唐山城市近地表灰尘重金属含量及环境质量评价
Heavy Metal Concentration and Assessment of Environmental Quality in Atmospheric Dust near Ground of Tangshan City

摘要： 以唐山市主城区161个城市近地表灰尘样品为研究对象，研究其重金属含量及环境质量状况。采用单因子指数法和尼梅罗综合指数法对唐山城市近地表灰尘中重金属进行环境质量评价，并应用ARCGIS的空间分析模块进行空间插值制图。结果表明，研究区城市近地表灰尘中重金属含量均超过当地背景值。近地表灰尘中重金属元素Zn、Cd、Pb、Cu、Hg、Cr、Ni和As的变异系数分别是4323%、21399%、11321%、2956%、7083%、5180%、2921%、3267%，其中含量变异系数较大的重金属是Cd、Pb等。重金属元素单因子指数评价表明，Cd、Zn为严重污染，Cr、Hg、Pb、Cu 、Ni为潜在污染，As为清洁，污染程度依次为Cd>Zn>Cu>Cr>Pb>Hg>Ni>As。尼梅罗综合指数法评价表明，唐山城市近地表灰尘重金属综合污染严重，清洁、潜在污染、轻污染、重污染、严重污染比例分别为0、372%、5219%、3851%、558%，重污染以上污染比例达到4409%，其严重污染区与工业区域、交通分布发达程度的分布相吻合，重金属污染可能与城市的燃煤、交通等污染源有关。
Abstract: The 161 atmospheric dust samples gathered near the ground of Tangshan City were studied for the concentration and environmental quality of heavy metals. The atmospheric dust near the ground of Tangshan City was assessed for the environmental quality of heavy metals with singlefactor contaminant index and Nemerow multifactor index method and was interpolated to a distribution map by using the spatial analysis module of ARCGIS. The results had shown that the actual content of all the heavy metals in the atmospheric dust near the ground of Tangshan City was over their original background level. The variance indices of Zn，Cd，Pb，Cu，Hg，Cr，Ni and As in the atmospheric dust near the ground of Tangshan City were 4323%，21399%，11321%，2956%，7083%，5180%，2921%，3267%, respectively. Cd and Pb were the strong variance elements. The results of the environmental quality of heavy metals with singlefactor contaminant index had shown that Cd and Zn were the serious pollution level and Cr，Hg，Pb，Cu，Ni were the potential pollution level, As was the clean level. The results showed that the elements, according to the environmental quality of heavy metals with singlefactor contaminant index，were followed by Cd>Zn>Cu>Cr>Pb>Hg>Ni>As. The results of the environmental quality of heavy metals with Nemerow multifactor index had shown the heavy metal pollution in the atmospheric dust near the ground of Tangshan city was serious. Considering synthetically the pollution level of heavy metals, the percentage of clean, potential pollution, light pollution, heavy pollution and severe pollution were 0,372%,5219%,3851%,558%,respectively. The sum of proportion of heavy pollution and severe pollution reached 4409%. High concentration of heavy metals in atmospheric dust was coincided with the distribution of industrial and developed transportation area. The heavy metal pollution may be associated with the use of coal and the traffic and other sources of pollution