The AQI is divided into six categories:
"Good" AQI is 0 - 50. Air quality is considered satisfactory, and air pollution poses little or no risk.
"Moderate" AQI is 51 - 100. Air quality is acceptable; however, for some pollutants there may be a moderate
health concern for a very small number of people. For example, people who are unusually sensitive to ozone
may experience respiratory symptoms.
"Unhealthy for Sensitive Groups" AQI is 101 - 150. Although general public is not likely to be affected at this
AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone,
whereas persons with heart and lung disease, older adults and children are at greater risk from the presence
of particles in the air.
"Unhealthy" AQI is 151 - 200. Everyone may begin to experience some adverse health effects, and members
of the sensitive groups may experience more serious effects.
"Very Unhealthy" AQI is 201 - 300. This would trigger a health alert signifying that everyone may experience
more serious health effects.
"Hazardous" AQI higher than 300. This would trigger a health warning of emergency condition. The entire
population is then more likely to be affected.
The outdoor air quality index (AQI) in the United States is provided by the U.S. Environmental Protection
Agency (EPA) as part of the AIRNow program. A list of sources and AIRNow partners can be found here.
The AQHI is divided into four categories:
"Low" AQHI is 1 - 3. At Risk Population: Enjoy your usual outdoor activities. General Population: Ideal air
quality for outdoor activities.
