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Traditional Toxicity Tests used for Protection of Aquatic Life and Behavioural Endpoints
Citation:
Lazorchak, J. Traditional Toxicity Tests used for Protection of Aquatic Life and Behavioural Endpoints. The behaviour of non-target organism after exposure to chemicals - Possibilities of implementation in the regulatory process, Dessau, GERMANY, October 30 - November 01, 2019.
Impact/Purpose:
Invited presentation on traditional toxicity endpoints used in the US and some comments on behavior endpoints for a workshop sponsored by German Environment Agency.
Description:
Toxicity tests used in regulatory programs to develop ambient water quality criteria (AWQC) or Environmental Quality Standards (EQS) have historically consisted of single organism assays of either 48-96 hr (acute) or 7-28-day (chronic or short term chronic) duration. Resulting data are used in assessing whole effluent, ambient water, or sediment toxicity, as well as ecological risk of high-volume production chemicals and pesticides. AWQC are derived for chemical exposures to protect from unacceptable effects on aquatic communities. Generally, EQS consider only those endpoints that have consequences at the population level of the considered test species. Most standard test methods include one or more relevant endpoints. Data from studies describing endpoints that do not include direct measurements of survival, development or reproduction, but, rather, describe behavioral effects, anatomical differences between control and treatment groups, effects at the tissue or sub-cellular level (such as changes in enzyme induction or gene expression) are generally considered unsuitable as the basis for EQS derivation. However, other endpoints, for example, anatomical changes in gonad development that would prevent successful reproduction or changes in behavior which would impair competitive fitness, may be relevant. Avoidance responses resulting in a decrease of suitable habitat due to contamination is also an important consideration. This presentation will provide an overview of the traditional tests and endpoints used in the EU and U.S. The presentation will also address the following questions: Are behavioral effects relevant at the population level? How reliable are behavioural studies and how can they be improved further? Can behavioral effects be added to current standard tests? Or is it time for a new standard? If not, what is needed? Which myths about behavioural endpoints need to be overcome to increase the use of behavioral data in chemicals regulation?