The potential acute and chronic toxicity of cyfluthrin on the soil model organism, Eisenia fetida

Abstract In this study, the acute (72 h and 14 d) and chronic (28 d and 8 weeks) effects of cyfluthrinon earthwormswere evaluated across different endpoints, which are mortality, growth, reproduction and enzyme activities. Cyfluthrinwas rated as moderately toxic in 72-h filter paper test and low toxic in 14-day soil test. The exposure of earthwormsto cyfluthrin-polluted soil for 8 weeks showed that growth of earthwormswas inhibited by cyfluthrin, cocoonproduction and hatching were inhibited by 20–60 mg/kg cyfluthrin. Moreover, 28-day soil teston the responses of enzymes associated with antioxidation and detoxification showed that the activities of catalase (CAT) and glutathione S- transferase (GST) were initially increased by cyfluthrinat 5–20 mg/kg, but reduced at 30–60 mg/kg, peroxidase (POD) was increased by 26–102% by cyfluthrinin the early period, except 5 mg/kg on day 7, and ethoxyresorufin-O-deethylase (EROD) was increased by 29–335% by cyfluthrinafter 3 days. Cyfluthrindegraded with a half-life of 24.8–34.8 d, showing the inconsistency between the continuous toxic responses of earthwormsand degradation of cyfluthrinin soil. The variable responses of these indexes indicated that different level endpoints should be jointly considered for better evaluation of the environmental risk of contaminants in soil.