Agrochemical use is important to secure global food supply in our current society. In addition to improved crop production, new agrochemicals developed and released into the market should comply with environmental considerations, for example, regulatory frameworks for chemical risk assessment. Degradation half-lives of chemicals are often required by regulation to assess environmental persistence and fate of chemicals, but the simulation tests recommended (such as OECD 307) are time- and resource-consuming. Simplified methods to predict degradation half-lives in the environment would facilitate persistence assessment in earlier stages of product development.
In the project ReadAcross, funded by and in collaboration with our industrial partner Syngenta, we are investigating ways to read biotransformation half-lives of chemicals across different compartments. We are building regression models to test if degradation half-lives of agrochemicals obtained from laboratory tests in soil can be estimated through half-lives from well-designed biotransformation experiments in activated sludge, which are less time and resource intense than experiments in soil and could be implemented early in the research and development phase. Previous work has shown notable potential of this approach:
Fenner, K.; Screpanti, C.; Renold, P.; Rouchdi, M.; Vogler, B.; Rich, S., Comparison of Small Molecule Biotransformation Half-Lives between Activated Sludge and Soil: Opportunities for Read-Across? Environ Sci Technol 2020, 54, (6), 3148-3158. (DOI: 10.1021/acs.est.9b05104)
Further experiments to test the domain of applicability, the biotransformation mechanisms and transformation products generated within this project will contribute to an improved understanding of future applications for read-across in estimating biotransformation half-lives in environmental compartments.