Maine Air Quality
Air Quality Index (AQI), #5
Air quality indices (AQI) are numbers used by government agencies to characterize the quality of the air at a given location. As the AQI increases, an increasingly large percentage of the population is likely to experience increasingly severe adverse health effects. Air quality index values are divided into ranges, and each range is assigned a descriptor and a color code. Standardized public health advisories are associated with each AQI range. The United States Environmental Protection Agency (EPA) uses the following AQI:
| Air Quality Index (AQI) Values | Levels of Health Concern | Colors |
| 0 to 50 | Good | Green |
| 51 to 100 | Moderate | Yellow |
| 101 to 150 | Unhealthy for Sensitive Groups | Orange |
| 151 to 200 | Unhealthy | Red |
| 201 to 300 | Very Unhealthy | Purple |
| 301 to 500 | Hazardous | Maroon |
Total Suspended Particulate (TSP)
Tiny airborne particles or aerosols that are less than 100 micrometers are collectively referred to as total suspended particulate matter (TSP).
Lead (TSP)
Pb (TSP) is a measurement of the amount of elemental lead in total suspended particulate (TSP).
Carbon Monoxide (CO)
Sulfur Dioxide (SO2)
Nitrogen Dioxide (NO2)
Ozone
Particulate Matter (PM)10
Particulate Matter (PM)10 is used to describe particles of 10 micrometers or less.
Particulate Matter (PM)2.5
Particulate Matter (PM)2.5 is used to describe particles of 2.5 micrometers or less.
The information on this page is based on the air quality database from the U.S. Environmental Protection Agency (EPA).
Maine has a total of 408 monitoring sites.