Air quality in the U.S. is measured by the Environmental Protection Agency (EPA) using an air quality index (AQI), which rates air quality on a scale of zero to 500. To determine a location’s ...

The Air Quality Index does not take into account many gas or particle contaminants that are produced during wildfires, particularly when houses, cars and other man-made materials go up in flames.

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

What the Air Quality Index doesn’t tell us about the air. As Los Angeles smolders, the AQI can’t capture the full picture of wildfire smoke. by Sam Delgado. Jan 18, 2025, 1:00 PM UTC ...

An AQI between 201-300 can cause breathing discomfort to most people on prolonged exposure. The AQI graph had first crossed 200 in the city on October 20, before hitting 250 on October 23.