Assessment of chemical footprints of hydrophobic pesticide/biocide contamination in western Kenya using polydimethylsiloxane silicone passive samplers.

In a previous study based on LC-HRMS screening of pesticides and other organic micropollutants, it was shown that pesticide pollution of water resources in western Kenya poses a significant risk to aquatic and human health. In the current study, this assessment was completed with the investigation of more hydrophobic organochlorine, organophosphate and pyrethroid pesticides in surface waters and wastewater treatment plant (WWTP) influents and effluents using polydimethylsiloxane silicone passive samplers and Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS). Chemical footprints were assessed based on the mixture risks of the detected pesticides on algae, fish and crustaceans determined using the Toxic Unit approach.