Why Climate Change Is Making Seasonal Allergies Worse : Short Wave We ask allergy expert Dr. Juanita Mora if seasonal allergies are getting worse. Plus, some quick tips for managing those pesky allergy symptoms.

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Micro Wave: Are Seasonal Allergies Getting Worse?

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You're listening to SHORT WAVE from NPR.

Hey, nerds. Today, we are talking allergies with SHORT WAVE producer and in-house allergy sufferer, Brit Hanson. Hiya, Brit.

BRIT HANSON, BYLINE: It's good to be back, Maddie.

SOFIA: OK, Brit, I know that you and more than 50 million other Americans are plagued by allergies.

HANSON: Yeah. Maddie, I don't want to be too whiny about this, but plagued is right.

SOFIA: (Laughter).

HANSON: We're talking pollen, mold...


HANSON: ...Dust, dust mites, pet dander. And, you know, spring just started. And I already have a very unpleasant combo of sticky eyes and itchy throat, which you can probably hear.

SOFIA: No, no. You sound great. You sound great. But honestly, Brit, I just started out having allergies, too, like, a couple of years ago. And it's a racket.

HANSON: It's the worst.

SOFIA: (Laughter).

HANSON: You know, Maddie, I've had allergies for a really long time. But I got to say it kind of seems like each spring, my allergies are getting worse. And that's what I want to talk about today because it's not just me. I swear.

SOFIA: (Laughter).

HANSON: I've heard this idea from a lot of people that allergies, especially the seasonal ones, are, quote, unquote, "a lot worse than they used to be." So I went looking for answers.

SOFIA: A little allergy investigation.

HANSON: (Laughter) Yes. I only take on the hard-hitting topics.

SOFIA: (Laughter) I know that about you. So today on the show, is allergy season actually getting worse every year? We ask an expert and get some quick tips for managing those pesky symptoms.

HANSON: Plus, a bit of listener mail that we'll share, too. I'm Brit Hanson.

SOFIA: And I'm Maddie Sofia. You're listening to SHORT WAVE, the daily science podcast from NPR.


SOFIA: OK, Brit, we are talking about whether or not allergy season is getting worse. So who'd you talk to?

HANSON: Yeah, so I called Dr. Juanita Mora. She's an allergist and immunologist based in Chicago.

JUANITA MORA: As an allergist, I get to treat people of all ages - from little babies all the way to adults with environmental allergies, asthma, hives, eczema.

HANSON: Maddie, she absolutely loves her job, especially because of that bit she mentioned about working with generations - babies, adolescents, parents, grandparents, all in the same family. And she does a lot of education and outreach in the community, too.

SOFIA: I want her to be my allergist, Brit.

HANSON: I know, right?

SOFIA: (Laughter).

HANSON: So, Maddie, one of the things that Juanita wanted to make really clear when I asked her about whether or not allergy season is getting longer is that we were specifically talking about seasonal allergies.

SOFIA: So, like, pollen.

HANSON: Exactly.

MORA: Springtime, which is tree pollen, summertime, which is grass pollen, and ragweed, which is fall. And then you have the mix of mold in the spring and fall, as well, too.

SOFIA: What a mix, Brit. What a mix. OK, so what did you find out? This is an investigative report, and I want answers.

HANSON: OK, OK, OK. I'm just going to play the tape.

It feels like allergy season is getting worse every year. Is that actually true? Is allergy season getting worse?

MORA: So definitely, allergy seasons are getting longer - so spanning more days. And we're also seeing higher numbers of pollen levels, as well, too.

SOFIA: OK. All right. Well, that was easy. You were right.

HANSON: (Laughter).

SOFIA: Do - I mean, do we know why the pollen levels are higher and the seasons are getting longer? I have an idea, but I want you to tell me.

HANSON: OK, so Juanita says that there are a couple of factors that are key to understanding why. So let's start with factor number one. There's just more pollen in general. And one big reason for that is more carbon dioxide.

MORA: We know that sunlight combined with carbon dioxide fuels the growth of plants. So whenever we have more carbon dioxide in the air, then we have more pollen production.

SOFIA: OK, so, basically, the more carbon dioxide in the atmosphere, the more pollen that is produced.

HANSON: Yeah, that's right. And here's the bad news. We know that carbon dioxide in the atmosphere has increased more than 25% over about 50 years' time. And a big reason for that is carbon emissions caused by humans. So as the carbon dioxide concentration in the atmosphere is rising, so is the amount of pollen being produced by lots of plants, at least up to a point.

SOFIA: OK, what is factor number two?

HANSON: Rising temperatures.

MORA: Now we have overlapping seasons as well, too, with the increased rising temperatures. So you have trees coexisting with grass. And now you have grass with actual ragweed and mold. So it makes allergy sufferers even more aware of their symptoms.

HANSON: So, Maddie, not only is there more pollen being produced in general because of carbon dioxide in the atmosphere. There's also more pollen because the longer warm weather lasts, the longer the pollen season.


HANSON: Basically, higher temperatures are causing pollen to start growing sooner and then keep it growing longer.

SOFIA: (Vocalizing).

HANSON: Yeah, one recent study found that the pollen season in North America has lengthened more than 20 days from 1990 to 2018.

SOFIA: Brit, I feel like a lot of this comes back to climate change - I mean, increased CO2, rising temperatures. Like, I know it's pretty complicated. Like, am I oversimplifying this here?

HANSON: You're not. Not at all. Juanita says that that's the capital B big factor - climate change. So let's take ragweed, for example. One study done in Europe estimates that by 2050, airborne ragweed concentrations could be about four times higher than they are right now. And researchers say that climate change is one of the major contributing factors.

MORA: because of the increased carbon dioxide levels, the rising temperatures. It's the perfect storm for this.

SOFIA: Wow. All right. Well, honestly, Brit, all you did was bring me bad news today.

HANSON: I'm the worst. So OK, how about this? I'll share a bit of helpful allergy advice with you and all of our fellow allergy sufferers.

SOFIA: I think at this point, it's the least you could do, Brit Hanson.

HANSON: (Laughter). OK. So Juanita shared a few tips with me, and I've been using them myself. So tip number one, if it's allergy season, do not sleep with your windows open. And if you like, go out for a drive, keep your windows up in the car, too.

SOFIA: OK, I didn't know that. Keep the outside out. Got it. Check.

HANSON: Exactly, so tip number two, if you are outside for any extended period of time, take a shower when you come home.

SOFIA: OK. Wash the outside off you and your clothes if you go out there.

HANSON: Yes. And lastly, tip number three, check the pollen count online. You can also, like, download one of these apps that shows you the pollen count in your area. It's really helpful.

SOFIA: OK, so, like, I know when it's getting really bad out there.

HANSON: Exactly.

SOFIA: All right. I'm about to download that. OK. All right, Brit. Thank you so much for validating the allergy struggle and also for sharing some tips with us.

HANSON: Oh, my God. No problem. Maddie, one more thing, though. Juanita says that these masks we're all wearing to keep ourselves and other people safe during the pandemic - those are great for Lessoning allergy symptoms, too. So bonus - wear your mask, everybody. Just do it.

SOFIA: Love it. Love it. OK, B. You ready for some listener mail?

HANSON: Yeah, let's do it.

SOFIA: So this email came from a listener who has been working her way through some of our earlier shows and came across an episode on perimenopause from last September.

HANSON: Yes, we love super fans.

SOFIA: Love them, love them. OK, I'm going to read you a part of this letter. (Reading) Hi, folks. I hope you're doing well. First of all, I really appreciate how gender-inclusive you were. Second, I wanted to add that perimenopause and menopause can happen to folks who don't have a uterus but do have ovaries. Lots of folks like myself are born without a uterus but still have ovaries present. And we go through hormonal cycles without the menstruation. It's the best of both worlds, in my opinion. So just wanted to include us in future eps about hormonal and menstrual-related things. Thanks as always for the show. I'm a big fan.

HANSON: Oh my God. Yes, Maddie, I love this note.

SOFIA: I knew you would. I knew you would.

HANSON: Thank you so much for sharing it. And, listener, thank you so much for writing in. Honestly, we're always looking for ways to be both more accurate and more inclusive. So thank you.

SOFIA: Absolutely. Absolutely. We love hearing from all of you. And you have taught us so much, just like this. So if you've got a note to share, email us at shortwave@npr.org.


HANSON: This episode was reported and produced by me, Brit Hanson.

SOFIA: Fact checked by Rasha Aridi and edited by Viet Le. The audio engineer for this episode was Josh Newell. I'm Maddie Sofia. Thanks for listening to SHORT WAVE from NPR.

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