中文摘要：

采集包头市街道灰尘样品，利用X-Ray荧光光谱仪测定样品中Co、Cr、Cu、Mn、Ni、Pb、Zn和V的含量，采用ArcGIS空间分析技术研究街道灰尘重金属的空间分布规律，运用地累积指数法和潜在生态风险指数法，评价包头市街道灰尘重金属的污染程度及生态风险。结果表明：包头市街道灰尘中除Ni外，其他重金属元素的平均含量均高于其区域土壤背景值。街道灰尘中Co、Cr、Pb的含量是区域土壤背景值的4.0～10.7、1.8～5.8和1.5～8.7倍。灰尘中重金属元素含量的空间差异较大，Co和Cr的高值区主要分布在工业企业附近；Cu、Zn和Pb的高值区主要分布在交通流量较大的商业中心和家居建材城附近。灰尘中各重金属的污染水平依次为Co〉Cr〉Pb〉Zn〉Cu〉V〉Mn〉Ni。Co处于中等潜在生态风险，而其他重金属均处于低潜在生态风险。灰尘中重金属总的潜在生态风险属于中等。

英文摘要：

This paper studied spatial distribution and ecological risk of heavy metals in street dust of Baotou City,Inner Mongolia,China in order to provide scientific guidance to improve the situation of heavy metal pollution of city living environment based on dust sampling and experiment analysis. The concentrations of Co,Cr,Cu,Mn,Ni,Pb,Zn and V in the street dust samples collected from Baotou City were measured by X-ray fluorescence spectroscopy. The spatial distribution of heavy metals in the street dust was analyzed using the geostatistical analysis of ArcGIS,and the pollution level and ecological risk of heavy metals in the street dust was evaluated with geoaccumulation index and potential ecological risk index. The results show that the content range of Co,Cr,Cu,Mn,Ni,Pb,V and Zn are 39.7-105.8,103.0-327.7,16.3-77.1,408.9-894.3,16.1-43.5,28.6-162.7,58.6-103.2 and 47.2-136.4 mg/kg,respectively. The average content of Co,Cr,Cu,Mn,Pb,Zn and V are higher than that of the regional background value. The contents of Co,Cr and Pb in the street dust are 4-10.7,1.8-5.8 and 1.5-8.7 times of the background values,respectively. The spatial variability of the analyzed heavy metals is large. The higher concentrations of Co and Cr are found in the vicinity of some industries and enterprises,while the higher values of Cu,Zn and Pb are located in the business center and furniture and building materials market with the heavy traffic. Spatial distribution of Mn and V is similar; the higher value appeared in the eastern part of the study area. The content of Ni in most samples is low; the higher value appeared in the middle of the study area. Pollution level of the heavy metals in the street dust is Co〉Cr〉Pb〉Zn〉Cu〉V〉Mn〉Ni. The mean Igeo of Co,Cr,Cu,Mn,Ni,Pb,V and Zn are 1.9,1.1,-0.02,-0.8,-0.8,1.1,-0.4 and 0.1,respectively. The mean Igeo of Co and Cr varies between 1 and 2,reveals moderate pollution. The mean [Igeo] and 58% Igeo of Cu is less than 0,means non-pollution. Igeo of Pb changes greatly,which is from light to mo