Could air pollution make your memory worse?

Summer is here, your windows are open and the smell of…car exhaust and the latest wildfire are wafting in. This air pollution is harmful to almost every organ https://evidence.nejm.org/doi/full/10.1056/EVIDra2200068?st_source=ai_mode, including the brain. Today on Short Wave, we talk about one way air pollution may cloud your memory. Interested in more episodes about how where we live affects us? Email us your question at [email protected] mailto:[email protected] and we may turn it into an episode! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave http://plus.npr.org/shortwave. See pcm.adswizz.com https://pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. NPR Privacy Policy https://www.npr.org/about-npr/179878450/privacy-policy

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• 0:00Speaker 00

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• 0:15Speaker 00

  You're listening to Short Wave from NPR.

• 0:20Emily Kwong?

  Hey, Shortwavers. Emily Kwong here.

• 0:22Speaker 02

  And Angela Zhang.

• 0:23Emily Kwong?

  With our bi-weekly science news roundup featuring Mary Louise Kelly from All Things Considered. Hello.

• 0:29Speaker 03

  Hello. Good to be back with you.

• 0:31Emily Kwong?

  Oh, thank you so much for joining us. We are going to start with something kind of serious today. I know, shocking because we're such clowns. But we're going to be talking about air pollution and health, specifically brain health. How are you feeling about your memory these days?

• 0:46Speaker 03

  I am great on things that happened years ago. I am not so great on where my car keys were left this morning.

• 0:53Emily Kwong?

  It is some complex science. Yeah, yeah, yeah. Memory is a complex thing, and our brains are fragile instruments in that way. So we're going to talk about that. And our second and third topics are about critters and what they can teach us about the world around them.

• 1:07Speaker 02

  We're going to dive deep to will graveyards, and then we're going to zoom in to ancient squirrel droppings, if you can believe that those words can even go together.

• 1:16Speaker 03

  I will come to believe them after you share these two things I definitely did not have on my radar this week.

• 1:22Emily Kwong?

  It is like, it is such show and tell. Short Wave roundup is like, here's some treasures that we harvested for you.

• 1:29Speaker 02

  Yeah, you know what they say. I mean, you know, you are what you eat, or at least poop out what you eat.

• 1:34Emily Kwong?

  And people may study it hundreds of years later. So today on the show, we've got stories on air, land, and sea. You're listening to Short Wave, the science podcast from NPR.

• 1:52Speaker 04

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• 2:29Speaker 00

  This message comes from Edward Jones, where they believe rich isn't about having life all figured out. It's opening yourself to all the possibilities. That's why your dedicated financial advisor provides long-term planning built around you, meeting you where you are and helping you get closer to where you want to be. So no matter where you're starting from or wherever life takes you, you can move forward with confidence. The key to being rich is knowing what counts. Let's find your rich together. Edward Jones. Member SIPC. This message comes from HomeServe. Got a burst pipe, HVAC outage, or electrical issue? HomeServe has your back. Go to homeserve.com/audio for 50% less your first year.

• 3:14Speaker 00

  Savings compared to renewal price, Fort Worth, Florida.

• 3:18Emily Kwong?

  All right, Angela and Mary Louise, our hosts, we have got a lot to get into. Um, what do you want to do first, Mary Louise?

• 3:24Speaker 03

  Let's do the air pollution and how it can affect your memory. Tell me more.

• 3:29Speaker 02

  So the study I have for you today is about these really, really tiny particles of air pollution, like 30 times smaller than the width of a human hair. And these particles are released by wildfires and car exhausts, among other things, and they're bad for your heart and your lungs, and they can also get directly to the brain through the blood.

• 3:48Speaker 03

  That sounds awful. What, what do we know about how they affect, say, a person's memory, though?

• 3:54Emily Kwong?

  Yeah, so to study how air pollution affects the brain, researchers used a database containing information about Black Americans living in California. The researchers looked at how much air pollution someone may have experienced based on their home address, and then looked at their cognitive test scores. And while we know pollution is bad for the brain in general, what the researchers found is that it also affected a specific type of memory.

• 4:17Speaker 05

  The people who had been exposed to more pollution over the years had weaker semantic memory. So really, that long-term pollution looked like it was aging the brain's memory ahead of schedule.

• 4:31Speaker 02

  That's Catherine Conlan, a study author. She's a professor of epidemiology at the University of California, Davis. She told me that semantic memory is how your brain stores information. So like that New Delhi is the capital of India, or that 3 plus 2 equals 5.

• 4:45Speaker 05

  When that's effective, we can think about how that's the kind of thing that... Might chip away at a person's independence or our ability to have the quality of life that we would hope to have.

• 4:56Speaker 03

  But how do they know it's air pollution and not some other factor in these people's lives?

• 5:00Emily Kwong?

  The researchers did control for differences in education and income. But when it comes to geography, you're right. It is hard to separate air pollution from things like noise exposure, which could also influence brain health. They can't say for sure that it's air pollution that is leading to worse memory.

• 5:16Speaker 02

  But including Black Americans in research, which is what the study did, means that solutions can hopefully reduce inequity since they're almost twice as likely as white Americans to have dementia and they're more likely to live in polluted or redlined neighborhoods.

• 5:29Speaker 03

  OK, so now we have this research. What do we do about it, Emily?

• 5:34Emily Kwong?

  Well, it definitely gives policymakers and urban designers something to chew on. But in the meantime, there are things individuals can do right now.

• 5:42Speaker 02

  Catherine said to, quote, "know your air by checking your local air quality on your weather app. And then during wildfires or smoggy days, keep your windows closed and buy or make your own air purifiers. And then lastly, don't make your indoor air worse. So skip the candles and gas stoves if you can.

• 5:59Speaker 03

  No, I love my candles.

• 6:00Emily Kwong?

  Just a few less candles.

• 6:02Speaker 03

  A few less candles. OK, let's turn to topic number two, from up in the air to under the sea. We are going to a whale graveyard. I'm trying to picture this, Emily.

• 6:14Emily Kwong?

  Yeah, it's a really cool place. So when whales die, many fall to the bottom of the sea. And when they land, their carcass has become an energy-rich habitat, drawing a wide variety of organisms from across the deep sea to feast. Scientists call these sites Whale Falls.

• 6:30Speaker 03

  Whale Falls because they're fallen whales.

• 6:32Emily Kwong?

  Yes.

• 6:32Speaker 03

  So now I'm picturing like a deep sea buffet for all these way-deep-down creatures.

• 6:38Emily Kwong?

  Yeah, who are used to just getting like snacks drifting down to the bottom. So it's really cool. And a research team in China may have found the deepest and most extensive whale graveyard in the world. Located in the Diamantina Zone in the Indian Ocean, the team published these findings in the journal Nature.

• 6:55Speaker 03

  What does this whale graveyard actually look like?

• 6:58Speaker 02

  Yeah, so you can picture a nearly 750 mile long stretch of whale fossils. These are bones that are shaped like chimneys or even giant cigars. And the oldest fossils were 5.3 million years old. It's pretty old.

• 7:12Emily Kwong?

  So old. And during dives with a submersible, the team also discovered five of those whale fals, these five whale carcasses teeming with scavengers. The team saw a whole thicket of microbes, squat lobsters, brittle stars, and jellyfish, and even species that may be new to science, like bone-eating worms.

• 7:29Speaker 03

  Bone-eating worms. Okay, Emily, Emily, you just said this is the Indian Ocean that we're in, right? Is there something specific about that, Angela, that so many whale carcasses end up in this particular part of the Indian Ocean?

• 7:44Speaker 02

  One reason offered by the lead author, Xiao Chongpeng, based at the Chinese Academy of Sciences, may have to do with the shape of the seafloor in this part of the world, or maybe even the currents that are around it.

• 7:53Speaker 06

  The surface currents and the deep currents can funnel or concentrate those carcasses on the seafloor.

• 8:04Emily Kwong?

  Biologists, by the way, are so excited about this finding because these ecosystems are incredibly unique. Stephen Godfrey, a paleontologist at the Calvert Marine Museum, who was not a part of the paper, said the study reminded him of a trailer for the first in a series of epic movies, and that he hopes there will be many more of these blockbusters to come.

• 8:22Speaker 03

  Here, here. Okay, that brings us to our last story. You mentioned prehistoric mysteries. You mentioned ancient squirrel poop.

• 8:32Emily Kwong?

  We got the goods.

• 8:33Speaker 03

  Where is this going, Angela?

• 8:36Speaker 02

  All right, so we got to go back in time to the Pleistocene epoch. This is one of the most critical turning points in Earth's history because, starting around 12,000 years ago, Earth went from chaotic cycles, so ice, warm spells, back to ice, to the Holocene, which is our current epoch.

• 8:51Emily Kwong?

  And a study out this week in Nature Communications zooms in on the Yukon in northwestern Canada, where we find an unassuming critter, the Arctic ground squirrel. The study's lead author, Tyler Murchy, refers to them this way.

• 9:03Speaker 07

  They're kind of like accidental Ice Age archivists.

• 9:07Speaker 03

  Archivists. Why archivists?

• 9:09Emily Kwong?

  Because they hibernate underground for about eight months of the year, and when hibernation ends, those squirrels are hungry. And just wake up like a zombie crawling out of the ground, you know?

• 9:19Speaker 02

  And finding anything they could eat in the landscape. That's ancient DNA researcher Mikel Winter Peterson. And what an image, right? He didn't work on this paper, but he says squirrels would have eaten really anything, plants, insects, and even the remains of animals bigger than them. So archiving their DNA, if you will.

• 9:38Emily Kwong?

  In their waste.

• 9:39Speaker 02

  In their waste.

• 9:40Emily Kwong?

  That's the archiving. Yeah.

• 9:42Speaker 02

  And sure enough, you know, they found these groups of plants, and they also found DNA from woolly mammoths, an extinct form of bison, caribou, an extinct Yukon horse, and then even some birds, all, if you can believe it, in these squirrel droppings.

• 9:57Speaker 03

  So we can study the DNA of woolly mammoths because of this ancient squirrel poop? I had no idea. You could learn all that from animal droppings.

• 10:05Speaker 02

  I know. And funny you should say that because in the past, researchers have sometimes dismissed animal excrement because they thought, well, it's only just going to show that animal's DNA, right?

• 10:14Emily Kwong?

  But the fact that they learned so much about the environment at this time shows this could be a method for understanding Earth's history. Here's Tyler.

• 10:23Speaker 07

  So if you're out for a hike and you see, you know, some old poop, you might think that's nothing. But the kind of data you can get is just remarkable with millions and millions of DNA fragments of all these organisms together that can paint a picture from something that you otherwise would have just thought nothing of passing by.

• 10:40Emily Kwong?

  So, Mary Louise, I hope that gives you something to think about on your next hike when you look at the ground or step in it.

• 10:46Speaker 03

  Who, who needs mountains? Who needs sparkling streams when we can be looking at squirrel poop?

• 10:51Speaker 02

  Totally. And if you're not a natural person, maybe you can just stay inside and watch some Ice Age and come chat with us as a movie club.

• 10:58Emily Kwong?

  Wow.

• 10:58Speaker 02

  Anyways.

• 10:59Emily Kwong?

  Anyways, I'm sure you want to.

• 11:01Speaker 02

  That could be for everybody.

• 11:02Emily Kwong?

  I'm sure you want to come back on our show. Thanks for, thanks for being here today.

• 11:06Speaker 03

  My total pleasure. Anytime.

• 11:12Speaker 02

  You can hear more of Mary Louise Kelly on Consider This, NPR's afternoon podcast on what the news means for you.

• 11:19Emily Kwong?

  And for more science stories, just like this one, follow Short Wave on whatever app you're listening to.

• 11:25Speaker 02

  This episode was produced by Rachel Carlson and Kai McNamee. It was edited by Rebecca Ramirez, Christopher Intagliata, and William Troop.

• 11:34Emily Kwong?

  Tyler Jones checked the facts. Maggie Luthar and Josephine Neonai were the audio engineers. I'm Emily Kwong.

• 11:39Speaker 02

  And I'm Angela Zhang. Thanks for listening to Short Wave, the science podcast from NPR.

• 12:00Emily Kwong?

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