The colorless gas is considered a secondary pollutant and usually remains high in the Earth's atmosphere where it helps ...

Ozone is an invisible, odorless gas that can either protect us or harm us depending on where it is found. Since at least the 1950’s the United States has been monitoring and regulating the amount of ...

IDEM said Monday that ozone levels are expected to be in the "Unhealthy ... View air quality information for all Indiana counties, including a state map of affected counties; Learn more about ...

Fires and agricultural soils can rival cars and factories in emitting chemicals that lead to ozone, making it hard to meet air quality standards.

Local officials say they are working to understand the reasons behind the recent rise in ozone levels and to find solutions to improve air quality. U.S. Sen. Mark Kelly, D-Ariz., is advocating for ...