内蒙古五原县某地土壤重金属生态健康风险评价

Ecological health risk assessment of soil heavy metals in Wuyuan County,Inner Mongolia

[研究目的]五原县位于河套平原,为查明该地区农田土壤重金属污染状况,系统采集了表层土壤样品1985件,农作物样品30件,饮用水样品5件,分析测定As、Cd、Cr、Cu、Hg、Ni、Pb、Zn 8种重金属元素含量。[研究方法]通过地累积指数法、内梅罗综合污染指数法和健康风险评估模型,对该区土壤、农作物及饮用水中的重金属污染程度和健康风险等进行评估。[研究结果]内梅罗综合污染指数评价该地区土壤尚清洁,局部地区存在As元素轻污染;人体健康风险评估显示,在口和皮肤多重摄入途径下,土壤会对居民造成致癌风险(9.97×10^(-6)),饮用水摄入As(1.62)对居民有一定的健康风险。[结论]Hg受人为影响较大,在临近五原县环城公路三叉口存在明显的强异常,其余元素主要受成土母质控制,As在建丰农场等地局部含量较高,超出风险筛选值。As在饮用水健康风险中贡献最大,应引起关注。

[Objective]Wuyuan County is located in the Hetao Plain.To find out the heavy metal pollution status of the farmland soil Wuyuan County,1985 surface soil samples,30 crop samples,and 5 drinking water samples were collected,and the contents of eight heavy metal elements,such As,Cd,Cr,Cu,Hg,Ni,Pb,and Zn were analyzed and determined.[Methods]The heavy metal pollution degree and health risks of the soil,crops,and drinking water were evaluated using the soil accumulation index and Nemerow comprehensive pollution index methods and a health risk assessment model.[Results]The Nemerow comprehensive pollution index showed that the soil in this area was still largely unpolluted,and there was only light pollution of As in some areas.According to the human health risk assessment,ingestion of soil through the mouth or skin is a carcinogenic risk to residents(9.97×10^(-6)),and ingestion of As in drinking water is a certain health risk to residents(1.62).[Conclusion]Hg is greatly influenced by humans,and there were obvious strong anomalies in Sankou near the Ring Road in Wuyuan County.The other elements were mainly controlled by the parent material.The local content of As was high in Jianfeng Farm and other places,which exceeded the risk screening value.Thus,As contributed the most to the drinking water health risk and should be a cause for concern.