Abstract
Actinomycetes are common soil microorganisms; however, they have also been detected in air samples, becoming important air contaminants in occupational and residential habitats. Concentrations of airborne actinomycetes and their distribution among different fractions of bioaerosol were determined in selected sites of two sanatorium types, ie a subterranean located in the former salt-mine of Bochnia and standard earth spa of Szczawnica. The average concentrations of actinomycetes ranged from 0 to almost 40 cfu m-3, for the sanatorium of Bochnia, and from 7 to 125 cfu m-3, for Szczawnica spa, throughout the year. The respiratory fraction of the bioaerosol ranged from 25 to 51% and from 78 to 81% in the subterranean sites and rooms of Szczawnica spa, respectively. For both sanatoriums, among isolated actinomycetes dominated species belonging to Rhodococcus, Streptomyces and Nocardia. The results indicate that patients can be differentially exposed to airborne actinomycetes in compared sanatoriums. The air of underground spa reveals to be of better quality, regarding the bacteria characteristics.