摘要
【目的】为了解陕西省西部某县农产品产地土壤重金属污染状况。【方法】采用单项污染指数法、内梅罗综合污染指数法和Hakanson潜在生态风险指数法对该区域表层土壤中5种重金属元素进行污染及生态风险评价。【结果/结论】结果表明:Cd、Pb、Hg、As、Cr等5种元素的平均值分别为0.318 mg/kg、29.6 mg/kg、0.138 mg/kg、14.0 mg/kg、68.4 mg/kg,污染累积指数表现为Cd>Pb>Hg>As>Cr特征,各元素含量超过背景值的比例分别为96.75%、99.77%、80.97%、76.57%、51.28%;研究区域综合潜在生态风险指数为266.1,属中等生态危害程度,其中52.67%土壤样点达到中等生态危害,9.28%土壤样点达到强及以上生态危害,应该引起相关政府部门的高度重视。
[Purpose]The main purpose of this study is to explore the contamination status of heavy metal in agricultural producing area soils in a western county of Shaanxi province. [Method]The single factor index method,the Nemerow comprehensive pollution index method and the potential ecological risk index method were used to assess the pollution degree and ecological risk of five heavy metal elements in the topsoil(0~20 cm)in the district. [Result/Conclusion]The results showed that:The average contents of heavy metal Cd,Pb,Hg,As and Cr in soils were 0.318,29.6,0.138,14.0 and 68.4 mg · kg~(-1),respectively. The percentage of heavy metal elements in soil exceeding the background values of the elements in the study area were as follow respectively:Cd(96.75%),Pb(99.77%),Hg(80.97%),As(76.57%)and Cr(51.28%). The results showed that the pollution rank was Cd>Pb>Hg>As>Cr. The average value of comprehensive potential ecological risk index is 266.1,which ranks at the degree of moderate ecological damage,52.67% samples reached moderate ecological harm,and 9.28% samples reached strong or above ecological hazards,which should be paid attention by relevant government agencies.
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