Provo worst CO2 polluter in nation 01

New and under-construction homes stand near Slate Canyon on Tuesday, Nov. 19, 2019, in Provo. Isaac Hale, Daily Herald

The air pollution control group Choose Clean Air declared Thursday and Friday as “action days” for Provo, Ogden and Salt Lake City, among other Utah cities, recommending that people who are sensitive to air pollution avoid excessive or prolonged outdoor physical activity.

According to, a government site used to track air quality throughout the county, action days are issued either when the air quality index (AQI), which is based on particle pollution, “is forecast to be Unhealthy for Sensitive Groups” or, occasionally, when air quality is not yet at but expected to reach unhealthy levels.

On Wednesday, when thick inversion coated Utah and Salt Lake counties, Provo’s AQI ranking was 107, a “Code Orange” level that is unhealthy for sensitive groups, such as children, people with heart or lung disease and older adults.

The air quality was better in Provo on Thursday evening, 77 on the AQI, a “Code Yellow” rating indicating “moderate” air quality. Ogden air quality received a “good” rating on Thursday while Salt Lake City ranked as “moderate.”

With a 109 AQI score, Tooele had the second worst air quality in the nation on Thursday, only behind Yosemite National Park in California with a score of 142.

Of the 11 regions where action days were issued on Thursday, six were in Utah: Provo, Ogden, Salt Lake City, Tooele, Logan and Brigham City. Other cities included Bakersfield, California; Fresno, California and Franklin County, Idaho.

Only seven regions were issued action days on Friday, a list that included these same six Utah cities as well as Franklin County. offers a number of tips for staying healthy during action days. Some pieces of advice are to reduce or eliminate fireplace and wood stove use, avoid using gas-powered equipment and avoid burning leaves, trash and other materials.

Connor Richards covers government, the environment and south Utah County for the Daily Herald. He can be reached at and 801-344-2599.

See what people are talking about at The Community Table!