Hazard identification of imidacloprid to aquatic environment

The authors tested commercial grade imidacloprid as well as the formulated product Confidor SL 200 (imidacloprid) for toxicity to aquatic species of bacteria (Vibrio fischeri), algae (Desmodesmus subspicatus), crustaceans (Daphnia magna), and fish (Danio rerio). Acute toxicity was evaluated for all species, and sublethal endpoints were examined for Daphnia magna. The formulated product Confidor SL 200 was more toxic to daphnids and adult zebrafish than the technical grade imidacloprid, and testing suggested that the toxicity resulted from a combined effect of imidacloprid and the solvents in the product. Their results showed the 48h EC50 for D. magna was 56.5 mg/L and the 21d NOEC was 1.25 mg/L of imidacloprid. However, the authors note that previous research has shown that D. magna is not as sensitive to imidacloprid as other aquatic invertebrates. Among the species tested, daphnids were most sensitive to imidacloprid. They found that imidacloprid was persistent in water samples and did not biodegrade readily.

Authors: 
Tisler, T., A. Jemec, B. Mozetic, and P. Trebse
Journal: 
Chemosphere
Year published: 
2009