2024 No Factors affecting variability in gaseous and particle microenvironmental air pollutant concentrations in Hong Kong primary and secondary schools https://onlinelibrary.wiley.com/doi/10.1111/ina.12725 Che, Wenwei Asia Review Elementary (K-5) Middle/Jr High (6-8) High School (9-12) Particulate Matter (PM) fine particulate matter (PM2.5) Indoor air quality Nitrogen dioxide (NO2) Ozone (O3) respirable particulate matter (PM10) School exposure In 32 Hong Kong schools, indoor PM and gas levels were largely driven by outdoor concentrations. Outdoor air accounted for 50-90% of indoor pollution. Findings support targeting ambient pollution and infiltration control to protect children’s health. 2021