大型古老锡矿影响区土壤和蔬菜重金属含量及其健康风险

Concentration and Health Risk of Heavy Metals in Vegetables and Soils in Region Affected by an Ancient Tin Ore

对云南大型古老锡矿影响区的主要种类蔬菜及其土壤取样调查,测定分析As、Cd、Co、Cr、Cu、Ni、Pb和Zn含量,通过暴露风险分析评价食用当地种植蔬菜引起重金属对人体的健康风险.结果发现,与非矿业影响区比较,锡矿影响区的蔬菜地土壤重金属污染严重,其中以As污染最严重,土壤平均As含量为1 225 mg.kg-1,Nemero指数平均为50.1.锡矿影响区的蔬菜食用部位的重金属含量超标严重,As和Pb尤为严重,其最高含量(以干重计)分别达856 mg.kg-1及506 mg.kg-1;各类蔬菜重金属含量表现出叶菜类>根茎类>果菜类的趋势;当地居民通过食用这些蔬菜引起的As和Pb的暴露风险非常高,暴露风险指数分别为158和13.3,对当地居民健康有极大的潜在危害.研究结果表明,有必要对当地的土壤和蔬菜重金属含量及其健康风险进行更为详尽的调查研究.

To investigate influences of mining activities on heavy metal contamination and health risk in vegetable of mining-affected area, the present study was undertaken as a preliminary survey of As, Cd, Co, Cr, Cu, Ni, Pb and Zn concentrations of majority vegetables and soils in area affected by an ancient tin ore, Yunnan province. Based on the soil heavy metals investigated, average Nemero index of soil heavy metals reach 50.1, showed that vegetable fields were contaminated by heavy metals, especially As ： average As concentration of soils could reach 1 225 mg.kg^-1 . Heavy metal concentrations in the edible portions of majority vegetables exceeded the national standards of China seriously, especially As and Pb, and the maximum of As and Pb concentrations （DW） could reach 856 mg.kg^-1 and 506 mg.kg^-1, respectively. Heavy metal concentrations among 3 kinds of vegetables decreased in following order： leaf vegetables 〉 fruit vegetables 〉 rhizome vegetables. Consumption of vegetables from the mining-affected area may pose extremely high health risk of As and Pb to local residents, which the exposed risk indexes could reach 158 and 13.3, respectively.