2022 No https://pubmed.ncbi.nlm.nih.gov/35312840/ Justine, Izabele North America Review Students Elementary (K-5) Asthma Indoor aerosol pollution Particle number concentration Particle mass concentration Particle size range Primary schools Children The incidence of asthma per school ranged from 1.8 to 6.0%. Mean indoor air pollution based on measurements in classrooms during the lessons was calculated for each school. Levels of PNC and PMC in schools ranged between 33.0 and 168.0 particles/cm3 and 1.7–6.8 µg/m3, respectively. There was a statistically significant correlation between the incidence of asthma and PNC as well as asthma and PMC in the particle size range of 0.3–1 µm (r = 0.66, p = 0.028) and (r = 0.71, p = 0.017) respectively. No significant correlation was found between asthma incidence and indoor air pollution in the particle size range of 0.3–2.5 and 0.3–10 µm.