锰矿区农作物重金属含量及健康风险评价

Analysis on The Content of Heavy Metal in the Food Crops and Assessment on Human Health Risk of Manganese Mine

对广西三锰矿恢复区的土壤和农作物进行调查和重金属含量分析,并采用污染指数法和靶标危害系数方法对人体的健康风险进行评价,结果表明,矿区土壤Cd含量远超过GB 15618-1995《土壤环境质量标准》二级标准值。三锰矿区农作物Cu、Pb、Cd、Zn、Mn和Cr的含量范围分别是0.26~12.64 mg/kg、0.05~1.37 mg/kg、0~3.3 mg/kg、2.68~25.13 mg/kg、1.14~303.37 mg/kg和0~12.37 mg/kg。受Pb、Cd和Cr较重,受Pb、Cd和Cr污染率分别为58.3%、75.0%、83.3%。从综合污染指数来看,受污染率高达83.3%。重金属暴露接触对人体健康的风险评估表明,三锰矿区居民通过食用当地农作物摄入的Cd对其健康存在较高潜在风险。因此在矿区废弃地上,如土壤不经过特别的修复,不宜直接种植可食用农作物。

A systematic survey and determination of heavy-metal concentrations in crops and the corresponding soils was conducted in the three manganese mine recovery areas in Guangxi.The possible health risk to local inhabitants via consumption of crops was assessed based on target hazard quotients(THQ)and pollution index. The results showed that Cd concentra-tions in the minesoils exceeded the threshold levels of China Environmental Quality Standard for Soils(GB 15618-1995 Class II).The heavy metal concentrations in the crops were 0.26~12.64 mg/kg for Cu, 0.05~1.37 mg/kg for Pb,0~3.3 mg/kg for Cd,2.68~25.13 mg/kg for Zn,1.14~303.37 mg/kg for Mn and 0~12.37 mg/kg for Cr. The crops were heavily polluted by Pb, Cd and Cr,with the pollution rate being 58.3%,75.0%,83.3%, respectively. Comprehensive pollution index indicated that the crops of 83.3% were heavily polluted. THQ indicating shows that the local inhabitants experience a high potential health risks by intake of Cd via consumption of these crops.So in mine wastelands,such as soil without special repair, unfavorable edible crops directly.