Henry County Under an Air Quality Alert

Wildfire Smoke Contributes to Exceedances of Ozone Air Quality Standards

May 24, 2023

DES MOINES – Wildfire smoke carries particulates as well as massive amounts of gases and a cocktail of chemicals that can enhance ozone formation hundreds or even thousands of miles downwind.

Smoke from wildfires in Canada has impacted Iowa the last several days and exceedances of the National Ambient Air Quality Standard (NAAQS) for ozone were measured at two sites in northwest Iowa Monday and six sites across Iowa yesterday, May 23rd–Emmetsburg and Pisgah in western Iowa, Waverly and two sites in Cedar Rapids in northeast Iowa, and just north of Davenport in eastern Iowa all measured ozone levels considered unhealthy for sensitive groups.

Smoke from the fires has been evident across much of the state recently and elevated particulate and ozone levels may be a concern over the next several days.

Groups most likely to suffer adverse health effects from ozone and particulates in smoke include asthmatics, those with respiratory difficulties or heart disease, the elderly, children and pregnant women. The DNR encourages members of these groups to limit outdoor activity when air quality conditions are at or above unhealthy levels.

Current fire and smoke information can be found on EPA’s fire and smoke map at