中文摘要：

基于对水源地石油污染等现场调查数据为基础，选取典型污染物苯，利用可传递参数差异的蒙特卡罗技术方法，分析了乙烯厂不同分区苯污染经过呼吸和饮水暴露途径造成人体健康风险的不确定性，量化不确定性因素影响的A地区人体健康风险水平．结果表明，裂解装置区是苯污染影响人体健康风险水平的主要来源，产生的健康风险水平均值为1．17×10^-4，而其他3个分区的影响较小；所有分区苯污染对A地区产生的人体健康总风险均值为1．18×10^-4，大于美国环保局人体健康风险建议值10^-6，对人体健康已产生影响；受不确定性因素影响，根据不同的人体健康可以承受的风险水平限值，污染对人体健康产生影响的概率存在差异．因此量化不确定性对风险水平的影响，可为污染场地的风险管理和修复行动提供科学依据．

英文摘要：

Lots of uncertainties he in the procedure of environmental risk assessment （ERA） and how to analyze them exactly is studied comprehensively. Based on the investigation of petroleum contamination in a contaminated site, the representative benzene contaminant in soil was selected to analyze uncertainty of environmental risk resulting from drinking and inhalation exposure routes, using the Monte-Carlo simulations. According to the analysis results, the total health risk average value caused by benzene contamination from the alkene factory is 1.18 ~ 10-4 for the people living on the district A, which is more than the risk limit of U.S.EPA 10^-4 and means contamination hazard to health. In four different areas of the alkene factory, the main source of risk comes from the cracking equipments with 1.17 ×10^-4 . With the impact factors of the uncertainty, the contamination harm to the human health＇ s probability is different referring to the different risk level, which is a criteria value meaning no harm to health issued by different institution. The study results provide an important foundation of effective control and remediation actions of contaminated sites.