ADRIAN MA, HOST:
Across the northeastern U.S., people are struggling to breathe because of wildfire smoke. For the past few days, smoke from Canadian wildfires has drifted as far north as Wisconsin and as far south as Virginia, enveloping many cities in this sickly haze. And even in places where the air quality has improved a bit, there still remains a kind of acrid, plasticky smell.
Derek Mallia is a professor at the University of Utah's Atmospheric Sciences Department and an expert on wildfire smoke. We've asked him to come here to help us understand this smoke and how it changes as it's carried hundreds of miles away from its source. Derek Mallia, thanks for taking the time.
DEREK MALLIA: Yeah. Thank you for the invitation. Happy to be here.
MA: And to start off, I have to say that we're not really used to this kind of smoke in our part of the country. What's your reaction when you see smoke like this kind of blanketing the East Coast?
MALLIA: Yeah, yeah. So this is definitely really unusual. I think we've only seen this a couple times over the past 20 or 30 or so years. I'm actually originally from the East Coast, and this is definitely not something that I saw a whole lot when I was a kid. I think there was one instance in, like, 2002 where there was smoke from Canada. But otherwise, I don't really have any recollection of this happening in that region.
MA: You know, one might expect smoke from wildfires to smell kind of like a campfire, you know? But this smoke has a different quality to it. In addition to smelling different, it can even create a sort of burning sensation when you breathe it in. Why is that?
MALLIA: Yeah. So, you know, whether smoke smells, you know, like a campfire or if it smells like something different is really dependent on, you know, how old is that smoke? That's a big driving factor. So the age of that smoke will dictate how many chemical reactions it undergoes in the atmosphere. So of course, it's - as smoke is moving through the atmosphere, it's interacting with those other pollutants, and so that can actually modify the smoke and have it, you know, basically have a different smell. So that is one maybe potential driver of that.
Another thing is, too, is that when you're really close to a wildfire or it's traveled not that long in terms of a distance, the smoke might be less diluted, and so you get kind of this fresher smoke smell. And so those are some of the factors that kind of dictate what that smoke smells like. But along those lines, all smoke, whether it's new or old, it's still not good for your health because it's really small. It can penetrate deep into your lungs. It's just not good for your health. So yeah, I think smoke, unfortunately, of all flavors, is - just has a lot of health concerns.
MA: Well, say more about that. How dangerous, from a health perspective, is inhaling this wildfire smoke?
MALLIA: Yeah. So there's been a few studies, one that came out of San Diego as part of the Scripps Institution. And they found that in terms of pollution types - so those pollution types were, you know, wildfire smoke, dust and anthropogenic pollution sources - and it was actually the wildfire smoke that was actually the most hazardous, which kind of surprised me 'cause you would think that because it comes from a natural source that maybe that would be slightly better for you. But unfortunately, that is actually not the case. So that was surprising. And there's been a few studies that have shown that now since then. And that study came out loosely, I think, around 2020, 2021.
MA: How concerned are you about the prevalence of wildfire smoke events in the future?
MALLIA: Yeah. So, you know, unfortunately, wildfires have been shown to have one of the strongest linkages to climate change of a lot of the weather phenomena that we observe. It's one of the most kind of concrete signals that we see, and that's just because with climate change, you'll see more droughts, more hotter conditions. And both of those things basically dry out your vegetation and make that vegetation easier to burn, and so the fires can move quickly and consume a larger amount of forest.
And so along those lines, yeah, I am definitely concerned that, you know, due to climate change, that we are going to see bigger wildfires. There's been a number of studies that have shown that. And yeah, I think, unfortunately, the cat is out of the bag in the sense that we're already seeing worse wildfire seasons across the Western U.S. The trends are a little bit less conclusive for Canada, but it is expected that, like the Western U.S., you would see those similar trends in Canada, and we might already be starting to see that. So I think in terms of air quality hazards, wildfire smoke in the future - of all the air quality hazards, I think that's the one that concerns me the most.
MA: Derek Mallia is a professor at the University of Utah. Thanks again for taking the time.
MALLIA: Cool. Thank you. Transcript provided by NPR, Copyright NPR.
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