Geochemical characteristics and pollution sources identification of the atmospheric dust-fall in Jinan city

Samples of atmospheric dust- falls and pollution end- members were collected in the urban area of Jinan City. The characteristics of element content in atmospheric dust- falls and pollution end- members were systematically analyzed, and the spatial distribution of atmospheric dust- falls and their pollution sources were studied. The results show that the concentrations of elements vary obviously in different pollution end- members. A comparative study of the concentrations of elements in different pollution end-members shows that the As, Cd, F, Pb content in coal dust are over 3 times that in vehicle exhaust dust, and 1.26- 2.35 times that in street dust, smelt dust, building dust and other pollution end- members, thus greatly affecting the environment quality. The concentrations of Cr, Ni, S, Zn in vehicle exhausts are the highest, those of Co, Ni, Pb, F in smelt dust are somewhat higher, whereas the concentrations of most elements in building dust are the lowest. Compared with the background values of soil, the concentrations of Cr, Cu, Pb, Zn, Cd, F, S in atmospheric dust-falls of Jinan city are slightly higher. These data show that the atmospheric dust- falls are polluted by human activities in different degrees. The coefficient and factor analysis suggests that, in atmospheric dust-falls, Cd, Cu, Hg, Pb, As mainly come from enterprise coal consumption, the values of these four elements near chemical factories, steel plants and smeltery plants are generally high, which is consistent with the spatial distribution of the coal pollution sources. F and S might be related to vehicle exhausts, while As and Cr mainly come from traffic discharges. These three kinds of dusts (coal consumption, vehicle exhausts and traffic discharges) are the main pollution sources of atmospheric dust-falls in Jinan City, with the contribution proportion of atmospheric dust- falls up to 60.42%. Studies reveal that industrial coal emissions have gradually replaced the vehicle exhausts and become a major source of Pb in atmospheric dust-falls.