Particulate matter in rural and urban nursery schools in Portugal

Abstract Studies have been showing strong associations between exposures to indoor particulate matter (PM) and health effects on children. Urban and rural nursery schools have different known environmental and social differences which make their study relevant. Thus, this study aimed to evaluate indoor PM concentrations on different microenvironments of three rural nursery schools and one urban nursery school, being the only study comparing urban and rural nursery schools considering the PM 1 , PM 2.5 and PM 10 fractions (measured continuously and in terms of mass). Outdoor PM 2.5 and PM 10 were also obtained and I/O ratios have been determined. Indoor PM mean concentrations were higher in the urban nursery than in rural ones, which might have been related to traffic emissions. However, I/O ratios allowed concluding that the recorded concentrations depended more significantly of indoor sources. WHO guidelines and Portuguese legislation exceedances for PM 2.5 and PM 10 were observed mainly in the urban nursery school.