The Environmental Protection Agency breaks down the six different air quality categories on its AQI website. "Think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value ...

Mussel samples are a yardstick for coastal water quality. But with mussel numbers in decline, scientists are inventing new ...

"When an Air Quality Alert is issued by the IEPA ... t mean there are 300 pollutants in the air), the number is more of a yardstick to show pollution levels. The higher the AQI value, the greater ...