Atmospheric air samples for bacteriological assays were collected by the sedimentation and impaction methods. The samples were used for quantification of psychrotrophic and mesophilous bacteria in atmospheric air in the centre of Olsztyn and in Kortowo, a suburb of the town. It was found that counts of microorganisms were much higher when air was sampled by the sedimentation method rather than the impaction one. Besides, it was demonstrated that the determined groups of bacteria were more numerous in summer (July, August) than in the other months. Higher bacteriological contamination was determined at the three sampling sites in the centre of Olszyn than at the control site in a forest by Kortowskie Lake, in Kortowo.
Mycological analyses were carried out on air samples collected with the sedimentation and impactor methods. Fungi were assayed in atmospheric air sampled in the city centre of Olsztyn and in the forest at Lake Kortowskie. The experiment aimed at evaluating the contamination of atmospheric air with fungal microflora in the city centre of Olsztyn (3 stations) and in the forest at Lake Kortowskie (one station), collected with the sedimentation and impactor methods. Differentiated population numbers of fungi, reported in the atmospheric air of the city of Olsztyn, appeared to depend, to a great extent, on meteorological conditions.