广西锰矿恢复区食用农作物重金属污染评价

对广西平乐、荔浦两锰矿恢复区种植的食用农作物进行了调查和重金属含量分析.结果表明:两锰矿区农作物Zn、Pb、Cr、Cu和Cd的含量范围分别在1.18~20.46、0.52~16.16、0.33~6.62、0.01~6.24和0.01~2.76mg.kg-1之间.其中,豆类作物中的重金属含量最高,其次是薯类.单因子污染指数评价表明,农作物基本未受Zn、Cu污染,但受Pb、Cd和Cr污染严重,以Pb污染最重,受污染率达100%,Cr和Cd受污染率分别为96.9%和75.0%;从综合污染指数来看,农作物受污染率达100%,其中,重、中、轻污染分别占87.5%、9.4%和3.1%.表明在锰矿废弃地直接种植食用农作物存在较大风险,应重新考虑其恢复利用模式.

Heavy metal concentrations and pollution assessment of edible crops grown on restored manganese mine lands in Guangxi, South China

A survey on the crops grown on the restored manganese mine lands in Pingle and Lipu of Guangxi was conducted, and the heavy metal concentrations in the edible parts of the crops were analyzed. The results showed that the heavy metal concentrations in the crops were 1.18-20.46 mg x kg(-1) for Zn, 0.52-16.16 mg x kg(-1) for Pb, 0.33-6.62 mg x kg(-1) for Cr, 0.01-6.24 mg x kg(-1) for Cu, and 0.01-2.76 mg x kg(-1) for Cd. Among the crops, beans had the highest concentrations of almost all test metals, followed by potatoes. The assessment of single factor pollution indices indicated that in the main, the crops were not polluted by Zn and Cu, but heavily polluted by Pb, Cr and Cd, with the pollution rate being 100%, 96.9% and 75.0%, respectively. Comprehensive pollution index indicated that all the crops were polluted by heavy metals, with the heavy, medium and light pollution grade being 87.5%, 9.4% and 3.1%, respectively. Planting edible crops directly on manganese mine wastelands might have great risk for human health, and the existing restoration patterns should be reconsidered.