干旱地区设施土壤和蔬菜重金属含量及人体健康风险--以白银市为例

A survey of heavy metal concentrations in soils and vegetables in Baiyin green house production and their health risk

以白银市设施土壤和蔬菜为研究对象,对大坝、金山、雒家滩、重坪四个设施蔬菜产地土壤及蔬菜Cd、Pb、Cu、Zn和Ni含量进行了测定,并对白银市居民蔬菜重金属摄入量进行了健康风险分析（DIM）。结果表明：白银市设施蔬菜产地土壤中Cd含量是温室蔬菜产地环境质量评价标准（HJ333-2006）限量值的1.35~20.98倍,在所有产地中雒家滩污染最严重,其中Pb的平均含量超过了限定标准（HJ333-2006）。各类蔬菜中Cd平均含量是国家限量标准（0.05 mg/kg）的1.80~4.20倍,而Cu、Zn和Ni的平均含量均未超过国家或联合国粮农组织（FAO）的限量标准,豆角中Cd和Pb的平均含量明显高于其它蔬菜种类。DIM分析结果表明,重金属的健康风险为Cd〉Pb〉Cu〉Zn〉Ni。白银市部分居民通过蔬菜途径摄入的Cd和Pb对其健康存在较大的潜在风险。

This survey was made to investigate soils and vegetables of greenhouse vegetable production in Baiyin. The concentrations of heavy metals in greenhouse soils and vegetables in Daba, Jinshan Luojiatan and Chongping were measured. In addition, health risk of heavy metals via daily intake （DIM） of vegetable was analyzed. Re- suits show that the mean concentration of Cd in greenhouse soils collected from Baiyin was 1.35 - 20, 98 times of the standard threshold （ HJ 333 - 2006） set for greenhouse vegetable production, of which Luojiatan was suffer- ing from serious metal contamination and its mean concentration of Pb exceeds the maximum permit level of HJ 333 -2006. The mean concentration of Cd was 1.80 - 4.20 times of the maximum permit levels （0.05 mg/kg）, whereas Cu, Zn and Ni concentration were below the＇safe＇limits of China or FAO standards in all vegetables. The mean concentrations of Cd and Pb in cowpea （ Vigna unguiculate L. ） were the highest among the sampled vege- tables. The assessment of DIM suggests that the risk of heavy metals presented a trend in the order： Cd 〉 Pb 〉 Cu 〉 Zn 〉 Ni. Part of the local inhabitants experienced a high potential health risks by intake of Pb or Cd via consumption of these vegetables.