IN-VIVO STUDIES ON GENOTOXICITY OF A SOIL FUMIGANT, DAZOMET

Dazomet is a soil fumigant effective against germinating weed seeds, n ematodes, soil fungi, and soil insects. Dazomet is primarily used For preplanting control in tobacco and forest nursery crops and is now mar keted for a wider range of open field and greenhouse crops (e.g., vege tables, fruits, ornamental plants, lawns, and turfs). Swiss CD1 mole a nd 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 frequenc y due to treatment with the soil fumigant was observed in the experime ntal animals. Dose-dependent DNA adduct formation was detected in the liver, kidneys, and lungs of mice. DNA adduct levels in these three or gans were 6.0 +/- 0.4 (SD), 4.8 +/- 0.1 (SD), and 2.2 +/- 0.4 (SD) add ucts/10(8) nucleotides, respectively, at the highest dose of the soil Fumigant tested (90 mg/kg). No adduct Formation was observed in contro l mice. A significant increase in DNA single-strand breaks was detecte d in the liver and kidneys of mice treated with 100 mg/kg of dazomet ( P < 0.05). A significant increase in micronuclei Frequency was observe d in the bone marrow of mice treated with 100 mg/kg of dazomet (P < 0. 05). (C) 1998 Wiley-Liss, Inc.