Spatial and temporal variations in particulate matter concentrations in twelve schools environment in urban and overpopulated camps landscape

Abstract

Potential adverse effects on children health may result from school exposure to airborne particles. To address this issue, the variations of indoor and outdoor PM10 and PM2.5 concentrations in inner urban city and overpopulated camps school buildings located in the Mediterranean area were evaluated. Thirty six classrooms in twelve school buildings were investigated during fall, winter and spring seasons of 2011 and 2012. The results of the study show there were greater masses of PM10 and PM2.5 indoors that controlled by outdoor sources. For urban schools, the average concentration of indoor PM10 and PM2.5 were 320.0 μg/m3 and 86.2 μg/m3, respectively. Meanwhile, the average concentration of indoor PM10 and PM2.5 for overpopulated camps schools were 396.5 μg/m3 and 109.0 μg/m3, respectively. Almost all PM showed I/O ratios higher than one which denotes an important contribution from indoor source at urban and overpopulated camps schools. Different spatial distribution pattern among and within the schools was observed. For most of the schools a coefficients of divergence (COD) values varied from spatial homogeneity to moderate spatial heterogeneity. Across the all monitored schools, temporal variation of PM10 concentration was observed and significantly highly influenced by the seasonal variation. In both areas, the PM10 concentration displayed a bimodal pattern, with peaks between 7:00 and 11:00 a.m. during spring. Meanwhile a unimodal pattern displayed with peaks between 09:00 and 10:00 a.m. and between 12:30 and 01:30 p.m. for winter and fall, respectively. These peaks were attributed to enhanced anthropogenic activity and to the influence of meteorological conditions.