
Thousands of people across the United States have been told to stop burning amid concerns over air pollution levels.
The National Weather Service (NWS) has issued a series of air quality alerts across parts of Idaho, Washington and Colorado on Friday.
The warnings mean that ground-level ozone and particulate concentrations are forecast to reach dangerous levels, largely due to pollution from drifting wildfire smoke.
Why It Matters
The NWS warned that sensitive groups — children, seniors, and individuals with preexisting respiratory or heart conditions — might experience health effects linked to poor air quality in the affected regions.
“Air pollutants can cause breathing difficulties for children, the elderly, as well as persons with respiratory problems,” it said.
“Those individuals who are sensitive to increased particulate matter or smoke are encouraged to avoid prolonged or strenuous outdoor activity during this advisory.”

Marcio Jose Sanchez/AP
What To Know
In Idaho, an air quality alert has been issued for Boundary, Bonner, and Shoshone counties until midday on Friday. Air quality is forecast to be unhealthy for sensitive groups.
The Idaho Department of Environmental Quality said: “Open burning is prohibited by air quality rule. It is also recommended that all other individuals limit prolonged or strenuous activity outdoors.”
In Washington, the Olympic Region Clean Air Agency has issued an air quality alert for Mason County until 9 a.m. due to wildfire smoke from the Bear Gulch Fire.
“Health impacts and recommended actions: when air quality is very unhealthy or hazardous, everyone should reduce exposure. Stay inside and filter indoor air to keep it cleaner. Go elsewhere for cleaner air, if needed. Burning restrictions are in effect,” the agency said.
Meanwhile in Colorado, an air quality healthy advisory for wildfire smoke has been issued until 9 a.m. for large swathes of the northwest and southwest, including the city of Durango.
The Colorado Department of Public Health and Environment (CDPHE) said: “The Stoner Mesa fire in eastern Dolores County will create periods of moderate to heavy smoke on Thursday and Friday within the advisory area. The heaviest smoke impacts will likely be in locations near the fire and low-lying areas, including Rico, Dolores, Cortez, and Durango.”
What People Are Saying
The CDPHE said in a statement: “If smoke is thick or becomes thick in your neighborhood you may want to remain indoors. This is especially true for those with heart disease, respiratory illnesses, the very young, and older adults. Consider limiting outdoor activity when moderate to heavy smoke is present. Consider relocating temporarily if smoke is present indoors and is making you ill. If visibility is less than 5 miles in smoke in your neighborhood, smoke has reached levels that are unhealthy.”
Jonathan Grigg, a professor of pediatric respiratory and environmental medicine at Queen Mary University of London, previously told Newsweek that there are “very clear links” between inhaling particles and earlier death from both respiratory and cardiovascular diseases.
He added: “There are vulnerable groups and classically they are children because they’ve got an extra issue to do with their lungs developing, whereas our lungs are not developing as adults.”
What Happens Next
The warnings are currently set to remain in force until Friday morning in Washington and Idaho, and midday in Colorado.
Regular updates regarding air pollution levels are issued on the NWS website and on the Environmental Protection Agency’s AirNow interactive map.