[Concentration and health risk of heavy metals in vegetables and soils in region affected by an ancient tin ore].

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 1225 mg x 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 x kg(-1) and 506 mg x 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.