PHOENIX (AP) - A high pollution advisory has been issued for Maricopa County.
Arizona Department of Environmental Quality officials say ozone levels are expected to exceed the federal health standard on Monday.
They say that can irritate some resident's respiratory system, worsen asthma symptoms and impact the immune system's ability to fight off respiratory problems.
ADEQ officials say people most affected by ozone are children, senior citizens and people who work or exercise outdoors.
They are advising people to limit outdoor activity while the high pollution advisory is in effect.