Possible Application of Non-Testing Methods in Setting Environmental Quality Standards (EQS)
The Water Framework Directive is one of the most important pieces of European environmental legislation in recent years, requiring all inland and coastal waters to achieve good status by 2015. Article 16 of the Directive describes how and by when Environmental Quality Standards (EQS) for pollutants should be developed, and states that pollutants presenting a significant risk to or via water should be identified by the European Commission and classified as priority substances, with the most hazardous of these classified as priority hazardous substances.
Generation of ecotoxicity test data is one option for filling gaps when deriving EQS but there are also options that avoid testing, such as the use of (Quantitative) Structure Activity Relationships ([Q]SARs), Quantitative Structure-Property Relationships (QSPRs), Activity-Activity Relationships (AARs), Quantitative Structure Activity-Activity Relationships, or read-across from similar substances. All of these non-testing methods are based on the idea that properties (including biological activities) of a chemical substance depend on its intrinsic nature and can be directly predicted from its molecular structure and inferred from the properties of similar compounds whose activities are known.
This report explores application of the widely used and freely available EPIWIN suite of QSARs, particularly the ecotoxicity software ECOSAR, for derivation of EQS under the WFD. The predictive ability of these QSARs is examined using the 33 priority substances in the Water Framework Directive Daughter Directive on Priority Substances, plus the additional substances recommended for inclusion by the European Parliament, as representative substances for EQS derivation. We also investigated use of the OECD QSAR Application Toolbox version 1 for read across of data. We address the following questions:
1. How effective are the QSARs in EPIWIN at identifying the selected substances as Persistent, Bioaccumulative and Toxic (PBT) or very Persistent and very Bioaccumulative (vPvB)? These substances would potentially be classifiable as priority hazardous substances and would also require consideration of sediment toxicity and secondary poisoning through the food chain.
2. How accurate and precise is ECOSAR at estimating acute and chronic toxicity for fish, invertebrates and algae for these substances?
3. How similar are EQS for these substances based on measured data and ECOSAR estimates?
4. To what extent is the most sensitive trophic group accurately predicted by ECOSAR for acute or chronic exposure?
5. Can a formal approach for defining similarity for read-across help to group substances in a defensible way that increases the amount of data available overall for EQS derivation?
The following conclusions and recommendations apply generally on the assumption that the substances analysed in this report are representative of the types of substances for which EQS may also need to be set in the future.
CRANE Mark;
WATTS Christopher;
DAGINNUS Klaus;
WORTH Andrew;
2009-02-10
OPOCE
JRC50067
1018-5593,
EUR 23758 EN,
Additional supporting files
| File name | Description | File type | |
|---|
