Microbial air quality at Szczawnica sanatorium, Poland.

Nowadays, sanatorium treatment is undergoing a renaissance; however, data on air quality in such premises are scarce. The aim of this study was to characterize microbial air quality at the Szczawnica sanatorium in Southern Poland. The bioaerosol measurements were carried out using a 6-stage Andersen impactor over a period of one year in 3 naturally ventilated sanatorium premises (where different curative treatments took place) and in outdoor air. The indoor and outdoor concentrations of fungal aerosol were always below 1,600 cfu/m(3). With regard to bacterial contamination, the highest concentrations (up to 6,223 cfu/m(3)) were usually noted when the patients were present and underwent curative procedures. Such concentrations crossed the Polish threshold limit values, which suggest that natural ventilation in this type of premises did not ensure the proper air quality; therefore a high-performance ventilation or air-conditioning system should be introduced to provide the "clean" air into the curative treatment rooms. Qualitative evaluation of bioaerosols revealed that the most prevalent indoors were Gram-positive cocci, mesophilic actinomycetes, and filamentous fungi. Analysis of microclimate parameters confirmed that ony relative humidity of the air influenced significantly the levels and composition of microbial aerosols. Hence, the constant control of this parameter should be scrupulously supervised at sanatorium premises.