Air Quality Index*
AQI Values | Level of Health Concern (Air Quality Condition) |
|---|---|
0–50 | Good |
51–100 | Moderate |
101–150 | Unhealthy for members of sensitive groups† |
151–200 | Unhealthy |
201–300 | Very unhealthy |
301–500 | Hazardous |
* The AQI is based on the levels of 5 pollutants regulated by the U.S. Environmental Protection Agency under the Clean Air Act. The pollutants are ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. | |
† Members of sensitive groups include people with lung or heart disease, children, and older adults. | |
AQI = air quality index. | |
Adapted from US Environmental Protection Agency: Air quality index: A guide to air quality and your health. Research Triangle Park, NC, 2009. Air Quality Index (AQI) | AirNow.gov | |