Trace elements in size-segregated urban aerosol in relation to the anthropogenic emission sources and the resuspension

Abstract

Size segregated particulate samples of atmospheric aerosols in urban site of continental part of Balkans were collected during 6 months in 2008. Six stages impactor in the size ranges: Dp LT = 0.49 mu m, 0.49 LT Dp LT = 0.95 mu m, 0.95 LT Dp LT = 1.5 mu m, 1.5 LT Dp LT = 3.0 mu m, 3.0 LT Dp LT = 7.2 mu m, and 7.2 LT Dp LT = 10.0 mu m was applied for sampling. ICP-MS was used to quantify elements: Al, As, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Na, Ni, Mg, Mn, Pb, Sb, V, and Zn. Two main groups of elements were investigated: (1) K, V, Ni, Zn, Pb, As, and Cd with high domination in nuclei mode indicating the combustion processes as a dominant sources and (2) Al, Fe, Ca, Mg, Na, Cr, Ga, Co, and Li in coarse mode indicating mechanical processes as their main origin. The strictly crustal origin is for Mg, Fe, Ca, and Co while for As, Cd, K, V, Ni, Cu, Pb, and Zn dominates the anthropogenic influence. The PCA analysis has shown that main contribution is of resuspension (PC1, sigma(2)approximate to 30 %) followed by traffic (PC2, sigma(2)approximate to 20 %) that are together contributing around 50 % of elements in the investigated urban aerosol. The EF model shows that major origin of Cd, K, V, Ni, Cu, Pb, Zn, and As in the fine mode is from the anthropogenic sources while increase of their contents in the coarse particles indicates their deposition from the atmosphere and soil contamination. This approach is useful for the assessment of the local resuspension influence on element's contents in the aerosol and also for the evaluation of the historical pollution of soil caused by deposition of metals from the atmosphere.