场地粘性土壤中特殊苯系物的非致癌毒性风险预测及风险控制限值的研究

摘要

利用基于定量构效关系(QSAR)开发的T.E.S.T评估软件中的3种方法(层析法、FDA法和邻近法)对10种苯系物的大鼠经口半致死量LD50进行了拟合和验证.层析法线性拟合回归系数R可达0.9379,其次为FDA法(R=0.6639)和邻近法(R=0.5146),层析法预测结果较准确.采用常规苯系物大鼠经口(LD50)和人体健康非致癌毒性因子(RfDo)之间的拟合曲线推导特殊苯系物的RfDo.该研究基于长三角地区(以上海为例)场地典型粘性土壤环境特征及保守暴露场景的假设,针对四甲苯、五甲苯、六甲苯3种分子量较大的特殊苯系物开展非致癌毒性风险预测,研究分析后初步确定上述3种苯系物在场地粘性土壤中的风险控制值分别为2540,2733和2896 mg/kg.上述3种苯系物场地健康风险控制值的研究推导和确定在国内尚属首次.%By using three methods, namely hierarchical clustering , FDA and nearest neighbor, in the T.E.S.T assessment softwarewhichisbasedonquantitativestructure-activityrelationships(QSAR),rat oral LD50of 10 BTEX was fitted and verified. The linear fitting regression coefficient R of Hierarchical clustering method is up to 0.9379, followed by FDA method (R=0.6639) and Nearest neighbor (R=0.5146),and the Hierarchical clustering method is most accurate. It derives RfDo of the special BTEX by using the fitting curve between the rat oral LD50 of conventional BTEX and non-carcinogenic health factors RfDo. In this paper, given the typical viscidity environment in Yangtze River Delta region (for example Shanghai) and relatively conserved exposure scenario, it carries out non-carcinogenic risk prediction of three larger molecular weights BTEX including tetramethylbenzene, pentamethylbenzene and hexamethylbenzene to calculate and preliminary determine the risk control values which respectively were 2540,2733 and 2896 mg/kg in sites clayey soils. It is the first time to deduce and calculate these three risk control values worldwide.