The U.S. Air Quality Index (AQI) is the Environmental Protection Agency’s tool for reporting outdoor air quality and health.

Nitrates in the atmosphere reduce air quality and play an important role in climate change. An international team led by ...

Plumes of smoke are blanketing large swaths of the U.S. and parts of Europe, which presents risks for those breathing it. The Midwest, Northeast and Great Lakes regions of the U.S. have “very ...