Indoor environmental quality classification of school environments by monitoring PM and CO2 concentration levels

Nowadays the control of indoor healthiness and comfort has become a key issue in school environments. Indoor environment quality (IEQ) as regards indoor air quality (IAQ), ventilation requirement as well as health effects assessed by Hazard Index and Cancer Risk were investigated in a naturally ventilated school by monitoring indoor/outdoor CO2 concentrations and particulate matter (PM) levels. This way, a CO2 fluxes balance permitted to calculate actual ventilation rates used to classify the classrooms on the basis of the proposal contained in fpEN 16,798 standard. The relationship between ventilation, CO2 levels and PM was also studied. In absence of appreciable internal pollution sources, the indoor concentrations of chemical pollutants were correlated to the corresponding outdoor concentrations by the comparison of indoor/outdoor PM whose differences in this case depend only by indoor deposit and resuspension. Heavy metals (As, Cd, Ni, Pb) and PAHs were considered as required by CEN recommendations. A simple procedure was carried on to assess the potential health hazards of pollutants on students. Hazard Index and the total Cancer Risk of the inhalation exposure were evaluated as proposed by United States Environmental Protection Agency. The calculated values resulted normally acceptable if related to daily school period, but not completely satisfactory because they highlighted that the indoor contaminant concentrations were not acceptable for 24 h exposure. Therefore these chemical pollutants reduce the no health hazard exposure capacity of the children in the remaining part of the day.