上饶市某铜矿废弃地土壤重金属污染特征及健康风险评价

Characteristics and Health Risk Assessment of Heavy Metals in Polluted Abandon Soil of Shangrao, Jiangxi

以上饶某铜矿废弃地土壤为研究对象,共采集50份采场边坡废弃地土壤样品,对该铜矿区废弃地土壤重金属污染特征、来源及其对人体的健康风险进行探析,为矿山开采及废弃地重金属污染防治提供理论依据。使用原子吸收分光光度计测定Cu、Cd、Cr、Pb和Zn含量并对其理化性质进行测定,分析该铜矿废弃地重金属含量及其与理化性质之间的相关性。采用单因子指数法结合内梅罗综合指数法和健康风险评价模型对该矿区废弃地土壤重金属污染状况及人体健康风险进行评价。结果表明,该矿区土壤重金属中Cu和Cd均远超过国家土壤环境二级标准和江西省土壤背景值,Zn、Pb和Cr含量都超过江西省土壤背景值;Cd、Pb、Cr、Cu和Zn的变异系数分别为95%、98%、71%、60%和18%。聚类分析结果表明,Cd受理化性质的影响较为显著。主成分分析表明,土壤样品中的Cd受TN的影响较大,各重金属均受到理化性质的不同程度影响,且在不同的主成分上的比重各异,表明它们具有同源性。污染指数评价结果表明,5种重金属中Cu和Cd的污染最为严重,Cr的污染相对较轻。健康风险评价结果表明,5种重金属对成人和儿童产生的非致癌暴露风险值均为Cr>Cd>Pb>Cu>Zn,其中Cr对周围居民所产生的健康风险不容忽视。

This paper attempts to examine the characteristics, sources and health risks of heavy metals in copper mine wasteland. It took the waste soil of Shangrao copper mine as the research object, and 50 soil samples were collected. The contents of Cu, Cd, Cr, Pb and Zn in soils were measured by atomic absorption spectrometry and the physical and chemical properties were also tested. Subsequently, the correlation between the composition of heavy metal and the physico-chemical properties in Shangrao copper mine wasteland were analyzed. The pollution index evaluation model （including single factor index and Nemerow index） and the health risk assessment model were used to evaluate the soil heavy metal pollution status and human health risk in the mining area. The results showed that the contents of Cu and Cd in soil were far beyond the national secondary standard of soil environment and the background value of soil in Jiangxi Province. And the contents of Zn, Pb and Cr in soil also exceeded the background of Jiangxi Province soil. The coefficients of variation of Cd, Pb, Cr, Cu and Zn were 95%, 98%, 71%, 60% and 18%, respectively. The results of cluster analysis showed that Cd was more significantly influenced by physical and chemical properties. The principal component analysis showed that the Cd in soil samples was greatly influenced by TN. Each heavy metal was influenced by physical and chemical properties in varying degrees, and the proportion of different principal components was different, indicating that they had homology. Meanwhile, The results of pollution index evaluation showed that the pollution of Cu and Cd was the most serious, and the pollution of Cr was relatively light among the five kinds of heavy metals. Finally, the results of health risk assessment showed that the risk of non-carcinogenic exposure of five kinds of heavy metals to adults and children were both ranked as follows： Cr〉Cd〉Pb〉Cu〉Zn, and Cr had a definite health risk to the surrounding residents. Our findings are expected to provide a theoretical basis for the prevention and control of heavy metal pollution in mine polluted mining and wasteland.