Investigation of indoor air quality at urban schools in Qatar

Information about indoor conditions of classrooms in Qatari schools is very scarce and availability of indoor air quality (IAQ) data is important as children are vulnerable to health hazards and spend long times in classrooms. Therefore, IAQ was investigated in 16 mechanically ventilated schools in Qatar during the winter season. Parameters such as temperature, relative humidity, carbon monoxide (CO), carbon dioxide (CO2) and particulate matters (PM10 and PM2.5) were measured indoors and outdoors simultaneously. High indoor CO2 and PM concentrations were found in many classrooms and exceeded the ASHRAE standard and US-EPA air quality standards as there are currently no established IAQ standards in Qatar. The mean indoor CO2 concentration in all classrooms was 1776 +/- 887 ppm with mean indoor/outdoor ratio of 3.89 +/- 2.03. The mean indoor PM10 and PM2.5 concentrations were 93.2 +/- 42.4 mu g/m(3) and 60.1 +/- 28.8 mu g/m(3), respectively. High indoor PM concentrations were found to be highly influenced by outdoor levels. Mean indoor/outdoor ratios for PM10 and PM2.5 in all classrooms were 0.87 +/- 0.43 and 0.80 +/- 0.34, respectively. The current study also identified many factors associated with increased indoor levels of PM. According to results of this study, some recommendations were suggested to reduce exposure of school children to high indoor levels of these pollutants as well as to provide comfortable learning environments.