RBCA和CLEA模型在某重金属污染场地环境风险评价中的应用比较

应用美国的RBCA模型和英国的CLEA模型对某重金属污染场地中的4种主要重金属污染物As，Cd，Pb和Zn进行健康风险评价，并利用克里格插值方法初步分析了案例场地中风险的空间分布特征.结果表明，RBCA和CLEA模型各有其优缺点，应根据场地的实际情况选择模型进行风险评价.该场地重金属污染的非致癌风险主要来自Pb和Cd，致癌风险主要来自As.尽管w(Zn)很高，但其风险很低，远低于可接受的风险水平.分别应用2种模型计算的风险在大部分情况下基本一致，尽管有一些差异，但均在同1个数量级之内.对于部分采样点的Cd的风险，2种模型的计算结果相差2个数量级，致使总非致癌风险的计算结果差异很大，这主要是由于2种模型在暴露途径的选取上的差异所致.从暴露途径的贡献率来看，地下水摄入途径引起的风险较高，贡献率为50%以上；蔬菜摄入途径引起的风险贡献率为20%左右.风险的空间分布也由于2种模型在暴露途径的选取上存在差异而表现出一定的不同. 

Comparison of Application of RBCA and CLEA Model for Health Risk Assessment of a Heavy Metal Contaminated Site

In a heavy metal-contaminated site,the health risks of As,Cd,Pb and Zn were assessed independently by the RBCA and CLEA models,and spatial distribution of the risks was demonstrated through interpolation.The results showed that the RBCA and CLEA models had different merits,and their application should be selected based on conditions at the actual site.In the present study,the non-carcinogenic risks were mainly from Pb and Cd,and the carcinogenic risks were mainly related to As.Although Zn concentration was ...