克拉玛依市地表灰尘重金属空间分布特征与来源解析

从新疆典型石油城市-克拉玛依市采集52个地表灰尘样品，分析其中As、Cd、Cr、Cu、Pb和Hg等6种重金属元素的含量，采用污染负荷指数法（PLI）评价地表灰尘中重金属元素污染水平，基于GIS技术与地统学理论，分析重金属元素含量空间分布格局，利用多元统计分析法，讨论地表灰尘中重金属元素的主要来源。结果表明：克拉玛依市地表灰尘中As、Cd、Cu、Pb和Hg等元素平均含量分别为新疆土壤背景值的1.61、1.75、1.50、1.23和2.94倍。地表灰尘中Hg呈现中度污染，As、Cu、Cr和Pb呈现轻度污染，Cd呈现轻微污染。从空间分布结果来看，克拉玛依市地表灰尘重金属元素含量及污染高值区主要分布于研究区西北部。从污染来源来看，研究区地表灰尘中Hg、As、Pb和Cd等元素主要受到人为污染源的影响，Cu与Cr主要受到土壤地球化学特征的控制。

Spatial Distribution and Source Apportionment of Heavy Metals in Road Dust of Karamay City

A total of 52 road dust samples were collected from a typical petroleum city, Karamay, Xinjiang, and the concentrations of six heavy metals, such as As, Cd, Cr, Cu, Pb, and Hg were measured. The pollution level of heavy metals in road dust was analyzed using the pollution load index (PLI), while the spatial distribution patterns of heavy metals were analyzed based on the GIS technology and the Geo-statistical analysis methods, and the sources of heavy metals in road dust was discussed using the multivariate statistical analysis. The results showed that the average concentrations of As, Cd, Cu, Pb, and Hg in road dust of Karamay city is 1.61, 1.75, 1.50, 1.23, and 2.94 times of the soil background in Xinjiang, respectively. Road dust is moderately polluted by Hg, and slightly polluted by As, Cu, Cr, and Pb, and less polluted by Cd. The spatial distribution pattern of heavy metals in road dust of Karamay indicated higher concentrations and higher pollution level in the northwestern parts of the city. The pollution sources analysis showed that Hg, As, Pb, and Cd are mainly originated from anthropogenic sources, while Cu and Cr are mainly controlled by the geochemical characteristics of soil.