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DENVER (KDVR) — The Colorado Department of Public Health and Environment along with the Regional Air Quality Council have extended the Action Alert Day for multiple pollutants through 4 p.m. Monday.

Wildfire smoke from Western fires and high ozone concentrations in the air prompted an Action Alert Day on Saturday, but officials have now extended it at least through Monday.

Officials said the highest ozone level in the Air Quality Index was 90, recorded at 1 p.m. That level is categorized as moderate, meaning people with sensitivity to poor air quality should reduce prolonged or heavy outdoor exertion.

The highest particulate matter registered at 167 on the AQI and officials said people with heart or lung disease, older adults, and children should avoid extensive active time outside. Everyone else should limit active time outside.

The Action Alert Day is in effect for the Front Range from Douglas County north to Larimer and Weld counties, including the Denver-Boulder area, Fort Collins and Greeley.