基于Monte Carlo模拟的土壤重金属综合风险评价与案例分析

Comprehensive Risk Assessment of Soil Heavy Metals Based on Monte Carlo Simulation and Case Study

基于不确定性理论,将Monte Carlo模拟计算应用到土壤重金属风险评价中,构建了生态风险和健康风险的随机不确定模型,结合多元统计方法进行实例研究.结果表明,研究区土壤Cd、Co和Cr污染水平较高,主要富集在建矿时间较长的工业园区;综合单因子指数和综合风险因子指数评价显示土壤重金属主要为轻度污染(相应概率分别为53.2%和55.6%);手-口摄入是研究区土壤重金属暴露的主要途径,Cr为主要致癌因子;儿童承担的健康风险较高,其非致癌风险指数分别为成人的5.0倍(手-口摄入途径)和8.2倍(皮肤暴露途径),两种暴露途径下其致癌风险指数均高于USEPA推荐的安全水平.

Based on the stochastic theory,the Monte Carlo simulation was introduced in ecological risk assessment and health risk assessment. Together with the multi-statistical technique,the proposed models were used for risk analysis in the Bin-Chang Coal Chemical industry park. The results showed that high levels of Cd,Co,and Cr were found in the area with long time mining. The comprehensive single index and comprehensive risk index showed that the ecological risk of soil metals fell into the poor level,with probabilities of 53. 2% and 55. 6%,respectively. The health risk caused by hand to mouth ingestion was significantly greater than that by dermal exposure,and Cr was of prime concern for pollution control. Children were taking a major health risk. Their non-cancer risks were maintained at a high level,and 5. 0-fold higher than adults under hand to mouth ingestion,and 8. 2-fold higher than adults under dermal exposure. The cancer risk for children under these two exposure ways were both above the safety standard suggested by USEPA.