南京不同功能区街道路面积尘重金属污染评价与源分析

以南京不同功能区(商业区、居住区、交通区、风景区、文教区、工业区和城乡结合区)的街道路面积尘为研究对象，测定其w(Cd)，w(Cr)，w(Cu)，w(Ni)，w(Pb)，w(Zn)，w(Mn)，w(As)，w(V)，w(Fe)和w(Ti). 通过富集因子法和综合污染指数法评价重金属污染水平，采用主因子分析法分析重金属可能的污染源. 富集因子法评价结果表明，Cr和Ni为中度富集，其中Cr在商业区的富集程度最大，Ni在工业区的富集程度最大. Cd，Cu，Pb，Zn和As为显著富集，其中Cd在居住区的富集程度最大，Cu，Pb，Zn和As在商业区的富集程度最大. 内梅罗综合污染指数法评价结果表明，Cr在警戒限内，属于尚清洁；Cu，Ni和Zn属于轻度污染；Cd为重度污染. 不同功能区的内梅罗污染指数各不相同，如商业区、居住区和交通区的Pb，Zn，Ni和Cd的内梅罗污染指数较高. 主因子分析结果显示，污染可能来自3个方面:Ni，Mn，Fe，Ti和V可能来自于当地的土壤；Cd，Cu，Pb，Zn和As可能来自于混合源；Cr可能来自于石化工业源. 

Assessment of Heavy Metal Contamination and Source Identification of Dust Deposited on Roads Collected from Different Land-Use Zones in Nanjing

Thirty-five samples of dust deposited on roads were collected from seven different land-use zones (commercial, residential, traffic, scenic, educational, industrial and suburban) in Nanjing, China. The contents of metals (Cd, Cr, Cu, Ni, Pb, Zn, Mn, As, V, Fe and Ti) in these samples were determined. An assessment of heavy-metal contamination was conducted by the methods of enrichment factor and Nemerow pollution index. Principal component analysis was applied to the data matrix to identify the possible pollution sources of the metals. The enrichment factor results showed that Cr and Ni had moderate enrichment, in which the highest Cr enrichment was in the commercial zone, and the highest Ni enrichment was in the industrial zone. Cd, Cu, Pb, Zn and As were significantly enriched in the studied samples, in which the highest Cd enrichment was in the residential zone, and the highest Cu, Pb, Zn and As enrichments were in the commercial zone. The Nemerow pollution index results showed that Cr was below the safe threshold, belonging to still clean, while Cu, Ni and Zn represented mild pollution and Cd represented severe pollution in the studied samples. The Nemerow pollution indices in the different land-use zones were different from each other. The Nemerow pollution indices for Pb, Zn, Ni and Cd were relatively higher in the commercial, residential and traffic zones. Principal factor analysis showed that heavy metal contamination in dust deposited on these roads was likely from three sources. Ni, Mn, Fe, Ti and V were likely from local soil. Cd, Cu, Pb, Zn and As were likely from mixed sources. Cr was likely from petroleum industry sources.