毒理学关注阈值方法在农药活性成分转化产物慢性膳食风险评估中的应用

Applicability of thresholds of toxicological concern in the chronic dietary risk assessment of transformation products of pesticide active substance

目的以氨基甲酸酯类农药抗蚜威为模式化学物，建立可用于农药活性成分转化产物的慢性膳食暴露评估方法。方法建立基于Cramer结构分类的毒理学关注阈值（TTC）决策树方法，利用Lazar软件对7种抗蚜威活性成分转化产物（R34836、R34885、R35140、R31805、R34865、R16210和R16192）的遗传毒性进行预测。利用2002年中国居民营养与健康状况调查数据和2011年全国污染物监测网中抗蚜威活性成分残留的监测数据，估计我国全人群以及不同年龄组人群抗蚜威活性成分转化产物的慢性膳食暴露，并按照Trc决策树方法对其进行风险评估。结果在抗蚜威活性成分转化产物的慢性膳食暴露中，2—6岁年龄段的均值和高端（第97．5百分位数，B97.5）暴露量均最高，7种转化产物即R34836、R34885、R35140、R31805、R34865、R16210和R16192的平均暴露量分别为0．0290、0．0207、0．0015、0．0320、0．0005、0．6918和0．1274μg/kg，高端暴露量分别为0．0817、0．0581、0．0042、0．0900、0．0014、1．9459和0．3585μg／kg。其中又以转化产物R16210的慢性暴露最大，分别为0．6918、1．9459μg／kg，分别占Trc阈值的46．12％和129．73％。结论TTC决策树方法是一种有效的风险评估工具，可用于农药活性成分转化产物的优先筛选和初步评估。

Objective To establish the threshold of toxicological concern（TYC） approach and to apply it in the risk assessment of metabolites, degradation and reaction products of pirimicarb. Methods TYC decision tree approach based on Cramer classification was established and Lazar software was used to predict the genotoxicity of the seven transformation products of pirimicarb, namely, R34836, R34885, R35140, R31805, R34865, R16210 and R16192. Dietary exposure in general population as well as in six age population groups was estimated by using data from the Chinese National Nutrition and Health Survey and pirimicarb residue data from national chemical surveillance data in 2011. Trc decision tree approach was used for risk assessment and the exposure was compared with the corresponding TFC values. Results Of the seven transformations of pirimicarb active substance, namely, R34836, R34885, R35140, R31805, R34865,R16210 and R16192, the maximum dietary exposure of mean and large portion（P97.5 ） were all belong to 2 - 6 age group. The mean exposures of the seven transformation products for 2 - 6 age group, were 0. 0290,0. 0207,0. 0015,0. 0320,0. 0005,0. 6918 and 0. 1274μg/kg, respectively, and the corresponding P97.5 exposures were 0. 0817,0. 0581,0. 0042,0. 0900,0. 0014, 1. 9459 and 0. 3585μg/kg. Besides, the mean and P97.5 exposure of R16210 for 2 -6 age group was the largest ,which were 0. 6918 and 1. 9459μg/kg, aeeouting for 46. 12% and 129. 73% of the TTC threshold, respectively. Conclusion Trc decision tree approach is a useful tool for prior screening and primary risk assessment of the transformation products of pesticide active substance.