An ozone health watch remains in place Monday. A health watch was also in place over the weekend, though ozone levels did not get as high as expected due to increased afternoon winds.
The Arizona Department of Environmental Quality issues a health watch when ozone levels approach federal standards.
Ozone is created when other pollutants are heated. It can aggravate existing respiratory conditions and cause cough or sore throat. People sensitive to respiratory illness should limit time outdoors.
See http://www.azdeq.gov/ensemble.pdf for more information.