宝鸡市街尘中As和Hg含量及其环境风险评价

利用原子荧光分光光度计对宝鸡市38个街尘样品进行分析测试，以研究街尘中As和Hg含量的水平及其空间分布特征，并与中国土壤及其他城市街尘中的含量进行对比.结果表明:宝鸡市街尘中w(As)为8.985～42.822 　μg/g，平均值为19.764 　μg/g，约为中国土壤元素背景值(11.2 　μg/g)的1.8倍，是其他城市街尘w(As)均值的2～4倍；w(Hg)为0.483～2.318 　μg/g，平均值为1.112 μg/g，约为中国土壤元素背景值(0.065 　μg/g)的17.1倍，为其他城市街尘w(Hg)均值的10倍.工业区街尘中w(As)相对较高，商业区街尘中w(Hg)相对较高.利用污染指数法和地积累指数法对宝鸡市街尘中As和Hg的环境风险进行评价，结果表明:宝鸡市街尘中As的污染指数平均值为1.765，地积累指数平均值为0.144，存在轻度的污染；Hg的污染指数平均值为17.106，地积累指数平均值为3.425，呈现出偏重污染. 

The Contents of Arsenic and Mercury and Environmental Risk Assessment of Street Dusts in Baoji

A total of 38 samples of street dusts collected from Baoji were analyzed by the Atomic Fluorescence Spectrophotometer (AFS) to study the contents and the spatial distributions of arsenic and mercury of street dusts of Baoji, and compared with the contents of Chinese Soil Element Background Value (CSEBV) and the contents of arsenic and mercury of other cities. The results show that the arsenic content ranged from 8.985 to 42.822　μg/g, with the mean of 19.764　μg/g, which is 1.8 times of CSEBV (11.2　μg/g) and 2～4 times of the arsenic content of other cities; the mercury content ranged from 0.483 to 2.318　μg/g, with the mean of 1.112　μg/g, which is 17.1 times of CSEBV (0.065　μg/g) and 10 times of the mercury content of other cities. The arsenic content of the industrial district and the mercury content of the commercial district were relatively higher. The assessment for the environmental risk of arsenic and mercury with the methods of Pollution Index and Geo-accumulation Index shown that the Pollution Index and the Geo-accumulation Index of arsenic were 1.765 and 0.144 on average, and the arsenichad light pollution; and the Pollution Index and the Geo-accumulation Index ofmercury were 17.106 and 3.425 on average, and the mercury had heavy pollution.