Millions Across 3 States Told To Stay Indoors

Newsweek

17-07-2025

Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources.
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Millions of people across three states have been urged to remain indoors amid concerns over high air pollution levels.
Air quality advisories were issued on Thursday for parts of Connecticut, Colorado and Oregon.
The warnings mean ground-level ozone concentrations are forecast to reach dangerous levels that could pose a risk to sensitive groups and the general public.
Smoke billowing into the sky from a wildfire in Oregon in June.
Smoke billowing into the sky from a wildfire in Oregon in June.
Oregon Department of Transportation/AP
Why It Matters
In its alert notices, the National Weather Service (NWS) warned that people particularly sensitive to elevated pollution levels include those with "heart or lung problems and young children."
"Pollutants in smoke can cause burning eyes, runny nose, aggravate heart and lung diseases, and aggravate other serious health problems," it said.
The alert added, "Active children and adults, and people with lung disease, such as asthma, should reduce prolonged or heavy outdoor exertion."
What To Know
The Connecticut Department of Energy and Environmental Protection issued an Air Quality Action Day for parts of Fairfield and New Haven counties until 11 p.m. on Thursday.
The alert is issued when ground level ozone levels are forecast to approach or exceed unhealthy standards.
The Colorado Department of Public Health and Environment issued an Ozone Action Day Alert until 4 p.m. on Thursday. The alert covers Douglas, Jefferson, Denver, Arapahoe, Adams, Broomfield, Boulder, Larimer and Weld counties.
"Warming temperatures and light winds may allow ozone to reach levels that are unhealthy for sensitive groups on Thursday," the NWS notice said.
"The highest concentrations are expected along the western portions of the northern Front Range, from western Denver northward to Fort Collins."
It added, "If possible, please help us reduce ozone pollution by limiting driving gas and diesel-powered vehicles until at least 4 p.m."
Meanwhile, Oregon's Department of Environmental Quality issued an air quality advisory for Klamath County until 10 a.m.
It added that many health and local air agencies had issued wood-burning restrictions, limiting outdoor burning and the use of wood stoves or fireplaces.
What People Are Saying
The Oregon Department of Environmental Quality said in the NWS alert: "People can take the following precautions to protect their health: follow local burn restrictions to prevent deteriorating air quality; avoid strenuous outdoor activity during periods of poor air quality; people with heart or lung problems and young children are especially vulnerable. These people should stay indoors while smoke levels are high; use certified High Efficiency Particulate Air (HEPA) filters in indoor heating, ventilation, cooling and air purification systems; avoid using wood-burning stoves and other sources of indoor smoke if possible."
The Colorado Department of Public Health and Environment said: "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 air quality alert in Colorado is set to remain in effect until 11 p.m. on Thursday, while Connecticut's is active until 4 p.m. and Oregon's until 10 a.m.
The NWS issues regular air quality updates on its website.