Smoke, Pollution In Metro Denver: Saturday Forecast

DENVER, CO — Ozone concentrations are expected to be in the 'unhealthy for sensitive groups' category Saturday in west and south metro Denver, public health officials said.

Fine particulate matter concentrations from the smoke along the Front Range and foothills have improved, however — they are expected to be in the 'good' to 'moderate' categories Saturday, the Colorado Department of Public Health and Environment said.

"Active children and adults, and people with lung disease, such as asthma, should reduce prolonged or heavy outdoor exertion from noon to 8 pm," the agency said.

Visibility in Denver is expected to be in the 'poor' category again on Saturday, health officials said.

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The combination of the smoke and the ozone has made it difficult for many Coloradans to enjoy a summer outdoors. More than 50 action day alerts for ozone have been issued for metro Denver and Boulder since May.

Ozone pollution, often called smog, forms when gases that come out of tailpipes and smokestacks, among other sources, come into contact with sunlight. Ozone is "one of the most dangerous and widespread pollutants in the U.S.," the lung association said.

Ozone can damage people's airways, make their lungs more susceptible to infection and aggravate lung diseases, according to the U.S. Environmental Protection Agency.

>> Read the full air quality advisory here.