The Arizona Department of Environmental Quality has issued a PM-2.5 High Pollution Advisory for Sunday, Dec. 18.

A “No Burn Day” will be in effect during this advisory.

Contractors cannot use leaf blowers on governmental properties on HPA days.

Open burning activity is restricted in Maricopa County. This includes individuals and businesses which have burn permits for open burning.

PM-2.5 stands for particulate matter measuring 2.5 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. PM, or 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.

"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.