Air quality worsens in eastern US as Canadian wildfire smoke hangs over Midwest

Chicago Tribune

2 days ago

PORTLAND, Maine — Smoke from Canadian wildfires started making air quality worse in the eastern U.S. on Wednesday as several Midwestern states battled conditions deemed unhealthy by the federal government.
The fires have forced thousands of Canadians to flee their homes and sent smoke as far as Europe.
In the U.S., smoke lingered on the skylines of cities from Kansas City to Minneapolis, and a swath of the region had unhealthy air quality Wednesday, according to an Environmental Protection Agency map.
Iowa issued a statewide air quality alert through early Thursday, urging residents to limit certain outdoor activities and warning of possible health effects due to the thick smoke. Wisconsin officials made similar suggestions as the smoke drifted southeast across the state.
In Michigan's Upper Peninsula, authorities advised people shut windows at night, avoid strenuous activity outside and watch for breathing issues.
Parts of Maine, Vermont, New Hampshire and New York had areas of moderate air quality concern, and officials advised sensitive people to consider reducing outdoor activity.
New Hampshire authorities hoped conditions would improve by late Wednesday.
'The particle air pollution event is the result of extensive wildfires in central and western Canada,' the state's Department of Environmental Services said. 'Wind patterns are forecasted to transport plumes of smoke from these fires across much of New England and New Hampshire.'
The Minnesota Pollution Control Agency issued an alert for almost the entire state into Wednesday, but the Twin Cities area got the region's worst of it Tuesday.
'As the smoke continues to move across the state Tuesday, air quality will slowly improve from northwest to southeast for the remainder of the alert area,' the agency said. 'The smoke is expected to leave the state by Wednesday at noon.'
The Iowa Department of Natural Resources warned that air quality in a band from the state's southwest corner to the northeast could fall into the unhealthy category through Thursday morning. The agency recommended that people — especially those with heart and lung disease — avoid long or intense activities and to take extra breaks during strenuous activity outdoors.
The U.S. Environmental Protection Agency's AirNow map showed a swath of red for 'unhealthy' conditions across Wisconsin and northern Iowa. Conditions in northern Michigan also reflected many unhealthy zones. The Air Quality Index was around 160 in many parts of the upper Midwest, indicating poor conditions.
The Air Quality Index — AQI — measures how clean or polluted the air is, indicating which health effects might be experienced within a few hours or days after breathing polluted air. It is based on ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide and nitrogen dioxide. Particulates are the main issue from the fires.
The index ranges from green, indicating satisfactory air quality that poses little or no risk, to maroon, which is considered hazardous. That level comes with health warnings of emergency conditions which are more likely to affect everyone.
There were areas of reduced air quality all over the U.S. on Wednesday, with numerous advisories about moderate air quality concerns as far from the fires as Kansas and Georgia.
Canada is having another bad wildfire season. Most of the smoke reaching the American Midwest has been coming from fires northwest of the provincial capital of Winnipeg in Manitoba.
Canada's worst-ever wildfire season was in 2023 and choked much of North America with dangerous smoke for months.
This season's Canadian wildfires are so large and intense that the smoke is even reaching Europe, where it is causing hazy skies but isn't expected to affect surface-air quality, according to the European climate service Copernicus.
The smoke over western Europe is expected to keep moving eastward, according to the National Oceanographic and Atmospheric Administration. It's causing hazy skies, but not expected to affect surface-air quality. However, it could rise high enough to be carried that far, indicating the immense size and intensity of the fires, according to Copernicus.