Susceptibility of five nontarget organisms to aqueous diazinon exposure

Static aqueous toxicity experiments were conducted in the laboratory to examine the susceptibility of five nontarget species to aqueous diazinon exposure. The organisms were Ceriodaphnia dubia, Daphnia magna, Hyalella azteca, Chironomus tentans, and Pimephales promelas. Results showed that C. dubia was the most sensitive specie, with a 48-h LC sub(50) of 0.92 mu g/l. This specie was followed by D. magna, H. azteca, C. tentans, and P. promelas at mean 48-h LC sub(50) values of 2.39, 15.07, 52.47, and 15,940 mu g/l, respectively.