Spatial distribution of fine particulate matters in urban school classrooms during high-concentration events in South Korea

Abstract

The assessment of indoor fine particulate matter (particularly PM1.0) in classrooms is a recent concern due to its negative effects on the health and performance of young students, most of whom spend 6-8 h per day in schools. A field investigation of 20 urban schools with uncontrolled classroom conditions found that the hourly average concentrations of PM2.5 and PM1.0 in 20 classrooms ranged from 6.5 μg m−3 to 36.9 μg m−3 and 4.3 μg m−3 to 27.4 μg m−3, respectively. The ratios of indoor to outdoor (I/O) concentrations were 0.46 to 1.32 for PM2.5 and 0.43 to 0.97 for PM1.0. The size-based ratios of fine-to-coarse (F/C) were 0.46 to 0.88 for PM1.0/PM2.5 in indoor environments and 0.57 to 0.93 outdoors. During high-concentration events caused by yellow dust and heavy local smog, the F/C ratio (PM1.0/PM2.5) in the classroom was 0.22 and 0.93, respectively, and the respective I/O values for PM2.5 and PM1.0 were 0.68 and 0.60. These findings can inform the development of school guidelines for managing the health of young students.