Estimation of Total VOC Emission and Ozone Removal Rates in a Primary School Classroom

Measurements of gaseous and particulate pollutants were conducted inside and outside a classroom in an urban area of Athens, Greece, using both reference instruments and low cost sensors. These data were used to evaluate indoor air quality and to estimate the emissions of total volatile organic compounds (VOCs) inside the classroom. The average air exchange rate during classes was estimated at 6.4 h^-1, based on the CO₂ concentration measurements. Paints, craft materials, and cleaning products have been identified as major indoor sources of VOCs. Total VOC emission rates varied depending on the type of class activities, with an average value of 1.3 mg min^-1 during classes. Emitted VOCs included formaldehyde, acetaldehyde, acetone, methanol, ethanol, C8-C9 aromatics, etc. A classroom indoor air quality model reproduced the observed indoor concentrations of carbon monoxide, nitrogen dioxide, and fine particulate matter, assuming that outdoor sources were the only source of these pollutants. The average ozone removal rate constant was estimated at 10 h^-1 during classes.