包头某铝厂周边土壤重金属污染及健康风险评价

以包头市某铝业周边500 m内土壤为研究对象,测定其东北、东南、西北、西南4个方向不同水平距离及深度处土样中Cu、Cd、Pb、Zn、Ni和Cr的含量,并采用地累积指数法和健康风险评价法对重金属污染状况进行评价。结果表明,该区域表层土壤中6种重金属普遍高于内蒙古土壤背景值,且在西南方向50 m处含量最高,人类活动对该区域重金属干扰强烈,而风向对重金属分布影响不大;铝厂周围土壤中Cd、Pb处于中污染-重污染,Cu和Ni处于无污染-中污染,Zn和Cr为无污染,各金属污染程度随土壤深度的增加而减轻;健康风险评价表明,研究区域内Cu、Pb、Ni和Cd均不存在非致癌健康风险,而Cd的致癌危害虽在可接受范围内,但已存在潜在致癌风险,Ni的致癌健康风险指数已超过预警值,应予以高度重视和防治。

Contamination and Health Risk Assessment of Heavy Metals in Soil Surrounding an Aluminum Factory in Baotou, China

Based on soil in the vicinity 500 m of an aluminum factory in Baotou, soil in different horizontal distance and depth from the northeast, southeast, northwest, southwest direction of research region were sampled, and the heavy metal content included Cu, Cd, Pb, Zn, Ni and Cr were measured. The heavy metal pollution status was analyzed by using index of geoaccumulation and health risk assessment. The results showed that the content of six heavy metals in the region topsoil were higher than the soil background values in Inner Mongolia, maximum content were found at 50m in the southwest. The local heavy metal pollution had a close relationship with human activity, but not with wind direction. Around the aluminum industry, Cd and Pb were at the medium-heavy pollution, Cu and Ni were at the non-medium pollution, Zn and Cr were not polluted. The heavy metal pollution reduced with the increase of soil depth. By application of the health risk assessment, the health risk of cancer by Cu,Pb,Ni and Cd were not exist, and Cd carcinogenic hazards was within the acceptable range, but had a potential risk of cancer. The cancer risks indexes of Ni had exceed warning value, which should be highly valued and prevention.