2024 Yes https://www.sciencedirect.com/science/article/pii/S0048969723061235?via%3Dihub Jung, Chien-Cheng Asia Exposure Study Elementary (K-5) Particulate Matter (PM) Humidity Aerosol Crustal element Heavy metal Indoor/outdoor air quality Source apportionment We found that the average ratio of PM2.5/PM10 (<10 ?m in particle size) was <0.6 in the school near the corn farm, and that the indoor PM2.5/PM10 ratio was significantly associated (r = 0.93, p < 0.05) with the outdoor ratio. Moreover, the potassium (K) concentration in the school near the corn farm (189.2 +/- 119 ng/m3) was higher than that near the rice farm (140.9 +/- 116.0 ng/m3). There were higher concentrations of K and crustal elements, and a greater crustal elements/heavy metals ratio, in the school near the corn farm during the sowing and soil covering stages than during other cultivation stages. Positive matrix factorization (PMF) results indicate that agricultural activity was a predominant contributor of PM2.5 in the schools near corn and rice farms, however, PM2.5 from industrial and traffic emissions also affected schools' air quality. In summary, agricultural activity influenced the air quality of schools, especially near the corn farm. Governments should develop air quality management policies to reduce the risk of children suffering exposure to high particle concentrations in these schools and further suggest that the impact of industrial and traffic emissions on air quality also requires attention.