In vivo studies on genotoxicity of a soil fumigant, dazomet.

Dazomet is a soil fumigant effective against germinating weed seeds, nematodes, soil fungi, and soil insects. Dazomet is primarily used for preplanting control in tobacco and forest nursery crops and is now marketed for a wider range of open field and greenhouse crops (e.g., vegetables, fruits, ornamental plants, lawns, and turfs). Swiss CD1 male and female mice were intraperitoneally treated with dazomet in order to evaluate its potential genotoxicity. DNA damage activity, namely, DNA single-strand breaks, DNA adducts, and increased micronuclei frequency due to treatment with the soil fumigant was observed in the experimental animals. Dose-dependent DNA adduct formation was detected in the liver, kidneys, and lungs of mice. DNA adduct levels in these three organs were 6.0 +/- 0.4 (SD), 4.8 +/- 0.1 (SD), and 2.2 +/- 0.4 (SD) adducts/10(8) nucleotides, respectively, at the highest dose of the soil fumigant tested (90 mg/kg). No adduct formation was observed in control mice. A significant increase in DNA single-strand breaks was detected in the liver and kidneys of mice treated with 100 mg/kg of dazomet (P < 0.05). A significant increase in micronuclei frequency was observed in the bone marrow of mice treated with 100 mg/kg of dazomet (P < 0.05).