Poor air quality poses risks to children and young adults, with student athletes being particularly vulnerable due to their elevated breathing rates during physical activity. To better characterize youth exposures, we deployed a network of low-cost sensors that measure outdoor PM2.5 and PM10 at 35 high school athletic fields across Utah, and that measure indoor PM2.5 and CO2 at 15 early childhood education centers. During approximately one year of measurements (April 2024–May 2025), fifteen high schools recorded a total of 28 days exceeding the PM2.5 24-hour AQI threshold for Unhealthy for Sensitive Groups (35.5 µg/m³) and 2 days exceeding the Unhealthy threshold (55.5 µg/m³). Meanwhile, 21 schools recorded 46, 11, 4, and 6 exceedance days for PM10 at the Unhealthy for Sensitive Groups (155 µg/m³), Unhealthy (255 µg/m³), Very Unhealthy (355 µg/m³), and Hazardous (425 µg/m³) thresholds, respectively. Indoors, mean PM2.5 concentrations were low across early childhood education centers (1.32±1.18 µg/m3), yet eight childcare centers experienced a total of 50 days exceeding the WHO 24-hour PM2.5 concentration guideline (15 µg/m3). Additionally, our team has collaborated with the State Board of Education, the State Department of Public Health, athletic trainer/medical associations, and school nurses to develop uniform air quality guidelines for outdoor activities. These guidelines have led to state legislation that is currently under consideration. These results support the need for localized, actionable air quality information in school environments.
