南京市城郊零散菜地土壤及青菜中重金属含量特征

Concentrations of heavy metals in soils and Chinese cabbages(Brassica chinensis)from some urban vegetable fields around Nanjing

采集了南京市城郊零散菜地土壤和青菜配对样品各18个,用原子吸收光谱仪测定了其中铜、锌、铅、镉的含量,结果表明:南京市城郊菜地土壤中Cu、Zn、Pb、Cd全量高于农区菜地土壤,Cu、Zn达到显著差异,重金属含量在土样之间有较大的变异性,反映了人为活动已对南京城郊土壤重金属产生了明显影响。城郊土壤上种植的青菜其可食部分重金属含量高于农区,尤其是对人体健康影响较大的Pb、Cd含量与农区相比存在显著差异,大大超过国家食品卫生标准。

We are facing the environmental pollution in urban area with the increasing population and urbanization in China. However, a portion of urban people relies on the vegetables grown in local fields around city, but the concentration of heavy metals in them have been hardly discussed. In this paper, 18 soils and 18 Chinese cabbages were sampled. The concentration of Cu, Zn, Pb and Cd in soil and Chinese cabbages samples were determined by AAS. Data indicated that the contents of heavy metals in suburban soil were larger than in rural soil, and the contents of Cu, Zn had a significant difference. Coefficient of variation(CV) of heavy metal concentrations showed that suburban soil were anthropogenically contaminated. Data also indicated that the contents of heavy metals were higher in leaves of Chinese cabbages planted in suburban soil than rural soil, especially Pb and Cd, the concentrations of which exceed the national hygienic standard for foods.