PM-2.5 and PM-10 samples were collected in the centre of Katowice, Poland during February to May 2001. They were analyzed by gravimetry, X-ray photoelectron spectroscopy and scanning electron microscopy combined with an energy dispersive spectrometer and electron paramagnetic resonance. The combination of these methods allows us to analyze elemental composition, size and morphology of more than three hundred individual atmospheric particles. The composition of the aerosol particles is strongly influenced by meteorological conditions such as wind speed and direction. Mineral elements mainly existed in large-size particles. The anthropogenic pol-lution elements, however, are contained in corpuscles (< 2 ěm). In comparison with the situation in the wintertime, the number of particles rich in some heavy metals in springtime was found to be lower. The EPR spectra are complex and their features correspond to: I type: Cu2+ centra in a low-symmetry host site, II type: radical species in the soot, which appears as the paramagnetic pyrolyzed product.