Air Quality
The dashboard displays the Air Quality Index (AQI) value for each school, indicating how safe the air is for children to breathe and play outside. The AQI is measured at the county level using data from the nearest air quality monitor to the school. The AQI ranges from 0-500, with lower numbers indicating better air quality. When AQI is over 100, sensitive groups (including children) may experience health effects. When it's over 150, everyone should limit outdoor activity. Poor air quality can trigger asthma attacks and other health problems, especially for children. The AQI value shown on the dashboard helps parents and caregivers understand air quality risks and make informed decisions about outdoor activities for children.
Methodology
Air quality data is originally available at the county level from the EPA's Outdoor Air Quality Data, which provides median AQI values based on measurements from air quality monitors. To map this data to schools:
- County-to-School Mapping: Schools are assigned AQI values based on their county location. Each school is matched to its county using the county identifier, and the school receives the median AQI value for that county.
- Missing Data Imputation: For counties where AQI data is not available, we use geospatial nearest neighbor imputation. This assigns the AQI value from the nearest county (based on geographic centroids) that has available AQI data. This ensures that all schools have an AQI value for display and for use in calculating the Green Grade.
The AQI values displayed on the dashboard represent the county-level median AQI, which provides a regional indicator of air quality conditions affecting schools in that area.
Data Sources
EPA - Outdoor Air Quality Data
Air quality data from the EPA's Outdoor Air Quality Data, which collects air quality data at outdoor monitors across the US, providing county-level AQI values.