Abstract

A preliminary ecotoxicological risk assessement of pesticides in groundwater has been performed. Predictable environmental concentrations in shallow groundwater, based on both calculations of pesticide leaching and detected levels during monitoring programmes, have been compared with aquatic ecotoxicity data. Among pesticides detected in groundwater only the levels of aldicarb (including metabolites), 1,3-dichloropropene, and ethoprophos exceed risk boundaries. Among pesticides of which calculations show that they can be expected in concentrations of 0.1 mug/l or higher a much large number of substances exceed risk boundaries. In particular, cypermethrin, 1,3-dichloropropene, fenpropathrin, pendimethalin, pirimicarb, pirimiphos-methyl, propoxur, terbufos, thiram, and trichlorphon have a large potential risk for groundwater ecosystems.