PM2.5 in the central part of Upper Silesia, Poland: concentrations, elemental composition, and mobility of components

The paper discusses ambient concentrations of PM_2.5 (ambient fine particles) and of 29 PM_2.5-related elements in Zabrze and Katowice, Poland, in 2007. The elemental composition of PM_2.5 was determined using energy dispersive X-ray fluorescence (EDXRF). The mobility (cumulative percentage of the water-soluble and exchangeable fractions of an element in its total concentration) of 18 PM_2.5-related elements in Zabrze and Katowice was computed by using sequential extraction and EDXRF combined into a simple method. The samples were extracted twice: in deionized water and in ammonium acetate. In general, the mobility and the concentrations of the majority of the elements were the same in both cities. S, Cl, K, Ca, Zn, Br, Ba, and Pb in both cities, Ti and Se in Katowice, and Sr in Zabrze had the mobility greater than 70%. Mobility of typical crustal elements, Al, Si, and Ti, because of high proportion of their exchangeable fractions in PM, was from 40 to 66%. Mobility of Fe and Cu was lower than 30%. Probable sources of PM_2.5 were determined by applying principal component analysis and multiple regression analysis and computing enrichment factors. Great part of PM_2.5 (78% in Katowice and 36% in Zabrze) originated from combustion of fuels in domestic furnaces (fossil fuels, biomass and wastes, etc.) and liquid fuels in car engines. Other identified sources were: power plants, soil, and roads in Zabrze and in Katowice an industrial source, probably a non-ferrous smelter or/and a steelwork, and power plants.