Irene Wittmer

TL;DR: An extensive analytical screening was carried out using liquid chromatography-high-resolution mass spectrometry, covering 86% of all polar organic pesticides sold in Switzerland and applied to agricultural or urban land, plus 134 transformation products; each of which could be quantified in the low ng/L range.

TL;DR: It can be safely concluded that in catchments of mixed land use, the contributions of biocide and pesticide inputs into surface waters from urban areas are at least as important as those from agricultural areas.

TL;DR: Comparisons of the agricultural application and the seasonal concentration and load pattern in the main creek from March to November revealed that the occurrence of glyphosate cannot be explained by agricultural use only and more than half of the load during selected rain events originates from urban areas.

TL;DR: It could be shown that risks can be underestimated by more than a factor of 10 in vulnerable catchments and that an increased temporal resolution is essential to cover acute risks but that a focused selection of substances is a possibility to reduce expenditures.

TL;DR: This study demonstrates that in catchments with mixed land use, mitigation strategies have to pay sufficient attention to the urban sources, and relates the biocide and pesticide loads found in surface waters to their respective urban and agricultural usage (loss rates).