Carbosulfan insecticide is widely used in agriculture and was recently proposed for treatment against pyrethroid-resistant mosquitoes. The mutagenic and genotoxic effect of carbosulfan was carried out in fish Channa punctatus using micronucleus (MN) test and comet assay. The 96h LC(50), estimated by probit analysis in a semi-static bioassay experiment, was 0.268 mg l(-1). Based on the LC(50) value, three sub-lethal concentrations of carbosulfan (1/4th LC(50)= approximately 67 microg l(-1), 1/2nd LC(50)= approximately 134 microg l(-1) and 3/4th LC(50)= approximately 201 microg l(-1)) were selected and fishes were exposed to the said concentrations for 96h and the samplings were done at regular intervals of 24h for assessment of the MN frequencies and DNA damage. In general, significant effects (P<0.01) from both concentrations and time of exposure were observed in exposed fishes. The MN induction was highest on 96h at all the concentrations in the peripheral blood. Similar trend was observed for the DNA damage measured in terms of the percentage of tail DNA in the erythrocyte and gill cells. This study confirmed that the comet and micronucleus assays are useful tools in determining potential genotoxicity of water pollutants and might be appropriate as a part of monitoring program.
Copyright 2009 Elsevier Ltd. All rights reserved.