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DENVER — A smoky haze will continue to linger along the Front Range on Friday, prompting the Colorado Department of Public Health and Environment to issue another air quality health advisory.

Ozone and pollution from western wildfire smoke are infiltrating Colorado skies and will stick around for the weekend.

A multiple pollutant action day alert will be in effect until 4 p.m. Friday. The health department and doctors say the air quality is most worrisome for people with lung and heart conditions.

Those patients need to be closely monitored. But even healthy people can be affected by eye and throat irritation and a stuffy nose, and outdoor activity should be limited.

“Sometimes what we see though is either those symptoms become so bothersome that you have to avoid the outdoors or sometimes you may be on the course to developing a minor chronic condition and this may be the kind of environment where you learn that you have a mild degree of asthma or some other chronic condition,” said David Beuther with National Jewish Health.

“We’re finding that patients are almost universally experiencing increased symptoms. Sometimes they’re actually getting sick enough to require more medication or unscheduled health care visits and so it’s a time to really be closely monitoring patients with chronic lung disease.”

Beuther said people with chronic heart or lung conditions should stay indoors with windows closed and the air conditioning running.

Symptoms to keep an eye out for are shortness of breath, increased cough and anything else out of the ordinary.