Wildfire smoke can irritate your lungs, and may be as dangerous as cigarettes. Here's how to protect yourself.

• Wildfires across Canada are giving off smoke that is spilling into the US.
• Hazy skies cloaked the East Coast and Midwest on Tuesday, and the EPA issued air quality alerts.

Wildfires are sweeping across Canada, and the smoke is spilling down into the United States, cloaking the East Coast with haze and an acrid smell.

US authorities issued air quality alerts from Cleveland to New York City, urging people to stay inside.

While eerily beautiful, the yellow atmosphere, red-orb sun, and lavender mist are a result of fine-particle pollution (or, PM 2.5), Dr. David Hill, a pulmonologist with the American Lung Association, told the AP.

"We have defenses in our upper airway to trap larger particles and prevent them from getting down into the lungs. These are sort of the right size to get past those defenses," Hill said. "When those particles get down into the respiratory space, they cause the body to have an inflammatory reaction to them."

What is the risk of wildfire smoke?

Fine-particle air pollution can cause inflammation in the lungs and reduce heart function – lasting effects similar to smoking cigarettes or exposure to diesel exhaust, the New York Times reported.

Dr. Kari Nadeau, a physician and scientist at Stanford University, told the Times she believes the risk to our health is higher than that of smoking cigarettes. "Cigarettes at least have filters," Nadeau said.

This kind of air pollution is particularly risky for children, whose lungs are still developing.

"They breathe in more air per unit of body weight," Laura Kate Bender, the lung association's National Assistant Vice President of healthy air, told the AP.

The risk of lung and heart irritation is also higher for older adults and people with lung or cardiovascular conditions, including asthma.

6 ways to stay safe when it's smoky outside

• Keep an eye on the air quality in your area to determine how long you should exercise caution. Until the risk passes, there are easy things you can do to protect yourself from experiencing long-term lung inflammation.
• If possible, stay inside and close your windows, Hill said. (You can punch your zip code into AirNow.gov to find out the air quality in your area.)
• Do not burn candles, light a fire, or smoke indoors. That increases indoor pollution, according to a blog post from epidemiologist Katelyn Jetelina, of the University of Texas Health Science Center.
• Do not vacuum. That also affects your indoor air by kicking up any fine particles that may have come in through your window or door, Jetelina said.
• If you do go outside, wear an N95 mask, which — if fitted correctly — blocks out 95% of particles larger than 0.3 microns. As such, they effectively keep out 2.5-micron particles, which we're seeing from the wildfire smoke. "N95 masks are the type of face covering protection that I would recommend for somebody who is outside during the air pollution caused by wildfires," Marina Vance, an assistant professor of mechanical engineering at the University of Colorado, Boulder, told Healthline.
• While inside, you can run your air-conditioning unit if it has a good HVAC filter, and an air purifier can help too, the American Lung Association recommends.