Assessment of chemical and microbiological parameters of indoor swimming pool atmosphere using multiple comparisons

: The aim of this study was to evaluate the air quality of an indoor swimming pool, analyzing diurnal and seasonal variations in microbiological counts and chemical parameters. The results indicated that yeast and bacteria counts, as well as carbon dioxide (CO2 ), nitrogen oxides (NOx ) and O3 concentrations, showed significant diurnal difference. On the other hand, temperature, relative humidity (R.H.), yeast counts and concentrations of CO2 , particles, O3 , toluene, and benzene showed seasonal differences. In addition, the relationship between indoor and outdoor air and the degree of correlation between the different parameters have been calculated, suggesting that CO2 , fine particles and NOx would have indoor origin due to the human activity and secondary reactions favored by the chemical and environmental conditions of the swimming pool; while O3 , benzene and toluene, would come from outside, mainly. The overall results indicated that indoor air quality (IAQ) in the swimming pool building was deficient by the high levels of CO2 and microorganisms, low temperatures, and high R.H., because frequently the limits established by the legislation were exceeded. This fact could be due to the poor ventilation and the inadequate operation of heating, ventilation, and air-conditioning systems.