The Air Quality Index (AQI) is a critical tool designed to ... AQI Categories and Health Impacts Each AQI range carries ...

This measure, based on data from the Environmental Protection Agency, evaluates states on the number of days the Air Quality Index in counties was not rated “good.” U.S. News calculated a ...

As the country continues to battle deadly smog and high levels of air pollution, Karachi's air quality index fluctuated in ...