Diagnoses on Heavy Metal Pollution in Soil in the Tailing Dam of Baotou Steel

After the soil samples in 5 sites in tailings dam of Baotou steel were investigated,the content of heavy metal(Cu,Zn,Cd,Pb,As)in Baotou steel were estimated by single factor pollution index method and the composite pollution index method according to the state environmental quality standards for soils(GB 15618-1995).The results showed that the contents of Cu,Pb,Cd, Zn and As in the soil in tailing dam of Baotou steel were under pollution level mostly and not polluted according to Ⅱ-class criteria for heavy metals in soil.The first grade standard evaluation results showed that Cu,Pb and Zn were pollution-free,Zn is the slight-degree pollution(PZn1),Cd was middle-degree pollution(2PCd3),and their pollution index was 1.949 and 2.390 mg/kg resp.The pollution degree in 5 sampling sites was in the decreasing order as south west center east north.