Improved strategy to assess chemical persistence at the water-sediment interface (LRI ECO18-EAWAG)

Abstract: Persistence of chemical pollutants in surface water sediments is an important endpoint for the environmental risk assessment of chemical pollutants. In different regulatory frameworks for, e.g., plant protection products, pharmaceuticals and industrial chemicals, a sediment-water study according to the OECD 308 guideline needs to be carried out to assess persistence in sediment. This guideline has been questioned as to its fitness for purpose and the interpretability of the results obtained therefrom.

In this project sponsored by Cefic-LRI (http://www.cefic-lri.org/), the goal is to systematically investigate the suitability of studies carried out according to OECD 308 guidelines to obtain robust information on persistence at the sediment-surface water interface that is useful for exposure modeling and persistence assessment. For this purpose, different test design variants will be tested for a suite of substances that characteristically differ in their sorption behavior and biodegradability. Existing OECD 308 data will further be analyzed using kinetic models of increasing complexity and Bayesian data analysis to evaluate the suitability of these data to derive robust, system-independent and meaningful indicators of persistence.

Partners: Thomas Junker, Jörg Römbke (ECT Oekotoxikologie GmbH, Germany); Dieter Hennecke, Stefan Hahn (Fraunhofer IME/ITEM, Germany); Martin Scheringer, ETH Zürich

Project collaborator: Kathrin Fenner, Rani Bakkour (PhD)