Department Environmental Toxicology

Process Engineer Adriano Joss from Eawag water research institute has been working for many years on wastewater treatment plants and the removal of micropollutants from water. Together with Ralf Kägi, Head of the Eawag Particle Laboratory, he has compiled the current status of knowledge on microplastics. In an interview, he presents the most important findings. We have recently posted detailed information on the website “Microplastics in the environment”.

Swiss groundwater contains numerous pesticide degradation products. This has been discovered by an extensive screening by Eawag and ETH Zurich. The transformation products (metabolites) originate predominantly from pesticides from agriculture.

Two studies by Eawag and the Ecotox Centre have once again shown that surface waters in agricultural catchment areas are heavily contaminated with plant protection products. Concentrations of individual substances persisting for several months pose a risk of chronic toxicity and, for extended periods, exceed the levels at which a risk of acute toxicity exists for aquatic plants and organisms. In most of the samples, 30 or more different active ingredients were detected. Studies of stream biodiversity and bioassays confirmed the threat posed by these mixtures of substances.