properties are currently unknown. Here we test the hypotheses that (1) faecal pellets are a vector for transport of microplastics, (2) polystyrene microplastics can alter the properties and sinking rates of zooplankton egests and, (3) faecal pellets can facilitate the transfer of plastics to coprophagous biota. Following exposure to 20.6 μm polystyrene microplastics (1000 microplastics mL(-1)) and natural prey (∼1650 algae mL(-1)) the copepod Calanus helgolandicus egested faecal pellets with significantly (P < 0.001) reduced densities, a 2.25-fold reduction in sinking rates, and a higher propensity for fragmentation. We further show that microplastics, encapsulated within egests of the copepod Centropages typicus, could be transferred to C. helgolandicus via coprophagy. Our results support the proposal that sinking faecal matter represents a mechanism by which floating plastics can be vertically transported away from surface waters.
Abstract.
Nelms SE, Duncan EM, Broderick AC, Galloway TS, Godfrey MH, Hamann M, Lindeque PK, Godley BJ (2016). Plastic and marine turtles: a review and call for research.
ICES JOURNAL OF MARINE SCIENCE,
73(2), 165-181.
Author URL.
Karami A, Romano N, Galloway T, Hamzah H (2016). Virgin microplastics cause toxicity and modulate the impacts of phenanthrene on biomarker responses in African catfish (Clarias gariepinus).
Environ Res,
151, 58-70.
Abstract:
Virgin microplastics cause toxicity and modulate the impacts of phenanthrene on biomarker responses in African catfish (Clarias gariepinus).
Despite the ubiquity of microplastics (MPs) in aquatic environments and their proven ability to carry a wide variety of chemicals, very little is known about the impacts of virgin or contaminant-loaded MPs on organisms. The primary aim of this study was to investigate the impacts of virgin or phenanthrene (Phe)-loaded low-density polyethylene (LDPE) fragments on a suite of biomarker responses in juvenile African catfish (Clarias gariepinus). Virgin LDPE (50 or 500µg/L) were preloaded with one of two nominal Phe concentrations (10 or 100µg/L) and were exposed to the fish for 96h. Our findings showed one or both Phe treatments significantly increased the degree of tissue change (DTC) in the liver while decreased the transcription levels of forkhead box L2 (foxl2) and tryptophan hydroxylase2 (tph2) in the brain of C. gariepinus. Exposure to either levels of virgin MPs increased the DTC in the liver and plasma albumin: globulin ratio while decreased the transcription levels of tph2. Moreover, MPs modulated (interacted with) the impact of Phe on the DTC in the gill, plasma concentrations of cholesterol, high-density lipoprotein (HDL), total protein (TP), albumin, and globulin, and the transcription levels of fushi tarazu-factor 1 (ftz-f1), gonadotropin-releasing hormone (GnRH), 11 β-hydroxysteroid dehydrogenase type 2 (11β-hsd2), and liver glycogen stores. Results of this study highlight the ability of virgin LDPE fragments to cause toxicity and to modulate the adverse impacts of Phe in C. gariepinus. Due to the wide distribution of MPs and other classes of contaminants in aquatic environments, further studies are urgently needed to elucidate the toxicity of virgin or contaminant-loaded MPs on organisms.
Abstract.
Author URL.
2015
Song L, Vijver MG, Peijnenburg WJGM, Galloway TS, Tyler CR (2015). A comparative analysis on the in vivo toxicity of copper nanoparticles in three species of freshwater fish.
Chemosphere,
139, 181-189.
Abstract:
A comparative analysis on the in vivo toxicity of copper nanoparticles in three species of freshwater fish.
Copper nanoparticles (CuNPs) are used extensively in a wide range of products and the potential for toxicological impacts in the aquatic environment is of high concern. In this study, the fate and the acute toxicity of spherical 50nm copper nanoparticles was assessed in juvenile rainbow trout (Oncorhynchus mykiss), fathead minnow (Pimephales promelas) and zebrafish (Danio rerio) for in vivo aqueous exposures following standardized OECD 203 guideline tests. The fate of the CuNPs in the aqueous media was temperature dependent. At the higher study temperature (26±1°C), there was both an enhanced particle aggregation and higher rate of dissolution compared with that at the lower study temperature (15±1°C). 96h LC50s of the CuNPs were 0.68±0.15, 0.28±0.04 and 0.22±0.08mg Cu/L for rainbow trout, fathead minnow and zebrafish, respectively. The 96h lowest-observed-effect concentration (LOEC) for the CuNPs were 0.17, 0.023 and
Abstract.
Author URL.
Rancière F, Lyons JG, Loh VHY, Botton J, Galloway T, Wang T, Shaw JE, Magliano DJ (2015). Bisphenol a and the risk of cardiometabolic disorders: a systematic review with meta-analysis of the epidemiological evidence.
Environmental Health: a Global Access Science Source,
14(1).
Abstract:
Bisphenol a and the risk of cardiometabolic disorders: a systematic review with meta-analysis of the epidemiological evidence
Bisphenol a (BPA) is suspected to be associated with several chronic metabolic diseases. The aim of the present study was to review the epidemiological literature on the relation between BPA exposure and the risk of cardiometabolic disorders. PubMed and Embase databases were searched up to August 2014 by two independent investigators using standardized subject terms. We included observational studies (cohort, case-control and cross-sectional studies) carried out in children or adults, measuring urinary BPA (uBPA), including at least 100 participants and published in English. The health outcomes of interest were diabetes, hyperglycemia, measures of anthropometry, cardiovascular disease (CVD) and hypertension. Data were extracted and meta-analyzed when feasible, using a random-effects model. Thirty-three studies with sample size ranging from 239 to 4811 met the inclusion criteria, including five with a prospective design. Twelve studies reported on diabetes or hyperglycemia, 16 on anthropometry, 6 on CVD and 3 on hypertension. Evidence for a positive association between uBPA concentrations and diabetes, overweight, obesity, elevated waist circumference (WC), CVD and hypertension was found in 7/8, 2/7, 6/7, 5/5, 4/5 and 2/3 of the cross-sectional studies, respectively. We were able to conduct outcome-specific meta-analyses including 12 studies. When comparing the highest vs. the lowest uBPA concentrations, the pooled ORs were 1.47 (95 % CI: 1.21-1.80) for diabetes, 1.21 (95 % CI: 0.98-1.50) for overweight, 1.67 (95 % CI: 1.41-1.98) for obesity, 1.48 (95 % CI: 1.25-1.76) for elevated WC, and 1.41 (95 % CI: 1.12-1.79) for hypertension. Moreover, among the five prospective studies, 3 reported significant findings, relating BPA exposure to incident diabetes, incident coronary artery disease, and weight gain. To conclude, there is evidence from the large body of cross-sectional studies that individuals with higher uBPA concentrations are more likely to suffer from diabetes, general/abdominal obesity and hypertension than those with lower uBPA concentrations. Given the potential importance for public health, prospective cohort studies with proper adjustment for dietary characteristics and identification of critical windows of exposure are urgently needed to further improve knowledge about potential causal links between BPA exposure and the development of chronic disease.
Abstract.
Rancière F, Lyons JG, Loh VHY, Botton J, Galloway T, Wang T, Shaw JE, Magliano DJ (2015). Bisphenol a and the risk of cardiometabolic disorders: a systematic review with meta-analysis of the epidemiological evidence.
Environ Health,
14Abstract:
Bisphenol a and the risk of cardiometabolic disorders: a systematic review with meta-analysis of the epidemiological evidence.
Bisphenol a (BPA) is suspected to be associated with several chronic metabolic diseases. The aim of the present study was to review the epidemiological literature on the relation between BPA exposure and the risk of cardiometabolic disorders. PubMed and Embase databases were searched up to August 2014 by two independent investigators using standardized subject terms. We included observational studies (cohort, case-control and cross-sectional studies) carried out in children or adults, measuring urinary BPA (uBPA), including at least 100 participants and published in English. The health outcomes of interest were diabetes, hyperglycemia, measures of anthropometry, cardiovascular disease (CVD) and hypertension. Data were extracted and meta-analyzed when feasible, using a random-effects model. Thirty-three studies with sample size ranging from 239 to 4811 met the inclusion criteria, including five with a prospective design. Twelve studies reported on diabetes or hyperglycemia, 16 on anthropometry, 6 on CVD and 3 on hypertension. Evidence for a positive association between uBPA concentrations and diabetes, overweight, obesity, elevated waist circumference (WC), CVD and hypertension was found in 7/8, 2/7, 6/7, 5/5, 4/5 and 2/3 of the cross-sectional studies, respectively. We were able to conduct outcome-specific meta-analyses including 12 studies. When comparing the highest vs. the lowest uBPA concentrations, the pooled ORs were 1.47 (95% CI: 1.21-1.80) for diabetes, 1.21 (95% CI: 0.98-1.50) for overweight, 1.67 (95% CI: 1.41-1.98) for obesity, 1.48 (95% CI: 1.25-1.76) for elevated WC, and 1.41 (95% CI: 1.12-1.79) for hypertension. Moreover, among the five prospective studies, 3 reported significant findings, relating BPA exposure to incident diabetes, incident coronary artery disease, and weight gain. To conclude, there is evidence from the large body of cross-sectional studies that individuals with higher uBPA concentrations are more likely to suffer from diabetes, general/abdominal obesity and hypertension than those with lower uBPA concentrations. Given the potential importance for public health, prospective cohort studies with proper adjustment for dietary characteristics and identification of critical windows of exposure are urgently needed to further improve knowledge about potential causal links between BPA exposure and the development of chronic disease.
Abstract.
Author URL.
Cole M, Galloway TS (2015). Ingestion of Nanoplastics and Microplastics by Pacific Oyster Larvae.
ENVIRONMENTAL SCIENCE & TECHNOLOGY,
49(24), 14625-14632.
Author URL.
Watts AJR, Urbina MA, Corr S, Lewis C, Galloway TS (2015). Ingestion of Plastic Microfibers by the Crab Carcinus maenas and its Effect on Food Consumption and Energy Balance.
Environ Sci Technol,
49(24), 14597-14604.
Abstract:
Ingestion of Plastic Microfibers by the Crab Carcinus maenas and its Effect on Food Consumption and Energy Balance.
Microscopic plastic fragments (
Abstract.
Author URL.
Galloway TS (2015). Micro- and nano-plastics and human health. In (Ed)
Marine Anthropogenic Litter, 343-366.
Abstract:
Micro- and nano-plastics and human health
Abstract.
Browne MA, Dissanayake A, Galloway TS (2015). Organophosphorous biocides reduce tenacity and cellular viability but not esterase activities in a non-target prosobranch (limpet).
Environmental Pollution,
203, 208-213.
Abstract:
Organophosphorous biocides reduce tenacity and cellular viability but not esterase activities in a non-target prosobranch (limpet)
Detecting impacts of organophosphorus biocides (OP) is facilitated by analysing "biomarkers" - biological responses to environmental insults. Understanding is hampered by studying biomarkers in isolation at different levels of biological response and limited work on ecologically-important species. We tested the relevance of esterases as biomarkers of OP-exposure in limpets (Patella vulgata), abundant prosobranchs that structure the assemblages on rocky shores through their grazing. We characterized esterases in haemolymph and tissue, and quantified their dose-dependent inhibition by chlorfenvinphos (0.1-3.0 mM) in vitro. To determine whether esterases are useful biomarkers we exposed limpets to chlorfenvinphos (0-10 μg L-1). Despite reduced tenacity (ability to stick to a surface) and haemocyte-viability, esterases remained unaffected. Tenacity was reduced by >50% at 5 μg L-1 and by 95% at 10 μg L-1, whilst haemocyte-viability was more sensitive with >40% reductions at concentrations of 0.5 μg L-1 and above. We discuss results in relation to linking sub-lethal and ecological impacts at contaminated sites.
Abstract.
Galloway TS, Fletcher T, Thomas OJ, Lee BP, Pilling LC, Harries LW (2015). PFOA and PFOS are associated with reduced expression of the parathyroid hormone 2 receptor (PTH2R) gene in women.
Chemosphere,
120, 555-562.
Abstract:
PFOA and PFOS are associated with reduced expression of the parathyroid hormone 2 receptor (PTH2R) gene in women.
Little is known about interactions between environmental and genetic risk factors for osteoarthritis (OA). Genetic factors include variation or mutation in genes involved in parathyroid hormone signalling. Exposure to the endocrine disrupting chemicals perfluoro-octanoic acid (PFOA) or perfluorooctane sulfonate (PFOS) have been suggested as potential environmental contributors, although evidence to support this association is conflicting. Here we test the hypothesis that PFOA and PFOS may alter the mRNA expression of genes in the parathyroid signalling cascade to provide evidence on possible pathways between these chemicals and OA. We measured the relationship between PFOA or PFOS serum levels and the in vivo expression of the Parathyroid hormone 1 and 2 genes (PTH, PTH2), Parathyroid hormone 1 and 2 receptor genes (PTH1R, PTH2R) and the parathyroid hormone-like (PTHLH) gene in peripheral blood from a cross-sectional population study designed to assess the potential health effects of these chemicals. We used multivariate linear regression models and found that PFOA or PFOS was inversely correlated with parathyroid hormone 2 receptor (PTH2R) expression (coefficients=-0.43 and -0.32, p=p=0.017 and 0.006 for PFOA and PFOS respectively) in 189 female subjects. The levels of PTH2 transcripts encoding the ligand of PTH2r, were also found to be lower in women with OA (median 2.08) compared with controls (median 3.41, p=0.046). As the parathyroid signalling cascade is a known candidate for osteoarthritis risk and our findings raise the possibility that exposure to these chemicals may contribute to the pathogenesis of OA in some individuals.
Abstract.
Author URL.
Cole M, Lindeque P, Fileman E, Halsband C, Galloway TS (2015). The impact of polystyrene microplastics on feeding, function and fecundity in the marine copepod Calanus helgolandicus.
Environ Sci Technol,
49(2), 1130-1137.
Abstract:
The impact of polystyrene microplastics on feeding, function and fecundity in the marine copepod Calanus helgolandicus.
Microscopic plastic debris, termed “microplastics”, are of increasing environmental concern. Recent studies have demonstrated that a range of zooplankton, including copepods, can ingest microplastics. Copepods are a globally abundant class of zooplankton that form a key trophic link between primary producers and higher trophic marine organisms. Here we demonstrate that ingestion of microplastics can significantly alter the feeding capacity of the pelagic copepod Calanus helgolandicus. Exposed to 20 μm polystyrene beads (75 microplastics mL(–1)) and cultured algae ([250 μg C L(–1)) for 24 h, C. helgolandicus ingested 11% fewer algal cells (P = 0.33) and 40% less carbon biomass (P < 0.01). There was a net downward shift in the mean size of algal prey consumed (P < 0.001), with a 3.6 fold increase in ingestion rate for the smallest size class of algal prey (11.6–12.6 μm), suggestive of postcapture or postingestion rejection. Prolonged exposure to polystyrene microplastics significantly decreased reproductive output, but there were no significant differences in egg production rates, respiration or survival. We constructed a conceptual energetic (carbon) budget showing that microplastic-exposed copepods suffer energetic depletion over time. We conclude that microplastics impede feeding in copepods, which over time could lead to sustained reductions in ingested carbon biomass.
Abstract.
Author URL.
Goodhead RM, Moger J, Galloway TS, Tyler CR (2015). Tracing engineered nanomaterials in biological tissues using coherent anti-Stokes Raman scattering (CARS) microscopy - a critical review.
Nanotoxicology,
9(7), 928-939.
Abstract:
Tracing engineered nanomaterials in biological tissues using coherent anti-Stokes Raman scattering (CARS) microscopy - a critical review.
Nanomaterials (NMs) are used in an extremely diverse range of products and are increasingly entering the environment, driving a need to better understand their potential health effects in both humans and wildlife. A major challenge in nanoparticle (eco)toxicology is the ability to localise NMs post exposure, to enable more targeted biological effects analyses. A range of imaging techniques have been applied to do so, but they are limited, requiring either extensive processing of the material, staining or use of high intensity illumination that can lead to photo damage and/or have limited tissue penetration. Coherent anti-Stokes Raman scattering (CARS) microscopy is a label-free imaging technique, providing contrast based on the intrinsic molecular vibrations of a specimen, circumventing the need for chemical perturbation by exogenous labels. CARS uses near infra-red excitation wavelengths which allow microscopy at depths of several hundred microns in intact tissues and minimises photo-damage to live and delicate samples. Here we provide an overview of the CARS process and present a series of illustrative examples demonstrating its application for detecting NMs within biological tissues, ranging from isolated cells to whole organisms and including materials spanning metals to polymers. We highlight the advantages of this technique which include chemically selective live imaging and substantial depth penetration, but we also discuss its limitations when applied to nanotoxicology, which most notably include the lack of resolution for studies on single nanoparticles.
Abstract.
Author URL.
Cross RK, Tyler C, Galloway TS (2015). Transformations that affect fate, form and bioavailability of inorganic nanoparticles in aquatic sediments.
Author URL.
2014
Cipelli R, Harries L, Okuda K, Yoshihara S, Melzer D, Galloway T (2014). Bisphenol a modulates the metabolic regulator oestrogen-related receptor-α in T-cells.
Reproduction,
147(4), 419-426.
Abstract:
Bisphenol a modulates the metabolic regulator oestrogen-related receptor-α in T-cells.
Bisphenol a (BPA) is a widely used plastics constituent that has been associated with endocrine, immune and metabolic effects. Evidence for how BPA exerts significant biological effects at chronic low levels of exposure has remained elusive. In adult men, exposure to BPA has been associated with higher expression of two nuclear receptors, oestrogen receptor-β (ERβ) and oestrogen-related-receptor-α (ERRα), in peripheral white blood cells in vivo. In this study, we explore the expression of ESR2 (ERβ) and ESRRA (ERRα) in human leukaemic T-cell lymphoblasts (Jurkat cells) exposed to BPA in vitro. We show that exposure to BPA led to enhanced expression of ESRRA within 6 h of exposure (mean±s.e.m.: 1.43±0.08-fold increase compared with the control, P
Abstract.
Author URL.
Adams JA, Galloway TS, Mondal D, Esteves SC, Mathews F (2014). Effect of mobile telephones on sperm quality: a systematic review and meta-analysis.
Environ Int,
70, 106-112.
Abstract:
Effect of mobile telephones on sperm quality: a systematic review and meta-analysis.
Mobile phones are owned by most of the adult population worldwide. Radio-frequency electromagnetic radiation (RF-EMR) from these devices could potentially affect sperm development and function. Around 14% of couples in high- and middle-income countries have difficulty conceiving, and there are unexplained declines in semen quality reported in several countries. Given the ubiquity of mobile phone use, the potential role of this environmental exposure needs to be clarified. A systematic review was therefore conducted, followed by meta-analysis using random effects models, to determine whether exposure to RF-EMR emitted from mobile phones affects human sperm quality. Participants were from fertility clinic and research centres. The sperm quality outcome measures were motility, viability and concentration, which are the parameters most frequently used in clinical settings to assess fertility. We used ten studies in the meta-analysis, including 1492 samples. Exposure to mobile phones was associated with reduced sperm motility (mean difference -8.1% (95% CI -13.1, -3.2)) and viability (mean difference -9.1% (95% CI -18.4, 0.2)), but the effects on concentration were more equivocal. The results were consistent across experimental in vitro and observational in vivo studies. We conclude that pooled results from in vitro and in vivo studies suggest that mobile phone exposure negatively affects sperm quality. Further study is required to determine the full clinical implications for both sub-fertile men and the general population.
Abstract.
Author URL.
Mondal D, Galloway T, Bailey TC, Mathews F (2014). Elevated risk of stillbirth in males: systematic review and meta-analysis of more than 30 million births. BMC Medicine, 12
Cole MJ (2014). Impact of microplastics on zooplankton.
Baker TJ, Tyler CR, Galloway TS (2014). Impacts of metal and metal oxide nanoparticles on marine organisms.
Environmental Pollution,
186, 257-271.
Abstract:
Impacts of metal and metal oxide nanoparticles on marine organisms
Increasing use of metal and metal oxide nanoparticles [Me(O)NPs] in products means many will inevitably find their way into marine systems. Their likely fate here is sedimentation following hetero-aggregation with natural organic matter and/or free anions, putting benthic, sediment-dwelling and filter feeding organisms most at risk. In marine systems, Me(O)NPs can absorb to micro-organisms with potential for trophic transfer following consumption. Filter feeders, especially bivalves, accumulate Me(O)NPs through trapping them in mucus prior to ingestion. Benthic in-fauna may directly ingest sedimented Me(O)NPs. In fish, uptake is principally via the gut following drinking, whilst Me(O)NPs caught in gill mucus may affect respiratory processes and ion transport. Currently, environmentally-realistic Me(O)NP concentrations are unlikely to cause significant adverse acute health problems, however sub-lethal effects e.g. oxidative stresses have been noted in many organisms, often deriving from dissolution of Ag, Cu or Zn ions, and this could result in chronic health impacts. © 2013 Published by Elsevier Ltd. All rights reserved.
Abstract.
Baker TJ, Tyler CR, Galloway TS (2014). Impacts of metal and metal oxide nanoparticles on marine organisms.
Environ Pollut,
186, 257-271.
Abstract:
Impacts of metal and metal oxide nanoparticles on marine organisms.
Increasing use of metal and metal oxide nanoparticles [Me(O)NPs] in products means many will inevitably find their way into marine systems. Their likely fate here is sedimentation following hetero-aggregation with natural organic matter and/or free anions, putting benthic, sediment-dwelling and filter feeding organisms most at risk. In marine systems, Me(O)NPs can absorb to micro-organisms with potential for trophic transfer following consumption. Filter feeders, especially bivalves, accumulate Me(O)NPs through trapping them in mucus prior to ingestion. Benthic in-fauna may directly ingest sedimented Me(O)NPs. In fish, uptake is principally via the gut following drinking, whilst Me(O)NPs caught in gill mucus may affect respiratory processes and ion transport. Currently, environmentally-realistic Me(O)NP concentrations are unlikely to cause significant adverse acute health problems, however sub-lethal effects e.g. oxidative stresses have been noted in many organisms, often deriving from dissolution of Ag, Cu or Zn ions, and this could result in chronic health impacts.
Abstract.
Author URL.
Cole M, Webb H, Lindeque PK, Fileman ES, Halsband C, Galloway TS (2014). Isolation of microplastics in biota-rich seawater samples and marine organisms.
Sci Rep,
4Abstract:
Isolation of microplastics in biota-rich seawater samples and marine organisms.
Microplastic litter is a pervasive pollutant present in aquatic systems across the globe. A range of marine organisms have the capacity to ingest microplastics, resulting in adverse health effects. Developing methods to accurately quantify microplastics in productive marine waters, and those internalized by marine organisms, is of growing importance. Here we investigate the efficacy of using acid, alkaline and enzymatic digestion techniques in mineralizing biological material from marine surface trawls to reveal any microplastics present. Our optimized enzymatic protocol can digest >97% (by weight) of the material present in plankton-rich seawater samples without destroying any microplastic debris present. In applying the method to replicate marine samples from the western English Channel, we identified 0.27 microplastics m(-3). The protocol was further used to extract microplastics ingested by marine zooplankton under laboratory conditions. Our findings illustrate that enzymatic digestion can aid the detection of microplastic debris within seawater samples and marine biota.
Abstract.
Author URL.
Vogeler S, Galloway TS, Lyons BP, Bean TP (2014). The nuclear receptor gene family in the Pacific oyster, Crassostrea gigas, contains a novel subfamily group. Acta Veterinaria Scandinavica, 369-369.
Vogeler S, Galloway TS, Lyons BP, Bean TP (2014). The nuclear receptor gene family in the Pacific oyster, Crassostrea gigas, contains a novel subfamily group.
BMC Genomics,
15(1).
Abstract:
The nuclear receptor gene family in the Pacific oyster, Crassostrea gigas, contains a novel subfamily group
Background: Nuclear receptors are a superfamily of transcription factors important in key biological, developmental and reproductive processes. Several of these receptors are ligand- activated and through their ability to bind endogenous and exogenous ligands, are potentially vulnerable to xenobiotics. Molluscs are key ecological species in defining aquatic and terrestrial habitats and are sensitive to xenobiotic compounds in the environment. However, the understanding of nuclear receptor presence, function and xenobiotic disruption in the phylum Mollusca is limited.Results: Here, forty-three nuclear receptor sequences were mined from the genome of the Pacific oyster, Crassostrea gigas. They include members of NR0-NR5 subfamilies, notably lacking any NR6 members. Phylogenetic analyses of the oyster nuclear receptors have been conducted showing the presence of a large novel subfamily group not previously reported, which is named NR1P. Homologues to all previous identified nuclear receptors in other mollusc species have also been determined including the putative heterodimer partner retinoid X receptor, estrogen receptor and estrogen related receptor.Conclusion: C. gigas contains a highly diverse set of nuclear receptors including a novel NR1 group, which provides important information on presence and evolution of this transcription factor superfamily in invertebrates. The Pacific oyster possesses two members of NR3, the sex steroid hormone receptor analogues, of which there are 9 in humans. This provides increasing evidence that steroid ligand specific expansion of this family is deuterostome specific. This new knowledge on divergence and emergence of nuclear receptors in C. gigas provides essential information for studying regulation of molluscan gene expression and the potential effects of xenobiotics. © 2014 Vogeler et al.; licensee BioMed Central Ltd.
Abstract.
McQuillan JS, Kille P, Powell K, Galloway TS (2014). The regulation of copper stress response genes in the polychaete Nereis diversicolor during prolonged extreme copper contamination.
Environ Sci Technol,
48(22), 13085-13092.
Abstract:
The regulation of copper stress response genes in the polychaete Nereis diversicolor during prolonged extreme copper contamination.
Polychaetes are frequented in toxicological studies, one reason being that some members occupy shallow burrows in sediments and are maximally exposed to the contaminants that accumulate within them. We have been studying one population of the polychaete Nereis (Hediste) diversicolor exhibiting inheritable tolerance to extreme copper contamination in estuarine sediment. Using transcriptome sequencing data we have identified a suite of genes with putative roles in metal detoxification and tolerance, and measured their regulation. Copper tolerant individuals display significantly different gene expression profiles compared to animals from a nearby population living without remarkable copper levels. Gene transcripts encoding principle copper homeostasis proteins including membrane copper ion transporters, copper ion chaperones and putative metallothionein-like proteins were significantly more abundant in tolerant animals occupying contaminated sediment. In contrast, those encoding antioxidants and cellular repair pathways were unchanged. Nontolerant animals living in contaminated sediment showed no difference in copper homeostasis-related gene expression but did have significantly elevated levels of mRNAs encoding Glutathione Peroxidase enzymes. This study represents the first use of functional genomics to investigate the copper tolerance trait in this species and provides insight into the mechanism used by these individuals to survive and flourish in conditions which are lethal to their conspecifics.
Abstract.
Author URL.
Watts AJR, Lewis C, Goodhead RM, Beckett SJ, Moger J, Tyler CR, Galloway TS (2014). Uptake and retention of microplastics by the shore crab Carcinus maenas.
Environ Sci Technol,
48(15), 8823-8830.
Abstract:
Uptake and retention of microplastics by the shore crab Carcinus maenas.
Microplastics, plastics particles
Abstract.
Author URL.
2013
Fletcher T, Galloway TS, Melzer D, Holcroft P, Cipelli R, Pilling LC, Mondal D, Luster M, Harries LW (2013). Associations between PFOA, PFOS and changes in the expression of genes involved in cholesterol metabolism in humans.
Environ Int,
57-58, 2-10.
Abstract:
Associations between PFOA, PFOS and changes in the expression of genes involved in cholesterol metabolism in humans.
Perfluorooctanoic acid (PFOA, 'C8') and perfluoroctane sulphonate (PFOS) are environmentally stable compounds with industrial and consumer uses and long half-lives in humans. Concern has been raised over chronic exposure effects to human health, especially in relation to cholesterol metabolism. Here, we explore the association between exposure to PFOA and PFOS and the in vivo expression of genes involved in cholesterol metabolism. We studied 290 individuals exposed to background levels of PFOS and elevated concentrations of PFOA through drinking water. Using adjusted linear regression models, we found inverse associations between serum PFOA levels and the whole blood expression level of genes involved in cholesterol transport (NR1H2, NPC1 and ABCG1; p=0.002, 0.026 and 0.014 respectively). A positive association was seen between PFOS and a transcript involved in cholesterol mobilisation (NCEH1; p=0.018), and a negative relationship with a transcript involved in cholesterol transport (NR1H3; p=0.044). When sexes were analysed separately, reductions in the levels of mRNAs involved in cholesterol transport were seen with PFOA in men (NPC1, ABCG1, and PPARA; p=0.025, 0.024 and 0.012 respectively) and in women (NR1H2 expression; p=0.019), whereas an increase in the levels of a cholesterol mobilisation transcript (NCEH1; p=0.036) was noted in women alone. PFOS was positively associated with expression of genes involved in both cholesterol mobilisation and transport in women (NCEH1 and PPARA; p=0.003 and 0.039 respectively), but no effects were evident in men. This is the first report of associations between the in vivo expression of genes involved in cholesterol metabolism and exposure to PFOA or PFOS, suggested that exposure to these compounds may promote a hypercholesterolaemic environment, with wider implications for human disease.
Abstract.
Author URL.
Tyrrell J, Melzer D, Henley W, Galloway TS, Osborne NJ (2013). Associations between socioeconomic status and environmental toxicant concentrations in adults in the USA: NHANES 2001-2010.
Environ Int,
59, 328-335.
Abstract:
Associations between socioeconomic status and environmental toxicant concentrations in adults in the USA: NHANES 2001-2010.
Low level chronic exposure to toxicants is associated with a range of adverse health effects. Understanding the various factors that influence the chemical burden of an individual is of critical importance to public health strategies. We investigated the relationships between socioeconomic status (SES) and bio-monitored chemical concentration in five cross-sectional waves of the U.S. National Health and Nutrition Examination Survey (NHANES). We utilised adjusted linear regression models to investigate the association between 179 toxicants and the poverty income ratio (PIR) for five NHANES waves. We then selected a subset of chemicals associated with PIR in 3 or more NHANES waves and investigated potential mediating factors using structural equation modelling. PIR was associated with 18 chemicals in 3 or more NHANES waves. Higher SES individuals had higher burdens of serum and urinary mercury, arsenic, caesium, thallium, perfluorooctanoic acid, perfluorononanoic acid, mono(carboxyoctyl) phthalate and benzophenone-3. Inverse associations were noted between PIR and serum and urinary lead and cadmium, antimony, bisphenol a and three phthalates (mono-benzyl, mono-isobutyl, mono-n-butyl). Key mediators included fish and shellfish consumption for the PIR, mercury, arsenic, thallium and perfluorononanoic acid associations. Sunscreen use was an important mediator in the benzophenone-3/PIR relationship. The association between PIR and cadmium or lead was partially mediated by smoking, occupation and diet. These results provide a comprehensive analysis of exposure patterns as a function of socioeconomic status in US adults, providing important information to guide future public health remediation measures to decrease toxicant and disease burdens within society.
Abstract.
Author URL.
Fletcher T, Harries LW, Galloway T, Yucesoy B, Kashon M, Luster M (2013). Genetic and transcriptomic studies of PFOA and PFOS: thyroid hormones, lipid metabolism and transporter proteins.
Tyrrell J, Galloway TS, Abo-Zaid G, Melzer D, Depledge MH, Osborne NJ (2013). High urinary tungsten concentration is associated with stroke in the National Health and Nutrition Examination Survey 1999-2010.
PLoS One,
8(11).
Abstract:
High urinary tungsten concentration is associated with stroke in the National Health and Nutrition Examination Survey 1999-2010.
BACKGROUND: in recent years there has been an exponential increase in tungsten demand, potentially increasing human exposure to the metal. Currently, the toxicology of tungsten is poorly understood, but mounting evidence suggests that both the elemental metal and its alloys have cytotoxic effects. Here, we investigate the association between tungsten and cardiovascular disease (CVD) or stroke using six waves of the National Health and Nutrition Examination Survey (NHANES). METHODS: We investigated associations using crude and adjusted logistic regression models in a cohort of 8614 adults (18-74 years) with 193 reported stroke diagnoses and 428 reported diagnoses of CVD. We also stratified our data to characterize associations in a subset of younger individuals (18-50 years). RESULTS: Elevated tungsten concentrations were strongly associated with an increase in the prevalence of stroke, independent of typical risk factors (Odds Ratio (OR): 1.66, 95% Confidence Interval (95% CI): 1.17, 2.34). The association between tungsten and stroke in the young age category was still evident (OR: 2.17, 95% CI: 1.33, 3.53). CONCLUSION: This study represents the most comprehensive analysis of the human health effects of tungsten to date. Individuals with higher urinary tungsten concentrations have double the odds of reported stroke. We hypothesize that the pathological pathway resulting from tungsten exposure may involve oxidative stress.
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Author URL.
Cole MJ, Galloway T (2013). Ingestion of microplastics by zooplankton.
Environmental Science & Technology,
47, 6646-6655.
Abstract:
Ingestion of microplastics by zooplankton
Small plastic detritus, termed “microplastics”, are a widespread and ubiquitous contaminant of marine ecosystems across the globe. Ingestion of microplastics by marine biota, including mussels, worms, fish, and seabirds, has been widely reported, but despite their vital ecological role in marine food-webs, the impact of microplastics on zooplankton remains under-researched. Here, we show that microplastics are ingested by, and may impact upon, zooplankton. We used bioimaging techniques to document ingestion, egestion, and adherence of microplastics in a range of zooplankton common to the northeast Atlantic, and employed feeding rate studies to determine the impact of plastic detritus on algal ingestion rates in copepods. Using fluorescence and coherent anti-Stokes Raman scattering (CARS) microscopy we identified that thirteen zooplankton taxa had the capacity to ingest 1.7–30.6 μm polystyrene beads, with uptake varying by taxa, life-stage and bead-size. Post-ingestion, copepods egested faecal pellets laden with microplastics. We further observed microplastics adhered to the external carapace and appendages of exposed zooplankton. Exposure of the copepod Centropages typicus to natural assemblages of algae with and without microplastics showed that 7.3 μm microplastics (>4000 mL–1) significantly decreased algal feeding. Our findings imply that marine microplastic debris can negatively impact upon zooplankton function and health.
Abstract.
Cole M, Lindeque P, Fileman E, Halsband C, Goodhead R, Moger J, Galloway TS (2013). Microplastic ingestion by zooplankton.
Environ Sci Technol,
47(12), 6646-6655.
Abstract:
Microplastic ingestion by zooplankton.
Small plastic detritus, termed "microplastics", are a widespread and ubiquitous contaminant of marine ecosystems across the globe. Ingestion of microplastics by marine biota, including mussels, worms, fish, and seabirds, has been widely reported, but despite their vital ecological role in marine food-webs, the impact of microplastics on zooplankton remains under-researched. Here, we show that microplastics are ingested by, and may impact upon, zooplankton. We used bioimaging techniques to document ingestion, egestion, and adherence of microplastics in a range of zooplankton common to the northeast Atlantic, and employed feeding rate studies to determine the impact of plastic detritus on algal ingestion rates in copepods. Using fluorescence and coherent anti-Stokes Raman scattering (CARS) microscopy we identified that thirteen zooplankton taxa had the capacity to ingest 1.7-30.6 μm polystyrene beads, with uptake varying by taxa, life-stage and bead-size. Post-ingestion, copepods egested faecal pellets laden with microplastics. We further observed microplastics adhered to the external carapace and appendages of exposed zooplankton. Exposure of the copepod Centropages typicus to natural assemblages of algae with and without microplastics showed that 7.3 μm microplastics (>4000 mL(-1)) significantly decreased algal feeding. Our findings imply that marine microplastic debris can negatively impact upon zooplankton function and health.
Abstract.
Author URL.
Wright SL, Rowe D, Thompson RC, Galloway TS (2013). Microplastic ingestion decreases energy reserves in marine worms.
Curr Biol,
23(23), R1031-R1033.
Abstract:
Microplastic ingestion decreases energy reserves in marine worms.
The indiscriminate disposal of plastic to the environment is of concern. Microscopic plastic litter (
Abstract.
Author URL.
Browne MA, Niven SJ, Galloway TS, Rowland SJ, Thompson RC (2013). Microplastic moves pollutants and additives to worms, reducing functions linked to health and biodiversity.
Curr Biol,
23(23), 2388-2392.
Abstract:
Microplastic moves pollutants and additives to worms, reducing functions linked to health and biodiversity.
Inadequate products, waste management, and policy are struggling to prevent plastic waste from infiltrating ecosystems [1, 2]. Disintegration into smaller pieces means that the abundance of micrometer-sized plastic (microplastic) in habitats has increased [3] and outnumbers larger debris [2, 4]. When ingested by animals, plastic provides a feasible pathway to transfer attached pollutants and additive chemicals into their tissues [5-15]. Despite positive correlations between concentrations of ingested plastic and pollutants in tissues of animals, few, if any, controlled experiments have examined whether ingested plastic transfers pollutants and additives to animals. We exposed lugworms (Arenicola marina) to sand with 5% microplastic that was presorbed with pollutants (nonylphenol and phenanthrene) and additive chemicals (Triclosan and PBDE-47). Microplastic transferred pollutants and additive chemicals into gut tissues of lugworms, causing some biological effects, although clean sand transferred larger concentrations of pollutants into their tissues. Uptake of nonylphenol from PVC or sand reduced the ability of coelomocytes to remove pathogenic bacteria by >60%. Uptake of Triclosan from PVC diminished the ability of worms to engineer sediments and caused mortality, each by >55%, while PVC alone made worms >30% more susceptible to oxidative stress. As global microplastic contamination accelerates, our findings indicate that large concentrations of microplastic and additives can harm ecophysiological functions performed by organisms.
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Author URL.
Wright SL, Thompson RC, Galloway TS (2013). The physical impacts of microplastics on marine organisms: a review.
Environmental pollution (Barking, Essex : 1987),
178, 483-492.
Abstract:
The physical impacts of microplastics on marine organisms: a review.
Plastic debris at the micro-, and potentially also the nano-scale, are widespread in the environment. Microplastics have accumulated in oceans and sediments worldwide in recent years, with maximum concentrations reaching 100 000 particles m(3). Due to their small size, microplastics may be ingested by low trophic fauna, with uncertain consequences for the health of the organism. This review focuses on marine invertebrates and their susceptibility to the physical impacts of microplastic uptake. Some of the main points discussed are (1) an evaluation of the factors contributing to the bioavailability of microplastics including size and density; (2) an assessment of the relative susceptibility of different feeding guilds; (3) an overview of the factors most likely to influence the physical impacts of microplastics such as accumulation and translocation; and (4) the trophic transfer of microplastics. These findings are important in guiding future marine litter research and management strategies. Copyright © 2013 Elsevier Ltd. All rights reserved.
Abstract.
Wright SL, Thompson RC, Galloway TS (2013). The physical impacts of microplastics on marine organisms: a review.
Environmental pollution (Barking, Essex : 1987),
178, 483-492.
Abstract:
The physical impacts of microplastics on marine organisms: a review.
Plastic debris at the micro-, and potentially also the nano-scale, are widespread in the environment. Microplastics have accumulated in oceans and sediments worldwide in recent years, with maximum concentrations reaching 100 000 particles m(3). Due to their small size, microplastics may be ingested by low trophic fauna, with uncertain consequences for the health of the organism. This review focuses on marine invertebrates and their susceptibility to the physical impacts of microplastic uptake. Some of the main points discussed are (1) an evaluation of the factors contributing to the bioavailability of microplastics including size and density; (2) an assessment of the relative susceptibility of different feeding guilds; (3) an overview of the factors most likely to influence the physical impacts of microplastics such as accumulation and translocation; and (4) the trophic transfer of microplastics. These findings are important in guiding future marine litter research and management strategies. Copyright © 2013 Elsevier Ltd. All rights reserved.
Abstract.
Wright SL, Thompson RC, Galloway TS (2013). The physical impacts of microplastics on marine organisms: a review.
Environ Pollut,
178, 483-492.
Abstract:
The physical impacts of microplastics on marine organisms: a review.
Plastic debris at the micro-, and potentially also the nano-scale, are widespread in the environment. Microplastics have accumulated in oceans and sediments worldwide in recent years, with maximum concentrations reaching 100 000 particles m(3). Due to their small size, microplastics may be ingested by low trophic fauna, with uncertain consequences for the health of the organism. This review focuses on marine invertebrates and their susceptibility to the physical impacts of microplastic uptake. Some of the main points discussed are (1) an evaluation of the factors contributing to the bioavailability of microplastics including size and density; (2) an assessment of the relative susceptibility of different feeding guilds; (3) an overview of the factors most likely to influence the physical impacts of microplastics such as accumulation and translocation; and (4) the trophic transfer of microplastics. These findings are important in guiding future marine litter research and management strategies.
Abstract.
Author URL.
2012
Melzer D, Gates P, Osborn NJ, Henley WE, Cipelli R, Young A, Money C, McCormack P, Schofield P, Mosedale D, et al (2012). Correction: Urinary Bisphenol a Concentration and Angiography-Defined Coronary Artery Stenosis.
PLoS One,
7(11).
Abstract:
Correction: Urinary Bisphenol a Concentration and Angiography-Defined Coronary Artery Stenosis.
[This corrects the article on p. e43378 in vol. 7.].
Abstract.
Author URL.
Fletcher T, Harries L, Galloway T, Melzer D, Luster M (2012). O-134.
Scarlett AG, West CE, Jones D, Galloway TS, Rowland SJ (2012). Predicted toxicity of naphthenic acids present in oil sands process-affected waters to a range of environmental and human endpoints.
Sci Total Environ,
425, 119-127.
Abstract:
Predicted toxicity of naphthenic acids present in oil sands process-affected waters to a range of environmental and human endpoints.
Naphthenic acids (NAs) are considered to be a major toxic component of oil sands process-affected waters (OSPW) and are also widely used for industrial processes. The effects of previously identified NAs (54 in total), together with six alkylphenols, were modelled for a range of environmental and human toxicity related endpoints using ADMET predictor™ software. In addition to the models, experimental CALUX® assays were performed on seven tricyclic diamondoid acids. Most of the NAs modelled were predicted to have lethal median concentrations (LC(50)) >100 μM for the three aquatic species modelled. Polycyclic acids containing a single aromatic ring were predicted to be the most toxic to fathead minnows with LC(50)s typically ca 1 μM. Some of these compounds were also predicted to be the most carcinogenic (based on rat and mouse models), possess human estrogenic and androgenic activity and potentially disrupt reproductive processes. Some aliphatic pentacyclic acids also were predicted to exhibit androgenic activity and, uniquely amongst the compounds tested, act as substrates for the cytochrome P450 enzyme CYP3A4. Consistent with the models' predictions for the tricyclic acids, no estrogenic or androgenic activity was detected by ER/AR CALUX®. Further experimental validation of the predictions should now be performed for the compounds highlighted by the models (e.g. priority should perhaps be focused on the polycyclic monoaromatic acids and the aliphatic pentacyclic acids). If shown to be accurate, these compounds can then be targeted for toxicity reduction remediation efforts.
Abstract.
Author URL.
Fabrega J, Tantra R, Amer A, Stolpe B, Tomkins J, Fry T, Lead JR, Tyler CR, Galloway TS (2012). Sequestration of zinc from zinc oxide nanoparticles and life cycle effects in the sediment dweller amphipod Corophium volutator.
Environ Sci Technol,
46(2), 1128-1135.
Abstract:
Sequestration of zinc from zinc oxide nanoparticles and life cycle effects in the sediment dweller amphipod Corophium volutator.
We studied the effects of ZnO nanoparticles [ZnO NPs, primary particle size 35 ± 10 nm (circular diameter, TEM)], bulk [160 ± 81 nm (circular diameter, TEM)], and Zn ions (from ZnCl(2)) on mortality, growth, and reproductive endpoints in the sediment dwelling marine amphipod Corophium volutator over a complete lifecycle (100 days). ZnO NPs were characterized by size, aggregation, morphology, dissolution, and surface properties. ZnO NPs underwent aggregation and partial dissolution in the seawater exposure medium, resulting in a size distribution that ranged in size from discrete nanoparticles to the largest aggregate of several micrometers. Exposure via water to all forms of zinc in the range of 0.2-1.0 mg L(-1) delayed growth and affected the reproductive outcome of the exposed populations. STEM-EDX analysis was used to characterize insoluble zinc precipitates (sphaerites) of high sulfur content, which accumulated in the hepatopancreas following exposures. The elemental composition of the sphaerites did not differ for ZnO NP, Zn(2+), and bulk ZnO exposed organisms. These results provide an illustration of the comparable toxicity of Zn in bulk, soluble, and nanoscale forms on critical lifecycle parameters in a sediment dwelling organism.
Abstract.
Author URL.
Hagger JA, Galloway TS, Copplestone D (2012). The Use of Biomarkers as Simple, Rapid Cost-Effective Techniques to Aid in an Integrated Approach to Environmental Management and Risk Assessment with Particular Emphasis on Radionuclides. In (Ed)
Treatise on Estuarine and Coastal Science, 339-353.
Abstract:
The Use of Biomarkers as Simple, Rapid Cost-Effective Techniques to Aid in an Integrated Approach to Environmental Management and Risk Assessment with Particular Emphasis on Radionuclides
Abstract.
Larner F, Dogra Y, Dybowska A, Fabrega J, Stolpe B, Bridgestock LJ, Goodhead R, Weiss DJ, Moger J, Lead JR, et al (2012). Tracing bioavailability of ZnO nanoparticles using stable isotope labeling.
Environ Sci Technol,
46(21), 12137-12145.
Abstract:
Tracing bioavailability of ZnO nanoparticles using stable isotope labeling.
Zinc oxide nanoparticles (ZnO NPs) are widely used in commercial products and knowledge of their environmental fate is a priority for ecological protection. Here we synthesized model ZnO NPs that were made from and thus labeled with the stable isotope (68)Zn and this enables highly sensitive and selective detection of labeled components against high natural Zn background levels. We combine high precision stable isotope measurements and novel bioimaging techniques to characterize parallel water-borne exposures of the common mudshrimp Corophium volutator to (68)ZnO NPs, bulk (68)ZnO, and soluble (68)ZnCl(2) in the presence of sediment. C. volutator is an important component of coastal ecosystems where river-borne NPs will accumulate and is used on a routine basis for toxicity assessments. Our results demonstrate that ionic Zn from ZnO NPs is bioavailable to C. volutator and that Zn uptake is active. Bioavailability appears to be governed primarily by the dissolved Zn content of the water, whereby Zn uptake occurs via the aqueous phase and/or the ingestion of sediment particles with adsorbed Zn from dissolution of ZnO particles. The high sorption capacity of sediments for Zn thus enhances the potential for trophic transfer of Zn derived from readily soluble ZnO NPs. The uncertainties of our isotopic data are too large, however, to conclusively rule out any additional direct uptake route of ZnO NPs by C. volutator.
Abstract.
Author URL.
Melzer D, Osborne NJ, Henley WE, Cipelli R, Young A, Money C, McCormack P, Luben R, Khaw K-T, Wareham NJ, et al (2012). Urinary bisphenol a concentration and risk of future coronary artery disease in apparently healthy men and women.
Circulation,
125(12), 1482-1490.
Abstract:
Urinary bisphenol a concentration and risk of future coronary artery disease in apparently healthy men and women.
BACKGROUND: the endocrine-disrupting chemical bisphenol a (BPA) is widely used in food and beverage packaging. Higher urinary BPA concentrations were cross-sectionally associated with heart disease in National Health and Nutrition Examination Survey (NHANES) 2003-2004 and NHANES 2005-2006, independent of traditional risk factors. METHODS AND RESULTS: We included 758 incident coronary artery disease (CAD) cases and 861 controls followed for 10.8 years from the European Prospective Investigation of Cancer-Norfolk UK. Respondents aged 40 to 74 years and free of CAD, stroke, or diabetes mellitus provided baseline spot urine samples. Urinary BPA concentrations (median value, 1.3 ng/mL) were low. Per-SD (4.56 ng/mL) increases in urinary BPA concentration were associated with incident CAD in age-, sex-, and urinary creatinine-adjusted models (n=1919; odds ratio=1.13; 95% confidence interval, 1.02-1.24; P=0.017). With CAD risk factor adjustment (including education, occupational social class, body mass index category, systolic blood pressure, lipid concentrations, and exercise), the estimate was similar but narrowly missed 2-sided significance (n=1744; odds ratio=1.11; 95% confidence interval, 1.00-1.23; P=0.058). Sensitivity analyses with the fully adjusted model, excluding those with early CAD (30, or abnormal renal function or with additional adjustment for vitamin C, C-reactive protein, or alcohol consumption, all produced similar estimates, and all showed associations at P≤0.05. CONCLUSIONS: Associations between higher BPA exposure (reflected in higher urinary concentrations) and incident CAD during >10 years of follow-up showed trends similar to previously reported cross-sectional findings in the more highly exposed NHANES respondents. Further work is needed to accurately estimate the prospective exposure-response curve and to establish the underlying mechanisms.
Abstract.
Author URL.
Melzer D, Gates P, Osborne NJ, Henley WE, Cipelli R, Young A, Money C, McCormack P, Schofield P, Mosedale D, et al (2012). Urinary bisphenol a concentration and angiography-defined coronary artery stenosis.
PLoS One,
7(8).
Abstract:
Urinary bisphenol a concentration and angiography-defined coronary artery stenosis.
BACKGROUND: Bisphenol a is widely used in food and drinks packaging. There is evidence of associations between raised urinary bisphenol a (uBPA) and increased incidence of reported cardiovascular diagnoses. METHODOLOGY/PRINCIPAL FINDINGS: to estimate associations between BPA exposure and angiographically graded coronary atherosclerosis. 591 patients participating in the Metabonomics and Genomics in Coronary Artery Disease (MaGiCAD) study in Cambridgeshire UK, comparing urinary BPA (uBPA) with grades of severity of coronary artery disease (CAD) on angiography. Linear models were adjusted for BMI, occupational social class and diabetes status. Severe (one to three vessel) CAD was present in 385 patients, 86 had intermediate disease (n=86) and 120 had normal coronary arteries. The (unadjusted) median uBPA concentration was 1.28 ng/mL with normal coronary arteries, and 1.53 ng/mL with severe CAD. Compared to those with normal coronary arteries, uBPA concentration was significantly higher in those with severe CAD (OR per uBPA SD=5.96 ng/ml OR=1.43, CI 1.03 to 1.98, p=0.033), and near significant for intermediate disease (OR=1.69, CI 0.98 to 2.94, p=0.061). There was no significant uBPA difference between patients with severe CAD (needing surgery) and the remaining groups combined. CONCLUSIONS/SIGNIFICANCE: BPA exposure was higher in those with severe coronary artery stenoses compared to those with no vessel disease. Larger studies are needed to estimate true dose response relationships. The mechanisms underlying the association remain to be established.
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Author URL.
2011
Hagger JA, Galloway TS, Copplestone D (2011). 4.12 the Use of Biomarkers as Simple, Rapid Cost-Effective Techniques to Aid in an Integrated Approach to Environmental Management and Risk Assessment with Particular Emphasis on Radionuclides. In (Ed) Treatise on Estuarine and Coastal Science, 339-353.
Browne MA, Crump P, Niven SJ, Teuten E, Tonkin A, Galloway T, Thompson R (2011). Accumulation of microplastic on shorelines woldwide: sources and sinks.
Environ Sci Technol,
45(21), 9175-9179.
Abstract:
Accumulation of microplastic on shorelines woldwide: sources and sinks.
Plastic debris 1900 fibers per wash. This suggests that a large proportion of microplastic fibers found in the marine environment may be derived from sewage as a consequence of washing of clothes. As the human population grows and people use more synthetic textiles, contamination of habitats and animals by microplastic is likely to increase.
Abstract.
Author URL.
Melzer D, Galloway T (2011). Bisphenol a and adult disease: making sense of fragmentary data and competing inferences.
Ann Intern Med,
155(6), 392-394.
Author URL.
Melzer D, Harries L, Cipelli R, Henley W, Money C, McCormack P, Young A, Guralnik J, Ferrucci L, Bandinelli S, et al (2011). Bisphenol a exposure is associated with in vivo estrogenic gene expression in adults.
Environ Health Perspect,
119(12), 1788-1793.
Abstract:
Bisphenol a exposure is associated with in vivo estrogenic gene expression in adults.
BACKGROUND: Bisphenol a (BPA) is a synthetic estrogen commonly used in polycarbonate plastic and resin-lined food and beverage containers. Exposure of animal and cell models to doses of BPA below the recommended tolerable daily intake (TDI) of 50 μg/kg/day have been shown to alter specific estrogen-responsive gene expression, but this has not previously been shown in humans. OBJECTIVE: We investigated associations between BPA exposure and in vivo estrogenic gene expression in humans. METHODS: We studied 96 adult men from the InCHIANTI population study and examined in vivo expression of six estrogen receptor, estrogen-related receptor, and androgen receptor genes in peripheral blood leukocytes. RESULTS: the geometric mean urinary BPA concentration was 3.65 ng/mL [95% confidence interval (CI): 3.13, 4.28], giving an estimated mean excretion of 5.84 μg/day (95% CI: 5.00, 6.85), significantly below the current TDI. In age-adjusted models, there were positive associations between higher BPA concentrations and higher ESR2 [estrogen receptor 2 (ER beta)] expression (unstandardized linear regression coefficient = 0.1804; 95% CI: 0.0388, 0.3221; p = 0.013) and ESRRA (estrogen related receptor alpha) expression (coefficient = 0.1718; 95% CI: 0.0213, 0.3223; p = 0.026): These associations were little changed after adjusting for potential confounders, including obesity, serum lipid concentrations, and white cell subtype percentages. Upper-tertile BPA excretors (urinary BPA > 4.6 ng/mL) had 65% higher mean ESR2 expression than did lower-tertile BPA excretors (0-2.4 ng/mL). CONCLUSIONS: Because activation of nuclear-receptor-mediated pathways by BPA is consistently found in laboratory studies, such activation in humans provides evidence that BPA is likely to function as a xenoestrogen in this sample of adults.
Abstract.
Author URL.
Cole M, Lindeque P, Halsband C, Galloway TS (2011). Microplastics as contaminants in the marine environment: a review.
Mar Pollut Bull,
62(12), 2588-2597.
Abstract:
Microplastics as contaminants in the marine environment: a review.
Since the mass production of plastics began in the 1940s, microplastic contamination of the marine environment has been a growing problem. Here, a review of the literature has been conducted with the following objectives: (1) to summarise the properties, nomenclature and sources of microplastics; (2) to discuss the routes by which microplastics enter the marine environment; (3) to evaluate the methods by which microplastics are detected in the marine environment; (4) to assess spatial and temporal trends of microplastic abundance; and (5) to discuss the environmental impact of microplastics. Microplastics are both abundant and widespread within the marine environment, found in their highest concentrations along coastlines and within mid-ocean gyres. Ingestion of microplastics has been demonstrated in a range of marine organisms, a process which may facilitate the transfer of chemical additives or hydrophobic waterborne pollutants to biota. We conclude by highlighting key future research areas for scientists and policymakers.
Abstract.
Author URL.
Noventa S, Pavoni B, Galloway TS (2011). Periwinkle (Littorina littorea) as a sentinel species: a field study integrating chemical and biological analyses.
Environ Sci Technol,
45(7), 2634-2640.
Abstract:
Periwinkle (Littorina littorea) as a sentinel species: a field study integrating chemical and biological analyses.
The gastropod Littorina littorea (common periwinkle) is an abundant and widespread North Atlantic species. The characteristic development of Intersex in L. littorea has been widely applied as a biomarker for tributyltin (TBT) contamination. Here, we assess the potential of L. littorea as a novel sentinel species for evaluating the sublethal effects in wild populations of widely distributed contaminants. We collected animals from six sites across the South coast of England. Tissue concentrations of polycyclic aromatic hydrocarbons (PAHs), organotin compounds (OTCs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were measured and compared with biomarkers of damage to DNA (Comet assay), lysosomal stability (NRR assay), and endocrine disruption (Intersex development). There was a strong correlation between DNA damage and PAH bioaccumulation (n=6, r=0.84, p
Abstract.
Author URL.
Dissanayake A, Galloway TS, Jones MB (2011). Seasonal differences in the physiology of Carcinus maenas (Crustacea: Decapoda) from estuaries with varying levels of anthropogenic contamination.
Estuarine, Coastal and Shelf Science,
93(4), 320-327.
Abstract:
Seasonal differences in the physiology of Carcinus maenas (Crustacea: Decapoda) from estuaries with varying levels of anthropogenic contamination
This study reports the seasonal variability in aspects of the physiology of the shore crab Carcinus maenas from three estuaries in South-west England, each with varying anthropogenic inputs: Avon Estuary ('relatively low' impact), Yealm Estuary ('intermediate' impact) and Plym Estuary ('relatively high' impact). Crabs collected over 12 months from the Avon had a significantly 'lower' physiological condition in winter and spring compared to summer and autumn; in particular, haemocyte phagocytic capability (a general indicator of immune function) was significantly higher in winter and spring compared to summer and autumn, and total haemolymph antioxidant status (an indicator of oxidative stress) was significantly lower in winter compared to the remainder of the year. Potentially, shore crabs may be more susceptible to the effects of contaminant exposure, such as increased immunotoxicity (thus, reduction of immune function) and/or oxyradicals (or reactive oxygen species) exposure) especially in seasons of increased susceptibility i.e. summer/autumn (lower phagocytic capability) and winter (lowest antioxidant function). As the Avon was taken to represent the 'reference' site, this pattern is considered to reflect the 'normal' seasonal variability in shore crab physiology. Shore crab physiological condition from the 'relatively high' impact estuary (Plym) revealed increased cellular viability and antioxidant status in autumn and winter compared with that of the 'standard' pattern (Avon) However, crabs from the intermediate impact estuary (Yealm) only demonstrated significant physiological differences in summer as shown by a lower cellular viability. All crabs had been exposed to PAHs (confirmed by the presence of PAH metabolites in their urine) which may account for the observed differences in shore crab physiology. In conclusion, to aid understanding of the potential contaminant impacts on biota it is imperative that the 'normal' seasonal variability of physiological condition be established. Biological effects-based monitoring studies should therefore be employed seasonally to potentially highlight 'windows of sensitivity' to contaminant impact. © 2011 Elsevier Ltd.
Abstract.
Fabrega J, Luoma SN, Tyler CR, Galloway TS, Lead JR (2011). Silver nanoparticles: behaviour and effects in the aquatic environment.
Environ Int,
37(2), 517-531.
Abstract:
Silver nanoparticles: behaviour and effects in the aquatic environment.
This review summarises and evaluates the present knowledge on the behaviour, the biological effects and the routes of uptake of silver nanoparticles (Ag NPs) to organisms, with considerations on the nanoparticle physicochemistry in the ecotoxicity testing systems used. Different types of Ag NP syntheses, characterisation techniques and predicted current and future concentrations in the environment are also outlined. Rapid progress in this area has been made over the last few years, but there is still a critical lack of understanding of the need for characterisation and synthesis in environmental and ecotoxicological studies. Concentration and form of nanomaterials in the environment are difficult to quantify and methodological progress is needed, although sophisticated exposure models show that predicted environmental concentrations (PECs) for Ag NPs in different environmental compartments are at the range of ng L(-1) to mg kg(-1). The ecotoxicological literature shows that concentrations of Ag NPs below the current and future PECs, as low as just a few ng L(-1), can affect prokaryotes, invertebrates and fish indicating a significant potential, though poorly characterised, risk to the environment. Mechanisms of toxicity are still poorly understood although it seems clear that in some cases nanoscale specific properties may cause biouptake and toxicity over and above that caused by the dissolved Ag ion. This review concludes with a set of recommendations for the advancement of understanding of the role of nanoscale silver in environmental and ecotoxicological research.
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Author URL.
2010
Melzer D, Rice N, Depledge MH, Henley WE, Galloway TS (2010). Association between serum perfluorooctanoic acid (PFOA) and thyroid disease in the U.S. National Health and Nutrition Examination Survey.
Environ Health Perspect,
118(5), 686-692.
Abstract:
Association between serum perfluorooctanoic acid (PFOA) and thyroid disease in the U.S. National Health and Nutrition Examination Survey.
BACKGROUND: Perfluorooctanoic acid (PFOA, also known as C8) and perfluorooctane sulfonate (PFOS) are stable compounds with many industrial and consumer uses. Their persistence in the environment plus toxicity in animal models has raised concern over low-level chronic exposure effects on human health. OBJECTIVES: We estimated associations between serum PFOA and PFOS concentrations and thyroid disease prevalence in representative samples of the U.S. general population. METHODS: Analyses of PFOA/PFOS versus disease status in the National Health and Nutrition Examination Survey (NHANES) for 1999-2000, 2003-2004, and 2005-2006 included 3,974 adults with measured concentrations for perfluorinated chemicals. Regression models were adjusted for age, sex, race/ethnicity, education, smoking status, body mass index, and alcohol intake. RESULTS: the NHANES-weighted prevalence of reporting any thyroid disease was 16.18% (n = 292) in women and 3.06% (n = 69) in men; prevalence of current thyroid disease with related medication was 9.89% (n = 163) in women and 1.88% (n = 46) in men. In fully adjusted logistic models, women with PFOA >or= 5.7 ng/mL [fourth (highest) population quartile] were more likely to report current treated thyroid disease [odds ratio (OR) = 2.24; 95% confidence interval (CI), 1.38-3.65; p = 0.002] compared with PFOA or= 36.8 ng/mL (quartile 4) versus
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Melzer D, Rice NE, Lewis C, Henley WE, Galloway TS (2010). Association of urinary bisphenol a concentration with heart disease: evidence from NHANES 2003/06.
PLoS One,
5(1).
Abstract:
Association of urinary bisphenol a concentration with heart disease: evidence from NHANES 2003/06.
BACKGROUND: Bisphenol a (BPA) is a high production volume chemical widely used in food and drinks packaging. Associations have previously been reported between urinary BPA concentrations and heart disease, diabetes and liver enzymes in adult participants of the National Health and Nutrition Examination Survey (NHANES) 2003/04. We aimed to estimate associations between urinary BPA concentrations and health measures in NHANES 2005/06 and in data pooled across collection years. METHODOLOGY AND FINDINGS: a cross-sectional analysis of NHANES: subjects were n = 1455 (2003/04) and n = 1493 (2005/06) adults aged 18-74 years, representative of the general adult population of the United States. Regression models were adjusted for age, sex, race/ethnicity, education, income, smoking, BMI, waist circumference, and urinary creatinine concentration. Main outcomes were reported diagnoses of heart attack, coronary heart disease, angina and diabetes and serum liver enzyme levels. Urinary BPA concentrations in 2005/06 (geometric mean 1.79 ng/ml, 95% CI: 1.64 to 1.96) were lower than in 2003/04 (2.49 ng/ml, CI: 2.20 to 2.83, difference p-value = 0.00002). Higher BPA concentrations were associated with coronary heart disease in 2005/06 (OR per z-score increase in BPA = 1.33, 95%CI: 1.01 to 1.75, p = 0.043) and in pooled data (OR = 1.42, CI: 1.17 to 1.72, p = 0.001). Associations with diabetes did not reach significance in 2005/06, but pooled estimates remained significant (OR = 1.24, CI: 1.10 to 1.40, p = 0.001). There was no overall association with gamma glutamyl transferase concentrations, but pooled associations with alkaline phosphatase and lactate dehydrogenase remained significant. CONCLUSIONS: Higher BPA exposure, reflected in higher urinary concentrations of BPA, is consistently associated with reported heart disease in the general adult population of the USA. Studies to clarify the mechanisms of these associations are urgently needed.
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Author URL.
Melzer D, Galloway T (2010). Burden of proof.
NEW SCIENTIST,
208(2783), 26-27.
Author URL.
Frenzel M, Scarlett A, Rowland SJ, Galloway TS, Burton SK, Lappin-Scott HM, Booth AM (2010). Complications with remediation strategies involving the biodegradation and detoxification of recalcitrant contaminant aromatic hydrocarbons.
Sci Total Environ,
408(19), 4093-4101.
Abstract:
Complications with remediation strategies involving the biodegradation and detoxification of recalcitrant contaminant aromatic hydrocarbons.
Environmentally persistent aromatic hydrocarbons known as unresolved complex mixtures (UCMs) derived from crude oil can be accumulated by, and elicit toxicological responses in, marine organisms (e.g. mussels, Mytilus edulis). Comprehensive two-dimensional gas chromatography time-of-flight mass-spectrometry (GCxGC-ToF-MS) previously revealed that these UCMs included highly branched alkylated aromatic hydrocarbons. Here, the effects of biodegradation on the toxicity and chemical composition of an aromatic UCM hydrocarbon fraction isolated from Tia Juana Pesado (TJP) crude oil were examined. 48h exposure of mussels to the aromatic hydrocarbon fraction (F2) resulted in tissue concentrations of 900microgg(-1) (dry wt.) and approximately 45% decrease in clearance rate. Over 90% of the hydrocarbon burden corresponded to an UCM. Following a 5day recovery period, GCxGC-ToF-MS analysis of the tissues indicated depuration of most accumulated hydrocarbons and clearance rates returned to those observed in controls. To assess the potential of biodegradation to reduce UCM toxicity, TJP F2 was exposed to bacteria isolated from Whitley Bay, UK, for 46days. Mussels exposed to the undegraded TJP F2 from the abiotic control exhibited a reduction in clearance rate comparable with values for the pure crude oil TJP F2. Clearance rates of mussels exposed to biodegraded TJP F2 were statistically similar to seawater controls, suggesting biodegradation had reduced the TJP F2 toxicity. GCxGC-ToF-MS analysis revealed the same compound groups in the tissue of mussels exposed to pure TJP F2, undegraded TJP F2 and biodegraded TJP F2 samples; however >300 fewer compounds were observed in the biodegraded (954 compounds) compared to the undegraded TJP F2 (1261). The compound distributions were markedly different, possibly accounting for the decrease in toxicity. Extraction and analysis of pelleted bacterial cell material revealed that a significant proportion of the TJP F2 had adsorbed onto the cells. Thus extreme care must be taken in interpreting biodegradation data from recalcitrant UCM hydrocarbons.
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Galloway T, Cipelli R, Guralnik J, Ferrucci L, Bandinelli S, Corsi AM, Money C, McCormack P, Melzer D (2010). Daily bisphenol a excretion and associations with sex hormone concentrations: results from the InCHIANTI adult population study.
Environ Health Perspect,
118(11), 1603-1608.
Abstract:
Daily bisphenol a excretion and associations with sex hormone concentrations: results from the InCHIANTI adult population study.
BACKGROUND: Bisphenol a (BPA) is a high production volume chemical widely used in packaging for food and beverages. Numerous studies have demonstrated that BPA can alter endocrine function in animals, yet human studies remain limited. OBJECTIVE: We estimated daily excretion of BPA among adults and examined hypothesized associations with serum estrogen and testosterone concentrations. METHODS: We conducted cross-sectional analyses using data from the InCHIANTI Study, a prospective population-based study of Italian adults. Our study included 715 adults between 20 and 74 years old. BPA concentrations were measured by liquid chromatography-mass spectrometry in 24-hr urine samples. The main outcome measures were serum concentrations of total testosterone and 17beta-estradiol. RESULTS: Geometric mean urinary BPA concentration was 3.59 ng/mL [95% confidence interval (CI), 3.42-3.77 ng/mL], and mean excretion was 5.63 microg/day (5th population percentile, 2.1 microg/day; 95th percentile, 16.4 microg/day). We found higher excretion rates among men, younger respondents, and those with increasing waist circumference (p = 0.013) and weight (p = 0.003). Higher daily BPA excretion was associated with higher total testosterone concentrations in men, in models adjusted for age and study site (p = 0.044), and in models additionally adjusted for smoking, measures of obesity, and urinary creatinine concentrations (beta = 0.046; 95% CI, 0.015-0.076; p = 0.004). We found no associations with the other serum measures. We also found no associations with the primary outcomes among women, but we did find an association between BPA and SHBG concentrations in the 60 premenopausal women. CONCLUSION: Higher BPA exposure may be associated with endocrine changes in men. The mechanisms involved in the observed cross-sectional association with total testosterone concentrations need to be clarified.
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Hannam ML, Bamber SD, Galloway TS, John Moody A, Jones MB (2010). Effects of the model PAH phenanthrene on immune function and oxidative stress in the haemolymph of the temperate scallop Pecten maximus.
Chemosphere,
78(7), 779-784.
Abstract:
Effects of the model PAH phenanthrene on immune function and oxidative stress in the haemolymph of the temperate scallop Pecten maximus.
Phenanthrene, a major component of crude oil, is one of the most abundant PAHs in aquatic ecosystems, and is readily bioavailable and toxic to a range of marine invertebrates. Within bivalves, the haemolymph acts as a transfer medium for these pollutants and their metabolic products, leaving haemocytes susceptible to deleterious effects. Using a suite of biological endpoints, this study determined the sublethal (7-d exposure to 50, 100 and 200microgL(-1)) effects of phenanthrene on several oxidative stress and immunological parameters in the haemolymph of the commercially-important scallop Pecten maximus. Phenanthrene exposure (200microgL(-1)) resulted in immune modulation with significant reductions in cell membrane stability (P
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Hannam ML, Bamber SD, Galloway TS, John Moody A, Jones MB (2010). Functional immune response in Pecten maximus: combined effects of a pathogen-associated molecular pattern and PAH exposure.
Fish Shellfish Immunol,
28(1), 249-252.
Abstract:
Functional immune response in Pecten maximus: combined effects of a pathogen-associated molecular pattern and PAH exposure.
Pathogen-associated molecular patterns (PAMPs) enable recognition of structures present in microorganisms such as lipopolysaccharides (LPS). LPS are an essential constituent of the outer membrane of Gram-negative bacteria, stimulating the innate immune system of invertebrates. Here, LPS from Escherichia coli (055:B5) were used to investigate the functional immune response of Pecten maximus after stimulation with a PAMP and to determine the combined effect of a phenanthrene exposure and LPS challenge. Organisms were exposed to 200 mug l(-1) phenanthrene and after 7 d were injected with either physiological saline (injection controls) or LPS solution, and returned to their respective exposure tanks. Haemolymph was sampled from the scallops 48 h post-injection and immune function was assessed using a combination of cellular biological responses. The LPS challenge significantly altered the immune response in P. maximus with increased cell counts and phagocytic activity. An immunosuppressive effect of phenanthrene was also observed in this study; however, exposure to phenanthrene did not significantly impair the organism's ability to respond to a PAMP challenge. The overall level of phagocytosis and cytotoxic capability following the LPS challenge was lower in phenanthrene exposed scallops and may have consequences for disease resistance in this commercially-exploited species.
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Lewis C, Guitart C, Pook C, Scarlett A, Readman J, Galloway T (2010). INTEGRATED ASSESSMENT OF OIL POLLUTION USING BIOLOGICAL MONITORING
AND CHEMICAL FINGERPRINTING. Environmental Toxicology and Chemistry, 29(6), 1358-1366.
Hannam ML, Bamber SD, Moody AJ, Galloway TS, Jones MB (2010). Immunotoxicity and oxidative stress in the Arctic scallop Chlamys islandica: effects of acute oil exposure.
Ecotoxicol Environ Saf,
73(6), 1440-1448.
Abstract:
Immunotoxicity and oxidative stress in the Arctic scallop Chlamys islandica: effects of acute oil exposure.
With increasing oil exploration in Arctic regions, the risk of an accidental oil spill into the environment is inevitably elevated. As a result, concerns have been raised over the potential impact of oil exposure on Arctic organisms. This study assessed the effects of an acute oil exposure (mimicking an accidental spill) on the immune function and oxidative stress status of the Arctic scallop Chlamys islandica. Scallops were exposed to the water accommodated fraction of crude oil over 21 d (maximum SigmaPAH 163 microg l(-1)) and immune endpoints and oxidative stress parameters were measured. Mortalities were recorded during the exposure and reductions in immunocompetence were observed, with significant impairment of phagocytosis and cell membrane stability. Scallops were also subjected to oxidative stress, with a significant reduction in glutathione levels and induction of lipid peroxidation. After the acute oil exposure had subsided, no recovery of immune function was observed indicating potential for prolonged sublethal effects.
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Author URL.
Lewis C, Caldwell G, Galloway T (2010). Impacts of Environmental Contamination on the Reproductive Ecology of Marine Invertebrates. Meeting of the Division of Chemical Toxicology of the American-Chemical-Society. 16th - 20th Aug 2009.
Browne MA, Galloway TS, Thompson RC (2010). Spatial patterns of plastic debris along Estuarine shorelines.
Environ Sci Technol,
44(9), 3404-3409.
Abstract:
Spatial patterns of plastic debris along Estuarine shorelines.
The human population generates vast quantities of waste material. Macro (>1 mm) and microscopic (
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Lewis C, Galloway T (2010). Sperm toxicity and the reproductive ecology of marine invertebrates.
Integr Environ Assess Manag,
6(1), 188-190.
Author URL.
Galloway T, Lewis C, Dolciotti I, Johnston BD, Moger J, Regoli F (2010). Sublethal toxicity of nano-titanium dioxide and carbon nanotubes in a sediment dwelling marine polychaete.
Environ Pollut,
158(5), 1748-1755.
Abstract:
Sublethal toxicity of nano-titanium dioxide and carbon nanotubes in a sediment dwelling marine polychaete.
The ecotoxicology of manufactured nanoparticles (MNPs) in estuarine environments is not well understood. Here we explore the hypothesis that nanoTiO(2) and single walled nanotubes (SWNT) cause sublethal impacts to the infaunal species Arenicola marina (lugworm) exposed through natural sediments. Using a 10 day OECD/ASTM 1990 acute toxicity test, no significant effects were seen for SWNT up to 0.03 g/kg and no uptake of SWNTs into tissues was observed. A significant decrease in casting rate (P = 0.018), increase in cellular damage (P = 0.04) and DNA damage in coelomocytes (P = 0.008) was measured for nanoTiO(2), with a preliminary LOEC of 1 g/kg. Coherent anti-stokes Raman scattering microscopy (CARS) located aggregates of TiO(2) of >200 nm within the lumen of the gut and adhered to the outer epithelium of the worms, although no visible uptake of particles into tissues was detected.
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Bouskill NJ, Barker-Finkel J, Galloway TS, Handy RD, Ford TE (2010). Temporal bacterial diversity associated with metal-contaminated river sediments.
Ecotoxicology,
19(2), 317-328.
Abstract:
Temporal bacterial diversity associated with metal-contaminated river sediments.
The temporal activity, abundance and diversity of microbial communities were evaluated across a metal-contamination gradient around a Superfund site in Montana. In order to analyze short-term variability, samples were collected from six sites on four occasions over 12 months. Measurements of community activity, diversity and richness, quantified by dehydrogenase activity and through denaturant gradient gel electrophoresis (DGGE), respectively, were higher at contaminated sites adjacent to the smelter, relative to reference sites. 16S rRNA gene copy numbers, measured by quantitative PCR, showed seasonal variability, yet were generally higher within polluted sediments. Jaccard similarity coefficients of DGGE profiles, found sites to cluster based primarily on geographical proximity rather than geochemical similarities. Intra-site clustering of the most polluted sites also suggests a stable metal-tolerant community. Sequences from DGGE-extracted bands were predominantly Beta and Gammaproteobacteria, although the communities at all sites generally maintained a diverse phylogeny changing in composition throughout the sampling period. Spearman's rank correlations analysis found statistically significant relationships between community composition and organic carbon (r-value = 0.786) and metals (r-values As = 0.65; Cu = 0.63; Zn = 0.62). A diverse and abundant community at the most polluted site indicates that historical contamination selects for a metal-resistant microbial community, a finding that must be accounted for when using the microbial community within ecosystem monitoring studies. This study highlights the importance of using multiple time-points to draw conclusions on the affect of metal contamination.
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Hagger JA, Lowe D, Dissanayake A, Jones MB, Galloway TS (2010). The influence of seasonality on biomarker responses in Mytilus edulis.
Ecotoxicology,
19(5), 953-962.
Abstract:
The influence of seasonality on biomarker responses in Mytilus edulis.
The utility of some biomarkers in environmental monitoring may be limited due to the lack of knowledge that exists on how they respond to extrinsic abiotic and intrinsic biotic factors. During the present study we investigated the seasonal responses of three biomarkers, Neutral Red Retention, clearance/filtration rate and heart rate in the common blue mussel Mytilus edulis located in the Exe Estuary, UK during September 2006-September 2007. During the current study, a significant decrease in feeding rate was observed in mussels during June, July and August 2007, coinciding with the period following spawning when the mussels lay down nutrient reserves. Heart rate also increased between April and September 2007 and corresponded with times when mussels were spawning and laying down nutrient reserves. By integrating the individual biomarker responses into a Biomarker Response Index (BRI) we were able to identify times of the year when environmental impact was highest and hence when the timing of monitoring programmes using biomarkers should be carried out. For many years the lack of knowledge of normal physiological ranges of biomarkers has impeded their applied use, however by integrating biomarker responses into the BRI and creating an index of health, we have shown that we can limit the natural variability of individual responses; and thus we are better able to make informed judgements on the overall health status of these populations of mussels.
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Sheir SK, Handy RD, Galloway TS (2010). Tissue injury and cellular immune responses to mercuric chloride exposure in the common mussel Mytilus edulis: modulation by lipopolysaccharide.
Ecotoxicol Environ Saf,
73(6), 1338-1344.
Abstract:
Tissue injury and cellular immune responses to mercuric chloride exposure in the common mussel Mytilus edulis: modulation by lipopolysaccharide.
Little is known about the immunotoxic effects of sublethal mercury (Hg) exposure in bivalves, and whether or not stimulation of the immune system exacerbates Hg toxicity. The mussel, Mytilus edulis, was exposed to a total inorganic Hg concentration of 50 microgl(-1) as HgCl2 for up to 11 days compared to no added Hg controls. Then the immune functions of haemocytes, haematology, biochemistry and organ histology were assessed. Selected experiments were then repeated in mussels injected with lipopolysaccharide (LPS) to stimulate the immune system prior to Hg exposure. Hg exposure alone caused Hg accumulation mainly in gills and digestive gland, and to a lesser extent in the adductor muscle and haemolymph. This general pattern of Hg accumulation also occurred during the Hg plus LPS experiments. Hg exposure alone caused a transient increase of phagocytosis, but no Hg-dependent effects on neutral red retention or the cytotoxicity of haemocytes. Changes in haemolymph Na+, K+ and glucose levels were negligible during Hg exposure alone compared to controls. However, histological examination showed tissues injuries consistent with inflammation in the gills, digestive gland and adductor muscle during Hg exposure alone. LPS injection had a significant effect (Kruskal Wallis, P=0.02) on circulating haemocytes numbers at the end of the experiment compared to saline injected controls and the Hg+LPS treatment (mean+/-S.E.M. n=6, cells ml(-1)x10(6)); control, 2.1+/-0.08; LPS treated, 3.18+/-0.36, and LPS+Hg, 2.1+/-0.2. The Hg+LPS treatment also caused a transient decline in superoxide dismutase activity in haemocytes (85% decline, Kruskal Wallis, P=0.006) compared to controls. Target tissue inflammation and injury was greatly increased by the effect of Hg exposure with an LPS injection compared to either treatment alone. We conclude that Hg can cause inflammation in mussels in vivo, and that stimulation with LPS can greatly increase Hg-dependent immunotoxicity.
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Author URL.
2009
Morales-Caselles C, Lewis C, Riba I, Delvalls TA, Galloway T (2009). A multibiomarker approach using the polychaete Arenicola marina to assess oil-contaminated sediments.
Environ Sci Pollut Res Int,
16(6), 618-629.
Abstract:
A multibiomarker approach using the polychaete Arenicola marina to assess oil-contaminated sediments.
BACKGROUND, AIM AND SCOPE: Marine and coastal sediments can accumulate substantial concentrations of metals and hydrocarbons, yet the consequences of this contamination for exposed biota in situ can be difficult to establish. Here, we examine the hypothesis that exposure to contaminated sediments can lead to detrimental effects in sediment-dwelling species. The combination of chemical and biological assessment allows the identification of the impact of chemical contamination, and their use as assessment tools is becoming increasingly important. MATERIALS AND METHODS: the study was applied to marine sediments from the Bay of Algeciras (S Spain) impacted by multiple, low-level contaminant inputs, and the Galician Coast (NW Spain), historically impacted by an oil spill (Prestige 2002), with two reference sites selected in UK and Spain. The common lugworm Arenicola marina was exposed in the laboratory for 14 days to the marine sediments, and a suite of biomarkers of sublethal toxicity was combined with analytical chemistry to test for relationships between sediment contamination and effect. RESULTS: Moderate to strong correlations between organics, metals, and biological responses were observed, with DNA damage as measured using the Comet assay forming the largest contribution toward the observed differences (p < 0.05). The responses of worms from sites experiencing different contamination loads were clearly distinguishable. DISCUSSION: We show how a combination of multibiomarkers with analytical chemistry can be used to investigate the toxicity of marine sediments, enabling the differentiation of sites showing different types of contamination. There are clear relationships in sublethal assays that can be related to the putative mode of toxicity of the contaminants. CONCLUSIONS: the use of A. marina in this way provides a sensitive, holistic approach to sediment toxicity assessment, enabling comparisons between oil-polluted sites to be quantified. RECOMMENDATIONS AND PERSPECTIVES: These tools provide a relatively simple, rapid, and economic way to test the environmental status of oil-contaminated sediment.
Abstract.
Author URL.
Lang IA, Scarlett A, Guralnik JM, Depledge MH, Melzer D, Galloway TS (2009). Age-related impairments of mobility associated with cobalt and other heavy metals: Data from NHANES 1999-2004.
Journal of Toxicology and Environmental Health - Part A: Current Issues,
72(6), 402-409.
Abstract:
Age-related impairments of mobility associated with cobalt and other heavy metals: Data from NHANES 1999-2004
Exposure to heavy metals promotes oxidative stress and damage to cellular components, and may accelerate age-related disease and disability. Physical mobility is a validated biomarker of age-related disability and is predictive of hospitalization and mortality. Our study examined associations between selected heavy metals and impaired lower limb mobility in a representative older human population. Data for 1615 adults aged ≥60 yr from the National Health and Nutrition Examination Survey (NHANES) 1999 to 2004 were used to identify associations between urinary concentrations of 10 metals with self-reported and measured significant walking impairments. Models were adjusted for confounding factors, including smoking. In models adjusted for age, gender, and ethnicity, elevated levels of cadmium, cobalt, and uranium were associated with impairment of the ability to walk a quarter mile. In fully adjusted models, cobalt was the only metal that remained associated: the odds ratio (OR) for reporting walking problems with a 1-unit increase in logged cobalt concentration (μg/L) was 1.43 (95% CI 1.12 to 1.84). Cobalt was also the only metal associated with a significant increased measured time to walk a 20-ft course. In analyses of disease categories to explain the mobility finding, cobalt was associated with physician diagnosed arthritis (1-unit increase OR = 1.22 (95% CI 1.00 to 1.49). Low-level cobalt exposure, assessed through urinary concentrations of this essential heavy metal, may be a risk factor for age-related physical impairments. Independent replication is needed to confirm this association. Copyright © Taylor & Francis Group, LLC.
Abstract.
Hagger JA, Galloway TS, Langston WJ, Jones MB (2009). Application of biomarkers to assess the condition of European Marine Sites.
Environ Pollut,
157(7), 2003-2010.
Abstract:
Application of biomarkers to assess the condition of European Marine Sites.
A series of European Marine Sites has been designated as Special Areas of Conservation (SAC) in England. The aim of this study was to develop a practical methodology to assess the condition of SACs by applying a suite of biomarkers. Biomarkers were applied to the blue mussel Mytilus edulis and the shore crab Carcinus maenas from the Fal and Helford SAC (Cornwall). Individual biomarkers provided useful diagnostic information on the activity of certain classes of contaminants and an integrated Biomarker Response Index (BRI) was used to achieve a more holistic understanding of the condition of the SAC. The BRI indicated that the general health of both organisms was impacted in the upper part of the SAC (Fal Estuary) which correlated well with known chemical hotspots and sources of contamination. The BRI allows a pragmatic way to prioritise SAC sites that may require further investigative studies.
Abstract.
Author URL.
Melzer D, Lang IA, Galloway TS (2009). Association of Bisphenol a with Diabetes and Other Abnormalities Reply.
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION,
301(7), 721-722.
Author URL.
Scarlett A, Dissanayake A, Rowland SJ, Galloway TS (2009). Behavioral, physiological, and cellular responses following trophic transfer of toxic monoaromatic hydrocarbons.
Environmental Toxicology and Chemistry,
28(2), 381-387.
Abstract:
Behavioral, physiological, and cellular responses following trophic transfer of toxic monoaromatic hydrocarbons
The trophic transfer of monoaromatic hydrocarbons to predatory organisms feeding upon contaminated marine animals is not well reported within the scientific literature. Branched alkylbenzenes (BABs) unresolved by gas chromatography have been reported to be principal toxic components of bioaccumulated hydrocarbons in the tissues of some wild mussel, Mytllus edulis, populations with poor health status. Mussels, M. edulis, contaminated with a commercial mixture of BABs were fed to shore crabs, Garcinus maenas, for 7 d, and effects upon the behavior, heart rate, hemolymph cellular viability, and immune response of the crabs were assessed. Accumulation of BABs in crab midgut gland tissue was quantified by gas chromatography-mass spectrometry, and the presence of BABs in crab urine was detected spectrophotometrically using ultraviolet fluorescence spectroscopy. Analysis of crab tissues and urine revealed a proportion of the BABs was transferred from the mussel tissues to the crabs, but the majority was not present 3 d after consumption of the mussels and may have been metabolized, excreted, or both. The results do not support the hypothesis that BABs are likely to be biomagnified, at least by crabs, in the marine environment. Alterations to measured cellular and physiological responses of crabs fed BAB-exposed mussels were not significant. Consumption of contaminated mussels was shown to cause highly significant abnormal behavior that, in the wild, may affect the feeding ability of crabs and make them more vulnerable to predation. © 2009 SETAC.
Abstract.
Hagger JA, Galloway TS (2009). Biological markers of exposure and effect for water pollution monitoring. In Gonzalez DC, Greenwood DR, Quevauviller PP (Eds.)
Rapid Chemical and Biological Techniques for Water Monitoring, London, UK: John Wiley & Sons inc.
Abstract:
Biological markers of exposure and effect for water pollution monitoring
Abstract.
Hannam ML, Bamber SD, Moody JA, Galloway TS, Jones MB (2009). Immune function in the Arctic Scallop, Chlamys islandica, following dispersed oil exposure.
Aquat Toxicol,
92(3), 187-194.
Abstract:
Immune function in the Arctic Scallop, Chlamys islandica, following dispersed oil exposure.
With the current expansion of offshore oil activities in Arctic regions, there is an urgent need to establish the potential effects of oil-related compounds on Arctic organisms. As susceptibility to growth, disease and survival is determined partly by the condition of an organism's immune system, measurement of endpoints linked to the latter system provide important early warning signals of the sub-lethal effects of exposure to contaminants. This study assessed the impact of dispersed oil exposure on immune endpoints in the Arctic Scallop Chlamys islandica, using a combination of cellular and humoral biological responses. Laboratory exposures of C. islandica to sub-lethal dispersed oil concentrations (0.06 and 0.25 mg l(-1)) were conducted over 15 days, followed by a 7-day recovery period in clean, filtered seawater. Cellular endpoints were significantly altered following dispersed oil exposure: haemocyte counts (P
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Author URL.
Hannam ML, Bamber SD, Sundt RC, Galloway TS (2009). Immune modulation in the blue mussel Mytilus edulis exposed to North Sea produced water.
Environ Pollut,
157(6), 1939-1944.
Abstract:
Immune modulation in the blue mussel Mytilus edulis exposed to North Sea produced water.
The discharge of oil well produced water (PW) provides a constant source of contaminants to the marine environment including polycyclic aromatic hydrocarbons, alkylated phenols, metals and production chemicals. High concentrations of PW cause adverse effects to exposed biota, including reduced survival, growth and reproduction. Here we explore the effects of PW on immune function in the blue mussel, Mytilus edulis. Mussels were exposed for 21 days to sublethal PW concentrations (0.125-0.5%) and cellular parameters were measured. Cell viability, phagocytosis and cytotoxicity were inhibited after exposure to 0.25% and 0.5% PW, whilst the 0.125% PW treatment produced significant increases in these biomarker responses. This biphasic response was only observed after 7 days exposure; longer exposure periods led to a reduction in immune parameters. Results indicate that PW concentrations close to the discharge point cause modulation to cellular immunity. The implications for longer-term disease resistance are discussed.
Abstract.
Author URL.
Melzer D, Lang IA, Galloway TS (2009). In reply. JAMA, 301(7), 721-722.
Lewis C, Beggah S, Pook C, Guitart C, Redshaw C, van der Meer JR, Readman JW, Galloway T (2009). Novel use of a whole cell E. coli bioreporter as a urinary exposure biomarker.
Environ Sci Technol,
43(2), 423-428.
Abstract:
Novel use of a whole cell E. coli bioreporter as a urinary exposure biomarker.
Bacterial bioreporters have substantial potential for contaminant assessment but their real world application is currently impaired by a lack of sensitivity. Here, we exploit the bioconcentration of chemicals in the urine of animals to facilitate pollutant detection. The shore crab Carcinus maenas was exposed to the organic contaminant 2-hydroxybiphenyl, and urine was screened using an Escherichia coli-based luciferase gene (luxAB) reporter assay specific to this compound. Bioassay measurements differentiated between the original contaminant and its metabolites, quantifying bioconcentration factors of up to one hundred-fold in crab urine. Our results reveal the substantial potential of using bacterial bioreporter assays in real-time monitoring of biological matricesto determine exposure histories, with wide ranging potential for the in situ measurement of xenobiotics in risk assessments and epidemiology.
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Author URL.
Dissanayake A, Galloway TS, Jones MB (2009). Physiological condition and intraspecific agonistic behaviour in Carcinus maenas (Crustacea: Decapoda).
Journal of Experimental Marine Biology and Ecology,
375(1-2), 57-63.
Abstract:
Physiological condition and intraspecific agonistic behaviour in Carcinus maenas (Crustacea: Decapoda)
This study tested the hypothesis that physiological condition is a key factor in determining the outcome of intraspecific agonistic interactions for food in male shore crabs Carcinus maenas of equal body size. Physiological condition was manipulated by maintaining crabs under different food regimes (using the cockle Cerastoderma edule) in combination with exposure to a sub-lethal concentration (200 μg L- 1) of pyrene, a polyaromatic hydrocarbon (PAH). After 14 days, crabs were used in staged agonistic interactions, whereby, an unexposed crab was paired with a pyrene-exposed crab from the same dietary regime, using a whole cockle (C. edule; 0.35 ± 0.05 g wet weight) as the limited resource. Agonistic behaviour was recorded over 15 min, then crabs were separated and their energetic status was assessed based on haemolymph glucose and lactate concentrations. Fully-fed (fed 2 g of food each day) crabs had significantly higher concentrations of circulating glucose and lactate compared to starved (no food) and diet-restricted crabs (fed 1 g of food on alternate days after an initial starvation period of 3 days). In fully-fed crabs, blood glucose concentrations were lower, on average, in individuals exposed to pyrene. Physiological condition had no significant effect on most behavioural measures used to describe the agonistic behaviour in crabs (e.g. number of fights, number of wrestles, fight duration, wrestle duration, contest duration and contest intensity); however, starved pyrene-exposed individuals had significantly higher resource possession (defined as % time in possession of the resource) and significantly decreased inter-bout intervals (defined as time spent away from an opponent after an agonistic encounter) compared with starved unexposed individuals. Results show that a reduced physiological condition ('lower' RHP) in starved contaminant-exposed crabs resulted in an unexpected increased competitive ability over starved unexposed individuals. © 2009 Elsevier B.V. All rights reserved.
Abstract.
Lewis C, Galloway T (2009). Reproductive consequences of paternal genotoxin exposure in marine invertebrates.
Environ Sci Technol,
43(3), 928-933.
Abstract:
Reproductive consequences of paternal genotoxin exposure in marine invertebrates.
Chemicals with the potential to damage DNA are increasingly present in the marine environment; yet our understanding of the long-term consequences of DNA damage for populations remains limited. We explore the impact of paternal genotoxin exposure on the reproductive biology of two ecologically important free-spawning marine invertebrates: the polychaete Arenicola marina and the mussel Mytilus edulis. Males were exposed in vivo for 72 h to methyl methanesulfonate and benzo(a)pyrene and the impact on somatic cells and sperm assessed using the Comet assay. A strong correlation between DNA damage in somatic cells and sperm was observed after 24 h exposure (P < 0.001). Recovery in sperm was significantly lower than in coelomocytes after 72 h. The fertilization success of DNA-damaged sperm was unaffected, but a significant percentage of embryos derived from sperm with induced DNA damage exhibited severe developmental abnormalities within 24 h of fertilization with potential long-term consequences for population success. Further research is required to determine the mechanism by which paternal DNA damage causes disruption of development at this early stage.
Abstract.
Author URL.
Lewis C, Caldwell GS, Galloway TS (2009). TOXI 33-Impacts of environmental contamination on the reproductive ecology of marine invertebrates.
Author URL.
Pook C, Lewis C, Galloway T (2009). The metabolic and fitness costs associated with metal resistance in Nereis diversicolor.
Mar Pollut Bull,
58(7), 1063-1071.
Abstract:
The metabolic and fitness costs associated with metal resistance in Nereis diversicolor.
The population of Nereis diversicolor inhabiting the upper reaches of Restronguet Creek, Cornwall, UK is highly resistant to acute zinc and copper toxicity. Here we employ bioenergetic accounting and fecundity counts to demonstrate the energetic costs associated with this phenomenon in terms of the worms' allocation of metabolic resources and reproductive output [P(r)]. Metal-resistant animals exhibited a scope for growth that was 46-62% less than that of animals from two non-resistant reference populations, corresponding to a mean metabolic cost of 1.31 mJ h(-1)mg DW(-1). The resistant population also contained 13% less lipid than animals from the reference populations and 73-81% less carbohydrates. Consequently, mass-specific fecundity was reduced in resistant animals by 39-45%, although material investment in individual gametes did not appear to vary. This demonstrates fitness costs associated with metal resistance in this ecologically important polychaete and adds to our understanding of phenotypic trade-offs associated with resistance.
Abstract.
Author URL.
Teuten EL, Saquing JM, Knappe DRU, Barlaz MA, Jonsson S, Björn A, Rowland SJ, Thompson RC, Galloway TS, Yamashita R, et al (2009). Transport and release of chemicals from plastics to the environment and to wildlife.
Philosophical Transactions of the Royal Society B: Biological Sciences,
364(1526), 2027-2045.
Abstract:
Transport and release of chemicals from plastics to the environment and to wildlife
Plastics debris in themarine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2′-bis(p- chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g-1 to μg g-1. Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both amathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of contaminants from plastic to organisms. A feeding experiment indicated that PCBs could transfer from contaminated plastics to streaked shearwater chicks. Plasticizers, other plastics additives and constitutional monomers also present potential threats in terrestrial environments because they can leach fromwaste disposal sites into groundwater and/or surfacewaters. Leaching and degradation of plasticizers and polymers are complex phenomena dependent on environmental conditions in the landfill and the chemical properties of each additive. Bisphenol a concentrations in leachates from municipal waste disposal sites in tropical Asia ranged from sub μg l-1 to μg l-1 and were correlated with the level of economic development. © 2009 the Royal Society.
Abstract.
2008
Jones, M.B. Leonard, P. Owen, R. (2008). Application of biomarkers for improving risk assessments of chemicals under the Water Framework Directive: a case study. Marine Pollution Bulletin, 56, 1111-1118.
Galloway, T.S. Scarlett, A. Henley, W. (2008). Association of urinary bisphenol a concentration with medical disorders and laboratory abnormalities in adults (accompanying editorial JAMA. 2008;300(11):1353-1355.pp).
Journal of the American Medical Association,
300, 1303-1310.
Author URL.
Galloway, T.S. Hagger, J.A. Jones, M.B. (2008). Biomarkers and environmental risk assessment: guiding principles from the human health field. Marine Pollution Bulletin, 56, 613-619.
Melzer D, Lang IA, Scarlett A, Galloway TS (2008). Bisphenol A, Age, Ethnicity and Health Outcomes.
Author URL.
Hannam ML, Hagger JA, Jones MB, Galloway TS (2008). Characterisation of esterases as potential biomarkers of pesticide exposure in the lugworm Arenicola marina (Annelida: Polychaeta).
Environ Pollut,
152(2), 342-350.
Abstract:
Characterisation of esterases as potential biomarkers of pesticide exposure in the lugworm Arenicola marina (Annelida: Polychaeta).
Here, we identify and characterise cholinesterase (ChE) and carboxylesterase (CbE) activities in the body tissues of the sediment dwelling worm Arenicola marina. Exposure to the organophosphorus pesticide azamethiphos yielded an in vitro IC50 of 5 microg l(-1) for propionylcholinesterase (PChE). PChE was significantly inhibited in vivo after a 10 day exposure to 100 microg l(-1) azamethiphos, equivalent to the recommended aquatic application rate (ANOVA; F=2.75, P=0.033). To determine sensitivity to environmental conditions, A. marina were exposed for 10 days to field collected sediments. PChE activity was significantly lower in worms exposed to sediments from an estuary classified to be at high risk from point source pollution by the UK Environment Agency (ANOVA; F=15.33, P
Abstract.
Author URL.
Rowland, S. Galloway, T.S. Lewis, A. (2008). Chronic sublethal effects associated with branched alkylbenzenes bioaccumulated by mussels. Environmental Toxicology and Chemistry, 27, 561-567.
Bentley, M. Galloway, T.S. (2008). Effects of 4-nonylphenol on the endocrine system of the shore crab, <em>Carcinus maenas</em>. Environmental Toxicology, 23, 309-318.
Lewis C, Galloway, T.S. (2008). Genotoxic damage. in polychaetes: a study of species and cell-type sensitivities. Mutation Research-Genetic Toxicology and Environmental Mutagenesis, 654, 69-75.
Browne MA, Dissanayake A, Galloway TS, Lowe DM, Thompson RC (2008). Ingested microscopic plastic translocates to the circulatory system of the mussel, Mytilus edulis (L.).
Environmental Science and Technology,
42(13), 5026-5031.
Abstract:
Ingested microscopic plastic translocates to the circulatory system of the mussel, Mytilus edulis (L.)
Plastics debris is accumulating in the environment and is fragmenting into smaller pieces; as it does, the potential for ingestion by animals increases. The consequences of macroplastic debris for wildlife are well documented, however the impacts of microplastic (
Abstract.
Galloway, T.S. Jones, M.B. (2008). Nutritional status of <em>Carcinus maenas</em> (Crustacea: decapoda) influences susceptibility to contaminant exposure. Aquatic Toxicology, 89, 40-46.
Galloway, T.S. Jones, M.H. (2008). Physiological responses of juvenile and adult shore crabs <em>Carcinuns maenas</em> (Crustacea: decapoda) to pyrene exposure. Marine Environmental Research, 66, 445-450.
Lewis C, Pook C, Galloway T (2008). Reproductive toxicity of the water accommodated fraction (WAF) of crude oil in the polychaetes Arenicola marina (L.) and Nereis virens (Sars).
Aquat Toxicol,
90(1), 73-81.
Abstract:
Reproductive toxicity of the water accommodated fraction (WAF) of crude oil in the polychaetes Arenicola marina (L.) and Nereis virens (Sars).
Accidental pollution incidents are common in the marine environment and are often caused by oil-related activities. Here the potential of such an incident to disrupt reproduction in two polychaete species is investigated, using an environmentally relevant preparation of weathered Forties crude oil, i.e. the water accommodated fraction (WAF). Oocytes were collected and exposed to three concentrations of WAF for 1h prior to the addition of sperm, so that fertilization took place under exposure conditions. Fertilization success was significantly reduced in both species by an exposure to WAF concentrations equivalent to 0.38 mgL(-1) PAHs, to just 26.8% in Arenicola marina compared to 76% in Nereis virens. The effects of WAF exposure on fertilization were greatly enhanced at lower sperm concentrations in N. virens, with a complete lack of fertilization reactions observed at sperm concentrations of 10(3)sperm per mL. We therefore suggest a mechanism of toxicity related to sperm swimming behaviour, resulting in reduced sperm:egg collision rates. WAF was found to reduce post-fertilization development rates and have teratogenic effects on early embryonic stages in both species, which exhibited abnormal cleavage patterns and high levels of fluctuating asymmetry. These results illustrate how the presence of crude oil in its soluble form in seawater at the time of a spawning event for either A. marina or N. virens could impact on fertilization success with implications for the fertilization ecology of these free spawning marine invertebrates.
Abstract.
Author URL.
Pook C, Lewis C, Galloway T (2008). The metabolic and fitness costs of resistance to copper and zinc toxicity in Nereis diversicolor.
Author URL.
2007
Dissanayake A, Worsey T, Jones M, Galloway T (2007). A multidisciplinary approach to evaluating physiological condition and intra-specific behaviour in the shore crab Carcinus maenas (Crustacea : Decapoda).
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY,
146(4), S76-S76.
Author URL.
Scarlett A, Canty, M.N. Smith, E.L. Rowland, S. (2007). Can amphipod behaviour help to predict chronic toxicity of sediments?. Human and Ecology Risk Assessment, 13, 506-518.
Scarlett A, Galloway, T.S. Rowland, S.J. (2007). Chronic toxicity of unresolved complex mixtures (UCM) of hydrocarbons in marine sediments. Journal of Soils and Sediments, 7, 200-206.
Filby AL, Neuparth T, Thorpe KL, Owen R, Galloway TS, Tyler CR (2007). Health impacts of estrogens in the environment, considering complex mixture effects.
Environ Health Perspect,
115(12), 1704-1710.
Abstract:
Health impacts of estrogens in the environment, considering complex mixture effects.
BACKGROUND: Environmental estrogens in wastewater treatment work (WwTW) effluents are well established as the principal cause of reproductive disruption in wild fish populations, but their possible role in the wider health effects of effluents has not been established. OBJECTIVES: We assessed the contribution of estrogens to adverse health effects induced in a model fish species by exposure to WwTW effluents and compared effects of an estrogen alone and as part of a complex mixture (i.e. spiked into effluent). METHODS: Growth, genotoxic, immunotoxic, metabolic, and endocrine (feminized) responses were compared in fathead minnows (Pimephales promelas) exposed for 21 days to a potent estrogenic effluent, a weakly estrogenic effluent before and after spiking with a steroidal estrogen [17 alpha-ethinyl-estradiol (EE2)], and to EE2 alone. RESULTS: in addition to endocrine disruption, effluent exposure induced genotoxic damage, modulated immune function, and altered metabolism; many of these effects were elicited in a sex-specific manner and were proportional to the estrogenic potencies of the effluents. A key finding was that some of the responses to EE2 were modified when it was present in a complex mixture (i.e. spiked into effluent), suggesting that mixture effects may not be easily modeled for effluent discharges or when the chemicals impact on a diverse array of biological axes. CONCLUSION: These data reveal a clear link between estrogens present in effluents and diverse, adverse, and sex-related health impacts. Our findings also highlight the need for an improved understanding of interactive effects of chemical toxicants on biological systems for understanding health effects of environmental mixtures.
Abstract.
Author URL.
Liber K, Goodfellow W, den Besten P, Clements W, Galloway T, Gerhardt A, Green A, Simpson S (2007). In situ-based effects measures: considerations for improving methods and approaches.
Integr Environ Assess Manag,
3(2), 246-258.
Abstract:
In situ-based effects measures: considerations for improving methods and approaches.
In situ-based effects measures have gained increased acceptance as a means to improve the link between cause and effect in aquatic ecotoxicological studies. These approaches have primarily been employed where more conventional laboratory tests with field collected samples and routine in-field community surveys have failed to provide reasonable answers with respect to causes of toxicity, primary routes of contaminant exposure, and what constitutes ecotoxicologically relevant contaminant levels, at least at a site-specific level. One of the main advantages provided by in situ tests compared to more conventional field-based monitoring approaches is that they provide better control over stressor exposure to a defined population of test animals under natural or near-natural field conditions. In situ techniques can also be used to avoid artifacts related to sampling, transport and storage of contaminated water and sediment intended for laboratory-based toxicity assessment. In short, they can reduce the need for laboratory to field extrapolation and, when conducted properly, in situ tests can provide improved diagnostic ability and high ecological relevance. This paper provides suggestions and considerations for designing in situ studies, choosing test species and test endpoints, avoiding or minimizing test artifacts, best addressing some of the limitations of in situ test techniques, and generally improving the overall quality of the in situ approach chosen.
Abstract.
Author URL.
Scarlett A, Rowland, S.J. Canty, M. Smith, E.L. (2007). Method for assessing chronic toxicity of marine and estuarine sediment-associated contaminants using the amphipod <em>Corophium volutator</em>. Marine Environmental Research, 63, 457-470.
Browne MA, Galloway T, Thompson R (2007). Microplastic--an emerging contaminant of potential concern?.
Integr Environ Assess Manag,
3(4), 559-561.
Author URL.
Galloway, T.S. (2007). Plastic bottles and moral codes. Marine Pollution Bulletin, 56, 163-165.
Rowland, S. Galloway, T.S. Thompson, R.C. (2007). Potential for plastics to transport hydrophobic contaminants.
Environmental Science and Technology Author URL.
Barnhart, E.P. Galloway, T.S. Handy, R.D. (2007). Quantification of different <em>Pseudomonas aeruginosa</em> Sod A, HTP X and Mt gene abundance in response to trace metal toxicity, a potential in situ biomarker of environmental health. FEMS Microbiology, 60, 276-286.
Canty MN, Hagger JA, Moore RTB, Cooper L, Galloway TS (2007). Sublethal impact of short term exposure to the organophosphate pesticide azamethiphos in the marine mollusc Mytilus edulis.
Mar Pollut Bull,
54(4), 396-402.
Abstract:
Sublethal impact of short term exposure to the organophosphate pesticide azamethiphos in the marine mollusc Mytilus edulis.
Concern has been raised that the increased use of pesticides in intensive aquaculture practices may cause adverse sublethal effects to non-target aquatic species. Azamethiphos is an organophosphate (OP) pesticide used to combat sea lice infestations in farmed salmonids. Here, the sublethal impact on the blue mussel, Mytilus edulis, of short term exposure to azamethiphos was determined. The testing regime included biomarkers of exposure (acetylcholinesterase activity), cytotoxicity (neutral red retention), immune function (phagocytic index) and physiological condition (feeding rate). The distribution and sensitivity of M. edulis acetylcholinesterase to inhibition by azamethiphos was first determined, yielding IC(50) values of 0.736 and 1.30 mg l(-1) for gill and haemolymph, respectively. Exposure of mussels to 0.1 mg l(-1) azamethiphos for periods of up to 24h caused a significant reduction in acetylcholinesterase activity in both the haemolymph (P
Abstract.
Author URL.
2006
Cheung VV, Simpson P, Knight AW, Cahill PA, Charles AK, Depledge MH, Owen R, Galloway TS (2006). A comparison of prokaryotic, eukaryotic, cytogenetic and direct toxicity assays to evaluate the toxicity of industrial effluents.
MARINE ENVIRONMENTAL RESEARCH,
62, S307-S308.
Author URL.
Hagger JA, Jones MB, Leonard DRP, Owen R, Galloway TS (2006). Biomarkers and integrated environmental risk assessment: are there more questions than answers?.
Integr Environ Assess Manag,
2(4), 312-329.
Abstract:
Biomarkers and integrated environmental risk assessment: are there more questions than answers?
The introduction of the European Commission's Water Framework Directive (WFD; 2000/60/EC) established a new era in environmental risk assessment. In addition to incorporating the compliance of chemical quality standards, the key objective of the WFD is the general protection of the aquatic environment in its entirety. This new approach emphasizes the need for an integrated environmental risk assessment and offers the potential for the incorporation of biological effects measures, including the use of biomarkers in this process. Biomarkers have been suggested as practical tools for environmental management for a number of decades, but their inclusion has not been universally accepted because of a number of unanswered questions regarding sensitivity, practicality, and reproducibility. With this in mind, this paper addresses these potential questions and shows how, by taking a weight-of-evidence approach, biomarkers may be successfully incorporated within environmental risk assessment frameworks such as the WFD.
Abstract.
Author URL.
Galloway TS (2006). Biomarkers in environmental and human health risk assessment.
Abstract:
Biomarkers in environmental and human health risk assessment.
Abstract.
Author URL.
Bouskill N, Handy R, Galloway T, Ford T (2006). Development and application of microbial molecular biomarkers for assessing trace metal contamination.
MARINE ENVIRONMENTAL RESEARCH,
62, S366-S367.
Author URL.
Cheung VV, Jha A, Owen R, Depledge MH, Galloway TS (2006). Development of the in vivo chromosome aberration assay in oyster (Crassostrea gigas) embryo-larvae for genotoxicity assessment.
Abstract:
Development of the in vivo chromosome aberration assay in oyster (Crassostrea gigas) embryo-larvae for genotoxicity assessment.
Abstract.
Author URL.
Ford, T.E. Handy, R.D. Galloway, T.S. (2006). Differentiating copper and arsenic toxicity using biochemical biomarkers in <em>Asellus aquaticus</em> and <em>Dreissena polymorpha</em>. Ecotoxicology and Environmental Safety, 65, 342-349.
Dissanayake A, Jones MB, Galloway TS (2006). Does size really matter an evaluation of ontogenetic differences in the biomarker responses of Carcinus maenas (L.) to a priority pollutant.
MARINE ENVIRONMENTAL RESEARCH,
62, S400-S401.
Author URL.
Elliott, M. Fountain, M. Galloway, T.S. (2006). European environmental management: Moving to an ecosystem approach. Integrated Environmental Assessment and Management, 2, 80-85.
Liney KE, Hagger JA, Tyler CR, Depledge MH, Galloway TS, Jobling S (2006). Health effects in fish of long-term exposure to effluents from wastewater treatment works.
Environ Health Perspect,
114 Suppl 1(Suppl 1), 81-89.
Abstract:
Health effects in fish of long-term exposure to effluents from wastewater treatment works.
Concern has been raised in recent years that exposure to wastewater treatment effluents containing estrogenic chemicals can disrupt the endocrine functioning of riverine fish and cause permanent alterations in the structure and function of the reproductive system. Reproductive disorders may not necessarily arise as a result of estrogenic effects alone, and there is a need for a better understanding of the relative importance of endocrine disruption in relation to other forms of toxicity. Here, the integrated health effects of long-term effluent exposure are reported (reproductive, endocrine, immune, genotoxic, nephrotoxic). Early life-stage roach, Rutilus rutilus, were exposed for 300 days to treated wastewater effluent at concentrations of 0, 15.2, 34.8, and 78.7% (with dechlorinated tap water as diluent). Concentrations of treated effluents that induced feminization of male roach, measured as vitellogenin induction and histological alteration to gonads, also caused statistically significant alterations in kidney development (tubule diameter), modulated immune function (differential cell count, total number of thrombocytes), and caused genotoxic damage (micronucleus induction and single-strand breaks in gill and blood cells). Genotoxic and immunotoxic effects occurred at concentrations of wastewater effluent lower than those required to induce recognizable changes in the structure and function of the reproductive endocrine system. These findings emphasize the need for multiple biological end points in tests that assess the potential health effects of wastewater effluents. They also suggest that for some effluents, genotoxic and immune end points may be more sensitive than estrogenic (endocrine-mediated) end points as indicators of exposure in fish.
Abstract.
Author URL.
Hagger, J. Tyler, C. Depledge, M.H. (2006). Integrated health effects in roach of exposure to sewage effluents. Environmental Health Perspectives, 114, 81-89.
Galloway TS, Goven AJ (2006). Invertebrate immunotoxicology. In (Ed)
Immunotoxicology and Immunopharmacology, Third Edition, 365-384.
Abstract:
Invertebrate immunotoxicology
Abstract.
DePledge M, Hagger J, Jobling S, Oehlmann J (2006). Is there a causal association between genotoxicity and the imposex effect?. Environmental Health Perspectives, 114, 20-26.
Galloway TS, Bastable H, Hagger J (2006). Mechanisms of endocrine toxicity: Carbonic anhydrase, calcium metabolism and imposex.
Author URL.
Brown, R.J. Dissanayake, A. Browne, M.A. (2006). The ECOMAN project: a novel approach to sustainable ecosystem function. Marine Pollution Bulletin, 53, 186-194.
Scally, G. (2006). The new marine green? Sustainability and health issues for coastal communities. Marine Pollution Bulletin, 52, 989-992.
2005
Mitchelmore, C. Woodley, C. Trapido-Rosenthal, H. (2005). A common sense approach for confronting coral reef decline associated with human activities. Marine Pollution Bulletin, 51, 481-485.
Scarlett A, Galloway TS, Canty M, Smith EL, Nilsson J, Rowland SJ (2005). Comparative toxicity of two oil dispersants, superdispersant-25 and corexit 9527, to a range of coastal species.
Environ Toxicol Chem,
24(5), 1219-1227.
Abstract:
Comparative toxicity of two oil dispersants, superdispersant-25 and corexit 9527, to a range of coastal species.
The acute toxicity of the oil dispersant Corexit 9527 reported in the literature is highly variable. No peer-reviewed data exist for Superdispersant-25 (SD-25). This study compares the toxicity of the two dispersants to a range of marine species representing different phyla occupying a wide range of niches: the marine sediment-dwelling amphipod Corophium volutator (Pallas), the common mussel Mytilus edulis (L.), the symbiotic snakelocks anemone Anemonia viridis (Forskål), and the seagrass Zostera marina (L.). Organisms were exposed to static dispersant concentrations for 48-h and median lethal concentration (LC50), median effect concentration (EC50), and lowest-observable-effect concentration (LOEC) values obtained. The sublethal effects of 48-h exposures and the ability of species to recover for up to 72 h after exposure were quantified relative to the 48-h endpoints. Results indicated that the anemone lethality test was the most sensitive with LOECs of 20 ppm followed by mussel feeding rate, seagrass photosynthetic index and amphipod lethality, with mussel lethality being the least sensitive with LOECs of 250 ppm for both dispersants. The results were consistent with current theory that dispersants act physically and irreversibly on the respiratory organs and reversibly, depending on exposure time, on the nervous system. Superdispersant-25 was found overall to be less toxic than Corexit 9527 and its sublethal effects more likely to be reversible following short-term exposure.
Abstract.
Author URL.
Galloway, T.S. Wilkin, T.J. (2005). Developments in the prediction of type 1 diabetes mellitus, with special reference to insulin autoantibodies. Diabetes/Metabolism Research and Reviews, 21, 395-415.
Galloway, T.S. Horton, S.J. Wilkin, T.J. (2005). Distinct idiotypes of insulin autoantibody in autoimmune polyendocrine syndrome type 2 and childhood onset type 1 diabetes. Journal of Clinical Endocrinology & Metabolism, 89, 5266-5270.
Depledge MH, Galloway TS (2005). Healthy animals, healthy ecosystems.
Frontiers in Ecology and the Environment,
3(5), 251-258.
Abstract:
Healthy animals, healthy ecosystems
The survival of humans as a species is intimately linked to the well-being of ecosystems and the resources they provide. The well-being of ecosystems depends, in turn, on minimizing the damaging impacts of human activities. Irrespective of the kinds of habitats we choose to protect or restore, we need to understand how ecosystems, and the organisms that inhabit them, respond to chemicals and radiation exposure. Recent technological advances in molecular biology and analytical science have allowed the development of rapid, robust, and sensitive diagnostic tests (biomarkers) that can be used to monitor exposure to, and the effects of, pollution. For the first time, we are able to make health assessments of individual organisms in much the same way that we evaluate human health. Here, we discuss how to best use this capability to ensure that pollution does not threaten the sustainability of our ecosystems and cause adverse effects in human and wildlife populations. © the Ecological Society of America.
Abstract.
Prowse G, Galloway, T.S. Foggo, A. (2005). Insecticidal activity of garlic juice in two dipterian pests. Agricultural and Forest Entomology, 7, 1-6.
Jay, J. Patel, A. Kile, M. (2005). Microbial biomarkers of contaminant stress: their future as monitoring tools. Environmental Health Perspectives, 113, 186-191.
Hagger JA, Depledge MH, Galloway TS (2005). Toxicity of tributyltin in the marine mollusc Mytilus edulis.
Mar Pollut Bull,
51(8-12), 811-816.
Abstract:
Toxicity of tributyltin in the marine mollusc Mytilus edulis.
Our previous studies have demonstrated that tributyltin (TBT) is genotoxic to the early life stages of marine mussels and worms. Here, the toxicity of TBT to adult organisms was determined using a suite of biomarkers designed to detect cytotoxic, immunotoxic and genotoxic effects. Exposure of adult mussels, Mytilus edulis, to environmentally realistic concentrations of TBTO for 7 days resulted in a statistically significant decrease in cell viability at concentrations of 0.5 microg/l and above. TBT had no effect on phagocytic activity or antioxidant capacity (FRAP assay). There was a statistically significant increase in DNA damage detected using the comet and micronucleus assays between the controls and 0.5, 1 and 5 microg/l of TBTO (P > 0.0005). Furthermore there was a strong correlation between DNA strand breaks (comet assay) and formation of micronuclei (P = 0.0005; R2 = 61.5%). Possible mechanisms by which TBT could damage DNA either directly or indirectly are discussed including the possibility that TBT is genotoxic due to its ability to disrupt calcium homeostasis.
Abstract.
Author URL.
Ford T, Jay J, Patel A, Kile M, Prommasith P, Galloway T, Sanger R, Smith K, Depledge M (2005). Use of ecotoxicological tools to evaluate the health of New Bedford Harbor sediments: a microbial biomarker approach.
Abstract:
Use of ecotoxicological tools to evaluate the health of New Bedford Harbor sediments: a microbial biomarker approach.
Abstract.
Author URL.
2004
Galloway TS, Brown RJ, Browne MA, Dissanayake A, Lowe D, Jones MB, Depledge MH (2004). A multibiomarker approach to environmental assessment.
Environ Sci Technol,
38(6), 1723-1731.
Abstract:
A multibiomarker approach to environmental assessment.
Incorporation of ecologically relevant biomarkers into routine environmental management programs has been advocated as a pragmatic means of linking environmental degradation with its causes. Here, suites of biomarkers, devised to measure molecular damage, developmental abnormality and physiological impairment, were combined with chemical analysis to determine exposure to and the effects of pollution at sites within Southampton Water (UK). Test species included a filter feeder, a grazer, and an omnivore to determine the sensitivity of organisms occupying different trophic levels. Linear regression confirmed a significant association between incidence of intersex in Littorina littorea and tributyltin (TBT) concentrations (R2 = 0.954) and between PAH metabolites in Carcinus maenas urine and PAHs in sediments (R2 = 0.754). Principal component analysis revealed a gradient of detrimental impact to biota from the head to the mouth of the estuary, coincident with high sediment concentrations of heavy metals, PAHs, and biocides. Multidimensional scaling identified C. maenas as the organism most sensitive to contamination. Carboxylesterase activity, metallothionein and total haemolymph protein were the most discriminating biomarkers among sites. This holistic approach to environmental assessment is encouraged as it helps to identify the integrated impact of chemical contamination on organisms and to provide a realistic measure of environmental quality.
Abstract.
Author URL.
Galloway, T.S. (2004). Acetylcholinesterase as a biomarker of effect: a study of the mussel <em>Mytilus edulis</em> exposed to the priority pollutant Chlorfenvinphos. Aquatic Toxicology, 67, 45-56.
Smith EL, Sutton PA, Lewis AC, Galloway T, Rowland SJ (2004). Analytical and toxicological methods for identification of unresolved complex mixtures ('humps') of hydrocarbons in the environment.
Author URL.
Stewart-Tull, DES, Bleakley CR & Galloway TS (2004). Characteristics of <em>Vibrio cholerae</em> proteinases: potential candidate vaccine immunogens. Vaccine, 22, 3026-3034.
Watson GM, Andersen OK, Depledge MH, Galloway TS (2004). Detecting a field gradient of PAH exposure in decapod crustacea using a novel urinary biomarker.
Marine Environmental Research,
58(2-5), 257-261.
Abstract:
Detecting a field gradient of PAH exposure in decapod crustacea using a novel urinary biomarker
Norwegian coastal waters are subject to PAH contamination from electrochemical industries such as aluminium smelters. Evidence of PAH exposure has been established in fish and bivalves. The present study tests the applicability of a novel crustacean PAH exposure biomarker to a PAH contamination gradient in the field (Karmsund Strait, SW Norway). Fluorescence analysis of urine samples collected from crabs at each site revealed 1-OH pyrene "equivalent" levels (indicative of pyrogenic PAH contamination) decreased with increasing distance from a point source of pyrogenic PAH (a large aluminium works). The assay was shown to be suitable for the detection of PAH exposure in wild crustacean populations, for discriminating between contaminated and clean sites and is also sufficiently sensitive to detect gradients of PAH contamination. The method provides a rapid, inexpensive and non-destructive measure of biologically available PAH in crustaceans. © 2004 Elsevier Ltd. All rights reserved.
Abstract.
Brown RJ, Galloway TS, Lowe D, Browne MA, Dissanayake A, Jones MB, Depledge MH (2004). Differential sensitivity of three marine invertebrates to copper assessed using multiple biomarkers.
Aquat Toxicol,
66(3), 267-278.
Abstract:
Differential sensitivity of three marine invertebrates to copper assessed using multiple biomarkers.
Understanding how biomarkers relate to each other on exposure to particular contaminants in different species is key to their widespread application in environmental management. However, few studies have systematically used multiple biomarkers in more than a single species to determine the variability of sublethal effects of a particular contaminant. In this study, three marine invertebrates, the shore crab Carcinus maenas, the common limpet Patella vulgata and the blue mussel Mytilus edulis, were exposed over 7 days in the laboratory to environmentally realistic concentrations of the priority pollutant copper. A combination of molecular, cellular and physiological biomarkers was measured in each organism to detect the toxic effects of copper. Biomarkers included lysosomal stability (neutral red retention), neurotoxicity (acetylcholinesterase activity), metabolic impairment (total haemolymph protein), physiological status (heart rate) and induction of protective metallothionein proteins. P. vulgata was the most sensitive to copper with significant effects measured in all biomarkers at concentrations of 6.1 microg Cu l(-1). In C. maenas, cellular and neurotoxic endpoints were affected significantly only at 68.1 microg Cu l(-1). Exposure to copper also induced metallothionein production in crabs. Over a 7-day exposure period, M. edulis was the most tolerant species to copper with significant effects being observed at the cellular level only at 68.1 microg Cu l(-1). In all three species, cellular and neurotoxic pathways were more sensitive to disruption than physiological processes (protein and heart rate). Results illustrate how a suite of biomarkers applied to different sentinel species can provide a 'diagnosis of stress', whereby, effects at the molecular level can be used to interpret the level of physiological impairment of the organism.
Abstract.
Author URL.
Galloway TS, Devendra D, Horton SJ, Knip M, Wilkin TJ (2004). Distinct idiotypes of insulin autoantibody in type 1 diabetes and autoimmune polyendocrine syndrome type 2.
Author URL.
Galloway TS, Brown RJ, Browne MA, Dissanayake A, Lowe D, Jones MB, Depledge MH (2004). Ecosystem management bioindicators: the ECOMAN project--a multi-biomarker approach to ecosystem management.
Abstract:
Ecosystem management bioindicators: the ECOMAN project--a multi-biomarker approach to ecosystem management.
Abstract.
Author URL.
Hagger, J. Dissanayake, A. Browne, M.A. (2004). Esterases of the bivalve <em>Adamussius colbecki</em> as biomarkers of environmental quality. Marine Pollution Bulletin, 49, 445-455.
Galloway, T.S. (2004). Evaluation of fixed wavelength fluorescence and synchronous fluorescence spectrophotometry as biomonitoring tools of environmental contamination. Marine Environmental Research, 58, 281-285.
Galloway, T.S. Browne, M.A. Dissanayake, A. (2004). Evaluation of toxicity in tribuitaries of the Mersey estuary using the isopod <em>Asellus aquaticus</em>. Marine Environmental Research, 58, 327-331.
Galloway, T.S. Horton, S.J. Wilkin, T.J. (2004). Exploring the idiotypes of insulin antibodies as markers of metabolic remission in type 1 diabetes. Diabetic Medicine, 21, 1316-1324.
Watson GM, Andersen O-K, Galloway TS, Depledge MH (2004). Rapid assessment of polycyclic aromatic hydrocarbon (PAH) exposure in decapod crustaceans by fluorimetric analysis of urine and haemolymph.
Aquat Toxicol,
67(2), 127-142.
Abstract:
Rapid assessment of polycyclic aromatic hydrocarbon (PAH) exposure in decapod crustaceans by fluorimetric analysis of urine and haemolymph.
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and potentially harmful contaminants of the coastal and marine environment. Studies of their bioavailability, disposition and metabolism in marine organisms are therefore important for environmental monitoring purposes. Detecting PAH compounds in the biological fluids of marine organisms provides a measure of their environmental exposure to PAHs. In the present study, the shore crab Carcinus maenas was exposed to waterborne pyrene for 48h. Urine and haemolymph samples were analysed by direct fluorimetry utilising both fixed wavelength (FF) and synchronous scanning fluorescence (SFS) techniques. Samples from exposed crabs exhibited fluorescence due to 1-OH pyrene equivalents, whilst samples from control crabs did not. Levels of equivalents were exposure dependent. Urine was shown to be a more suitable medium for the analysis of PAH equivalents. In a separate experiment, depuration of pyrene equivalents in urine was monitored over time. Urinary levels reached a maximum 2-4 days after initial exposure and decreased steadily thereafter. No unchanged parent pyrene was detected in samples from exposed crabs. While fluorimetric techniques could discriminate between 1-OH pyrene equivalents and parent pyrene, identification of specific metabolites was only possible with HPLC/F analysis. This revealed crabs had bio-transformed pyrene into 3 major conjugates of 1-OH pyrene, which were excreted in the urine. While such biotransformation of PAH is well documented in fish and several crustaceans, this is the first study to use direct fluorimetry to detect PAH equivalents in exposed crustacean urine. Fluorimetric results correlated well with those obtained by HPLC/F and ELISA techniques. The technique has great potential as a rapid, inexpensive and non-destructive technique for field biomonitoring of PAH exposure in crustaceans.
Abstract.
Author URL.
2003
Handy RD, Galloway TS, Depledge MH (2003). A proposal for the use of biomarkers for the assessment of chronic pollution and in regulatory toxicology.
Ecotoxicology,
12(1-4), 331-343.
Abstract:
A proposal for the use of biomarkers for the assessment of chronic pollution and in regulatory toxicology.
Despite a wealth of information on biomarkers, they are not routinely used for regulatory purposes, even though the potential benefits of biomarkers to rationalise complex exposure-response relationships are clear. Biomarkers can be inappropriately applied or misinterpreted, because the fundamental assumptions in exposure-response relations have not been considered. Factors causing temporal and spatial variability in biomarker responses are reviewed. These include numerous geochemical and biotic variables. The variation can be minimised by appropriate study site selection, experimental replication, multivariate epidemiological approaches, normalised controls, and temporal calibration of responses; so that the regulatory use of biomarkers for biomonitoring and tracking pollution events, including chronic or multiple exposures to complex mixtures is possible. We propose and define the characteristics of biomarkers of chronic exposure or effect, which must measure changes in pollution/effect against long-term changes in other general stresses (disease, nutrition, environmental quality), relate to cumulative injury, and remain responsive over months or years. Neuroendocrine, immunological, and histological biomarkers are suggested for chronic pollution. We propose a regulatory framework for biomarkers based on a weight of evidence approach that can integrate biomarkers in risk assessment and long-term monitoring programmes.
Abstract.
Author URL.
Handy, R.D. (2003). Immunotoxicity of organophosphorous pesticides. Ecotoxicology, 12, 345-363.
Horton SJ, Galloway TS, Devendra D, Wilkin TJ (2003). Novel reagents for the assay of IAA idiotypes. Towards the standardisation of diabetes-predictive IAA measurement.
Author URL.
Galloway TS, Ray K, Malhotra R (2003). Regulation of B lymphocytes in health and disease. Meeting review.
Abstract:
Regulation of B lymphocytes in health and disease. Meeting review.
Abstract.
Author URL.
Wilkin T, Devendra D, Galloway T, Horton S (2003). The use of phage display to distinguish insulin autoantibody (IAA) from insulin antibody (IA) iditypes. Diabetologia, 46(6), 802-809.
2002
Devendra D, Galloway TS, Horton SJ, Knip M, Wilkin TJ (2002). A novel anti idiotope reagent to characterize insulin autoantibody detection.
Author URL.
DePledge M, Galloway T, Sanger R, Smith R (2002). Rapid assessment of marine pollution using multiple biomarkers and chemical immunoassays. Environmental Science & Technology, 36(10), 2219-2226.
Galloway TS, Millward N, Browne MA, Depledge MH (2002). Rapid assessment of organophosphorous/carbamate exposure in the bivalve mollusc Mytilus edulis using combined esterase activities as biomarkers.
Aquat Toxicol,
61(3-4), 169-180.
Abstract:
Rapid assessment of organophosphorous/carbamate exposure in the bivalve mollusc Mytilus edulis using combined esterase activities as biomarkers.
Carboxylesterases in bivalve molluscs exhibit greater sensitivity to organophosphorous and carbamate pesticides than acetylcholinesterase and are present at higher levels. The aim of the present study was to combine measurement of both acetylcholinesterase and carboxylesterase activities in the marine bivalve Mytilus edulis in order to detect the effects of pesticide exposure. Spectrophotometric assays in microtitreplate format were optimised for use with M. edulis haemolymph and tissue homogenate samples. This permitted the nature and distribution of the enzymes to be determined. One predominant pharmacological form of activity consistent in its patterns of activation and inhibition with acetylcholinesterase was identified in the haemolymph with an apparent K(m) for acetylthiocholineiodide of 1.33 mM. Carboxylesterase activity in the tissues was characterised by its preferential hydrolysis of the substrate analogue phenylthioacetate. Concentration-dependent inhibition of both activities was demonstrated following in vitro incubation with diisopropylfluorophosphate (DFP), paraoxon and eserine in the range 0.1-3.0 mM. When M. edulis (n=10) were exposed for 24 h to concentrations of eserine or paraoxon of 0.05-1.0 mM, the percentage inhibition of acetylcholinesterase was in each case greater than for carboxylesterase and reached statistical significance at lower concentrations. In all exposures, a proportion of carboxylesterase activity was present which remained resistant to inhibition by either organophosphorous or carbamate compounds. The ecotoxicological significance of these findings for the environmental monitoring of pesticide exposure is discussed.
Abstract.
Author URL.
Fillmann G, Galloway TS, Sanger RC, Depledge MH, Readman JW (2002). Relative performance of immunochemical (enzyme-linked immunosorbent assay) and gas chromatography-electron-capture detection techniques to quantify polychlorinated biphenyls in mussel tissues.
Analytica Chimica Acta,
461(1), 75-84.
Abstract:
Relative performance of immunochemical (enzyme-linked immunosorbent assay) and gas chromatography-electron-capture detection techniques to quantify polychlorinated biphenyls in mussel tissues
Results from polychlorinated biphenyls (PCB) analyses of mussel tissue extracts by immunoassay (PCB RaPID Assay®) and conventional gas chromatography-electron-capture detection (GC-ECD) are described and compared. Mussels from natural populations with diverse concentrations of PCBs, mussel tissue fortified with technical Aroclor® 1254 and a certified reference material are included. A strong correlation is reported between "total" PCBs quantified by both techniques (r2=0.95, n=27). Immunoassay results, however, exhibited lower values compared to GC-ECD, particularly when GC results are corrected for procedural recovery. A reduced antibody response, due to differences in the congener composition between the mussel extracts and Aroclor® 1254 (used to raise and calibrate the ELISA), provides the most likely explanation for this difference. Non-parametric statistical analyses confirmed that, although differing from Aroclor® 1254, PCB congener compositions in the mussel extracts most closely resemble that of Aroclor® 1254. At very high PCB concentrations (>30μgg-1 dry weight), however, ELISA results are statistically different (P
Abstract.
2001
Galloway TS, Depledge MH (2001). Immunotoxicity in invertebrates: measurement and ecotoxicological relevance.
Ecotoxicology,
10(1), 5-23.
Abstract:
Immunotoxicity in invertebrates: measurement and ecotoxicological relevance.
Concern is growing regarding the impact of chemicals suspected of altering the function of the immune system in humans and wildlife. There are numerous examples of links between pollution and increased susceptibility to disease in wildlife species, including immunosuppression in harbour seals feeding on fish from contaminated sites, altered immune function in riverine fish and decreased host resistance in birds exposed to pollutants. Laboratory tests have identified potential immunological hazards posed by a range of anthropogenic chemicals in mammals and higher vertebrates. However, few reports have considered the ecological relevance of pollution-induced immunosuppression in invertebrate phyla, which constitute around 95% of all animal species and occupy key structural and functional roles in ecosystems. In this paper effects of chemicals on immune function in invertebrates are briefly reviewed and biomarkers of immunotoxicity are identified. Examples of new approaches for the measurement of immunological inflammatory reactions and stress in molluscan haemocytes are detailed. The relevance of defining the immune system as a target organ of toxicity in invertebrates is discussed and an integrated approach for the use of immunological biomarkers in environment management is proposed, combining measures of immune function and organismal viability at the biochemical, cellular and population level.
Abstract.
Author URL.
Trapioo-Rosenthal HG, Sharp KH, Galloway TS, Morrall CE (2001). Nitric oxide and cnidarian-dinoflagellate symbioses: pieces of a puzzle1.
Abstract:
Nitric oxide and cnidarian-dinoflagellate symbioses: pieces of a puzzle1
Abstract.
Sharpe, C. Morrall, C.E. Galloway, T.S. (2001). Nitric oxide and dinoflagellate symbiosis: pieces of a puzzle. American Zoology, 41, 111-121.
2000
Morrall CE, Galloway TS, Trapido-Rosenthal HG, Depledge MH (2000). Characterisation of nitric oxide synthase activity in the tropical sea anemone Aiptasia pallida.
Comp Biochem Physiol B Biochem Mol Biol,
125(4), 483-491.
Abstract:
Characterisation of nitric oxide synthase activity in the tropical sea anemone Aiptasia pallida.
The presence of nitric oxide synthase (EC 1.14.23 NOS) activity is demonstrated in the tropical marine cnidarian Aiptasia pallida (Verrill). Enzyme activity was assayed by measuring the conversion of [3H]arginine to [3H]citrulline. Optimal NOS activity was found to require NADPH. Activity was inhibited by the competitive NOS inhibitor NG-methyl-L-arginine (L-NMA), but not the arginase inhibitors L-valine and L-ornithine. NOS activity was predominantly cytosolic, and was characterised by a Km for arginine of 19.05 microM and a Vmax of 2.96 pmol/min per microgram protein. Histochemical localisation of NOS activity using NADPH diaphorase staining showed the enzyme to be predominantly present in the epidermal cells and at the extremities of the mesoglea. These results provide a preliminary biochemical characterisation and histochemical localisation of NOS activity in A. pallida, an ecologically important sentinel species in tropical marine ecosystems.
Abstract.
Author URL.
Galloway TS (2000). Monoclonal Antibodies: the Basics from Background to Bench.
Autoimmunity,
32(2).
Abstract:
Monoclonal Antibodies: the Basics from Background to Bench
H. Zola-BIOS Scientific Publishers “Basics” Series 19.95. © 2000, Informa UK Ltd all rights reserved: reproduction in whole or part not permitted. All rights reserved.
Abstract.
Smith KL, Galloway TS, Depledge MH (2000). Neuro-endocrine biomarkers of pollution-induced stress in marine invertebrates.
Abstract:
Neuro-endocrine biomarkers of pollution-induced stress in marine invertebrates.
Abstract.
Author URL.
Galloway TS, Fewster D, Crocker D, Noor M, Wilkin TJ (2000). Time clustering of high titre insulin autoantibodies (IAA) in the cord blood of infants born to non-diabetic mothers.
Autoimmunity,
32(1), 17-26.
Abstract:
Time clustering of high titre insulin autoantibodies (IAA) in the cord blood of infants born to non-diabetic mothers.
Insulin autoantibodies (IAA) are markers for autoimmune insulitis, and are reported in up to 100% of diabetic children before the age of five years, but in fewer than 1% of their controls. Their origins are unknown. In this report a cluster of high titre IAA in cord blood is reported, distinct from the low titre 'non-specific' binding previously described. The distributions of displaceable insulin binding measured in adults (Group A, n = 79), adolescents (Group B, n = 19), primary school children (Group C, n = 32) and third trimester pregnant women (Group D, n = 60) were all unimodal, normal and not different from each other (A = 0.57+/-0.64%, B = 0.87+/-0.45%, C = 0.81+/-0.87% and D = 0.35+/-0.48%). The distribution of insulin binding in the cord sera of consecutive newborns (n = 428) born between October and the following May, however, was bimodal. The first distribution, included 400 sera, was symmetrical and not different (0.79+/-0.45%) from groups A, B, C and D. The second distribution comprised the remaining 28 sera (7% of the total sample) with insulin-displaceable binding values in an IDW-validated radio assay ranging from 2.2% to 31.1%. The appearance of IAA was not HLA-restricted, but the frequency of IAA+ samples was seen to vary over five consecutive months. The timing is consistent with acute viral infection, but the implications for future insulin dependent diabetes will await long-term follow-up of the children and mothers involved.
Abstract.
Author URL.
1996
Galloway TS, Millward BA, Fewster D, Wilkin TJ (1996). Binding specificity of IAA in cord blood. The EarlyBird study.
DIABETOLOGIA,
39, 361-361.
Author URL.
1995
GALLOWAY TS, MILLWARD BA, CROCKER D, NOOR M, WILKIN TJ (1995). AUTOIMMUNE INSULITIS MAY START BEFORE BIRTH - THE EARLYBIRD PROJECT.
DIABETOLOGIA,
38, A90-A90.
Author URL.
1987
Galloway TS, van Heyningen S (1987). Binding of NAD+ by cholera toxin.
Biochem J,
244(1), 225-230.
Abstract:
Binding of NAD+ by cholera toxin.
1. The Km for NAD+ of cholera toxin working as an NAD+ glycohydrolase is 4 mM, and this is increased to about 50 mM in the presence of low-Mr ADP-ribose acceptors. Only molecules having both the adenine and nicotinamide moieties of NAD+ with minor alterations in the nicotinamide ring can be competitive inhibitors of this reaction. 2. This high Km for NAD+ is also reflected in the dissociation constant, Kd, which was determined by a variety of methods. 3. Results from equilibrium dialysis were subject to high error, but showed one binding site and a Kd of about 3 mM. 4. The A1 peptide of the toxin is digested by trypsin, and this digestion is completely prevented by concentrations of NAD+ above 50 mM. Measurement (by densitometric scanning of polyacrylamide-gel electrophoretograms) of the rate of tryptic digestion at different concentrations of NAD+ allowed a more accurate determination of Kd = 4.0 +/- 0.4 mM. Some analogues of NAD+ that are competitive inhibitors of the glycohydrolase reaction also prevented digestion.
Abstract.
Author URL.
Galloway TS, Tait RM, van Heyningen S (1987). Photolabelling of cholera toxin by NAD+.
Biochem J,
242(3), 927-930.
Abstract:
Photolabelling of cholera toxin by NAD+.
When cholera toxin is incubated under u.v. light with NAD+ labelled in either the adenine or the nicotinamide moiety, radioactivity becomes covalently bound to the protein. The reaction is specific for cholera toxin, and is inhibited by excess unlabelled NAD+ or NAD analogues. Only the active a 1 chain of the toxin is labelled. The u.v.-absorption spectrum of the product is very similar to that of NAD+, and shows the same reaction with cyanide. The nature of the product is therefore different from that found when diphtheria toxin is photolabelled [Carroll & Collier (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 3307-3311] in that the yield is lower, but both moieties of the NAD molecule become bound.
Abstract.
Author URL.
