PHOENIX — Environmental regulators have issued an ozone health watch for
metropolitan Phoenix on Thursday.
A health watch is issued when ozone levels are expected to approach federal
Ozone can irritate the lungs and aggravate existing health conditions such as
Officials said people who are unusually sensitive to air quality should consider
limiting their time outdoors.
Ozone is an invisible gas created when other pollutants in the air — such as
those created by combustion — are heated by the sun.