Sunday Air Quality Forecast For Boulder

BOULDER, CO — Unhealthy air quality can be expected in Boulder and many other Colorado cities Sunday as a massive plume of smoke drifts in from California wildfires, state public health officials said.

Fine particulate matter concentrations from the smoke along the Front Range and foothills are expected to be in the 'unhealthy' category Sunday, the Colorado Department of Public Health and Environment said.

Ozone concentrations are expected to be in the 'unhealthy for sensitive groups' to 'moderate' categories.

"People with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion on Sunday; everyone else should reduce prolonged or heavy exertion on Sunday," the agency said in its alert.

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Denver had the worst air quality in the world Saturday, according to the IQAir pollution ranking. Salt Lake City was briefly ranked No.4 on the IQAir list Saturday afternoon, and by 3 p.m., Denver had moved into the No. 2 spot, behind Johannesburg, South Africa.

The combination of the smoke and the ozone has made it difficult for many Coloradans to enjoy a summer outdoors. Dozens of action day alerts for ozone have been issued for metro Denver and Boulder so far this summer.

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.