Measuring students' exposure to particulate matter (PM) pollution across microenvironments and seasons using personal air monitors.

Particulate matter (PM) pollution is a significant concern in public health, yet children's exposure is not adequately characterized. This study evaluated PM exposures among primary school-aged children in NYS across different microenvironments. This study helps fill existing knowledge gaps by characterizing PM exposure among this population across seasons and microenvironments. Sixty students were recruited from randomly selected public primary schools representing various socioeconomic statuses. Individual real-time exposure to PM 2.5 was measured continuously using AirBeam personal monitors for 48 h. Children were consistently exposed to higher PM 2.5 concentrations in the fall (median: fall = 2.84, spring = 2.31, winter = 0.90 µg/m 3 ). At school, 2.19% of PM 2.5 measurements exceeded the EPA annual fine particle standard, 12 µg/m 3 (winter = 7.38%, fall = 2.39%, spring = 1.38%). In classrooms, PM 1-4 concentrations were higher in spring and overnight, while PM 7-10 concentrations were higher in fall and school hours. At home, 37.2% of fall measurements exceeded EPA standards (spring = 10.39%, winter = 4.37%). Overall, PM 2.5 levels in classrooms and during transportation never rose above the EPA standard for any significant length of time. However, PM 2.5 levels routinely exceeded these standards at home, in the fall, and the evening. More extensive studies are needed to confirm these results.