Ozone Action Day Alert Issued For Metro Denver, Boulder

Another action day alert for pollution was issued Sunday for parts of the Front Range and Eastern Plains.

Ozone concentrations are expected to be in the 'unhealthy for sensitive groups' to 'moderate' categories in metro Denver, Boulder, Longmont, Greeley and Fort Collins, the Colorado Department of Public Health and Environment said.

"In these areas active children and adults, and people with lung disease, such as asthma, should reduce prolonged or heavy outdoor exertion from noon to 8 pm on Sunday. Elsewhere throughout the Front Range," the agency said in its alert.

Fine particulate matter concentrations from wildfire smoke along the Front Range and Eastern Plains are expected to be in the 'moderate' to 'unhealthy for sensitive groups' categories Sunday, and visibility will be in the 'poor' category in Denver.

Carbon monoxide and nitrogen dioxide levels are expected to be in the 'good' category Sunday, health officials said.

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Dozens of action day alerts for ozone have been issued for metro Denver and Boulder so far this summer. Metro Denver is the 8th worst metro area in the nation for high ozone days, according to the American Lung Association's 2021 "State of the Air" report released in April.

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.