Genotoxicity of the organophosphorus insecticide chlorpyrifos based on human lymphocyte culture.

Abstract

Chlorpyrifos is one of the widely used organophosphorus insecticides. The compound and two of its main metabolites are known nucleic acid alkylating agents. Potential of the compound as a genotoxic agent was determined on the basis of chromosome damage and rates of sister chromatid exchanges in cultured human lymphocytes. Four treatments (0.02, 0.20, 2.00 and 20.00μg/ml), a solvent control and an untreated control were used in three replications of 4-hour and 24-hour exposures to assess damage to chromosomes. One replication of the four treatments and two controls based on 24-hour exposure was used to determine sister chromatid exchanges. Chromosome damage assessed primarily as gaps and breaks did not increase at a statistically significant level. The trend was almost similar for sister chromatid exchanges though for one of the controls, significance was reached for one treatment level. It seems that short term exposure to chlorpyrifos at these dosages is relatively safe. Efforts however, must continue for procurement of safer compounds that are not reactive to nucleic acids.