平凉市蔬菜产地土壤重金属现状调查与评价

Investigation and evaluation on heavy metal content of origin vegetables in Pingliang

以平凉市蔬菜产地土壤为研究对象,分析土壤重金属As、Hg、Pb、Cr、Cd的含量特征及分布现状,应用单因子污染指数法、内梅罗污染指数法对土壤重金属含量进行评价.结果表明:平凉市蔬菜产地土壤中As、Hg、Pb、Cr、Cd平均含量分别为9.96、0.038、32.16、65.98、0.119mg/kg,单项污染指数均小于0.7,土壤重金属污染程度表现为As>Cr>Cd>Pb>Hg的特征,综合污染指数为0.31,属于安全状态.但有2个样点As含量、1个样点Cd含量已达到二级污染,应采取防治措施,确保土壤环境及蔬菜质量安全.

Using single factor pollution index and N. L Nemerow synthetic pollution index, the content characteristics of As, Hg, Pb, Cr, Cd in soil were analyzed from vegetables growing fields in Pingliang, and the heavy metal concentrations and its pollution index were assessed. The results indicated that the content of As, Hg, Pb, Cr and Cd was 9. 96,0. 038,32. 16,65. 98 and 0. 119 mg/kg, single factor pollution index was less than 0.7, the pollution level of heavy metal arranged as As〉Cr〉Cd〉Pb〉Hg, comprehensive pollution index was 0. 31 ,which belonged to the safe state. However 2 samples of As content and 1 sample of Cd content achieved secondary pollution. It is suggested that protective measures should be taken to ensure the quality and safety of vegetables and soil environment.