Wildfires in Canada are sending smoke over U.S. cities like Detroit, Chicago and Pittsburgh.

Wildfire smoke contains fine particulates, also known as PM2.5, by scientists. These particles, lightweight and tiny, travel far and wide and can go deep into your lungs and bloodstream, causing inflammation, heart attacks, strokes, asthma and other breathing issues.

The Scripps Institution of Oceanography did a study in 2021 that found wildfire smoke is up to 10 times more harmful to humans than other types of pollution, like car exhaust, because of the abundance of PM2.5 particles.

If you can see the haze outside your window, the sky looks an unusual color or the air smells like campfire, it's best to stay indoors if possible.

Here are some more tips on how to protect yourself from wildfire smoke:

How to interpret the air quality index (AQI)

According to AirNow, the higher the AQI value in your area, the greater the level of air pollution and the greater the health concerns.

AQI of 100 or below

An AQI of 50 or below represents good air quality and won't pose risks. Air quality is still acceptable if the AQI is 51-100, but there may be a risk to people who are unusually sensitive to air pollution, such as those with respiratory illnesses.

AQI between 101 to 150

If the AQI is 100 to 150, people with respiratory or other medical issues should start taking precautions like avoiding the outdoors altogether or wearing a mask when outside.

AQI between 151 to 200

If the AQI is 151 to 200, most people will start noticing some minor effects like a scratchy throat, runny nose and maybe some nausea. If you're in a sensitive group – for example, if you've been diagnosed with asthma or chronic obstructive pulmonary disease (COPD) – then you'll want to look out for signs of more severe health problems, like chest tightness, an inability to catch your breath, and sudden dizziness or confusion.

AQI between 201 to 300

If the AQI is over 200 in your area – this should show as a purple color on a map – then health risks are increased for everyone, whether you have underlying issues or not. You might notice minor symptoms, such as coughing, but everyone should be alert to symptoms that might indicate a more serious problem, such as a tightening or weighted feeling in the chest or labored breathing.

AQI of 301 or above

If the AQI is 301, everyone will likely experience some form of smoke-related health issue. If you can, move all activities indoors or reschedule them for another day.

If you can, stay inside

If the AQI in your area is above 150, avoid going outside if you can. Avoid things like exercising outside or running errands that can wait until the air quality has improved. If you need to be outside, use a well-fitting N-95 mask if you have one. Because of those small pm2.5 particles, something like a bandana won't protect your lungs from the smoke.

Minimize your exposure indoors

Close all doors and windows to the outside. If your windows have cracks, use a damp towel to cover them to limit the air from outside.

If you have central air conditioning, run it because it should have an air filter that can help.

If you have an air purifier or air filter, those are best for improving your indoor air quality. You can also make a DIY box fan air filter for wildfire smoke.

If you're in the car on a smoky day, press that recirculate button. That way, your car won't be pulling air from outside but just recirculating the air that's already in the car.

Self-care for smoke-filled days

Try and use a hydrating moisturizer to keep those smoke particles out of your pores. This will also help if your skin feels dry from the smoky air.

If the smell of the fires is getting to you, try dabbing a bit of essential oil under your nose or use a strong-scented chapstick to mask the smell.

Stay hydrated! Fires usually happen where the air is dry and windy. And the weather patterns that carry the smoke can bring those conditions as well.

And try to stay calm. Smoke days are stressful and are an upsetting reminder of our overheating planet. Anxiety will worsen the health effects of smoke exposure, so it might be helpful to remember that other communities have come through similar or worse smoke situations, and the air will eventually clear.

The audio portion of this episode was produced by Sylvie Douglis and edited by Meghan Keane.

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