Smoke from Canadian wildfires blanketed large portions of the Midwest and Northeast on Wednesday, prompting health officials in multiple states to warn residents to stay inside in order to avoid exposure to unhealthy levels of particulate matter in the air.
Officials in Wisconsin and Michigan have issued statewide air quality alerts that will remain in place at least through Thursday as forecasters expect the smoke to continue to billow through the Great Lakes region. Alerts are also in place covering the majority of Minnesota, including the entire eastern half of the state. As of midday on Wednesday, Duluth, Minn., was experiencing some of the worst air quality in the country, with an Air Quality Index score of 902. Any score above 100 is considered unhealthy.
In the Northeast, states including New York and Massachusetts have also issued advisories warning that air quality may be unhealthy for sensitive groups, as wildfire smoke has created a yellow haze in the skies over cities like Boston and New York City. Alerts have also been issued for parts of Ohio, Illinois and Indiana.
Smoke forecast for 6 p.m. ET Wednesday, July 15, in the continental United States. Red and purple regions indicate areas with the highest smoke concentration.
(National Oceanic and Atmospheric Administration)
Where are the fires exactly?
The smoke is coming from hundreds of active wildfires burning across Canada. On Wednesday afternoon, the country’s wildfire monitoring agency listed more than 800 active fires, including 188 that were categorized as “out of control.”
Wildfire smoke is impacting parts of the U.S. that were already enduring a major heat wave, which has led the National Weather Service to issue major or extreme heat risk alerts for nearly 112 million Americans.
The NWS expects the smoke to continue to pour into the Midwest and Northeast at least through Friday, with bands spreading further South into Pennsylvania, West Virginia and Virginia.
Air quality forecast for Wednesday, July 15.
(U.S. Environmental Protection Agency)
Why is wildfire smoke dangerous?
Smoke from wildfires is filled with harmful gases and small pieces of particulate matter that can cause a wide range of serious health problems for people who are exposed to it.
“Fine particulate matter from wildfire smoke is particularly dangerous because it can penetrate deep into the lungs and enter the bloodstream, potentially causing damage to multiple body systems, including the cardiovascular and nervous systems,” Jessica Yu, a research scientist at Stanford University, said in a panel discussion at the school last year. Yu’s coresearcher, Lisa Patel, estimated that wildfire smoke is “10 times as toxic” as typical air pollution.
Smoke is especially dangerous for members of sensitive groups, including people with heart or lung disease, the elderly, small children and anyone who might be at risk of extended exposure, including outdoor workers.
How to stay safe
Health experts say the No. 1 way to protect yourself from wildfire smoke is to limit your exposure as much as possible. Avoid going outside unless it’s absolutely necessary and keep trips short whenever possible. Resources like AirNow, the federal government’s national air quality monitoring system, can help you understand how severe the risk is and plan accordingly.
If you are going to go outside, health officials advise that you wear a mask, but not all masks will get the job done. Experts say surgical masks, like the ones that were most commonly used during the COVID-19 pandemic, offer only minimal protection from the particulate matter in wildfire smoke. Respirator masks, such as an N95, are much more effective.
While indoors, it’s important to keep all windows and doors securely shut. Running the air conditioner can help filter particulates out of the air, but ensure that the system is recirculating air that’s already inside the home, not pulling in new air from outside. Using a commercial air filter, or fashioning your own using a fan and other household items, can be beneficial.
Officials also recommend turning part of your home into a “clean room” that is especially insulated from wildfire smoke, where all members of the household can gather together until the risk has passed.
