Special Episode: Carl Zimmer & Airborne

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Welcome to our newest episode in the TPWKY Book Club series, where I get to chat with authors about their latest books in science and medicine.

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By now, we are all fairly familiar with the concept of the microbiome, the community of microbes that live in a particular environment, such as your gut or your skin, or maybe even inside your belly button.

But how many of you have heard of the aerobiome?

We don't often think of the air as a medium teeming with microbial life, but as Carl Zimmer demonstrates in his latest book, Airborne, The Hidden History of the Life We Breathe, that may be a critical oversight.

In this book club episode, award-winning science writer Carl Zimmer joins me to discuss the long-neglected science of aerial life and the public health implications of this research.

Many of you may recall the debate that sprung up seemingly out of nowhere in the first couple of years of the COVID pandemic when scientists couldn't seem to agree on whether the virus was transmitted via respiratory droplets or whether it was airborne.

Why this distinction mattered and how the issue grew so contentious is just part of what Zimmer covers in Airborne.

By placing this debate in the broader context of the history of aerial biology, he draws a line from the early days of germ theory to the pioneers of this emerging field, from the height of biowarfare research to a Washington State choir in the first weeks of the COVID pandemic.

Linking together these disparate stories from the history of science, Zimmer presents a revelatory picture of a scientific field you didn't know existed.

How might the COVID pandemic have been different if we acknowledged the airborne potential of this virus earlier?

What lessons can we draw from this oversight to apply to future outbreaks?

What even lives in the air and why does it matter?

We get into all of these questions and so many more.

According to a quick Google search, we breathe about 22,000 breaths a day, breaths that we don't often think about.

But after this episode, you'll have a newfound respect for those breaths and the invisible airborne life all around us.

I am very excited to be bringing this episode to you, so let's just take a quick break and get started.

Carl, thank you so much for joining me today.

Thanks for having me.

I have long been such a fan of your work, and I really especially appreciated your latest book, Airborne, which tells this really fascinating story of discovery, dismissal, and then ultimately kind of redemption in the end.

To start us off, can you give us this big picture view of what the story that you explore in your book and what inspired you to write about it?

The story is about the air and how humanity has slowly come to appreciate the fact that it's alive.

In other words, we really are walking around on the floor of a giant living ocean that is filled with trillions upon trillions of organisms, thousands of different species,

a few of which we can see.

We can

a see a goose flying overhead, but for the most part, it's totally invisible to us.

And I guess I say this the seed of

this book came about during the COVID pandemic.

I was working at the New York Times and I, along with my colleagues, we were just trying to write as fast as we could about this totally new disease.

And, you know, it was challenging because scientists themselves are trying to figure out what exactly this disease is like.

And one of the biggest stumbling points, one of the areas with the most debate and uncertainty was how it spreads.

You had people telling you on TV to wipe down your groceries.

I know I did.

And just, you know, keep your distance from people and, you know, you'll be fine.

Then there were other, there were scientists, a small number of scientists at first, who were saying, we think this might be airborne.

World Health Organization explicitly saying COVID is not airborne.

And, you know, it took a couple years.

And then World Health Organization said, yeah, it's airborne.

And I just thought,

why was that so hard?

Yeah.

And the scientists themselves said to me, like, well, you need to understand the history.

One scientist said, you know, history set us up.

And so that led me down this path to discover this whole history of this science of life in the air, which is called aerobiology.

Yes.

And as you discuss, you know, this, we're living underneath this ocean of all of these different organisms, this, the aerobiome.

What can you tell me about the aerobiome?

Like, who, who's up there?

Who's floating around besides the geese that we see?

Well, all sorts of things.

The numbers are kind of crazy.

I mean, I actually have to write them down and double-check them because I'm like, did I get that right?

Because they're just, so I'll just give you one example.

So insects okay

so you know you

presumably seen you know some dragonflies flying by or maybe like a little swarm of mayflies or what have you I mean it's not unusual to see an insect in the air but scientists have long suspected that that maybe large numbers of insects fly long distances high in the air thousands of feet in the air the problem is you can't see them and so scientists have invented technology sort of barring radar and tuning it so that you can detect insects that are in large numbers that are way up in the air.

Lo and behold, there are a lot of insects up there.

And just to give you one example,

there's a study that came out last year from China, where just in a small region of China, they set up some radar systems to look up.

And over the course of a year, they recorded 9.4 trillion insects

just in that place.

I can't comprehend that.

Yeah.

Yeah, right.

No, these numbers are incomprehensible.

When you get to fungi, you walk around

in a forest trail, you see some mushrooms, you think you know what fungi are, but you really don't because they're everywhere, they're on everything, and they make a living by sending their spores into the air.

I mean, they have adapted beautiful, like little cannons and other devices to get their spores up high enough so that the air can carry them away.

And then they can go all the way up to the stratosphere.

Fungi alone, they lift up about a trillion trillion spores every year.

Again, I can't, I don't know what that means even.

Right, right.

What do you do with that?

The, you know, they're also bacteria, viruses, algae, lichen.

And again, they probably comprise

thousands, tens of thousands, maybe millions of species.

We've barely begun

to sample this habitat, this living habitat in the air called the aerobiome.

And I love how you describe it as an ecosystem of visitors.

You know, this is a, for most of these species, this is a transitory period.

If you take one, you know, cubic meter of air or something, wherever it is, how often that changes just within a second,

within a minute, within a day, it's completely different.

Yeah,

it really depends for the individual organism

on

how high they get up initially, you know, and what the air conditions are like when they get lofted into the air.

The oceans, for example,

every time a wave breaks, there are lots of tiny droplets that rise up, and some of them have bacteria, viruses, other marine organisms in them.

Now, if there's enough of a breeze, they may get carried up and maybe they fall right back down after, you know, a few seconds.

But it is possible for them to go up and then keep going up.

And then eventually they get so high that they're just riding along long-distance waves and they can actually go thousands of miles.

So they can be floating for days.

You know, eventually they will land.

I mean, it's just a matter of time.

But because there are so many things coming up all the time,

it's always a very lively space.

So, like the clouds, for example, every cloud you look at is alive.

It's got

trillions of bacteria, something on the order of that.

And the bacteria, there are signs that they might be growing in the clouds.

And that means that they are eating the clouds.

So it's a different way to look at the sky and think about what's up there.

Let's take a short break.

And when we get back, there's still so much to discuss.

Be honest.

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Welcome back, everyone.

I've been chatting with Carl Zimmer about his latest book, Airborne, The Hidden History of the Life We Breathe.

Let's get back into things.

Which certain types of pathogens are more likely to be airborne?

Do they share certain evolutionary history or drivers that might make them more likely to be airborne?

That's a really good question.

And I honestly, I don't think anybody has a good answer for you yet.

Part of the challenge is it's hard to really carefully study airborne disease if you're talking particularly about pathogens.

Now, certainly there are some very familiar pathogens that are clearly we know are airborne.

But that's by no means an exhaustive list.

There probably are lots of other things that we are not appreciating fully yet.

But just to give a couple examples, the biggest infectious disease killer by far is tuberculosis.

It's caused by bacteria, and those bacteria are totally airborne.

In other words, they really can't infect people in any other way other than people releasing little droplets that float out.

Not just, you know, maybe when they cough or sneeze, but even when they're just breathing, they are going to release droplets, some of which have tuberculosis bacteria in them.

These are so good at being airborne that they actually manipulate us.

They actually have adaptations to sort of essentially tickle our airway to get us to cough more because that gets them out and gets them into the air, propels them, and then they can float off and infect someone else.

And they make the droplets make their way into the very finest tips of our airway endings in the lungs, the alveoli, and that's where the bacteria can grow.

So, tuberculosis kills over a million people a year, but you know, it's also a huge threat to, in terms of pathogens, it's also a huge threat to our crops.

So, there are lots of diseases, particularly fungi, that spread through the air in part or entirely.

I write a lot about a kind of fungus called

rust,

which can just, you know, it can endanger the food supply of whole countries if it really breaks out seriously.

So I'm just giving you two examples, but there's a long list.

And, you know, is there something about airborne pathogens that, you know, they all have in common?

I would say they're rugged in the sense that they can survive being floating around in the air.

It's not easy.

to be a pathogen floating around out in the air.

It's hard.

And there's some viruses that don't last very long when they're exposed to air.

Other viruses can last a really long time.

And it might be that they sort of, they have adaptations that let them kind of use the chemicals inside of those droplets that come out of our lungs to sort of shield themselves from the elements.

This respiratory droplet versus airborne debate, you know, as you say, really took center stage during COVID, as we all remember.

And kind of like you, it seemed.

baffling.

Like, why is this so controversial?

Why is this something that we're so resistant to the idea of this being airborne?

Especially when it seemed like, you know, this research had been going on for quite some time.

And before we get into how that controversy started in the germ theory miasma debate, what role did people think the air played in diseases before germ theory?

So if you go all the way back to,

say, Hippocrates in the...

sort of the world of Western thought in particular, there was this idea that, well, obviously, you know, air is essential to us.

The Greeks considered it, you know, one of the main elements.

Obviously, we need to breathe, but people couldn't really say why.

And yet, there was sort of a sinister dark side to the atmosphere.

And, you know, like, I mean, we've all, I suppose we've all had that experience walking around.

It's, you know, today here in Connecticut, it's a beautiful sunny day.

The air feels very lovely, but, you know, there are also days where you're like, it smells really wrong or there's a there's a weird light in the sky because there are wildfires someplace and you know like the the the air is unpredictable and so greeks had this idea that the gods could visit curses on them and and they would call these miasmas and hippocrates said

sort of took that name and applied it to

what he called like corruptions of the air so that if you breathed in that air you would become sick and there were different miasmas for different diseases And even different species could get different diseases because they had their own miasmas, but they were all transformations of the air itself.

It had a certain explanatory power.

I mean, how was it that, you know, a bunch of people in the same town all would get the same disease around the same time?

You can imagine, well, you know, a breeze just came through and people all inhaled it and then they all killed over.

But that explained plague and,

you know, influenza and you malaria, literally like bad air.

That's

what the disease name means.

And so it held on for a long, long time until people who had been discovering and studying microbes said, no, wait, we think these are responsible for these diseases.

And it was a very...

you know, it was a very long slog.

I mean, to us in hindsight, it seems obvious, but this was a battle that started around 1700 and lasted up until about 1900.

So about 200 years of a long, drawn-out fight.

It seems like a blink of an eye, like Louis Pasteur came in and solved everything, but

that's not what actually happened.

But I think it's so interesting to think about miasma and airborne transmission because they seem like almost the same thing, right?

Like how was that distinction made between microbes in the air causing disease and miasma causing disease?

There were a lot of confusing, seemingly contradictory pieces of evidence flying around.

So Louis Pasteur, who you mentioned, who's an architect of the germ theory disease,

he actually was the first person to really clearly demonstrate that there were germs floating in the air.

I mean, and people said at the time when he was trying to persuade them of this, that this was crazy.

One journalist said, this is...

You want to lead us into a world that's too fantastic to believe.

I just love that line.

But he would would go outside with flasks and he would catch bacteria.

They would fall down the long neck of the flask and fall into sterile broth and start multiplying.

And

he did it in Paris streets.

He did it in farmland around France.

And he even climbed a glacier, which was my favorite episode of this.

And he actually initially said that he thought that lots of diseases were caused by these floating germs, by airborne germs.

But it didn't really go that way.

And

what happened instead was that

as scientists definitively showed that the diseases were caused by germs.

So for example, cholera, not caused by miasma, as the authorities claimed.

Instead, it was caused by Vibrio cholerae, like one particular bacteria.

And that particular bacteria spread in water.

So

you have a waterborne disease.

And then you have other bacteria that get into food and contaminate food.

So you have foodborne diseases.

You have bacteria that spread through sex, so sexually transmitted diseases, and on and on and on.

So it was like the germ theory disease was taking one disease after another out of the air.

Ah, yeah.

And by the early 1900s, you had very prominent public health figures saying,

we don't need to worry about the air anymore.

Like, this should be a relief.

The air, you know, has been this specter of infection since Hippocrates.

They literally said this, and now you don't need to worry.

I think that really did keep people from really thinking very much about life in the air.

And they also didn't have very good technology for really measuring and capturing life in the air.

So that combination really did lead to a real, very strong consensus starting in the early 1900s that has endured for over a century.

Let's take a quick break here.

We'll be back before you know it.

Hi, I'm Morgan Sung, host of Close All Tabs from KQED, where every week we reveal how the online world collides with everyday life.

There was the six-foot cartoon otter who came out from behind a curtain.

It actually really matters that driverless cars are going to mess up in ways that humans wouldn't.

Should I be telling this thing all about my love life?

I think we will see a Twitch stream or a president maybe within our lifetimes.

You can find Close All Tabs wherever you listen to podcasts.

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Welcome back, everyone.

I'm here chatting with Carl Zimmer about his book, Airborne, The Hidden History of the Life We Breathe.

Let's get into some more questions.

There were still some people that did remain intrigued by the concept of

living things, the aerobiome.

And I want to ask you about one of these, which is Fred Meyer.

How did he end up turning what was first a hobby into

this whole branch of science?

Yeah, Fred Meyer is a really remarkable figure.

And as is kind of typical for early aerobiology figures, completely forgotten.

So, you know, I had to dig into archives to really figure out what I could about his life.

So I had mentioned before about

how there are these pathogens of plants, particularly of crops.

So Fred Meyer was a plant pathologist.

He worked at the U.S.

Department of Agriculture ever since he was like 20 years old.

He was just his lifelong employer.

And he was part of this tradition of studying diseases that affected crops like watermelon and wheat and so on.

And they were very comfortable with the idea of airborne disease because there are these spectacular crop failures like, you know, the Great Irish Famine that was caused by potato blight that in part was airborne, that organism.

So by the early 1900s, plant pathologists, they knew that things moved through the air.

They just didn't know how far they could go or how high they could go.

And so eventually, Fred Meyer says, like, I am going to try to figure out how high and far I can go to catch them.

And this was something that his bosses did not want him to do.

So he just did it on the side on his off hours.

And it was kind of spectacular.

He would jump into planes, these open

cockpit biplanes, and

he'd have these petri dishes stuck onto handle, wooden handles, and he would just basically be waving his arms around

out of a flying plane in the clouds.

And the pilots would just be totally baffled by him.

But he'd bring these preacher dishes back to his lab and he would grow stuff.

He was catching things.

So then he started looking for opportunities to send more sophisticated devices higher and farther.

So for example, Charles and Ann Lindberg, they flew in 1934 across the North Atlantic over Greenland, and he talked them into trying to catch life as well.

And they did.

And then there were these explorers who got into sort of metal spheres that were attached to giant balloons and they went up to the stratosphere.

And so they took along with them probes that Meyer had to see if life could survive up in the stratosphere.

And then on a second voyage, they actually were able to catch stuff up there in the stratosphere.

So, what's really kind of unbelievable to me is that by 1937,

Meyer had done, assembled so much dazzling work

that he was able to talk the government into creating a whole new service

in the government, a kind of a centralized lab for life in the air.

And he was going to head it.

He coined

the word for the science that they were going to do, aerobiology.

He came up with that word in 1937 with this plan, and everything was looking great.

And then he went on his, you know, sort of maiden voyage across the Pacific in

search of life and was never heard from again.

So

I feel sometimes writing about these people, there's a certain curse that hangs over aerobiology.

I mean, I was shocked when that was like the twist in the story, but then also it did feel like fitting in a way.

Like, of course, this, like, there's more things, like you said, befell these people that, you know, can't quite get their ideas and their evidence to take hold in the public eye, I think in the public-facing side of science.

But as you talk about the military side of things, this really did gain hold.

There was more interest in aerobiology and the potential of air as a way to transmit disease and how to protect ourselves from that.

And I think it's interesting to think about these two sort of lenses through which people viewed aerobiology.

You have Fred Meyer on the one hand, who's just interested in the rich tapestry of life in the air.

And then you have more of the U.S.

government interest at the time, in part shaped by global politics, where it's like, but what about bioweapons?

What about biodefense?

And

how did that branch kind of grow more or gain more interest than Meyer's side?

Yeah.

When World War II begins and then the United States is starting to prepare to enter, there was

a serious concern that

Nazi Germany might be developing biological weapons that it might use in battle.

I mean,

it had never been done before, but there was this great fear.

For decades, there had been a fear that someone might somehow deploy these deadly germs against soldiers or even civilians.

So the U.S.

government actually started to reach out to these aerobiologists.

They would say, well,

what do you think are the risks that we face?

And so there was one aerobiologist named Ellen Stackman who wrote a very long memo based a lot on the work that he and Fred Meyer and others have been doing saying, yes, we could be attacked and here's what could happen.

So I mentioned stem rust.

So he said, you could imagine someone dropping a stem rust bomb over our farms and wiping out our food supply.

And, you know, they someone like Stackman, who had, you know, been involved in World War I could see like what happens when an army loses a food supply because Germany actually had its own potato blight, you know, this airborne disease that was devastating to its food supply.

And that may have really tipped the balance of the war.

So he said, we need to be aware of that.

We need to have like plant pathologists looking out for attack and so on.

But then it's quite amazing.

Like in writing, it's like,

we have to explore developing our own weapons.

It would be remiss of us not to.

It would be irresponsible for us not to start building our own arsenal.

You know, it's kind of like the nuclear sort of logic: like, well, if they're going to be building them, well, we should too as defense.

And he had this, he said, here, here's how you could go after Japan.

You know, they have these rubber plantations for their tires, for their vehicles.

Well, here's a microbe you could drop on their rubber plantations and wipe those out.

He really thought a lot about this.

And there were other aerobiologists, William and Mildred Wells, a a husband and wife team, who in the 1930s had been showing how people can spread diseases to each other through the air.

And William Wells in particular had developed all sorts of really elegant devices to demonstrate how germs can float in the air and also then to sort of measure how much you would need an animal to inhale to die.

The military, you know, at Camp Dietrich, they started building very similar devices.

They took secretly, without his awareness, they secretly started building these devices so that to figure out, well, instead of saying, well, how do we understand these airborne diseases to protect people?

How do we build better weapons?

Like, what's the minimum dose we need of anthrax in the air to kill these mice?

Right.

And they did all this research in a giant building, literally called the Aerobiology Building.

And, you know, the United States, the Soviet Union, and other countries, you know, would go on for decades to build huge stocks of biological weapons, all firmly based on this new science of aerobiology.

I mean, that is such an interesting aspect of the story where you have this

acceptance of this idea of how much the air can contribute to the spread of disease and the potential there.

So we have that happening in the military side of things.

What was happening in the more public-facing side of science and aerobiology with the Wellses?

The Wellses kind of come into the world of aerobiology kind of in a very peculiar sort of sideways manner.

You know, William Wells, he gets a bachelor's degree at MIT and sanitation, and he goes off to study typhoid and water.

And he gets into studying how it is that oysters actually can be really dangerous to eat because they filter all the bacteria that cause typhoid and you eat them raw and you die.

And so he's trying to figure out how do I purify the oysters and so on.

And then he gets pulled into World War I.

His job is to clean the water for the soldiers.

And so he is protecting American soldiers by providing clean water.

But meanwhile, they're dying of influenza,

not a waterborne disease.

And it's not really clear how it's spreading, but I think that the seeds were planted there that he thought, maybe this is airborne, despite that prevailing

view that diseases are not airborne.

So he comes back from the war.

He's married Mildred Wells.

She had gotten a medical degree, but she didn't practice medicine.

She was raising their son, who probably had some sort of psychiatric disorders, just judging from medical files I was able to come across later.

They have a good run in the 20s.

He continues studying oysters.

He gets famous for being the oyster godfather because he's figuring out how to breed oysters.

And then the Great Depression comes and he's out of a job.

Mildred somehow gets a job studying the epidemiology of polio, and she actually contributes to a book about it and she develops this idea that maybe polio is being spread through the air.

She doesn't really develop it a lot in her writings, but it definitely influenced William Wells.

He gets a job at Harvard teaching.

He's terrible at it.

Like it just, I mean, I'm not making it up.

Like

the dean of the School of Public Health says this is this is something that Wells does very badly.

Like it's in writing.

And he in particular had a very difficult time with communication and just he would get into arguments with people or long, long monologues.

Mildred was really fierce herself.

They didn't make friends, put it this way.

They're brilliant, but they alienated everybody.

But at Harvard, they start to do some experiments that actually establish some of the basic ideas about airborne infection.

In other words, that, you know, when you breathe, you are releasing droplets and some of them can have viruses or bacteria in them.

They can float around for hours, maybe days in the right conditions, primarily in indoor spaces.

And

they even show that you can use ultraviolet light to kill them in the air.

First they do this with

experiments on animals, but then when they moved to Philadelphia, they put ultraviolet lamps in a school.

And in 1940, there's an outbreak of a disease we've been hearing a lot about recently, measles.

At the time, there was no vaccine, so people were just very resigned to this terrible disease sweeping through.

The Philadelphia school was substantially protected from this measles outbreak by these ultraviolet lamps.

And, you know, this was not stuff they did in secret.

This was all heavily reported.

People were very excited.

They were like, wow, like we, maybe we don't have to worry about.

a new 1918 flu pandemic again because we know that influenza is airborne and we have a way to protect ourselves from it.

And yet nobody knows who the Wellses are these days.

They just, they crashed into obscurity later on.

So, you know, they may not have died in a plane crash like Fred Meyer, but they had their own crash nevertheless.

That's another kind of mysterious disappearance of its own, like why this work that could have such profound implications for public health just kind of went away.

And I'm curious to hear your thoughts on why that might be.

You know, was part of it any sort of taint that like the military's interest in bioweapons, like was that part of it?

You mentioned like antibiotics and vaccines and sort of the decline is like, we're winning the war against infectious disease.

What were some of the factors at play there?

Yeah, I think there are many of these factors that you mentioned that were all at play.

I think that, first of all, epidemiology and trying to establish how diseases get from one person to another, it's just difficult science.

You need just the right opportunity and just the right conditions.

You need to design your experiments just right to get really clear, compelling evidence.

And so, you know, if you're talking about water, like let's say that sewage is flowing into a river and a city is getting its drinking water supply just downstream and there are a bunch of typhoid cases like this literally happened in Lowell, Massachusetts in the 1890s.

You can, you know, you can say like, hey, let's stop getting our drinking water from there, shall we?

And then lo and behold, the typhoid goes away, you know, like, so like there, there's a certain sort of control to that.

Whereas the air is like, it's very hard to control.

It's, it's elusive.

And, and while there is a lot of life in the air, like it's, it's dilute.

You know, so you might be breathing, you know, 2,000 times a day, hundreds of thousands of times a month, but, you know, know, it could just take one of those breaths for you to take in COVID or what have you, and boom, you've got an infection.

So I'll just say it is hard to study, but you know, on top of that, I think there was this consensus that it really built in and people were very reluctant to shift away from it.

So they just, they, they would say, like, you need to really, really persuade me that diseases can be airborne.

So they really refused to look at good evidence.

And yeah, and I, and I I think with the with the biological warfare research, it's arguable that a lot of the best evidence that diseases are, in fact, airborne was being done in secrecy.

Right.

It was being done, you know, as classified research.

And some of that is still classified today.

So instead of being an open science, a science that was really like focused on human health and, you know, and understanding ecosystems, a huge amount of effort in the air biology world went into building weapons.

And so maybe people thought, Well, I suppose you could build a weapon that could really create an airborne disease, but that you'd need human intervention as opposed to just nature.

So there were

a lot of different reasons.

But what's remarkable is that even at the start of the COVID pandemic, a lot of these assumptions and a lot of these misunderstandings and so on that you can trace back a century were still present in public health guidelines.

Yeah.

And how and how public health organizations dealt with the COVID pandemic.

They were still in place.

Right.

And the message was respiratory droplet transmission.

Well, and that just to clarify, what they were talking about is like, if someone is just a cough in your face and like a big old droplet like goes boom and just hits you in the face.

That's what they're talking about.

Whereas

what someone like William Wells was talking about was saying, these tiny droplets that leave your nose and your mouth just as you breathe or talk or sing, and they can float.

So those big droplets, they drop to the ground because they're so heavy, the thinking was.

But in fact, there's all these tiny droplets, which can themselves have COVID viruses or influenza viruses or, you know, tuberculosis bacteria in them.

And, you know, they can fill a room if it's not well ventilated.

They can fill a room like smoke.

Think of those as viruses.

And this is something that seemed to emerge during the first SARS epidemic in 2002, 2003, with this idea that there was evidence for potential airborne transmission of this virus.

Why didn't we remember those lessons?

Is it just more of the same thing, like just the stickiness of this idea that airborne transmission is a minor, plays a minor role in the spread of most respiratory pathogens?

Like, why didn't we remember that?

Yeah, it would have been great if we had.

So in the SARS epidemic, what's really remarkable is that, you know, as this coronavirus, another coronavirus was emerging as a human disease,

there were a few scientists who were getting dissatisfied with the standard view held that these must be spread by kind of, you know, contact or

very short range droplets.

They're like, no, this is like spreading.

It seems like it's spreading through like buildings.

And they had to rediscover William and Mildred Wells.

Like these people were like, huh, I keep seeing these references to William and Mildred Wells.

Like, who are these people?

Like, nobody knew who they were.

And I talked to this one University of Hong Kong researcher named Yugu Li, who is just a, you know, now is like a world expert on airborne infection.

And at the time, he was trying to help understand SARS and he was like, hmm, it looks like Wells has written a book.

Wells wrote a book in 1955.

Nobody in Hong Kong had it.

And the only place he could find it was in one

university library in the United States.

And he asked them to photocopy it.

This is like the early 2000s.

So they photocopied the whole book for him and they mailed it to him.

And then so he gets this big stack of photocopied pages and he starts reading it and he says, ah, okay, now this is making sense.

These are droplets.

Okay.

And it's crazy to think that he had to go to these measures to discover what had been widely reported and widely known in the 1930s.

You know, that he had to dig this back up.

And thank goodness he did, because then he did a lot of research on SARS and really demonstrated how with the way it was spreading through buildings and hospital awards and so on, it really did look like it was behaving like what William Mildred Wells was talking about, an airborne disease.

The problem is,

among other problems, is that SARS, it's sort of a good news, bad news thing.

SARS was able to be controlled and then eradicated

because all you needed to do is as soon as people showed symptoms, that's when they started becoming infectious.

So you just be real careful about isolating people, you know, supporting them.

Some of them died, you know, about 800 people died of SARS worldwide, but they reigned it in.

And there is no SARS anymore.

So it wasn't something that you could be sort of studying year in, year out.

It was just this one terrible moment in history.

And, you know, there were these clues, you know, these studies that said, like, hey, maybe this is airborne.

But yeah, I'd say that it didn't really penetrate.

You know, all the pandemic preparedness that came afterwards was all based on this idea that it would not be truly airborne.

That shift did eventually happen during the COVID pandemic.

What came to a head to then finally change the tides to people realizing that airborne transmission is a real, not just a real possibility, but like at the forefront of what is maybe spreading a lot of these cases.

So there were people like Yugo Lee early in the pandemic, in early 2020, who would say, you know, this seems to be spreading like an airborne disease.

And they were just being emphatically ignored by public health officials or, you know, people were just sort of brushing them off or saying, no, no, there's the evidence says otherwise.

And so this group of people, at first, just a, you know, just a couple dozen experts, they got together and they tried to change the World Health Organization's view on this.

WHO didn't budge.

So then they went public.

They started trying to gin up support.

But it really took like a whole string of outbreaks and studies on those outbreaks to really demonstrate it.

I focus on one in particular that struck a choir in Washington state where on March 10th, 2020, about 60 people gathered together one night to sing, and they were being careful.

They were doing everything they were supposed to be doing and no one seemed to be sick.

No one was coughing, but there was an infected person who was breathing.

And then, you know, over 50 people came down with COVID in the next few days.

It took time, unfortunately, to sort of become aware of these outbreaks and then for these airborne advocates to say like hey we're gonna investigate these as sort of cases of airborne spread see if we can test this hypothesis and then eventually

enough evidence emerged that satisfied a lot of people and then the consensus shifted i mean i won't i you know i'm there are people who who will still say like no i'm not convinced but you know i would say like that most certainly most scientific societies that are relevant to this and so on have all agreed that it's airborne.

But yeah, it took a long time.

It did.

And it does, I think, beg the question of what could have been different

if we had recognized this before COVID.

I mean, not just before SARS, but just at least before COVID.

If we had recognized it, there would be at least the opportunity to deal with the disease as an airborne disease.

You know,

that takes a lot.

I think another reason for the

slow take-up of

recognizing this disease as airborne is that it's simpler to deal with a disease that is just caused by short-range droplets or by contact.

It is just, it's a simpler process.

If it's all around you as like a smoke, then you've got to do different things.

For one thing, we might have made sure, really sure, that we had a real stockpile of protective equipment which we didn't so you know people were just desperately reusing n95 masks which is crazy we could have invested in ventilation systems in schools and other places we could have had

ultraviolet light in places where ventilation wasn't a good solution i mean you know the these advocates of airborne uh disease that they were saying in the summer of 2020 like we can get kids back in school this fall if we take airborne infections seriously, if every classroom has

at least an air purifier or something.

But the ventilation of schools, unfortunately, is terrible.

So I think across the board, a lot of lives would have been saved if we had immediately responded to COVID, recognizing the possibility that it was airborne and really acting on that.

Has this recognition that not only airborne transmission of COVID is a possibility, but just the recognition of Wells' work work overall, the Wells' work, has that kind of revitalized the field of aerobiology?

Yes, it definitely has.

And these scientists who felt like they were just shouting into the wind, forgive the pun,

they really are trying to seize the moment.

There are whole research centers being built to study airborne transmission, and they are trying to translate these findings into real meaningful policy that can protect people, not just from new diseases, but from present ones.

You know, measles, tuberculosis, influenza, chickenpox, like there are lots of diseases that can spread through the air, at least to some degree.

What it hasn't led to has been real mandates.

Like there's no country anywhere yet that officially has standards in place.

You know, like if you're going to build a building, this is what you have to do to keep the air safe.

Doesn't exist yet.

If you walk into a building,

you kind of expect that, you know, there are building standards about the rebar and

the materials that they're used.

You know, you don't expect that they contain poisons that are going to waft through the air and kill you because there are standards.

But there are no standards yet for

how to keep the air clear of pathogens.

They've suggested mandates.

No one's taken them up quite yet.

It'll be interesting to see what the future holds in that regard, as long as people are allowed to continue to do basic research on

this sort of thing.

Which is an open question right now.

It's an open question, yeah.

Well, I really enjoyed chatting with you about this.

I loved your book, Airborne.

Everyone, go check it out.

And thanks so much for taking the time to chat with me today.

Thanks.

It's been a real pleasure.

Huge thanks again to Carl Zimmer for taking the time to chat with me.

This was such an eye-opening conversation.

If you enjoyed today's episode and would like to learn more, check out our website, thispodcastwillKillYou.com, where I'll post a link to where you can find Airborne, the hidden history of the life we breathe, as well as a link to Carl's website where you can find his other books.

And don't forget, you can check out our website for all sorts of other cool things, including but not limited to transcripts, quarantining and placebo-rita recipes, show notes and references for all of our episodes, links to merch, our bookshop.org affiliate account, our Goodreads list, a first-hand account form, and music by Bloodmobile.

Speaking of which, thank you to Bloodmobile for providing the music for this episode and all of our episodes.

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And thanks to you, listeners, for listening.

I hope you liked this episode and are loving being part of the TPWKY Book Club.

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We truly appreciate your support so much.

Well, until next time, keep washing those hands.

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