The Wisconsin Department of Natural Resources has issued an air quality alert for the entire state of Wisconsin to be effective until noon Friday because of persistent elevation in fine particle pollution.

The DNR issued the orange level warning because of the mass contamination emitted from combustion sources including power plants, factories, motor vehicle exhausts and wood fires.

Peter McMullen, program and policy analyst in the southeast region of the Bureau of Air Management, said the polluted particles are minuscule and will not fully combust in the air.

“They are microscopic dust, soot, liquid droplets and smoke particles that are 2.5 microns or smaller — much smaller than one strand of hair,” McMullen said.

Although all of Wisconsin is under an Air Quality Watch, the DNR issued an advisory stating that only Kenosha, La Crosse, Milwaukee, Ozaukee, Racine, St. Croix and Waukesha reached the orange level.

McMullen said an orange level warning is issued when the particles become detrimental to the health of sensitive groups including infants, elderly and people with lung diseases and asthmatic bronchitis.

“They go deep into the lungs which makes it hard to exhale,” McMullen said.

People who fall in these sensitive groups are recommended to refrain from strenuous activity and to monitor their symptoms. If they have a negative reaction to the particles in the air, they are advised to contact a physician immediately.

Lee Sensenbrenner, spokesperson for Gov. Jim Doyle, said his office is working to ensure Wisconsin has clean air.

“The governor has issued a new rule that has [reduced] mercury from power plants in Wisconsin and reduced emissions by 90 percent,” Sensenbrenner said.

In response to the air quality alert, the Dane County Clean Air Coalition declared Thursday the first wintertime Clean Air Action Day in order to raise the public’s awareness about fine particle pollution.

McMullen said if the polluted particles do not clear by noon, the warning may be extended.