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

Add Yahoo as a preferred source to see more of our stories on Google. The AQI is measured on a scale from 0 to 500, with the lower the number, the healthier the air. (Getty Creative) But many ...

PHILADELPHIA (WPVI) -- With smoke blowing into the Philadelphia region from the wildfires in Canada, you may have heard a lot about the Air Quality Index or AQI. But what it is, exactly? The Air ...

PHILADELPHIA (CBS) -- Air Quality Index (AQI) refers to the Environmental Protection Agency's scale regarding the health impact of air quality and pollution in the U.S., regulated under the Clear Air ...

NEW YORK (WABC) -- The Air Quality Index is a scale used for daily reporting of how clean or polluted the air is, and what health effects might be of concern. The AQI focuses on what you might ...

Over the past five years, as California wildfires increased in both intensity and scope, fall in the Bay Area has meant skies intermittently shrouded in smoke. This season, my morning routine has not ...

Canadian wildfire smoke is affecting air quality in parts of Michigan. The EPA's air quality index (AQI) uses a color-coded scale to inform the public about air quality and associated health risks.

The Air Quality Index is a scale used for daily reporting of how clean or polluted the air is, and what health effects might ...

After fires destroyed multiple neighborhoods across Los Angeles County, many residents looked up to find blue, smoke-free skies this week. The Air Quality Index (AQI) — which measures the ...