Ozone is a gas comprised of three oxygen (O3) atoms. It is unstable and reacts easily to other gases. In its natural state, it is a component in several levels of the atmosphere. At high altitudes ...

Some people are being advised to limit their time outdoors or stay indoors on Monday as the Line Fire continues to burn in ...

The Line Fire worsened air quality to "hazardous levels," according to the South Coast Air Quality Management District.

The air quality index is divided into six categories. Each category has a description that corresponds with its level of concern, according to AirNow. Unhealthy for sensitive groups, the third ...

All evacuations were lifted in a western Cincinnati suburb Wednesday evening, a day after a chemical leak from a railcar.

Some Southern Californians are being advised to reduce their time spent outdoors on Monday due to wildfires in Southern California. The Line Fire in San Bernardino County, which has burned over ...