Respirable Particle Concentrations in Primary School's Classrooms in Sari

Background and High concentrations of respirable particles in both the outdoor and indoor environments are associated with adverse health effects that could reduce the performance of students. This study was carried out to investigate the indoor concentrations of respirable particle and outdoor concentrations of PM2. 5 at classrooms in primary schools in Sari، north of Iran. We also evaluated the relationship between outdoor concentration of particles and other environmental factors. Six primary schools located in Sari city center were selected. A size selective GRIMM particle monitor was used to measure the indoor classrooms continuous real-time particle distribution and a real time Micro Dust Pro monitor was used for outdoor measurement. The maximum and minimum concentrations of indoor PM1 and PM2. 5 were observed in spring and autumn، respectively. The highest level of PM10 was seen in winter. The mean indoor PM2. 5 concentration in classrooms was (46. 6 µgm-3) which was higher (P<0. 05) than the mean outdoor PM2. 5 concentration (36. 9 µgm-3). Ambient temperature had a significant negative effect on indoor PM2. 5 levels. Resuspension of indoor particles and replacement of indoor and outdoor air are amongst the most effective determinants for indoor particle concentrations.