Microbiological and chemical quality of indoor air in kindergartens in Slovenia

The concentrations of microorganisms, aerosol black carbon and carbon dioxide (CO2) in indoor and outdoor air of two kindergartens were investigated during four seasons. The highest mean concentrations of aerobic mesophilic microorganisms in indoor air were detected in spring. Cladosporium, Penicillium and Aspergillus were the most common fungi in all air samples. The concentrations of Staphylococci, Enterobacteria and CO2 had a positive correlation with the number of persons in the rooms. The highest mean concentration of black carbon in indoor and outdoor air was obtained in winter. Concentrations of CO2 exceeded 1000 ppm in 89.3% of the indoor air measurements. The reduction of the number of children in individual playrooms and more frequent ventilation are recommended for lowering the concentration of CO2 and the number of microorganisms in the air, especially potential pathogen fungi. The renovation of buildings with installation of effective artificial ventilation is recommended as well.