Cytotoxicity, sister-chromatid exchange, chromosome aberration and transformation induced by 2,2-dichlorovinyl-O,O-dimethyl phosphate.

2,2-Dichlorovinyl-O,O-dimethyl phosphate (DDVP), an extensively used household insecticide, was assayed for its genotoxicity in primary rat tracheal epithelial (RTE) cells. Cytotoxicity of DDVP to RTE cells was dose-dependent, killing about 50% of the cell population at a dose of 80 micrograms/ml. Sister-chromatid exchange (SCE) and chromosomal aberrations induced by this insecticide were positive in RTE cells although the doses needed for significant inductions were much higher than those by a known genotoxic agent, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The level of transformation induced by DDVP in RTE cells was about 1/5 that induced by MNNG at a dose of similar cytotoxicity. The slope of the regression line for induced transformation is 1.27. DDVP probably induces the genotoxic effect in RTE cells by a one-hit mechanism.