Pollution and Potential Ecological Risk of Soil Heavy Metals in Zhejiang Vegetable Bases

The contents of soil heavy metals,such as Cd,Pb,Hg,Cu,As,Zn and Cr,in surface soil(0～20 cm) from the vegetable bases of modern agricultural production farmlands in Zhejiang Province,were investigated.Statistical analyses indicated that except a few of the metal contents in some soil samples,the mean contents of all metals were lower than their environmental quality evaluation standards for farmland of edible agricultural products(HJ/T 332-2006),whereas exceeded that of their regional background values soil.The mean accumulation index of Pb、Hg、Cu、As、Zn and Cr was lesser than 1,but in some soil samples was exceed 1,so this indicated that human activities effected the contents of soil heavy metals The potential ecological risk index(RI) ranged from 26.4 to 123.3,indicating a low ecological risk level,only in a few of vegetable bases the potential ecological risk index of Cd and Hg indicated moderate ecological risk.