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Faculty of Health and Life Sciences

Dr Garry Codling

Dr Garry Codling

Senior Lecturer in Water Chemistry


 CREWW Building 


Garry obtained his first degree in Biological Science (1999-2004) and his Masters in Applied Marine Science (2005-2006) at Plymouth University. He then went on to do a PhD (2007-2011) at the University of Lancaster on a project looking at the geochemical cycling or organic contaminants in cryospheric regions. The following four years (2011-2015) were spent at the Toxicology Center at the University of Saskatchewan in Canada, working on numerous projects including the Great Lakes Sediment Survey Project (GLSSP), Oil Sands Contaminant Monitoring in the Athabasca River system and multiple PFAS projects. He then moved to RECETOX, at Masaryk University (2015-2022) where he worked on non-target analytical methods for a wide range of matrices including human biofluids, marine and terrestrial systems. He was appointed as a Senior Lecturer in 2023 at Exeter University where he teaches for Geography and Biosciences and does research on contaminants in freshwater systems with the Center for Resilience in Environment Water and Waste (CREWW). 

Broad research specialisms: 

Environmental monitoring for contaminants, analytical chemistry, large data processing, climate change and toxicity. 

Research interests

My research interest has always been on environmental contaminants both anthropogenic and natural. There are millions of chemicals produced every day that improve our lives, these range from plant protection products, medicines, plastics and personal care products. However, over the last one hundred years many compounds have proven to have deleterious effects on our environment, ranging from increased levels of cancer to the loss of wild insects and the birds that fed on them. On top of those chemicals produced by man, climate change, nutrification of water systems and globalization has led to changes in the community assemblage of many systems including increases in harmful algal blooms that produce a range of toxins. There is a need-to-know what chemicals are in our environment, the sources and sinks, if they are accumulating and if they are a risk to human or environmental health. My work has taken me all over the globe to monitor a range of environments from tropical systems to the high arctic and I have developed novel methods for sample collection and monitoring. In the lab my work has been on target and non-target extraction methodology and using mass spectrometry to identify a wide range of compounds. Most recently my work has been on using non-target high resolution mass spectrometry for measuring hundreds or thousands of known chemicals as well as identifying suspect and unknown contaminants of concern.


PhD in Environmental Science from Lancaster University

MSc in Applied Marine Science from The University of Plymouth

BSc (Hons) in Biological Science from The University of Plymouth


2023-Present: Senior Lecturer in Water Chemistry, Exeter University

2019-2022: Marie Curie Fellow, University of Saskatchewan and Masaryk University

2017-2019: Senior Research Associate, RECETOX, Masaryk University

2015-2017: Senior Postdoctoral Research Associate, RECETOX, Masaryk University

2011-2015: Postdoctoral Research Associate, The Environment Center, University of Saskatchewan

2007-2008: Quality Control and Quality Assurance technician, Dow Chemicals

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Research interests

Background (General)

Primarily my research interests are in environmental monitoring for exogenous compounds in inorganic and organic matrices and identifying contaminants of concern. There are millions of chemicals in use, and it is estimated that each year 10 million new compounds are identified and synthesized. Not all have a use commercially, however, each month the USEPA reviews around 500 applications for compounds to enter commercial use in the US. In the UK and Europe, a similar number of applications are submitted. A few decades ago, our knowledge of what chemicals were in use, their toxicity and environmental fate was woefully limited. often it was only once effects were observed in the environment that there was any move to restrict or ban a compound and we are still paying the price. The group of chemicals known as PCBs for example are ubiquitous though in most countries use ended decades ago and hot spots often near dumps or production facilities are still being cleaned up. There is a need therefore to monitor for what compounds are emerging into our environment but also to not forget those legacy compounds that are still out there.

In addition to exogenous compounds, some of my work has also been on identifying markers of exposure/stress through biological chemical changes in response to environmental conditions. Global climate change and environmental contamination put additional pressure on organisms. Some of these changes may not be measurable directly but the biological response can be monitored. This area of work has included changes in the lipids in arctic fish or fish embryo changes in response to parental exposure to contaminants.

My work with CREWW (Center for Resilience in Environment, Water and Waste) focuses largely on the area of freshwater systems and monitoring for a range of synthetic and natural contaminants. It is vital that we know what chemicals are currently in our ecosystems and what may be emerging. 

Background (projects)

My previous research experiences encompass a diverse range of environments and sample types, with a current focus on aquatic contaminants. Allow me to provide a summary of some of my past projects:

  1. Great Lakes contaminants (GLSSP): I was involved in a comprehensive 5-year project aimed at assessing current and historical PFAS exposure in Great Lakes Sediment. This endeavor involved the collection and analysis of thousands of sediment samples from the Great Lakes region.

  2. Developing pull-down assays for targeted non-target analysis (PullED-MS, MSCA Fellowship): I explored the potential of utilizing cellular proteins as binding agents to selectively capture compounds of interest from environmental matrices. This innovative approach aimed to filter out non-relevant compounds and enhance the identification of biologically active substances.

  3. Human exposure to contaminants and Exposome (CETCOEN, HBM4EU): Within this project, I investigated the presence of contaminants in human biofluids as indicators of exposure. By employing high-resolution mass spectrometry, I conducted comprehensive analyses to examine the transfer of contaminants from mothers to their infants through placental and breastfeeding activities. Furthermore, I explored the potential health and developmental impacts associated with such exposures. This research contributes to the broader concept of the exposome, which recognizes that an individual's health is influenced by various factors throughout their lifetime. Identifying the most significant factors can guide targeted interventions to maximize societal benefits.

  4. Cryospheric environments and contaminant behavior: I conducted studies to measure organic contaminants in snow, air, sea ice, and water at ultra-trace concentrations. These investigations aimed to deepen our understanding of processes such as snow melt behavior and the influence of ice cover on contaminant dynamics between water and the atmosphere.

  5. Indoor exposure to contaminants: My research involved the analysis of house dust and air samples to assess the presence of persistent organic pollutants and plasticizers. By examining these indicators, I aimed to gain insights into potential indoor health risks.

  6. Development of high-resolution mass spectrometry methods: I have made significant contributions to the development of various libraries, processing methods, and tools that facilitate the comprehensive chemical analysis of complex data sets. These advancements have enabled more effective investigations in the field of chemical analysis.

These past projects have provided me with a broad understanding of environmental contamination issues and the application of advanced analytical techniques for comprehensive sample analysis. 

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Journal articles

Torres-Moreno AC, Mejia-Grau K, Puente-DelaCruz L, Codling G, Villa AL, Ríos-Marquez O, Patequiva-Chauta L, Cobo M, Johnson-Restrepo B (2023). Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) in human breast milk from Colombia: a probabilistic risk assessment approach. Chemosphere, 339 Abstract.  Author URL.
Palát J, Kukučka P, Codling GP, Price EJ, Janků P, Klánová J (2022). Application of 96-well plate SPE method for analysis of persistent organic pollutants in low volume blood serum samples. Chemosphere, 287 Abstract.
Tkalec Ž, Codling G, Klánová J, Horvat M, Kosjek T (2022). LC-HRMS based method for suspect/non-targeted screening for biomarkers of chemical exposure in human urine. Chemosphere, 300 Abstract.
Torres-Moreno C, Puente-DelaCruz L, Codling G, Villa AL, Cobo M, Klanova J, Johnson-Restrepo B (2022). Polycyclic aromatic hydrocarbons (PAHs) in human breast milk from Colombia: Spatial occurrence, sources and probabilistic risk assessment. Environmental Research, 204 Abstract.
Tkalec Ž, Codling G, Tratnik JS, Mazej D, Klánová J, Horvat M, Kosjek T (2022). Suspect and non-targeted screening-based human biomonitoring identified 74 biomarkers of exposure in urine of Slovenian children. Environmental Pollution, 313 Abstract.
Gong Y, Zhang K, Geng N, Wu M, Yi X, Liu R, Challis JK, Codling G, Xu EG, Giesy JP, et al (2021). Molecular mechanisms of zooplanktonic toxicity in the okadaic acid-producing dinoflagellate Prorocentrum lima. Environmental Pollution, 279 Abstract.
Price EJ, Palát J, Coufaliková K, Kukučka P, Codling G, Vitale CM, Koudelka Š, Klánová J (2021). Open, High-Resolution EI+ Spectral Library of Anthropogenic Compounds. Frontiers in Public Health, 9 Abstract.
Wang C, Gong Y, Deng F, Ding E, Tang J, Codling G, Challis JK, Green D, Wang J, Chen Q, et al (2021). Remodeling of Arctic char (Salvelinus alpinus) lipidome under a stimulated scenario of Arctic warming. Global Change Biology, 27(14), 3282-3298. Abstract.
Demirtepe H, Melymuk L, Codling G, Murínová ĽP, Richterová D, Rašplová V, Trnovec T, Klánová J (2021). Targeted and suspect screening of plasticizers in house dust to assess cumulative human exposure risk. Science of the Total Environment, 781 Abstract.
Tendler B, Ohiozebau E, Codling G, Giesy JP, Jones PD (2020). Concentrations of Metals in Fishes from the Athabasca and Slave Rivers of Northern Canada. Environmental Toxicology and Chemistry, 39(11), 2180-2195. Abstract.
Codling G, Yuan H, Jones PD, Giesy JP, Hecker M (2020). Metals and PFAS in stormwater and surface runoff in a semi-arid Canadian city subject to large variations in temperature among seasons. Environmental Science and Pollution Research, 27(15), 18232-18241. Abstract.
Lammel G, Kitanovski Z, Kukučka P, Novák J, Arangio AM, Codling GP, Filippi A, Hovorka J, Kuta J, Leoni C, et al (2020). Oxygenated and Nitrated Polycyclic Aromatic Hydrocarbons in Ambient Air - Levels, Phase Partitioning, Mass Size Distributions, and Inhalation Bioaccessibility. Environmental Science and Technology, 54(5), 2615-2625. Abstract.
Christensen ER, Zhang R, Codling G, Giesy JP, Li A (2019). Poly- and per-fluoroalkyl compounds in sediments of the Laurentian Great Lakes: Loadings, temporal trends, and sources determined by positive matrix factorization. Environmental Pollution, 255 Abstract.
Karásková P, Codling G, Melymuk L, Klánová J (2018). A critical assessment of passive air samplers for per- and polyfluoroalkyl substances. Atmospheric Environment, 185, 186-195. Abstract.
Naggar YA, Codling G, Giesy JP, Safer A (2018). Beekeeping and the Need for Pollination from an Agricultural Perspective in Egypt. Bee World, 95(4), 107-112.
Codling G, Hosseini S, Corcoran MB, Bonina S, Lin T, Li A, Sturchio NC, Rockne KJ, Ji K, Peng H, et al (2018). Current and historical concentrations of poly and perfluorinated compounds in sediments of the northern Great Lakes - Superior, Huron, and Michigan. Environ Pollut, 236, 373-381. Abstract.  Author URL.
Codling G, Naggar YA, Giesy JP, Robertson AJ (2018). Neonicotinoid insecticides in pollen, honey and adult bees in colonies of the European honey bee (Apis mellifera L.) in Egypt. Ecotoxicology, 27(2), 122-131. Abstract.
Codling G, Sturchio NC, Rockne KJ, Li A, Peng H, Tse TJ, Jones PD, Giesy JP (2018). Spatial and temporal trends in poly- and per-fluorinated compounds in the Laurentian Great Lakes Erie, Ontario and St. Clair. Environmental Pollution, 237, 396-405. Abstract.
Bonina SMC, Codling G, Corcoran MB, Guo J, Giesy JP, Li A, Sturchio NC, Rockne KJ (2018). Temporal and spatial differences in deposition of organic matter and black carbon in Lake Michigan sediments over the period 1850–2010. Journal of Great Lakes Research, 44(4), 705-715. Abstract.
Al Naggar Y, Codling G, Giesy JP (2017). Human dietary intake and hazard characterization for residues of neonicotinoides and organophosphorus pesticides in Egyptian honey. Toxicological and Environmental Chemistry, 99(9-10), 1397-1408. Abstract.
Peng H, Sun J, Saunders DMV, Codling G, Wiseman S, Jones PD, Giesy JP (2017). Hydroxylated 2-Ethylhexyl tetrabromobenzoate isomers in house dust and their agonistic potencies with several nuclear receptors. Environmental Pollution, 227, 578-586. Abstract.
Lammel G, Spitzy A, Audy O, Beckmann S, Codling GP, Kretzschmann L, Kukučka P, Stemmler I (2017). Organochlorine pesticides and polychlorinated biphenyls along an east-to-west gradient in subtropical North Atlantic surface water. Environmental Science and Pollution Research, 24(12), 11045-11052. Abstract.
Ohiozebau E, Tendler B, Codling G, Kelly E, Giesy JP, Jones PD (2017). Potential health risks posed by polycyclic aromatic hydrocarbons in muscle tissues of fishes from the Athabasca and Slave Rivers, Canada. Environ Geochem Health, 39(1), 139-160. Abstract.  Author URL.
Eichbaum K, Brinkmann M, Nuesser L, Buchinger S, Reifferscheid G, Codling G, Jones P, Giesy JP, Hecker M, Hollert H, et al (2016). Bioanalytical and instrumental screening of the uptake of sediment-borne, dioxin-like compounds in roach (Rutilus rutilus). Environmental Science and Pollution Research, 23(12), 12060-12074. Abstract.
Codling G, Al Naggar Y, Giesy JP, Robertson AJ (2016). Concentrations of neonicotinoid insecticides in honey, pollen and honey bees (Apis mellifera L.) in central Saskatchewan, Canada. Chemosphere, 144, 2321-2328. Abstract.
Lyu H, He Y, Tang J, Hecker M, Liu Q, Jones PD, Codling G, Giesy JP (2016). Effect of pyrolysis temperature on potential toxicity of biochar if applied to the environment. Environmental Pollution, 218, 1-7. Abstract.
Ohiozebau E, Tendler B, Hill A, Codling G, Kelly E, Giesy JP, Jones PD (2016). Products of biotransformation of polycyclic aromatic hydrocarbons in fishes of the Athabasca/Slave river system, Canada. Environ Geochem Health, 38(2), 577-591. Abstract.  Author URL.
Peng H, Chen C, Cantin J, Saunders DMV, Sun J, Tang S, Codling G, Hecker M, Wiseman S, Jones PD, et al (2016). Untargeted Screening and Distribution of Organo-Bromine Compounds in Sediments of Lake Michigan. Environmental Science and Technology, 50(1), 321-330. Abstract.
Peng H, Chen C, Cantin J, Saunders DMV, Sun J, Tang S, Codling G, Hecker M, Wiseman S, Jones PD, et al (2016). Untargeted Screening and Distribution of Organo-Iodine Compounds in Sediments from Lake Michigan and the Arctic Ocean. Environmental Science and Technology, 50(18), 10097-10105. Abstract.
Saunders DMV, Podaima M, Codling G, Giesy JP, Wiseman S (2015). A mixture of the novel brominated flame retardants TBPH and TBB affects fecundity and transcript profiles of the HPGL-axis in Japanese medaka. Aquatic Toxicology, 158, 14-21. Abstract.
Hong S, Khim JS, Wang T, Naile JE, Park J, Kwon BO, Song SJ, Ryu J, Codling G, Jones PD, et al (2015). Bioaccumulation characteristics of perfluoroalkyl acids (PFAAs) in coastal organisms from the west coast of South Korea. Chemosphere, 129, 157-163. Abstract.
Peng H, Saunders DMV, Sun J, Codling G, Wiseman S, Jones PD, Giesy JP (2015). Detection, identification, and quantification of hydroxylated bis(2-ethylhexyl)-tetrabromophthalate isomers in house dust. Environmental Science and Technology, 49(5), 2999-3006. Abstract.
ALNaggar Y, Vogt A, Codling G, Naiem E, Mona M, Seif A, Robertson AJ, Giesy JP (2015). Exposure of honeybees (Apis mellifera) in Saskatchewan, Canada to organophosphorus insecticides. Apidologie, 46(5), 667-678. Abstract.
Tse TJ, Doig LE, Leavitt PR, Quiñones-Rivera ZJ, Codling G, Lucas BT, Liber K, Giesy JP, Wheater H, Jones PD, et al (2015). Long-term spatial trends in sedimentary algal pigments in a narrow river-valley reservoir, Lake Diefenbaker, Canada. Journal of Great Lakes Research, 41, 56-66. Abstract.
Lu Z, Song L, Zhao Z, Ma Y, Wang J, Yang H, Ma H, Cai M, Codling G, Ebinghaus R, et al (2015). Occurrence and trends in concentrations of perfluoroalkyl substances (PFASs) in surface waters of eastern China. Chemosphere, 119, 820-827. Abstract.
Al Naggar Y, Codling G, Vogt A, Naiem E, Mona M, Seif A, Giesy JP (2015). Organophosphorus insecticides in honey, pollen and bees (Apis mellifera L.) and their potential hazard to bee colonies in Egypt. Ecotoxicology and Environmental Safety, 114, 1-8. Abstract.
Peng H, Chen C, Saunders DMV, Sun J, Tang S, Codling G, Hecker M, Wiseman S, Jones PD, Li A, et al (2015). Untargeted Identification of Organo-Bromine Compounds in Lake Sediments by Ultrahigh-Resolution Mass Spectrometry with the Data-Independent Precursor Isolation and Characteristic Fragment Method. Analytical Chemistry, 87(20), 10237-10246. Abstract.
Wang X, Halsall C, Codling G, Xie Z, Xu B, Zhao Z, Xue Y, Ebinghaus R, Jones KC (2014). Accumulation of perfluoroalkyl compounds in Tibetan mountain snow: Temporal patterns from 1980 to 2010. Environmental Science and Technology, 48(1), 173-181. Abstract.
Codling G, Vogt A, Jones PD, Wang T, Wang P, Lu YL, Corcoran M, Bonina S, Li A, Sturchio NC, et al (2014). Historical trends of inorganic and organic fluorine in sediments of Lake Michigan. Chemosphere, 114, 203-209. Abstract.
Tse TJ, Codling G, Jones PD, Thoms K, Liber K, Giesy JP, Wheater H, Doig LE (2014). Reconstructing long-term trends in municipal sewage discharge into a small lake in northern Manitoba, Canada. Chemosphere, 103, 299-305. Abstract.
Codling G, Halsall C, Ahrens L, Del Vento S, Wiberg K, Bergknut M, Laudon H, Ebinghaus R (2014). The fate of per- and polyfluoroalkyl substances within a melting snowpack of a boreal forest. Environmental Pollution, 191, 190-198. Abstract.
Hong S, Khim JS, Park J, Kim M, Kim WK, Jung J, Hyun S, Kim JG, Lee H, Choi HJ, et al (2013). In situ fate and partitioning of waterborne perfluoroalkyl acids (PFAAs) in the Youngsan and Nakdong River Estuaries of South Korea. Science of the Total Environment, 445-446, 136-145. Abstract.
Ahrens L, Shoeib M, Del Vento S, Codling G, Halsall C (2011). Polyfluoroalkyl compounds in the Canadian Arctic atmosphere. Environmental Chemistry, 8(4), 399-406. Abstract.

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Office Hours:

My normal work schedule is 9 till 5.30, I try and keep between 13.30 and 14:30 each day available for drop-in though it is best to email or book with the link below. 

Book time with Codling, Garry 

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