The Content and Migration Rule of Heavy Metals in the Soil-Rice System in Changchun Suburb

The pollution of heavy metals in the soil and rice from the suburb paddy field of Changchun were assessed using the single pollution index and the synthesis pollution(Nemerow index). The single pollution index of Cd,Hg,As,Cu,Pb,Cr,Zn and Ni in the research area showed that all sampling sites accorded with the standards of farmland product.The synthesis pollution index indicated that the content of heavy metals in the soils did not reach the level of soil pollution.The single pollution index and synthesis pollution index showed that the heavy metals of Cd,Hg,As,Cu,Pb,Cr and Zn in the rice were all in the safe scope according to edible criteria.The content of Cd,Hg,As,Cu,Pb,Cr and Zn in the rice were positively related to that in the soils except Hg,As and Pb.The relationships above indicated that these heavy metals migrate easily from soils into rice plant.