Exposure to Airborne Bacteria During Sport Activities Indoors: Preliminary Studies in the Small Halls Without Heating, Ventilation and Air Conditioning (HVAC) System |Biomedgrid

This work presents the concentration levels of the bacterial aerosol in two small sports halls in the Upper Silesia, Poland. The samples of airborne bacteria were collected using 6-stage Andersen cascade impactor (with aerodynamic cut-size diameters of 7.0, 4.7, 3.3, 2.1, 1.1 and 0.65 μm). Obtained results show that during sports activity there is a clear increase in the concentration of bacterial aerosol. The concentration of bacterial aerosol in the school gym was very high already in the first hour of classes, and it was growing rapidly from one lesson to another, reaching the level above 104 CFU m-3. Sport activity in the gym significantly changed the patterns of the size distribution of airborne bacteria, shifting the peak from the size range of 3.3-4.7 μm, to smaller bacterial particles – in the range from 1.1 to 2.1 μm. Using the obtained data, the dose of viable bacteria, inhaled during exposure, to the body weight of the exposed student in the gym (BID) was calculated. BID ranged from 296 to 660 CFU kg-1. The analysis of the bacteria species showed that bacteria of human origin, dominated in the tested air, mainly emitted from the respiratory tract and human skin. Especially, Gram-positive cocci and nonsporting Gram-positive rods were the dominant species there. It seems that exposure to the bacterial aerosol in the sports hall and gym does not pose a direct threat to health. However, long-term inhalation of such high doses of airborne bacteria can cause adverse health effects, especially in people who are allergic (allergic / atopy).