某河流域典型地区农田土壤中重金属铅、镉、铬的生态和健康风险评估

Ecological and health risk assessment of heavy metal(Pb,Cd and Cr)in farmland soil in a typical region of a river basin

目的评价某河流域典型地区280份农田土壤中铅、镉和铬的生态风险和健康风险。方法用多阶段随机抽样的方法,在某河流域典型农村地区,随机采集280份农田土壤样本。基于单因素污染指数、内梅罗综合指数和USEPA健康风险模型,开展生态风险和健康风险评价。结果该河流域典型地区农田土壤中铅、镉、铬的含量分别为26.10、0.16和64.97 mg/kg。3种重金属的污染程度,依次为镉>铬>铅,内梅罗综合污染指数均值为0.43,表示农田土壤整体水平安全清洁。镉和铬的致癌风险低于最大可接受致癌风险值10-6。铅、镉、铬产生的非致癌风险低于风险阈值1。结论从整体上评价,该河流域典型地区农田土壤清洁安全,健康风险可接受。少数地区农田有不同程度重金属污染,镉的致癌风险需加强关注。

Objective To assess the ecological and health risks of Pb,Cd and Cr in farmland soils in a typical region of a river basin.Methods 280 farmland soil samples were randomly collected by using a multi-stage random sampling method,in a typical rural area of a river basin.Ecological and health risk assessments were carried out based on the single factor pollution index,Nemero comprehensive index and USEPA health risk model.Results The contents of Pb,Cd and Cr in farmland soils in typical areas of the river basin were 26.10 mg/kg,0.16 mg/kg,and 64.97 mg/kg,respectively.The pollution of the three heavy metals were:Cd>Cr>Pb.The average value of nemero comprehensive pollution Index was 0.43,indicating that farmland soils,on the whole,were safe and clean.The carcinogenic risk of Cd and Cr were below the maximum acceptable carcinogenic risk value 10-6.The non-carcinogenic risk of Pb,Cd and Cr were below the risk threshold 1.Conclusion Farmland soils are clean and safe,and their health risks are acceptable in typical areas of the river basin in the holistic perspective.Heavy metal pollution of different level is found in farmland soils of a few areas,and the carcinogenesis risk of Cd should need more attention.