土壤理化性质对污染场地环境风险不确定性的影响  

Effects of Soil Physical-Chemical Properties on Risk Uncertainty in a Contaminated Site

作　　者：张大定[1,2] 曹云者[2] 汪群慧[1] 谢云峰[2] 柳晓娟[2] 李发生[2] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083 [2]环境基准与风险评估国家重点实验室,中国环境科学研究院,北京100012

出　　处：《环境科学研究》2012年第5期526-532,共7页Research of Environmental Sciences

基　　金：国家环境保护公益性行业科研专项(200709033;201109017)

摘　　要：以某化工污染场地中挥发性有机物苯的环境风险评价为例,研究了土壤有机质含量、土壤含水率、土壤容重等理化性质对风险评价结果的影响.在土壤污染物苯浓度不变的前提下,土壤有机质含量、土壤含水率和土壤容重在场地条件下随机取值的变异范围分别为0.31%～2.31%、0.12～0.25和1.25～1.75 g/cm3.10 000次蒙特卡罗模拟结果表明,在95%置信水平下,苯的总致癌风险(概率值)在1.45×10-5～2.74×10-5之间.在该场地条件下,土壤有机质含量是影响苯风险不确定性的最主要因素,其对风险评价结果不确定性的贡献率高达90.2%;土壤含水率和土壤容重的贡献率分别为5.6%和4.2%.因此,在土壤污染健康风险评价过程中,应对理化参数进行敏感性分析,对评价结果影响较大的关键参数取值需慎重.The effects of spatial heterogeneity of soil organic matter（SOM）,soil moisture（Pws） and soil bulk density（ρb） on benzene risk in a benzene-contaminated chemical plant were evaluated using Monte Carlo simulation.Under the conditions of identical benzene concentration,the values of SOM,Pws and ρb acquired from site investigation varied in the range of 0.31%-2.31%,0.12-0.25 and 1.25-1.75 g/cm3,respectively.The results of 10,000 times Monte Carlo simulation showed that at the 95% confidence level,the minimum and maximum carcinogenic risk of benzene was 1.45×10-5 and 2.74×10-5,respectively.SOM was the most sensitive soil parameter evaluated;it could explain 90.2% of the variance in the carcinogenic risk of benzene.The remaining variance was explained by Pws and ρb,with contributions of 5.6% and 4.2%,respectively.Therefore,the sensitivity analysis of the model parameters,especially soil physical-chemical parameters,is very important in contaminated site risk assessment.The value of the sensitive soil parameters must be determined very carefully to ensure a reasonable risk assessment result.

关 键 词：污染场地 环境风险评价 不确定性 苯 蒙特卡罗 

分 类 号：X53[环境科学与工程—环境工程]