ASSESSMENT OF LAMBDA-CYHALOTHRIN BIOACCUMULATION IN CYPRINUS CARPIO AND ITS ECOTOXICOLOGICAL SIGNIFICANCE

Abstract

Lambda-cyhalothrin is a commonly utilized synthetic pyrethroid insecticide that has known aquatic organism toxicity, but little evidence exists supporting its bioaccumulation with genetic damage in fish especially Cyprinus carpio. The ecotoxicological effects of lambda-cyhalothrin on freshwater fish were evaluated based on data retrieved from the U.S. EPA ECOTOX Knowledgebase under the headings of biological effects, tissue-specific responses, genetic effects, exposure duration and bioaccumulation. The fish-result data set comprised 465 fish-result records, most of which were for mortality, biochemical alterations, enzyme-related effects, and genetic responses. Of these, 75 were deemed as genetic effects (DNA damage, micronuclei and nuclear abnormalities, as well as other mitotic changes). Genetic response was reported after several hours up to 192 h (8 days), and liver, erythrocytes, brain, gills, muscle and kidney were the main response sites. There were only two records of direct bioaccumulation, 674.3 and 620.6 L/kg, for Danio rerio. The records included a total of ~48 h of exposure and 72 h of observation, which would show measurable short-term bioconcentration. There was no direct ECOTOX record relating the exposure to lambda-cyhalothrin, bioaccumulation and/or DNA damage in the Comet-assay test for C. carpio. The results indicate a lack of species-specific knowledge and stress the need to undertake common-carp studies that combine tissue-residue analysis, BCF/BAF estimation, exposure-duration assessment, and standardized endpoints for genotoxicity to facilitate improved ecological risk assessment.