What is the Air Quality Index?
The Air Quality Index, or AQI, is an index created by the U.S. Environmental Protection Agency (EPA) to monitor air quality on a daily basis in towns and cities across the country. The EPA says the AQI “tells how clean or unhealthy your air is and what associated health effects might be a concern.”
The index outlines a range of six air quality conditions from 0 (good) to 500 (hazardous, the highest level) with intermediate conditions labeled moderate, unhealthy for sensitive groups, unhealthy and very unhealthy. Each level (or value) is assigned a color for reporting purposes.
This is how a weatherman might convey air quality to his viewers or listeners:
It's a code red day for ozone.
This description correlates to the "red" level on the AQI and means that the air quality that day shows high levels of ozone and therefore is unhealthy.
The calculations of the AQI are based on four air pollutants that are regulated by the Clean Air Act: ground-level ozone, particle pollution (which is a mixture of solid and liquid droplets), carbon monoxide and sulfur dioxide. Because the AQI is a national index the values and colors used to explain air quality and health risks in any given local area are standard anywhere in the country.
The EPA also reports that the air quality inside your home may be up to five times greater than in the air outside. For information on helping to improve the air quality inside your home, see a side-by-side comparison of the HEPA and permanent filtration systems used in Oreck's full line of air purifiers.
This article based on information in the Air Quality Index: A Guide to Air Quality and Your Health found at www.epa.gov.