Particulate matter in UK school classrooms – building an evidence base for improving classroom air quality

Identifying factors that affect classroom concentrations of particulate matter is important for enabling effective mitigation of the associated negative health and cognitive effects, of which children can be especially susceptible. This study examines particulate matter concentrations in school classrooms from across the UK which have participated in the Schools’ Air quality Monitoring for Health and Education (SAMHE) project. Data from the 2023/2024 academic year is analysed and outdoor sources of particulate matter (PM) are shown to be a key source of PM in classrooms. Outdoor particulate matter events, taken to be short periods of elevated outdoor PM concentrations, are evidenced within classroom measurement and result in the likely classroom exposures during these events being significantly over-weighted within the longer-term exposure to PM over the academic year.