| As a typical industrial city, Zhuzhou has had a serious environmental pollution for several years. The environmental quality improved markedly after Zhuzhou city constructed as the demonstration plot of resource-economical and environment-friendly society. However,the pollution problem to local environment which led by years of heavy industrial production can still not to be ignored. Total 144 Atmospheric dust-fall samples were collected from 12 sampling sites in Zhuzhou during January to December in 2012. The contents of 28 kinds of elements in atmospheric dust-fall were measured by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to analyze the deposition flux, elementary composition and elements pollution degree of atmospheric dust-fall. The migration patterns and source of elements were researched as well as the difference of elementary composition influenced by human activities. The ecological risk and human health risk of atmospheric dust-fall were also assessed.The results showed that the dust-fall quantity of industrial area and mixed commercial and residential area(MCR area) were respectively 89.46 g·m-2 and 33.20 g·m-2 which in all sample points were between 23.14-114.67 g·m-2. There were 10 elements (Na, Mg, Al, K, Ca, Ti, Mn,Fe, Zn, Pb) in industrial area as well as 8 elements in MCR area which the content exceed 1000 g·m-2 in atmospheric dust-fall severally. Zinc content and Plumbum content were exceed 10000 mg·kg-1 in dust-fall of industrial area respectively, which were far higher than those in earth's crust. The mainly sources of dust-fall in Zhuzhou City were metal smelting, shallow ground dust, vehicle emission, construction dust and industrial production with specific elements (Mo, Ba). Correlation analysis, Principal Components Analysis (PCA) and transport characteristics. analysis showed that 13 elements (Mn, Fe, Co, Cu, Zn,As, Se, Ag, Cd, Sn, Sb, Tl, Pb) in dust fall mainly came from waste gas emission of industrial area in Zhuzhou, in which 7 heavy metal elements(Cu, Zn, As, Ag, Cd, Sb, Pb) caused serious pollution. The content of heavy metal in the industrial area is 7.4 to 4079.4 times the content defined in China Soil Elements Background Values, while that in MCR area is 3.6 to 1413.4 times the soil background value. Cadmium was the highest background ratio elements. The degree of contamination was obviously higher in industrial area than in MCR area. The results of environmental risk assessment showed thar serious potential ecological risk was existed in both industrial area and MCR area. Intake by hand and mouse was the main exposed approach of harmful elements to people. According to the health risk assessment, there were different levels of non-carcinogenic risks for adults and children in all areas of Zhuzhou City. Children were under extremely high non-carcinogenic risks in industrial area. There was no carcinogenic risks for residents in Zhuzhou City... |
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