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Urban surface dust due to the uniqueness of their environment interface, which contains heavy metals, it is easy to become a potential source of pollution impact on the urban environment. The one hand, the surface dust in some outside power conditions easily raised, to be absorbed into the body through the respiratory tract and skin and cause harm to human health; precipitation conditions, on the other hand, it into the river, the urban water environment caused directly pollution. The current domestic and international research mainly concentrated in urban street dust migration transformation, particle size composition, spatial distribution characteristics of heavy metals in the street dust, chemical speciation, Analysis of the source and its environmental effects, while the distribution of heavy metals in different size and enrichment patterns, as well as its less health risk assessment of human exposure. The paper selected as the research object Wuhu urban, the space heavy metals on the Wuhu three typical regional surface dust distribution, particle size enrichment patterns of their health risk study, the theoretical and practical significance. Distribution and genesis of this article Wuhu urban surface dust heavy metal content was determined using ICP-AES based the ARCGIS geostatistical analysis module, explore Wuhu urban dusts heavy metals space, combined with the method of statistical analysis, Wuhu urban surface dust heavy metal sentenced source Analysis. Heavy metal enrichment ratio changes by studying the different particle size ranges of Wuhu urban surface dust of a heavy metal particle size distribution law, and on this basis, the health risk assessment of Wuhu urban surface dust heavy metal, the main conclusions are as follows: (1) Wuhu urban dusts pH range of 7.65-12.36, average 9.75, alkaline, organic matter content in the range of 1.25% -16.84%, an average of 4.86%, dust, heavy metals Zn, Cd, Pb, Co, Ni, Mn, Cr, V, Cu average the contents were 313.53,1.95,138.61,8.19,21.38,589.87,110.31,55.19 and 135.42mg/kg. Cd, Pb, Cu, Zn pollution is more serious soil background value 10.3,5.6,4.2,4.1, which is the most serious pollution of Cd. (2) of Wuhu urban surface dust heavy metal space. Heavy metal content in the dust has close ties with the distance away from industrial areas, heavy traffic area, the closer the distance, the higher the content. Economic and Technological Development Zone, industrial and transportation activities frequently higher heavy metal content of the central city, while the heavy metal content of the university campus as the leading high-tech development zone is relatively low. The spatial distribution of the difference is mainly caused due to the differences in regional function. (3) statistical analysis found that industrial emissions and urban transport activities on the of Wuhu urban surface dust heavy metal a greater contribution. , Co, Ni, Mn, Cu and V by industrial sewage impact, Zn, Cd, Cr, and Pb mainly by the urban transport activities. (4) of Wuhu urban surface dust heavy metals showed significant effect of particle size, as the particle size decreases, the heavy metal content is showing increasing trend ,160-200 and gt; 200 mesh is the the major pollution particle size level. Gt; 200 mesh particle size on the level of enrichment proportion in about 50% of the size of the various elements in order: Cd gt; of Cu gt; Zn gt; the of Cr gt; Ni gt; Pb gt; Co. gt; V gt; Mn. (5) children of Wuhu urban Dusts lt; 75um levels of heavy metal exposure to hand - oral pathway gt; Skin inhalation gt; respiratory inhalation, the children's risk of surface dust, heavy metals mainly hand - oral pathway way. Heavy metals in the non-carcinogenic risk order: Pb gt; of Cr gt; Mn gt; V gt; of Cu gt; Cd gt; Co. gt; Ni gt; Zn lower than the non-carcinogenic risk threshold. Intake of heavy metals in many ways superimposed risk of 0.753, close to 1, indicating that the compound pollution of heavy metals in dust, health risks can not be ignored. Non-carcinogenic risk differentiation in space due to coal-fired power plants, industrial emissions and traffic activities together, Economic and Technological Development Zone, its heavy metal overlay non-carcinogenic risk greater than 1, there is a serious hazard. Cr, Cd, Co, and Ni cancer risk below the risk threshold, indicating a lower risk of cancer-causing. Although the city streets are not prominent dust on human health risks, but with the intensification of urban industrial activities and transport activities, the control of emissions of heavy metals in the urban environment is necessary, especially heavy metals, composite pollution and its spatial distribution The differences concern.
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