The Illinois EPA declared an Air Pollution Action Day in the Chicago metro area. See today's air quality index forecast for Illinois.

The Air Quality Index (AQI) is a national system developed by the U.S. Environmental Protection Agency (EPA) to translate various air pollutant concentrations into a single, easy-to-understand number.

The Illinois Environmental Protection Agency has issued an Air Pollution Action Day for Tuesday, July 15. Here's what to know ...

Manitoba is looking to expand the infrastructure it has to monitor air quality, a step experts say is important to better map ...

The current infrastructure also isn’t set up to fully account for the shifting behavior of wildfire smoke, which can travel ...

Delhi's air quality remains "satisfactory," with light rain recorded and a yellow alert for possible moderate rainfall on ...

These are the best air purifiers you can buy in every category, from Levoit Core 600S and BlueAir Blue Pure 411i Max to Dyson Purifier Cool PC1.

Columbus' air quality is yet again expected to dip into "unhealthy for sensitive groups" levels on June 12.

Many studies have shown how reduced air quality can compare to smoking cigarettes. Moderate air quality currently is like smoking one cigarette per day.

The EPA's Air Quality Index can tell you whether breathing outside air can hurt you. How to read the scale.

The Air Quality Health Index was first created to show possible health and environmental impacts to vegetation, visibility and human and animal health.