It was found that the pollutants adsorbed on airborne particulates are a real threat to the health of inhabitants as high values of mutation ratio were obtained in the Salmonella plate incorporation assay (Ames test) for extracts of air samples collected during the summer and winter seasons in the centre of the town of Wrocław. The presence of pollutants which might directly and indirectly affect the genetic material has been indicated in tested samples. Mutagenicity of the air samples was highest in winter and lowest in summer. The studied samples collected in different seasons of the year were mutagenic to all tested strains. The Salmonella typhimurium strains: TA 98, YG 1041 and YG 1042 have been found most useful for detection of genotoxic air pollutants in urban agglomerations.