铅锌矿厂区周围土壤环境中重金属污染评价

Assessment of soil heavy metal pollution around lead-zinc mine

通过采集四川会理县小石房铅锌矿厂区周围的42个土壤样品,对土壤中的5种重金属Pb、Cd、Hg、As、Cr的含量进行测定,评估其污染水平,并对该厂周围土壤的生态风险和健康风险水平进行了评价。结果表明,该厂区周围土壤中的Pb、Cd浓度高,各有4个点位超出国家三级标准,超标率为9.5%。从内梅罗综合污染指数来看,厂区周围土壤综合污染程度为轻度污染。从生态风险角度分析,厂区周围土壤的重金属总潜在生态风险为低度风险,建议企业将Cd、Hg和Pb作为首要考虑的重金属污染控制元素。所有重金属的非致癌风险值未超过1,非致癌风险控制在安全范围内,主要非致癌风险贡献元素为Cr、Pb和As。致癌金属Cd、As和Cr在该企业周围土壤中的健康风险值及总致癌风险值均小于10-6,表示这3种重金属的致癌风险较低,不会对人体造成致癌影响。

This study collected 42 soil samples from the surrounding area of Xiaoshifang lead-zinc mine in Huili County of Sichuan.Contents of 5 kinds of heavy metal Pb,Cd,Hg,As and Cr in these samples were measured and the pollution level of the soil was assessed,as well as the ecological and health risks were evaluated.Results showed that contents of Pb and Cd were higher than the restriction in Environmental quality standard for soils GB15618-1995,with an over-limit ratio of 9.5%.By the Nemerow multi-factor index,the soil around the mine was under mild contamination.By the view of ecological risk,the soil was in low risk and we suggested Cd,Hg and Pb considered as the primary controlling elements.The total non-cancerogenic risk was smaller than 1,meaning non cancerogenic risk in safe range.The total cancerogenic risk of carcinogenic metals Cd,As and Cr was less than 10-6,indicating the cancerogenic risk was low and would not impact human health.