Air Quality Alert: Health Effects, How To Stay Safe From Wildfire Smoke

Millions of Americans are facing poor air quality right now due to wildfire smoke, sparking concerns about the health effects.

As of Thursday, June 9, air quality advisories were in effect for more than 100 million people in the U.S. across 16 states spanning the Northeast, South and Midwest, NBC News' Emilie Ikeda reported on TODAY. Many Americans are now under alerts for the third day in a row.

In the Northeast, the poor air quality is a result of wildfire smoke from those raging in eastern Canada. Thick plumes of smoke from blazes in Nova Scotia and Quebec have drifted into the U.S., engulfing Boston, New York City and Philadelphia in a smoky haze.

Across the Midwest and South, high concentrations of ground-level ozone or smog are also causing unhealthy air quality levels in states like Texas and Illinois, NBC News reported.

In some cities, the wildfire smoke is so dense that people can see and smell it in the air. In New York City, many residents took to social media to express concern about the scent of campfire and share photos of the skyline in a reddish-orange haze.

The most common causes of poor air quality are high levels of ground-level ozone and particulate matter, according to the National Weather Service, which result from a mix of natural and human activities that cause air pollution.

Fine particulate matter are tiny airborne particles in smoke, soot, dust, and dirt emitted from things like vehicles, factories, and fires, per the NWS.

Air quality is measured with something called an Air Quality Index or AQI, which ranges from 0 to 500, according to AirNow.gov, which collects data and provides the public with air quality conditions.

The higher the AQI, the higher the level of air pollution and public health concern. An AQI value below 50 is considered good, any AQI over 100 is considered unhealthy for sensitive groups, an AQI over 150 is unhealthy for all groups, and anything over 300 is hazardous, per AirNow. In New York City, the AQI has ranged from 150 to nearly 400 since Tuesday.

"(The air quality) seems better than yesterday, but I want everyone to realize we are still at that dangerously unhealthy level," Dr. Roshini Rajapaksa of NYU Langone, said on TODAY June 8. "Everyone, even if you're not particularly high risk, needs to take this seriously and limit your exposure outdoors."

What are the possible health effects of poor air quality caused by wildfire smoke and how can people stay safe?

"When we inhale, the particles (from smoke) stimulate our airways to become inflamed to not function normally," Dr. Ronald Crystal, a pulmonologist and the chair of genetic medicine at Weill Cornell Medicine, tells TODAY.com.

Wildfire smoke can affect everyone, but certain groups are at higher risk of breathing difficulties and other health issues.

In healthy individuals, poor air quality isn't much of a concern in the short term, but it can cause irritation. "You may cough a bit or feel a little tickle in your throat ... but it's not a permanent problem," says Crystal, adding that these symptoms should resolve as air quality improves.

Per Rajapaksa, other common short-term effects include: burning in the eyes, eye irritation, cough, wheezing, chest tightness, fatigue and headaches. (If any of these symptoms feel severe or concerning, seek medical attention.)

"The risk is for individuals who have preexisting lung disease, particularly asthma, chronic obstructive pulmonary disease, and people who have post-COVID respiratory problems," says Crystal.

The particles can actually stimulate the airways to constrict, he adds. "These individuals already have a problem of constricted airways — for example, patients with asthma wheeze — so the inhalation of the particles can exacerbate the problem."

In addition to worsening underlying respiratory conditions, inhaling these particles also increases the risk of infection, and it can worsen allergies, Dr. Natalie Azar, NBC News Medical Contributor, said on TODAY in a segment aired June 8.

Over time, Dr. Purvi Parikh, an allergist and immunologist at NYU Langone Health, says the fine particulate matter from smoke can cause inflammation and damage the lungs, which can impact lung function or increase the risk of other issues.

Children, especially those who are immune-compromised, and the elderly are also at higher risk, as well as people with underlying heart disease. "Anything that stresses the lung can stress the heart," says Azar.

Fortunately, most of the effects of the poor air quality in the Northeast right now caused by the Canadian wildfire smoke will be short term, Crystal says. "I don't think people should worry about long-term effects because it’ll go away, particularly after rains, and a lot of the pollution will disappear," he explains.

While it's unclear exactly how many more days the air quality will remain unhealthy, Crystal speculates that it should rain in the Northeast in the next few days, which will help improve air quality.

However, you should still check the AQI or air quality reports (which are available on most weather apps and websites) if you live in an affected area.

Itchy eyes a light, dry cough or an irritated throat are usually reasons to be worried about your health in poor air quality, Azar said.

Parikh advised seeking medical attention if you experience any of the following:

When the air quality is considered unhealthy or you're impacted by events like the current wildfire smoke, there are a few steps you can take to protect yourself and minimize the health effects.

The most important thing you can do is stay indoors as much as possible, the experts note. This advice applies to everyone but especially to individuals with preexisting lung diseases such as asthma, COPD and post-COVID respiratory conditions, says Crystal.

"Anybody with pulmonary problems should be very, very careful and stay indoors as much as possible," says Crystal. The same goes for pregnant women, says Parikh, as they are also high risk because they are already in a "stressed" state.

When you're inside, make sure to keep all doors and windows shut to reduce the amount of outside polluted air getting indoors, says Parikh. "If you have a HEPA air purifier, you can run it in your home, as well," she adds.

If you're air purifier is too small to service your entire home or an entire large room, Rajapaksa suggested using it in a smaller room and trying to spend most of your time there.

And air conditioner should be set on recirculating air (mode), says Azar, so that the unit is not pulling in air from the outside. "If you have fans, turn them all on, (but) watch out for bathroom fans and also vent hoods if they blow in air from the outside," Azar adds.

Even if you’re very careful, some pollution will likely make its way into your home, so Rajapaksa also suggested limiting vacuuming and cooking, as these activities can worsen air quality indoors. For similar reasons, don't burn essential oils or vape or smoke inside when outdoor air quality is bad, Azar advised.

If you have to go outside when the air quality is bad, wear a mask, the experts emphasize. "Medical grade masks are best, such as N95s, KN95," says Parikh. Make sure the mask is worn correctly and covers the mouth and nose, fitting snugly on the face.

You should also consider driving instead of walking to wherever you need to do, Rajapaksa advised.

"Make sure you have enough of your preventative and controller medications if you have lung issues," says Parikh. If you use a rescue inhaler, for example, keep it with you at all times.

According to Azar, asthmatics who use a rescue inhaler such as albuterol can use it 15 minutes before going outside.

All exercise and sports should be indoors, says Parikh. You can use the AQI or AirNow.gov reports to find out when the air quality is no longer considered "unhealthy" and it's safe to exercise outside again, but always talk to your health care provider if you have questions.

"If you’re a runner, for example, you’re going to be breathing in more because you’re exercising, so you’re inhaling more air and exposing your lungs to more irritants," says Crystal, adding that this may make breathing uncomfortable or cause phlegm production.

"Right now, it's too dangerous (for anyone) to be exerting oneself outside with this air quality. ... It can put a strain on the lungs and heart," Parikh adds.

Caroline Kee is a health reporter at TODAY based in New York City.