中文摘要：

以西安城区为研究区域,采集58个地表灰尘样品,测定了地表灰尘中重金属As、Co、Cr、Cu、Mn、Ni、Pb和Zn的含量。西安城区地表灰尘中除As（9.8 mg/kg）和Mn（417.0 mg/kg）外,其余各元素含量（Co、Cr、Cu、Ni、Pb和Zn平均含量分别为12.6、213.0、59.4、48.7、145.4和234.2 mg/kg）均高于陕西省土壤元素背景值。Arc GIS空间插值分析表明As、Co、Cr、Pb、Mn和Ni主要在西郊和主城区富集,Cr主要累积在东郊以及北郊部分地区,Zn则在二环与主城区之间富集明显。多元统计分析结果显示地表灰尘中Co、Cu、Mn、Ni和Cr主要受工业活动影响,As、Pb和Zn主要来源于汽车尾气排放和商业活动等。利用Hakanson潜在生态风险指数研究重金属生态风险。重金属总的生态风险水平达到强度,Pb处于较强生态危害水平,Cu属中等生态危害程度,As、Co、Cr、Mn、Ni和Zn均为轻微生态危害。

英文摘要：

A total of 58 surface dust samples were collected from the urban areas of Xi＇an City and the concentrations of heavy metals including As, Co, Cr, Cu, Mn, Ni, Pb and Zn were determined. Except for As （9.8 mg/kg） and Mn （417.0 mg/kg）, the average contents of other elements （the contents of Co, Cr, Cu, Ni, Pb and Zn respectively as 12.6, 213.0, 59.4, 48.7, 145.4 and 234.2 mg/kg） were higher than that in soil element background values of Shaanxi Province. The result of spatial analysis of ArcGIS showed the higher concentrations for As, Co, Cr, Pb, Mn and Ni were mainly found in western suburb and main urban area, Cr in the east suburb and partial area of northern suburb, and Zn between the second ring road and the main urban area. The results of multivariate statistics indicated that Co, Cu, Mn, Ni and Cr were attributed to local industrial activities, As, Pb and Zn mainly originated from vehicle emissions and commercial activities. The assessment of potential ecological risk by mean of Hakanson ecological risk index indicated the total ecological risk of heavy metals was up to high level. Pb and Cu presented high and medium ecological risk, respectively. As, Co, Cr, Mn, Ni and Zn had low ecological risk.