RISK ASSESSMENT FOR PESTICIDES AND THEIR METABOLITES IN WATER

A method based on Hasse diagram is adopted to detect priority pesticid es among the 130 most used in Europe. Hasse diagrams rank pesticides i n groups of potential hazard to the water environment, according to pe sticide properties (water solubility, vapour pressure and persistence in soil) and usages. The procedure is applied on a territorial scale, selecting Germany, U.K. and Italy as case studies, and validated with the experimental results of monitoring programs. Most of the pesticide s ranked as a first priority by the model and analyzed for in water we re effectively found. The percentage of positive findings decreases fr om class 1 to 6 of priority in agreement with the theoretical predicti ons. The model suggests that each country must develop its own analyti cal protocol addressed to the detection of the most ''probable'' pesti cides. Pesticide metabolities of Italian priority pesticides are appra ised in detail and their risk is assessed according to their occurrenc e in surface and groundwater, persistence estimated from field data an d ecotoxicity data. The proposed procedure can steer research efforts towards compounds that really represent a risk for human health and aq uatic life.