Science Vs - Coronavirus: The Mask Wars
Episode Date: May 15, 2020When the pandemic started, we were told not to bother with masks. But now it looks like experts have done a 180 here, and a lot of us are being told to cover our mugs when we leave the house. So which... is it? Should we mask up or not? To find out, we talk to epidemiologist Professor Benjamin Cowling, microbiologist Dr. Anna Davies, and clinical psychologist Dr. Olga Perski. Also: RED DEVIL SQUID!! Here’s a link to our transcript: https://bit.ly/2LxuxTW And here’s a link to the squid video: https://youtu.be/iANgyT95bmA This episode was produced by Wendy Zukerman with help from Michelle Dang, Rose Rimler, Meryl Horn, Laura Morris and Sinduja Srinivasan. We’re edited by Blythe Terrell with help from Caitlin Kenney. Fact checking by Diane Kelly. Mix and sound design by Peter Leonard. Music written by Peter Leonard, Marcus Bagala, Emma Munger, and Bobby Lord. A huge thanks to all the researchers we got in touch with for this episode, including Dr. David Simons and Benjamin Burford. And special thanks to the Zukerman family and Joseph Lavelle Wilson. Learn more about your ad choices. Visit podcastchoices.com/adchoices
Transcript
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Hi, I'm Wendy Zuckerman, and you're listening to Science Versus from Gimlet.
On today's show, what does the science tell us about wearing masks?
Like, should we be putting them on or not?
Back in March, the message about masks was pretty clear.
Healthcare workers needed them.
But for the rest of us,
don't bother. Right now in the United States, people should not be walking around with masks.
Here at the CDC, they argue that having the average person wear an ordinary mask can be
counterproductive. The World Health Organization says unless you're sick, you don't need a mask.
But just a month later, by April, things started to change.
Like here in New York, we were told it's mandatory to wear masks.
All people in public, you must wear a mask.
The CDC was on the mask train too.
But they were like, don't wear medical masks.
What you should be wearing is a cloth mask.
And suddenly, it felt like Anthony Fauci was singing a different tune.
But some sort of mask-like facial covering,
I think for the time being,
should be a very regular part of how we prevent the spread of infection.
These days, there's such a push behind cloth masks
that even the Surgeon General is putting out tutorials
on how to whip one up at home.
Here's how you can make your own face covering in a few easy steps
with items you can find around the house.
It's that easy.
But is it that easy?
All this flip-flopping advice and confusion has landed us in a place where some people say,
yes, masks are super important for getting this under control,
while others are saying, forget about it.
We don't think they do anything.
And both sides claim to have science on their side.
So what is going on here?
Should we be wearing masks or not?
A couple of months ago, we published an episode about masks for healthcare workers.
But what about the rest of us?
When it comes to this pandemic, there's a lot of...
Put the mask on.
But then there's science.
Science versus the mask wars is coming up just after the break.
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New episodes drop every other Thursday, starting February 1st. Welcome back.
Today on the show, should we be wearing masks?
And if we should, what kind?
And we're going to start by looking into how good surgical masks are at blocking viruses.
These are those blue rectangular masks that you might see your dentist wearing.
And we know the CDC doesn't want the public wearing these masks.
They want to save them for healthcare workers.
But it looks like a lot of people around are still wearing them.
So to find out if wearing them is a good idea, we called up Ben Cowling,
a professor of epidemiology at Hong Kong University. And Ben moved to Hong Kong in 2004,
shortly after the SARS epidemic, and he's been researching outbreaks ever since.
We've always been ready to respond when there's another SARS,
and then 2020, here we are with SARS-2. Literally SARS-2.
Yeah, it's literally SARS-2. It is.
Ben just published one of the best studies out there
looking at how good surgical masks are at stopping viruses.
That's right.
So we wanted specifically to look at the question of whether
if a sick person wore a mask, would it help or not?
Here's what he did.
First step, he got this large and weird-looking machine.
It's the same size as a human, basically,
but it's got this big cone on the end of it.
It looks like something that could have come out
of Willy Wonka's factory, I reckon.
Ha, ha, ha.
Imagine a tuber connected to all these pipes and filters.
So, then got more than 100 people with viral infections
to come into his lab wearing masks and to cosy up to this machine.
And we asked the patient to sit on a stool with their head inside the cone,
just looking down through the cone to the other end,
and then sit there for 30 minutes.
So, when you told the participants in your study,
you've got to put your head in that cone for 30 minutes,
what was the general response?
I think they were kind of fascinated by the idea.
It's something people never even seen before,
probably never even imagined before.
And they're putting their heads in that cone
because this machine is going to capture everything that's coming out of their mouth, what they breathe, what they cough.
And Ben repeated this experiment where people were wearing no mask.
Now, this research was done before this new coronavirus.
So the people were infected with other stuff, like they had the flu and some were actually infected with other coronaviruses, ones that cause the common cold.
So Ben was looking at what came out of their mouth when they were wearing the mask and
when they weren't.
And when he zoomed in on those 20 or so people who had coronavirus infections, what did he
find?
Did the masks block those viruses? Yeah, so they block virus from common
cold coronaviruses in aerosols. So yeah, the masks did help block coronaviruses from getting through.
Now a wrinkle here is that although we kind of have this idea that sick people are just spraying
virus out all the time, In Ben's study, that actually
wasn't true. So even without the mask, a lot of people just weren't breathing out or coughing out
much virus. Another wrinkle, Ben wasn't measuring this coronavirus, SARS-CoV-2. So we don't have
enough data to say that these masks are a slam dunk here.
But just generally speaking, other studies have also found that surgical masks are pretty good at blocking viruses.
And Ben says that could be because of how these masks are put together.
They have these layers of different material that are designed to make it really hard for the virus to find its way through. So the middle piece is made of a filter material that forces the air to make a zigzaggy path.
It's like putting a drunk person in the start of a maze and asking them to find their way out. You
know, they'll just bounce around all the walls and they'll, you know, they'll collapse in a heat
before they make it out the other side of the maze. So that's the kind of concept, you know they'll collapse in a heap before they make it out the other side of the maze so that that's the kind of concept you know so it's not brilliant analogy but that's the kind
of concept the drug person is the the viral particle trying to make its way out into the world
so bottom line from your study and others in this space, do you think that if we, cheeky question, but if we had an unlimited supply, should the public be wearing surgical masks?
Yeah, if we had an unlimited supply of surgical face masks, I think everybody should be wearing them all the time.
Our study certainly supports the effectiveness of face masks.
The fact is, of course, that we don't have an unlimited supply of face masks.
Since we don't live in the land of masks and honey, and there is a short supply,
we're being asked to wear cloth masks.
Did they work?
Well, unfortunately, when Ben did his study, cloth masks weren't the big controversy they are today.
So he didn't look into it. But now looking back, I mean, we're kicking ourselves
because if we'd had data on a good type of cloth mask,
it would be really, really useful.
From across the ocean, I'm kicking you as well.
Ah, sorry. I know.
So to find out if cloth masks are worth our time,
we need to go elsewhere to say goodbye to Ben.
Bye-bye.
And hello to Anna.
Hang on.
Oh, just let me close the door.
I've got a Dungeons & Dragons game going on in the kitchen,
so let's shut that off.
Is it your game?
No, no, no.
It's my husband's.
My husband, too, has a Dungeons & Dragons game.
Oh, really?
Okay.
What have we done?
I don't know.
This is Dr Anna Davies.
We bonded over our appreciation of nice, normal dice with six sides.
None of this 20-sided dice business.
Anyway, we called up Anna because she's a microbiologist
and played a critical role in one of the few studies that we have
exploring if cloth masks really can block viruses.
She started it back in 2008. It was a few years after the original SARS outbreak in China.
And she'd seen all these images of people wearing homemade masks in the press.
And basically my boss at the time was sort of said, well, you know,
if there were no face masks, would a homemade mask do anything? And so that was, well, I think not an unreasonable study to do.
Well, we have now learned it definitely was not an unreasonable study.
I know.
And, you know, obviously I'm a bit surprised.
Anna's study has been getting a ton of attention
and she's been getting emails from all over about it.
So let's dive into what she did.
First, she grabbed some random materials
from around her house. They were slightly random household fabrics. I mean, I literally put myself
in the position of somebody at home thinking, oh, what have I got around my house? What could
I make a face mask out of? It was just a kind of, here's an old t-shirt, here's an old tea towel
from my kitchen. She also got a vacuum cleaner bag, a scarf and a pillowcase.
But it's so bizarre hearing Anna talk about this
because more than 10 years ago, it was all so abstract.
And now it's exactly what people are doing at home.
But here's what people can't do at home.
Test these fabrics to see if they actually work and block viruses.
So unlike the focus of Ben's study, where he looked at what viruses can get out when a sick
person wears a mask, Anna would look at whether cloth masks can stop stuff coming in. And to do
this, Anna took all those fabrics into the lab and then they spritzed a virus into the air. She was using a harmless virus that can't make people sick.
And she kind of turned it into a magic missile.
So when she launched it at the different fabrics...
You can basically see how well the fabric is filtering this aerosol.
It's really cool stuff.
Anna compared how many viral particles got through all the different fabrics.
And she spritzed some virus on surgical masks too,
so that she could see how the fabrics compared to those.
So, what did she find?
Well, surgical masks were the best in this experiment.
They blocked the most virus.
The second best?
Vacuum cleaner bags.
They stopped around 85% of viral particles
from coming into the bags.
It's high, but you can't make a mask out of it because you can't breathe through it.
Yeah, using a vacuum bag as a mask, it's going to suck.
Okay, and what about t-shirts, scarves, pillowcases?
The kinds of fabrics that are comfortable are not that great.
They blocked roughly half the viral particles coming through.
And so what does all this mean out in the real world,
where people are using cloth masks to try to stay safe?
If I'm healthy, would wearing a homemade mask help protect me,
based on your research?
It probably wouldn't have any...
I don't think our research goes that far.
If the results had been, yes, they're as good as surgical masks,
then we would have said, yeah, you can use those instead of surgical masks.
If the results had been, these are awful, do not use them,
they offer no benefit at all, then that would have been clear advice.
But the answer was, they're kind of not great, but they're not nothing.
Anna's hearing from people who are using her study to say that cloth masks can protect them.
And she kind of wishes they wouldn't do that.
I'd say it's really simple study. Like it's not. And, you know, we didn't try to test it against the actual virus.
We didn't test how, you know, what's the effect of wear? Because obviously you've got water vapor
in your mouth when you breathe out and that's going to have an effect on the fabric. It'll get
damp. What's the effect of cleaning on it? I don't know. I mean, there's lots of things that we didn't
look at. The few other studies that we have looking at how well cloth masks can block viruses or block particles the size of viruses, they're kind of all over the place.
Like some find that cloth masks are basically useless, while others find that, you know, they kind of work okay.
So where does this leave us?
Well, surgical masks are looking pretty good here.
And cloth masks?
Nah.
But remember, this is all about what happens in the lab under controlled circumstances.
And we all know that the real world is a lot messier than the lab.
So what happens when we take our masks out for a spin in the real and messy world?
How effective are they then? That's coming up just after the break.
Welcome back.
We've just found out that in the lab,
it looks like surgical masks should do pretty well at blocking viruses.
And even cloth masks, well, they block out some viral particles too.
But what happens out in the real world
when you take these masks for a spin?
Could they help stop this pandemic?
Well, when you look at places like Hong Kong,
where heaps and heaps of people wear masks, and you see that their infection rate is really low,
it sure seems like masks are the key here. But the problem is that places like that,
they're doing a ton of other stuff too to keep this pandemic at bay, like
really good screening and isolating people who are sick. So we have to look at other studies
to see if masks really can help here. And for that, we called up this scientist.
Hi. Oh, hello. Hello. Let's jump right in. Great. So can you please introduce yourself? So I'm Dr. Olga Persky.
Olga is a researcher at University College London. And to respond to the mask wars,
Olga and her team gathered up studies of regular people wearing masks out in the real world.
She wanted to find out, did it keep them from getting sick with stuff like the flu? Olga nixed any studies done in
healthcare settings because she just wanted to focus on regular Joe Schmoes, you and me. She
ended up with 11 randomized trials and all of these were about surgical masks. So researchers
would do stuff like take sick people and tell them or their families to wear surgical masks at home
and then they'd see who got sick. And Ogger also found studies that were outside of the home.
We also found a couple of studies in university halls and where participants were travelling
on pilgrimage. One of the studies got people to wear masks while on Hajj, a pilgrimage to Mecca.
And overall, here's what they found.
There was no good evidence for or against the wearing of face masks in community settings,
meaning that we can't actually say whether there is a benefit.
We're sitting on the fence, essentially.
Yeah, there was no difference in the groups told to wear the masks and those who didn't. Now, Olga's team has just finished that paper. It's still going through
peer review. But other published reviews have said the same thing. They don't find good evidence
that when we regular folk mask up, it stops us from getting sick. So why not? Like, given what we've seen in the lab, how can some virus particles
be blocked by masks, and yet they don't seem to do anything out in the real world? Well, Olga says,
we need to consider the different things that people do when wearing these masks.
And by this, she means that even though a mask might block some viruses,
it's possible that the way people wear them might cancel all that good out.
So, for example, Olga and others have speculated
that people might be touching their mask,
which could be bad because one study found
that this coronavirus can survive on masks for up to seven days.
So say you do get some virus on the outside of your mask.
You fiddle with your mask and you get some virus on your fingers.
Say your spring allergies are acting up.
You rub your eye and then that virus gets into your body.
There's the risk that instead of the mask protecting people,
it might actually act as another way of spreading the virus.
Another complicating factor here is that people are bad lab rats.
In a lot of these studies where scientists tell people,
hey, wear this mask, they don't do it like the nerds want them to.
So Ben, who you heard from before with the Willy Wonka Cone study, he's done a few
mask clinical trials. And he said in one of them, only a quarter of the healthy people stuck to
wearing masks throughout the study. Adherence wasn't great, right? So that's the kind of
real life difficulties of something like face masks. It's really not that easy.
When I look around New York right now,
because basically everyone's wearing some kind of mask,
and how they wear them is a total mess.
I mean, I see people push down their mask to talk to someone.
I saw a woman push down her mask and then cough into the air
and then put the mask back on.
Oh, no.
Point is, a lot of us are just bad at wearing masks.
And while we don't know if the people in these studies got sick
because of their crappy mask-wearing technique,
we did find one study which suggests
that if people do wear surgical masks properly, it can help.
It was a study done in a hospital ward
where basically everyone, doctors, patients
and visitors wore masks and the infections that they looked at dropped by half. So that's surgical
masks. What about cloth masks? What do we know about how they work in the real world? Well,
frustratingly, we don't have studies like the ones we just talked about
for cloth masks. The research just hasn't been done, which is a big reason why we have the great
mask war going on over cloth masks. Here's Ben again. So there's kind of two camps, two scientific
camps. One camp says that most likely they should do some good and so it's
better to have some good than nothing and you know despite there being no scientific evidence
there is a mechanistic plausibility there's a a good reason to believe that they work so we should
recommend them and that's the the scientific camp that's now kind of got public support in many parts of the world.
This scientific camp is sometimes using lab studies like Anna's to say, hey, it makes sense that cloth masks would block at least some nasty viruses.
Plus, when we saw cases rising across America and we found out that people could spread this virus before they showed any symptoms, some figured, well, cloth masks might be a helpful way to slow this all down.
But there's another group of scientists that say, you know, really without evidence, we're not comfortable in recommending something to be used because it may be doing nothing.
And since we don't have good data, there's the naysayers arguing,
well, it's possible that cloth masks could cause harm.
Because who knows?
Like, maybe people will feel invincible with their bandana around their face and they'll stop social distancing.
Anna Davies told us you could argue this either way.
The problem is there's so little data out there
that people tend to choose a standpoint based on intuition and gut
rather than any evidence and then find the evidence to support it.
So that explains some of this mixed stuff in the news.
When you look at the scientific picture,
we just don't have the evidence that we would like to say,
yes, cloth masks work or no, they don't.
So where do we at Science Versus stand?
Well, given that the good stuff, the good masks need to go to health care workers, perhaps we should see cloth masks as just one tool in the toolbox here.
And because we don't know if they're a 20-volt power drill or a broken dollar store drill,
we can't count on them to keep us safe.
I talked to Anna about this.
One way that I was trying to think about it is, like,
I guess if I wore it, I just need to think it doesn't work and then if it if it
helps some if it catches some viral particles that would have gone into my mouth great but I really
need to be thinking this isn't doing anything so then I keep social distancing and I keep my hands
away from my face and all that exactly you, you should still behave as though you're not wearing a mask
because that is the safest thing to do.
And now, time for a little NCBC.
Today, we're diving down more than 800 meters into the Pacific Ocean. That's more than 2,600 feet. And we're here to find Humboldt squid, also known as red devils.
They are super intense. These squids will squirt ink in your face if you get too close.
But it turns out they can also be a little chatty. They chat by flashing. That is,
they make their bodies glow with these light-producing organs and then flash patterns
with their specialized skin cells. And recently, scientists got a clue about what they might be saying to each other.
Researchers in California sent cameras down into the sea and recorded the flashing.
And they noticed that the squids seemed to flash their lights the most
when they were chasing down food while hanging out in groups.
So scientists think that some of this flashing
might be squids saying,
hey, look out, that's my fish,
to avoid, you know, fish food fights.
But who knows?
Maybe they're saying, I'm hungry.
Or maybe this is all just lunchroom gossip
and they're just talking crap about Jake.
You know Jake, that annoying squid. Oh my God, you talking crap about Jake. You know Jake, that annoying squid.
Oh my God, you totally know about Jake.
He's the one that can't mute his Zoom, or maybe he can mute his Zoom,
but he just wants us to hear all that chit-chat he's having with his pretty girlfriend.
That's science versus.
To see a video of the squids talking to each other,
head to our show notes.
Hello.
Hello, Michelle Dang, producer at Science Faces.
Hi, Wendy.
I actually looked at the number before you called me,
so I know it.
You got it.
All right.
So then how many citations are in this week's episode?
There are 94 citations. Oh, wow. 94. Yeah. And if people want to see these citations,
where should they go? They should check out the link to our transcript in our show notes.
Thanks, Michelle. Okay, bye.
This episode was produced by me, Wendy Zuckerman,
with help from Michelle Dang, Rose Rimler,
Meryl Horn, Laura Morris and Sindhuja Srinivasan.
We're edited by Blythe Terrell with help from Caitlin Kenney.
Backchecking by Diane Kelly.
Mix and sound design by Peter Leonard.
Music written by Peter Leonard, Marcus Begala,
Emma Munger and Bobby Lord.
A huge thanks to all the researchers we got in touch with for this episode,
including Dr David Simons and Benjamin Buford.
And special thanks to the Zuckerman family and Joseph Lavelle Wilson.
I'm Wendy Zuckerman.
I'll fact you next time.