浙江蔬菜基地土壤重金属污染及潜在生态风险

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

在浙江省现代农业园区(示范区、精品园)中随机选择了36个"菜篮子"种植基地,以这些基地表层土壤(0～20 cm)为调查对象,分析了土壤中重金属Cd、Pb、Hg、Cu、As、Zn和Cr的含量。调查结果表明,除个别点位外,7种重金属含量算术平均值均低于《食用农产品产地环境质量评价标准》(HJ/T 332-2006)中土壤重金属评价指标限值,但均超过浙江省土壤背景值。平均单项积累指数除Cd外,其余重金属均小于1,但各别点位还是存在重金属积累指数超标现象,表明基地重金属含量受人类活动影响。潜在生态风险评价表明,36个基地土壤重金属潜在生态风险指数(RI)为26.4～123.3,均处于轻微生态危害水平,但个别基地的Cd、Hg生态因子均处于中等危害水平。

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.