Diuron Degradation Process and Change of Toxicity by y-irradiation
γ-辐照对敌草隆的降解过程及毒性变化分析

The radiation-induced degradation process of diuron and change of toxicity by gamma-irradiation were investigated. The contribution to diuron degradation by the radicals is in the order of: *OH > e(aq)(-) > *H. The quantum efficiency ratios of *OH, e(aq)(-) and *H for the degradation of diuron are calculated as 3 : 1 : 2. e(aq)(-) and *H could reduce diuron and its degradation product by loss of the chlorine atoms and the addition reaction. Both the shift and alkaline substitute mutations firstly increase and then decrease with the increase of irradiation time. But, the sample only shows mutagenic potential in Ames assay (TA100 strain) when 22.2 min is selected as the irradiation time. The acute toxicity firstly decreases and then increases with the increase of irradiation time and the more toxic substances are produced.