In some parts of the United States right now, it's a bad time to breathe. With several metro areas engulfed in an ominous haze, about 87 million Americans face risks from poor air quality, due to drifting smoke from Canadian wildfires that've been raging since earlier this month. These wildfires have triggered air quality alerts across a large portion of the US. Chicago, Detroit and Minneapolis are now among the cities with the worst air quality in the world, according to the tracking service IQAir.com. Even North Carolina, where I live, is under air quality alerts.
Despite the heavy haze, there are some practical and effective steps you can take to protect yourself.
We got in touch with two air quality experts to gain insight into how Americans can take care of themselves. Dan Westervelt, who studies air pollution at the Columbia University Climate School's Lamont-Doherty Earth Observatory and acts as an air pollution advisor to the US State Department, and Richard Peltier, a professor in the Department of Environmental Health Sciences at the University of Massachusetts Amherst, provided their expert opinion via email. Here's what we learned.
How dangerous is poor air quality?
Poor air quality can be hazardous for everyone, but especially for people with respiratory issues such as asthma; individuals with lung and heart disease; the elderly; and pregnant people.
The Midwest is experiencing air pollution about 10 times higher than what health guidelines define as healthy levels for exposure. Westervelt said short-term exposure can lead to adverse health conditions such as coughing, a sore throat, shortness of breath, and stinging in the eyes, while long-term exposure can lead to chronic heart and lung conditions.
Woodsmoke exposure, especially, is associated with inducing asthma attacks and aggravating heart disease. That makes people more susceptible to respiratory infections and leads to an increase in deaths.
"Some people might think that woodsmoke should be harmless because it comes from a natural resource, in trees, but this couldn't be further from the truth," Peltier said. "We know that woodsmoke contains many toxic chemicals, some of which are known carcinogens, and there is clear evidence in the scientific research world that links woodsmoke exposure to really important adverse health outcomes."
Luckily, there are some effective methods you can use to limit exposure and potential side effects.
Tried-and-true ways to protect yourself when air quality is poor
Here are some high-impact steps to take to protect yourself when facing air pollution from wildfires and beyond, according to Westervelt and Peltier.
When indoors, you'll want to:
- Close all windows.
- Turn on your HEPA-filtered air purifier or air conditioner.
- Avoid any activities that generate more pollution, such as burning candles and intense cooking. You should also avoid using a gas stove if you have one.
Limiting outdoor time is crucial when air quality is poor, but if you must leave your home, Westervelt suggests wearing a face mask and avoiding strenuous activity that induces heavy breathing, like jogging or running. Both Peltier and Westervelt also recommend that each person in your household wear an N95 or KN95 mask, though a well-fitting surgical mask can also help block the majority of particulate matter.
Peltier also suggested asking your HVAC technician to upgrade your unit's filters to higher MERV ratings at your next system servicing. MERV is an industry standard that describes how well the filters can remove particulates — the best filters have higher MERV ratings, usually 13 and up. Not all HVAC systems will tolerate higher MERV filters, so it's important to get expert advice first.
"It's important to note that most window air conditioning units are not terribly useful to filter out these particles," Peltier said. "The filter materials they use have a very low MERV rate and don't do much."
Is using an air purifier effective for clean air?
Though air purifiers became more mainstream during the COVID-19 era, experts are divided on how effective they are. Manufacturers in the US aren't allowed to market air purifiers as health products, though CNET's hands-on testing has shown some to effectively filter particulate matter from the air, especially if they use a HEPA filter.
"For indoor air quality, many air purifiers work well, especially the ones that use high-efficiency particulate filters," Westervelt said.
He recommends avoiding air purifiers that generate ozone, which will be identified as electrostatic and ionizing air purifiers. The US Environmental Protection Agency also warns about the risk of ozone-generating purifiers, since ozone molecules can lead to harmful health consequences such as damage to the lungs.
Peltier said air purifiers can be an effective method for cleaning air, but there are two important aspects to remember: They must be the right size for the space you're trying to keep clean, and these spaces have to remain closed to the outdoors. He recommends using them only in the places where you spend most of your time, shifting the machine from room to room. For example, moving it to your bedroom at night or into the living room during the day.
(Learn more about how air purifiers can protect you from wildfire smoke, allergens and other particles.)
Westervelt said air quality forecasts can give you an accurate read on the air quality index for a given region. He recommends airnow.gov as a real-time source for finding air quality data for your city, state or ZIP code.
Peltier said to hope for the best but be prepared for the worst, considering the health risks associated with ongoing smoke exposure.
"We take about 20,000 breaths per day, and this happens whether the air is polluted or clean," Peltier said. "When we take a breath, we inhale air, but also the contents suspended in that air, including pollutants, and we draw this into the deepest parts of our lung. This delivers a wide range of different chemicals into our bodies that cause many adverse health effects."
For more tips to stay safe, read about how air purifiers can protect you from poor air quality and what to keep in mind when shopping for the best air purifier. You should also make sure your air purifier is in the right place and is clean to ensure it's working properly.
While the devastation of wildfires can be harrowing, there are many steps you can take to protect yourself, your home and your loved ones. Here are some additional resources: