The results of the PM10 and PM2.5 study in Zabrze, Upper Silesia, Poland, near a very busy city street intersection and in a site representing urban background air are presented. Airborne particles were sampled at both sites in parallel, three or five times a month from April to December 2005. Concentration of the ambient aerosol was determined gravimetrically. It has been found that the mean of the 24-hour concentration of PM10 and PM2.5 near the crossroads was 55 µg/m³ and 32 µg/m³, respectively; significantly higher than at the background site, where the mean concentration of PM10 and PM2.5 reached the level of 37 µg/m³ and 22 µg/m³, respectively. Five pairs of PM10 and four pairs of PM2.5 samples were selected for analysis of elemental composition of surface layer of collected particles. This analysis, performed using X-ray photoelectron spectroscopy (XPS), showed that the main components of the surface layer of all studied airborne particles were carbon, nitrogen and oxygen. Besides, the typical surface layer is composed of sodium, potassium, silicon, magnesium and aluminum. In some samples zinc and calcium also occurred. It has been documented that the surface layer of the airborne particles near the crossroads contained more carbon and less oxygen compared with particles from the background site.