The exposure and fate of insecticides and fungicides from agricultural fields into surface waters has not been studied in much detail, neither internationally nor in Switzerland, compared to the work done on herbicides. However, mainly insecticides can already affect aquatic organisms at very low concentrations in surface waters.
The aim of this project was therefore to better understand the exposure and fate of insecticides and fungicides in Swiss surface waters. During a situation analysis application patterns, sales statistics, degradation rates, physico-chemical properties, and ecotoxicological data were studied for all fungicides and insecticides that are registered in Switzerland. In a field study done in cooperation with cantonal authorities (March to July 2012), water samples as well as passive samples were collected at 5 different locations. The sampling locations were selected based on size and different land uses and ranged over the whole Swiss midlands. The samples were analyzed by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS/MS) as well as by gas chromatography with mass spectrometry (GC-MS/MS). The results show that especially insecticides exceed often the chronic quality standards in surface waters and thus are quite important for the assessment of the water quality. Selected insecticides and fungicides should be included into future monitoring programs.