Toxicity assessment of fosthiazate, metalaxyl-M and imidacloprid and their interaction with copper on Daphnia magna

Abstract

The toxic effects of three agrochemicals (fosthiazate, metalaxyl-M and imidacloprid) and copper were investigated in this study on the crustacean Daphnia magna. Copper was the most toxic tested compound with the lowest EC 50 value, equal to 0.11 mg/L. Among the three agrochemicals, fosthiazate was the most toxic with an EC50 value equal to 0.32 mg/L, about two orders of magnitude lower than the EC50 of metalaxyl-M and imidachloprid. The interactive effects of binary mixtures of fosthiazate, metalaxyl-M or imidacloprid and copper were also investigated. The interactive effects between agrochemicals and copper were antagonistic in most cases, while additive effects were observed for binary mixtures of metalaxyl-M and copper for low concentration combinations.