Comparative Hazard Assessment of Pesticides to the Aquatic Life Using Estimated Concentrations⁽¹⁾

Veska Kambourova*, Lubomir Simeonov**, Gyula Dura,*** Kosta Vassilev*, Maria Tasheva*

⁽¹⁾The study is part of the Environmental Programme for the Danube River Basin, supported by PHARE (E.C.) under the project “Danube Regional Pesticide Study” No. 95-0100.

Abstract:
The purpose of the study was to evaluate the potential hazard of pesticides used in the Danube basin for the aquatic life. The calculation of Predicted Environmental Concentrations (PEC) was performed using the Netherland’s Uniform System for the Evaluation of Substances (USES). Two kinds of quotients were used: the hazard quotient PEC/L(E)50 for fish, crustaceans and algae, and the quotient PEC/NEC for aquatic systems. A total of 275 pesticides were evaluated. The comparative hazard assessment demonstrated that there is no correspondence in the estimated hazard of acute effect of pesticides on the different species of the aquatic life. Algae are more sensitive to herbicides and more resistant to insecticides. Fish and crustaceans are more sensitive to insecticides and fungicides. The “worst case” method was used in the evaluation. Hazard assessment of ecosystems as a whole gives more general and adequate information concerning the adverse effect of pesticides on aquatic life. Nevertheless the limitations of the modelling investigations, the conclusion of the study is that the regulation of pesticides can be substantially improved through the use of models quantifying the hazard for the aquatic life.