Diurnal samples of PM(2.5) and PM(2.5-10) were taken in an urban background area in Zabrze (Upper Silesia in southern Poland) in the winter (January-March) and summer (July-September) of 2009. The samples were analyzed for carbon (organic and elemental), water soluble ions (Na(+), NH(4) (+), K(+), Mg(2+), Ca(2+), F(-), Cl(-), NO(3) (-), PO(4) (3-), SO(4) (2-)) and concentrations of 27 elements by using, respectively, a Behr C50 IRF carbon analyzer, a Herisau Metrohm AG ion chromatograph, and a PANalitycal EPSILON 5 X-ray fluorescence spectrometer. To perform the mass closure calculations for both dust fractions in the two periods, the particulate matter (PM) chemical components were categorized into organic matter, elemental carbon, secondary inorganic aerosol, crustal matter, marine components and unidentified matter. The chemical composition of the two dust fractions and the element enrichment coefficients in the two seasons, referred to proper emission profiles, proved about 80% of PM(2.5) and more than 50% (in winter 65%) of PM(2.5-10) mass coming from anthropogenic sources, mainly from fuel combustion and specific municipal emission shaping the winter emission of ambient dust in the area.