St. Paul County No. 19 - Percent Air Quality Hours

Percentage of hours at a given air quality level. The Air Quality Health Index (AQHI) is calculated based on the relative risks of a combination of common air pollutants that is known to harm human health. These pollutants are: Ozone (O3) at ground level, Particulate Matter (PM2.5/PM10), and Nitrogen Dioxide (NO2). Risks are defined as follows: 1-3 High Quality, 4-6 Moderate Quality, 7-9 Low Quality, 10+ Very Low Quality