Level of particulate matter pollution in the indoor and outdoor air of primary schools of Bandar Abbas, Iran

Air pollution in primary schools is a concerning issue, because young students, as a sensitive group, are present in such enclosed environments. The aim of this study was to deterrmine the level of particulate matter pollution in indoor and outdoor air of primary schools in Bandar Abbas, Iran.

In this descriptive-analytical study, during 9 sampling runs form winter to spring of 2018, the concentrations of particulate mattere with aerodynamic diameters below or equal to 10 (PM10) and 2.5 µm (PM2.5) were measured in indoor and outdoor air of 10 governmental primary schools of Bandar Abbas city using a HazDust-EPAM-5000 sampler. The PM10 and PM2.5 concentrations were analyzed by Excel software and the mean and standard deviation values of the concentrations were calculated. The correlation between the concentration of particulate matter (PM) in indoor and outdoor environments was evaluated by SPSS software using spearman test at a confidence level of 95%. Moreover, Wilcoxon test was used for comparing the mean concentrations of particulate matters in indoor and outdoor air of the schools.

The values of 10-min mean concentrations of PM2.5 and PM10 in indoor air of schools were 78.8±36.8 and 111.1±53.0 µg/m3, respectively, while these values for outdoor air were 72.3±34.9 and 100.2±47.2 µg/m3, respectively. The mean indoor/outdoor ratios for PM2.5 and PM10 were 1.24 and 1.23, respectively. Statistical analysis showed that there was a significant difference between the PM concentrations in indoor and outdoor of the schools.

The PM concentration in indoor air of primary schools in Bandar Abbas was higher than that of the ambient air, which may be due to the resuspension of deposited dusts through student activities. Accordingly, more efforts are needed for frequently cleaning of the indoor environment in the primary schools.