| Effects of clomazone at different concentration（0 mg·kg-1, 10 mg·kg-1, 20 mg·kg-1, 40 mg·kg-1, 80 mg·kg-1） on activity of antioxidative enzymes of SOD, CAT, GSH-Px, T-AOC and DNA damage in earthworm（Eisenia foetida） were studied with an artificial soil test in 14 days of exposure. During the exposure period, there was a trend on the SOD activity by an initial significant increase（P<0.05） and then following a gradual decrease. When the earthworms were exposed to 10 mg·kg-1 and 20 mg·kg-1 of clomazone, the activity of SOD increased significantly with induced rate of 19.56% and 13.03%, respectively. The activity of CAT had no significant change at the low concentrations（10 mg·kg-1, 20 mg·kg-1）, and was induced at the higher concentrations（40 mg·kg-1, 80 mg·kg-1） with induced rate of 43.42% and 68.08%, respectively. The content of T-AOC was inhibited first but induced, then recovering to the level of control gradually. The content of T-AOC exposed to the concentration of 20 mg·kg-1 decreased significantly with inhibition rate of 44.54%. The activity of GSH-Px was inhibited significantly during the period of exposure. The results showed that clomazone could induce DNA damage of earthworm coelomocytes at different exposure concentration. The significant dose-effect relationships were found among clomazone concentration and tail DNA percent, OTM as well as tail length（P<0.01）. The activity of antioxidative enzymes and DNA damage could be as biomarkers to indicate the direct toxic effect of clomazone on soil animals. The results indicated that clomazone had a potential ecological risk on soil environment. |
