Endocrine Active Chemicals (EACs) can be released into waterways from agricultural run-off or wastewater outflows, reaching markedly high concentrations in some freshwater systems. Photo credit: Katie Mintram.

Every individual has a role to play: getting more from our models for environmental risk

In a paper published last month in Critical Reviews in Toxicology, Katie Mintram, a PhD researcher at Exeter, discusses the environmental impacts of endocrine activating chemicals on freshwater fish.

Co-authored with University of Exeter colleagues Professor Charles Tyler and Dr Ross Brown, this research investigates better ways to protect populations by addressing the limitations to Environmental Risk Assessments for these pollutants and suggests ways to address these shortcomings.

Endocrine Active Chemicals (EACs) can be released into waterways from agricultural run-off or wastewater outflows, reaching markedly high concentrations in some freshwater systems. These chemicals have the ability to interfere with hormones – the components of the endocrine system – and can result in adverse health effects in individual organisms, such as fish, and their offspring. The effects of these chemicals can range from altered sexual behaviour to intersex, being the presence of male and female reproductive organs in the same fish.

Traditional Environmental Risk Assessments (ERAs) observe the effects of compounds on individual fish that are established in a laboratory and the data gathered is extrapolated to make predictions for wild populations; often missing the mark in the consideration of factors which vary widely between populations, such as physiological susceptibility. As a result we are not currently getting enough information to predict with any certainty what the impact of chemicals such as EACs may pose on freshwater fish populations.

In order to improve the accuracy of ERAs, lead author Katie suggests the use of Individual Based Models: 'Individual Based Models (IBMs) are becoming increasingly popular for assessing population-level effects of chemicals (and other disturbances) because they include individual variability, population-level interactions, and species specific behaviours'. IBMs are capable of incorporating end-points which are relevant to the impact of EACs – and if they are used to inform ERAs, may provide a better tool for prediction of the effects of chemicals such as these on organism biology in freshwater fish species.

Article written by Lauren Porter, Biosciences PressGang

Date: 2 November 2017

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