Lethal and sublethal effects of the pyrethroid insecticide tau-fluvalinate on the nontarget organism Gammarus roeseli: A study of acute toxicity, genotoxicity and locomotor activity

Abstract

Aquatic ecosystems are recipients of various contaminants including pesticides. For many years, pyrethroid insecticides (e.g., tau-fluvalinate) have been used extensively in agricultural activities to control pests. However, they can affect not only target organisms but also non-target organisms. This study was conducted to investigate the lethal and sublethal effects of tau-fluvalinate on the non-target organism Gammarus roeseli. To this end, acute toxicity of tau-fluvalinate was determined using a toxicity test with a 96-h exposure period, and the genotoxic effects of different sublethal concentrations on hemocytes of the test organism were assessed at 24-, 96 and 240-h exposure periods using the comet assay. Alterations in locomotor activity of the test organism in response to exposure to sublethal concentrations were evaluated at 120 and 240-h periods. The 96-h median lethal concentration (LC50) was found to be 17.29 μg/L, and tau-fluvalinate was observed to cause a significant increase in DNA damage and a significant reduction in locomotor activity at the tested sublethal concentrations (2.15, 4.30 and 8.60 μg/L). The results of this study suggest that the long-term existence of tau-fluvalinate in aquatic environments at high concentrations is a noteworthy threat to non-target organisms and that its use in agricultural activities should be reconsidered