McDowell Mountain Regional Park

Most people pretty much take the air surrounding us for granted. However, when the air gets polluted, it can make it more difficult for some people to breathe. Those with respiratory ailments such as asthma or COPD can have difficulty when the air becomes dirty.

The Arizona Department of Environmental Quality (ADEQ) and the Maricopa County Air Quality Department work in tandem to issue warnings on potential air quality issues and implement measures to reduce the impacts of those instances.

ADEQ monitors weather conditions along with air quality measurements and forecasts pollution potential a few days in advance and will issue a warning if indicated.

Maricopa County has its “Clean Air, Make More” program to provide information for the public on how to mitigate impacts of pollution.

Essentially, air quality is monitored in three categories including PM 10, PM 2.5 and ozone. PM stands for particulate matter, with the number and indication of the size of particles.

PM-10 stands for particulate matter measuring 10 microns or less. State and county agencies measure PM-10 and PM-2.5 which are extremely small solid particles and liquid droplets found circulating in the air.

Particulate matter comes from either combustion (cars, industry, woodburning) or dust stirred up into the air. High levels of PM are typically created when the air is especially stagnant, often in the winter.

PM-2.5 stands for particulate matter measuring 2.5 microns or less.

Ozone at ground level is formed by a chemical reaction that needs heat from sunlight, nitrogen oxides and volatile organic compounds [VOCs] to form. The months of April through September make up the Valley’s longer-than-normal “ozone season.”

A “High Pollution Advisory,” or “HPA,” means the highest concentration of pollution may exceed the federal health standard. Active children, adults and people with lung disease such as asthma should reduce prolonged or heavy outdoor exertion during an air pollution advisory.

Maricopa County employers enlisted in the Travel Reduction Program are asked to activate their HPA plans on high pollution advisory days.

Maricopa County also has restrictions which are implement during a pollution advisory.

The restrictions in Maricopa County include the following:

*Wood burning in residential fireplaces, chimineas, outdoor fire pits and similar outdoor fires is prohibited. This includes individuals and businesses which have burn permits for open burning.

*Employees and contractors of government entities are prohibited from operating leaf blowers. Residents are encouraged to avoid leaf blowing during HPAs.

*Off-highway vehicles are prohibited from being used during the HPA.

There are a number of measures citizens can take to help reduce air pollution during advisory periods.

*Eliminate wood burning in fireplaces, stoves, chimineas and outdoor fire pits.

*Drive as little as possible: carpool, use public transit or telecommute. For information on transportation alternatives, visit

*Avoid using leaf blowers. Use a rake or broom to keep debris out of the road and away from storm drains, ditches, and streams.

*Reduce waiting time in long drive-thru lines. For example, at coffee shops, fast-food restaurants or banks. Park the car and go inside.

For ozone related advisories during hot months consider the following:

*Fuel vehicles after dark or during cooler evening hours.

*Use low-VOC (Volatile Organic Compounds) or water-based paints, stains, finishes and paint strippers.

*Delay big painting projects until high-pollution advisories have passed.

*Make sure containers of household cleaners, garage and yard chemicals and other solvents are sealed properly to prevent vapors from evaporating into the air.