Research project A test to assess chemical persistence in the natural environment

The intention of the European Commission to include persistent & mobile chemicals among substances of very high concern is one example of the increasing importance of persistence in chemical regulation. Currently persistence tests focus on evaluating persistence in WWTPs; there is no regulatory test capable of assessing persistence in the aquatic environment. In a step towards overcoming this barrier, we recently showed that the OECD 309 test can be modified to make it environmentally relevant. Here we apply this test to measure persistence in water bodies from 4 regions on 3 continents. With these data we explore different proxies to explain spatial variability including cell count, employing chemical grouping and benchmarking. Furthermore, we conduct field measurements of persistence and compare these with the laboratory tests to derive translation factors. Finally, we prepare guidance on how the laboratory test could be used to assess persistence in a regulatory context.