TUCSON, Ariz. — The Pima County Department of Environmental Quality has issued an air quality watch for the Tucson area Thursday and Friday.
The DEQ says ground-level ozone air pollution triggered the watch, saying some people who are sensitive may experience hortness of breath, coughing, throat irritation, wheezing, and breathing discomfort.
Ozone levels are high more often in the afternoon, the DEQ says, and those sensitive to the gas should avoid outdoor exertion at that time.
According to the DEQ, a number of factors contribute to higher levels of ground-level ozone in the air, including car exhaust, industrial and power plant emissions, gasoline vapors, chemical solvents and even natural sources like wildfires and some vegetation.
You can learn more about air pollution in Pima County at the DEQ's website.