重工业城市土壤重金属含量分布特征及污染评价——以包头市为例

Heavy Metal Concentration and Contamination Evaluation for the Soil of Heavy Industry City——A Case Study of Baotou

以包头市区及近郊8个样点表土中重金属Cu、Zn、Pb和Cd测定结果为依据,分析了重工业城市重金属污染状况。结果显示:Pb、Cd含量较低,而Cu、Zn含量均高于所有参考值,分别为全国土壤几何均值的1.85和2.26倍;棕钙土含量的1.32和2.12倍;内蒙古土壤均值的2.90和3.22倍,重金属累积极为明显。单因子指数法和潜在生态危害指数法环境质量评价结果表明,麻池乡Cu污染严重(Pi=4.60),古城湾毛其来Zn污染严重(Pi=3.76)。后营子乡属清洁区,其它样点均有不同程度污染,工业生产是导致土壤重金属污染主要原因。

Soil samples were collected in eight sites in Baotou City to analyze Cu, Zn, Pb and Cd concentrations. The result showed that Pb, Cd contents were lower but Cu and Zn concentrations were higher than all of the reference values. Environment quality evaluation was conducted by methods of the single factor index and the potential ecology risk index （RI）. It revealed that Pb and Cd indicated no significant contamination because of their lower concentrations. Cu and Zn, accumulated 1 -2 times of the background values, exhibited contamination to some extents on the contrary. Industrial activities were the main factors for the pollution.