The Arizona Department of Environmental Quality (ADEQ) has issued an Ozone High Pollution Advisory for Maricopa County, scheduled for Wednesday, May 28 and Thursday, May 29, 2025. This advisory is due to expected ozone levels surpassing the federal health standard.
Ground-level ozone forms when emissions from vehicles, gasoline and diesel equipment, industrial and chemical processes react with sunlight. This type of pollution is more common during spring and summer months.
While some individuals are more sensitive than others, all residents in the county can be affected by ground-level ozone pollution. It poses a risk to lung health and can trigger asthma attacks. Children face the greatest risk as their lungs are still developing, they tend to be active outdoors, and they have a higher likelihood of having asthma compared to adults. Adults with asthma or other lung diseases and older adults are also vulnerable to ozone exposure. The public is advised to limit outdoor activities while the advisory is in effect, especially children and those with respiratory issues.
The ADEQ along with the Maricopa County Air Quality Department (MCAQD) suggest several measures for residents and businesses to help reduce ozone pollution:
– Encourage teleworking to minimize traffic.
– Opt for carpooling or use public transportation.
– Avoid long waits in drive-thru lines; park your vehicle instead.
– Consider biking or walking to work.
– Use a broom instead of leaf blowers.
– Refuel vehicles after dark or during cooler evening hours.
– Use low-VOC or water-based paints and delay painting projects until advisories have passed.
– Ensure containers of household cleaners and chemicals are sealed properly.
For more information on reducing air pollution, visit Maricopa.gov/AQ.
This advisory also includes specific restrictions:
– Prohibition on wood burning in residential fireplaces, chimeneas, outdoor fire pits within Maricopa County. This applies even if burn permits have been issued for open burning.
– Government employees are prohibited from using leaf blowers; residents should avoid them as well during HPAs.
– Avoid off-road vehicle use.
A High Pollution Advisory serves as a notification that an air pollutant level is anticipated to exceed federal health standards. Ground-level ozone results from reactions involving sunlight, nitrogen oxides (NOx), and volatile organic compounds (VOCs).
For media inquiries in English or Spanish contact Ari Halpert at 602-501-1266 (cell) or 602-506-6713 (desk), email: ari.halpert@maricopa.gov
The mission of MCAQD is improving air quality so that residents can live in a healthy environment. Governed by the Maricopa County Board of Supervisors, it adheres to standards set by the Clean Air Act. For resources on air quality visit Maricopa.gov/AQ.
Follow MCAQD on social media: Instagram @maricopaair; Twitter @maricopaair; Facebook @maricopaair
Download the Clean Air app available on iPhone/iPad via App Store or Android via Google Play.
