Assessment of indoor air quality in health clubs: insights into (ultra)fine and coarse particles and gaseous pollutants.

Introduction: Exercising on regular basis provides countless health benefits. To ensure the health, well-being and performance of athletes, optimal indoor air quality, regular maintenance and ventilation in sport facilities are essential.

Methods: This study assessed the levels of particulate, down to the ultrafine range (PM, PM, and particle number concentration in size range of 20-1,000 nm, i.e., - PNC), gaseous pollutants (total volatile organic compounds - TVOCs, CO, and O) and comfort parameters (temperature - T, relative humidity - RH) in different functional spaces of health clubs ( = 8), under specific occupancy and ventilation restrictions.

Results And Discussion: In all HCs human occupancy resulted in elevated particles (up to 2-3 times than those previously reported), considering mass concentrations (PM: 1.9-988.5 μg/m PM: 1.6-479.3 μg/m) and number (PNC 1.23 × 10 - 9.14 × 10 #/cm). Coarse and fine PM indicated a common origin (r = 0.888-0.909), while PNC showed low-moderate associations with particle mass (r = 0.264-0.629). In addition, up to twice-higher PM and PNC were detected in cardiofitness & bodybuilding (C&B) areas as these spaces were the most frequented, reinforcing the impacts of occupational activities. In all HCs, TVOCs (0.01-39.67 mg/m) highly exceeded the existent protection thresholds (1.6-8.9 times) due to the frequent use of cleaning products and disinfectants (2-28 times higher than in previous works). On contrary to PM and PNC, TVOCs were higher (1.1-4.2 times) in studios than in C&B areas, due to the limited ventilations combined with the smaller room areas/volumes. The occupancy restrictions also led to reduced CO (122-6,914 mg/m) than previously observed, with the lowest values in HCs with natural airing. Finally, the specific recommendations for RH and T in sport facilities were largely unmet thus emphasizing the need of proper ventilation procedures in these spaces.