The Arizona Department of Environmental Quality (ADEQ) has issued an Ozone High Pollution Advisory for Maricopa County for Tuesday, June 10, 2025. The advisory is due to expected ozone levels that may surpass the federal health standard.
Ground-level ozone forms when emissions from vehicles, gasoline and diesel equipment, industrial and chemical processes react with sunlight. These reactions are more common during spring and summer months.
Ozone pollution affects all residents, posing risks especially to children whose lungs are still developing. Adults with asthma or other lung diseases and older adults are also sensitive to ozone. During the advisory, it is recommended that outdoor activities be limited, particularly for children and those with respiratory issues.
To help reduce ozone pollution, ADEQ and the Maricopa County Air Quality Department (MCAQD) suggest teleworking to reduce traffic, carpooling or using public transport, avoiding long drive-thru lines by going inside instead, biking or walking to work, sweeping instead of using leaf blowers, refueling vehicles after dark or during cooler hours, using low-VOC paints and chemicals, delaying painting projects until advisories have passed, and sealing containers of household chemicals properly.
The advisory includes restrictions on wood burning in residential fireplaces and outdoor fire pits in Maricopa County. Leaf blower use by government employees is prohibited during HPAs; residents are also encouraged to avoid their use. Off-road vehicle use should be avoided as well.
High Pollution Advisories notify the public when air pollutant levels are expected to exceed federal standards. Ground-level ozone results from a reaction between sunlight, nitrogen oxides (NOx), and volatile organic compounds (VOCs).
For further information on reducing air pollution in Maricopa County, visit Maricopa.gov/AQ. Contact Ari Halpert at 602-501-1266 or ari.halpert@maricopa.gov for media inquiries.
The mission of MCAQD is to improve air quality so that people can live in a healthy environment. It operates under the standards set by the federal Clean Air Act.
Follow MCAQD on Instagram (@maricopaair), Twitter (@maricopaair), Facebook (@maricopaair), or download the Clean Air app available on both iOS and Android platforms for more updates.
