Aquatic toxicology of cypermethrin. I. Acute toxicity to some freshwater fish and invertebrates in laboratory tests

Abstract

Cypermethrin is a synthetic pyrethroid. Its acute toxicity to ten freshwater invertebrates ( Daphnia magna, Asellus aquaticus, Gammarus pulex, Cloeon dipterum, Gyrinus natator, Chironomus thummi, Aedes aegypti Cheoborus crystallinus, Corixa punctata, and Piona carnea) was determined in the laboratory using 24-h static water tests. The 24-h EC 50 values (based on reduced motility) ranged from 0.02 μg·l −1for A. aquaticus and P. carnea to 2 μg·l −1 for D. magna, and for seven of the species the EC 50 values were < 0.1 fig μg·l −1 The 24-h LC 50values for G. natator, C. thummi, and C. punctata were > 5 μg·l −1 For the seven more susceptible species the 24-h LC 50values ranged from 2 μg·l −1 to 0.05 μg·l −1 The acute toxicity of cypermethrin to some species of fish ( Cyprinus carpio. Scardinius erythrophthalmus, Salmo gairdneri, Salmo trutta and Tilapia nilotica) was determined using 96-h continuous-flow tests. The 96-h LC 50 values obtained were within the range 0.4–2.2 μg·l −1. The solubility of cypermethrin within the range of test temperatures (15–25°C was estimated to be in the range 5–10 μg·l −1.