Why Tear Gas Is Dangerous During The Coronavirus Pandemic : Short Wave In protests around the country, law enforcement agencies have used tear gas to disperse crowds. But is it safe? ProPublica environment reporter Lisa Song speaks with Short Wave reporter Emily Kwong about the potential dangers of that practice, especially in the middle of a respiratory pandemic.

How Tear Gas Affects The Body

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You're listening to SHORT WAVE from NPR.


Lisa Song is an environment reporter with ProPublica, and her recent reporting tackles something we've all seen floating in the air these weeks of protests on TV, maybe even in person - tear gas.


LISA SONG: I started seeing all the reports of law enforcement using tear gas all over the country.


UNIDENTIFIED REPORTER #1: Volley after volley of tear gas to try...

SONG: You know, in protest after protest, I saw the photos of the white smoke coming up...


SONG: ...Videos of protesters desperately washing out their eyes.


SONG: People were choking and gasping for air.


UNIDENTIFIED PERSON: Keep moving. Keep moving.


SONG: Tear gas clearly makes it hard to breathe.


UNIDENTIFIED PROTESTER: I've still got a very sore - what feels like a burnt throat from whatever it was.

SONG: And I just thought, what exactly is tear gas? It doesn't seem like a good idea to use in the middle of a respiratory pandemic.


UNIDENTIFIED REPORTER #2: We are moving back down the streets, as protesters are now picking up some of those canisters and trying to throw them back at police.

SONG: And this scene's unprecedented. Do we actually have any science about whether it's safe or not?


KWONG: So Lisa set out to answer those questions.

SONG: That's when I started talking to researchers and scientists and really getting a sense that the combination of the way that tear gas is being used in these protests - the huge quantities, the frequency with which it's used, the way police are using it - is really a cause for concern.

KWONG: Today on the show - why using tear gas could be especially dangerous right now during a respiratory pandemic and how some law enforcement tactics could be making its impact even worse. I'm reporter Emily Kwong. And this is SHORT WAVE, the daily science podcast from NPR.


KWONG: So as far as I understand, tear gas is a term that's broadly applied to describe a set of chemicals, right? And these are liquid chemicals, and it's not actually a gas.

SONG: Right. So the term tear gas is confusing because different people use them in different ways. Scientifically speaking, tear gas refers to several different chemicals that make your skin burn, that make it hard to breathe. It's really painful and stinging. The way that the CDC refers to tear gas and the way that law enforcement refers to tear gas, sometimes they're referring to a broader set of chemicals.

But in general, yes, tear gas is actually tiny liquid droplets. And my story focused on the most common type of tear gas used by law enforcement in the U.S., and that is a chemical called CS.

KWONG: And CS - how is it designed? How does it work?

SONG: So it's designed to cause pain. And the description I got from a scientist was that CS gas triggers a particular pain receptor in your body. It's the same receptor that's triggered when you eat wasabi, but it's much more powerful. So if you take that stinging sensation from eating wasabi and multiply it by up to a 100,000-fold. That is how much more powerful CS gas is.

KWONG: It sounds incredibly disorienting. How have those you've interviewed described being hit by tear gas, what that experience is like?

SONG: Yeah. I mean, I personally am very lucky and have never been exposed to tear gas. But the various protesters I interviewed, they just described this incredible feeling of fear and helplessness. Your eyes are burning. Your nose is running. Your mouth hurts. And you have trouble breathing. So you can't see. You're in pain. And you're having trouble catching a breath. And you feel like you're choking.

This one protester I interviewed was part of this protest in Philadelphia that got a lot of media coverage. And at one point, she was in a part of this highway that ran partially underground. So it was this dark, semi-enclosed space. And when the tear gas got in there, everyone panicked. You know, they couldn't see. Everything hurt. And they were trying to run away, but there was really nowhere to run. And she said that she actually feared for her life. She feared that, in the panic, she would get trampled, and she did actually get bruised all over because people were stomping on her as they were running away.

KWONG: So, Lisa, you looked at tear gas from a medical standpoint, what it does to the body. And one of the things that you discovered is that tear gas has a big impact on the lungs. Can you tell me about that?

SONG: Right. So one of the things scientists told me is that when you inhale tear gas, you're going to start wheezing and coughing. And that means that your lungs are working hard to try and get rid of this tear gas, so it doesn't have the same amount of strength or the same reserve to fight off any additional infections you might get. And that could make people who've inhaled tear gas more susceptible to getting the coronavirus, particularly if they already have asthma or some other respiratory condition because they are already at higher risk to catching infections, like influenza or the common cold. And so the fear is that tear gas could trigger an asthma attack or further weaken the body's ability to fight off COVID-19.

KWONG: Right. And the tear gas, it also weakens the demonstrators' protections against the coronavirus because it changes the way people are moving around in a crowd. It creates chaos.

SONG: Yes. And this is one of the things that public health professionals are worried about, is a lot of protesters are doing the responsible thing by wearing masks during the protest, but as soon as you're hit with tear gas, you're trying to breathe as much as possible because you're gasping for air. *****

SONG: ***** And at that point, instinctively, you're going to take off the mask to try and get some fresh air. And when you do that, you're going to be coughing because you're trying to get rid of the tear gas in your lungs, and we all know that coughing is one of the things that spreads COVID. So there's a lot of fear that people who have the coronavirus but are asymptomatic, as they're coughing while trying to deal with tear gas, that they're spreading the disease among other protesters in the crowd.

KWONG: From your reporting looking at protests around the country, I'm wondering, too, what patterns you've seen with how tear gas is being used by law enforcement.

SONG: We've seen it used in different ways, but a pattern that we've seen is that the police are often using a lot of tear gas. They are using it in quick succession. And it's that combination of the sheer volume of tear gas - and sometimes it's being used in situations when the protesters are trapped in an area and can't get away, like we've seen in Philadelphia, and that really compounds the dangers and risks of tear gas.

KWONG: Right. So it's not just that it's being used; it's how it's being used and how often.

SONG: Right. So tear gas comes in a variety of forms, and there are different tactics and tools that police can use. They can spray it from cans. They can shoot canisters filled with tear gas. And there are some manufacturers, for example, that will sell grenades that, not only does it expel tear gas, there's also bright lights and loud noise to further cause, you know, confusion and make the protesters try to disperse. There's also a type of product called a triple-chaser canister, where the canister of tear gas will break into multiple pieces when it lands so that the gas can cover a larger area.

KWONG: Wow. Yeah. Considering the tactics that you just described, it was also apparent in your reporting that it wasn't just the demonstrators who were at risk but also those in residential areas who were not participating in the protests.

SONG: Yeah. One of the things that surprised me was, because a lot of these protests are taking place near residential neighborhoods, you often have so much tear gas being used in the street that it's actually seeping into people's homes. So even people who are not part of the protests, are staying home, perhaps trying to socially distance as much as possible during the coronavirus, they could be sitting in their house and have tear gas come through their windows and doors. And so, you know, it really puts them in an impossible situation. They might have done everything possible to try to stay away from crowds, to stay safe during the coronavirus, and even as they're at home, tear gas is coming into their home.

KWONG: So, Lisa, what do we know about the long-term effects of tear gas? We absolutely have a very clear picture on the short term, from people coughing and running. What does it do to a person's body long term?

SONG: We don't have a lot of research on how it affects people in the long term, but the studies that we do have are showing that it leaves people at a higher risk for getting the flu or pneumonia or bronchitis. And it did that even for military recruits, who are healthier than the general population.

KWONG: And what about very severe tear gas poisoning, when a person is exposed to quite a bit of these chemicals?

SONG: So in the worst-case scenarios, tear gas can blind people or even kill them, either through just respiratory failure or through chemical burns. And these are really the worst-case scenarios. And I think one of the concerning things we're seeing is that a lot of protesters are going to multiple protests in one week. You know, day after day, they're showing up in demonstrations. And so it's likely some of them have been hit with tear gas multiple times in one week, and that repeated exposure is extra risky.

You know, one of the best - some of the studies that we have on people who are repeatedly exposed were done on people in Turkey. And we found that it made them more susceptible to getting various respiratory illnesses, sometimes for up to weeks after they breathed it in.

KWONG: Right. So I'm just curious, Lisa. I know you're an environmental reporter, and you've reported on chemicals and the use of chemicals in society plenty, so what was it like to work on this one?

SONG: I think this is one of the most disturbing stories I've ever reported. I've done a lot of reporting on water pollution, air pollution in neighborhoods and pollutants that can give people cancer and skin rashes and all sorts of effects. But this was just extra disturbing because of how physically and immediately painful the effects are. And just the idea that - where the police are now using large quantities of this at a time when we know so little about the actual health effects. It's just that combination of all of the factors that made it a difficult story to report.

KWONG: Well, Lisa, thank you so much for coming on SHORT WAVE and sharing this reporting with us.

SONG: Thanks for having me.


KWONG: Lisa Song is an environment reporter at ProPublica. You can read her full story on tear gas and the coronavirus in today's episode notes. Today's episode was produced by Brit Hanson, fact-checked by Emily Vaughn and edited by Viet Le. I'm Emily Kwong. And this is SHORT WAVE, the daily science podcast from NPR.

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