Poor air quality has prompted officials to issue an ozone high pollution advisory for Maricopa County through Thursday.

Ozone pollution was expected to exceed federal health standards, and residents were encouraged to be safe and not contribute ...

Residents of Houston and surrounding areas are being urged to limit emissions on Wednesday due to air quality concerns.

Kilometers above the Earth’s surface, the ozone layer protects humanity and all life from the sun’s harmful ultraviolet rays.

The decision bought officials time to avert economic harm, but raised concern from health advocates about the continued impacts of ozone on Arizonans.

As average ozone exposure in the first 2 years of life rose, so did the likelihood for caregiver-reported asthma and wheeze ...