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[目的]掌握6种磺酰脲类除草剂在土壤中的消解趋势及暴露致癌风险性,指导农药安全使用。[方法]通过UPLC-MS/MS测定其在施药后不同时间的残留量,计算其消解率,利用风险评估模型,分析对人体直接暴露致癌风险性随残留量的变化趋势。[结果]6种磺酰脲类除草剂在土壤中的消解趋势差异较大,理论半衰期最长的为28.9 d,最短的为18.7 d。施药后,土壤中残留的6种除草剂的最大致癌风险值为2.5×10~(-8),小于参考临界值×10~(-6)。经口摄入和皮肤接触2种暴露途径占主导,对直接暴露致癌风险的贡献率为99.78%。在P小于0.01水平下,除草剂原始沉积量、致癌风险值与施药量之间存在显著性相关,相关系数0.9831。[结论]在试验条件下,通过直接暴露途径对人体不会产生不可接受的致癌风险;选择低残留易消解除草剂,同时控制施药剂量是降低直接暴露致癌风险的有效途径。
[Objective] The study aimed to understand the tendency of 6 sulfonylurea herbicides in soil digestion and the carcinogenic risk of exposure, and guide the safe use of pesticides. [Method] The residues of residual carcinomas were determined by UPLC-MS / MS at different time points. The rate of digestion was calculated. The risk assessment model was used to analyze the trend of the carcinogenic risk of direct human exposure with residues. [Result] The diuretic trends of the six sulfonylurea herbicides differed greatly in soil. The longest theoretical half-life was 28.9 days and the shortest was 18.7 days. After application, the maximum carcinogenic value of the six herbicides remaining in the soil was 2.5 × 10 -8, less than the reference threshold × 10 -6. Oral intake and skin exposure dominated by the two routes of exposure, the risk of direct exposure to cancer contribution rate was 99.78%. At the level of P less than 0.01, there was a significant correlation between the initial deposition of herbicide, the value of carcinogenic risk and the dosage, the correlation coefficient was 0.9831. [Conclusion] The unacceptable carcinogenic risk to human beings would not be caused by direct exposure under the experimental conditions. Choosing low residues and easy to digest herbicides and controlling the dosage would be an effective way to reduce the direct exposure to carcinogenic risk.