The Story Behind the Six Foot Rule

Control and Prevention. Instead, they will now send numbers they tally of y U beds, ventilators, and more to a centralized health and Human services database that will not be available to the public. The government says the change will improve tracking, but experts fear this will politicize the data and obscure what's really happening with the disease. Walmart is going to require customers to wear masks in all of its US stores to protect against the coronavirus starting July.

Walmart's decision follows similar moves by Costco, Starbucks, and Best Buy. Also today, the National Retail Federation, the country's main industry trade group, called on retailers to set nationwide mask policies. The n r F said in a statement that shopping in stores is a privilege, not a right. Finally, Tokyo raised its alert level for coronavirus to the highest on a four point scale. The city reported one and sixty

five coronavirus cases on Wednesday. It has struggled to get a handle on growing infections as it reopens its economy. Tokyo Governor Euriko Koike urged residents to avoid stores that don't need safety guidelines, but has not called on businesses to close their doors. And now for today's main story, While wearing a mask or refusing to wear one has become politicized, there's one COVID safety measure we seem to

be comparatively united about. Everyone knows they should stand six feet away from other people in public, mask or no mask. But where did this guidance come from? As Kristin V. Brown reports, that one simple number is already changing our b behavior and will soon change the places where we live, work and play. When I go to the grocery store, there are these little vinyl stickers on the floor six ft apart tell me where to wait in line. When

I run in the park by my house. There are signs there too, demonstrating the distance that fellow exercisers should keep from one another. In the last few months, like many people, I have gotten really good eyeballing a distance of six ft in the midst of a surging pandemic. Six ft has become a number that we all live by. But where does that number come from exactly? It turns out the actual distance for safe social distancing is kind

of hard to pin down. I talked with Gabriel isaacman ven Worts, a scientist at Veraging Attack who studies the way that particles change in atmosphere. But there isn't some number that says, well, beyond this, there's no risk, and in front of that, you know, closer than this there is a risk, or beyond this all of the things that are infectious have been gone, are gone, they fall into the ground, and closer than that than there is

still infectious risk. Right, So that number is going to depend on sort of what is the activity, and what is the environment and what is the airflow? Right? Are you upwind of someone or downwind of someone? Are you inside the room? Are you outside? Is the air still? You know? What's the air ventilation? Rate in the room. And so I think a lot of the issue around around that uncertainty kind of stems from this issue that

it is fundamentally a question of circumstances. There is little doubt that strategies like wearing a mask and social distancing play a major role in stopping the spread of COVID nineteen. The question is how far apart you have to be in order to adequately avoid risk. The CDC recommends at least six ft from other people as a way to avoid the potentially infectious droplets a person launches into the air when they cough, sneeze, or talk. The World Health Organization,

on the other hand, recommends just three ft. But Gabriel says, the issue is that there isn't just one magic number. When we talk or sneeze or do anything, we're not releasing like some big particles and some small particles, and then that's it that we can talk about them separately. Right. We tend to release kind of these mixtures of particle sizes um and once they're in the air they can change more, so they can you know, our breath is very humid, so you can get out into the air.

That's what the fog is that we're seeing when we breathe out in the winter, and so I think the difficulty is that it's all sort of this continuum, and so you know, the question is how much do we need to breathe in and how infectious is it? Really? The three foot rule actually dates back to the turn of the last century. It talked with Kavin Handle, a medical historian at Virginia Tech, who was working to figure out the origins of these numbers. Interestingly, she says, we

don't really know where the rule comes from. At one point, diseases were regarded primarily as airborne, and at the beginning of the twentieth century, scientists moved towards the idea that when a person's sneezes or coughs, they produced infectious droplets that quickly fall to the ground. In the thirties, Harvard scientists suggested those droplets could travel three ft. Fast forward to the early ops, a study of stars transmission on a plane suggested droplets could travel more like six ft.

Another recent study found that coughs and sneezes create turbulent gas clouds that can carry pathogens a whopping twenty seven feet. More recently, the World Health Organization recognized that COVID nineteen can be airborne in indoor spaces with poor ventilation after pressure from hundreds of scientists. The issue, though, as Gabriel points out, is that there isn't a dichotomy here. It's not that a virus is either airborne or spreads through

droplets when we cough and sneeze. It's a spectrum. The bigger question instead is whether the virus is actually infectious in all of these different ways that we encounter it. Obviously, we know that sneezing and coughing produce a lot of different sized particles. We know they can travel fairly far. We have a pretty good body of literature now that says that even things like talking and singing produce some

of the smaller particles. We have some literature that says that in certain cases we can find we can basically find RNA, we can find viruns, We can find some information that says that coronavirus is in these smaller particles. But we don't have great information on is how infectious are those smaller particles. How much do we have to breathe in to get infected In that kind of thing, The thing is the world we live in isn't rearranging

itself to accommodate a spectrum of conditions. Our built world is starting to revolve around maintaining a distance of six feet. Parks, including San Francisco's famous Dolores Park, are painting white circles on the ground to designate where to sit as school's reopen. Guidelines from places like the American Pediatric Society have suggested that desks should be placed between three and six feet apart.

I also spoke with Eron Betsky, the director of Virginia Tech School of Architecture and Design, about what kinds of more permanent changes we might expect to our built world after the pandemic. Aaron says we can expect things like better ventilation in indoor spaces and more easily cleaned surfaces. He also said design will become more private and isolating.

This is going to be just one more layer of trying to isolate and insulate ourselves from other human beings in the real world, and in the end it will be used. Should we do it. Of course, we should do it. We need to protect people, We need to protect ourselves because we have made ourselves vulnerable. All that you will see is the erection of shields and separating devices.

So I think it's unfortunate that what had become a more collective and open environment workplace in many areas of people complain that they can't concentrate, is going to turn back into Dilbert Land. So we'll see a revenge at the office qube. Aaron says that design will also try to look safe, like the hospital rooms with rounded corners designed to prevent dirt from accumulating in them that cropped

up in the twenties and thirties. You're also going to see a style where things should need to look safe to reassure people. So I'm not saying that necessarily we're going to make things that are safer by having rounded corners, but we're going to make things that reassure people that there's not something hiding somewhere that's going to come out and bite them or make them sick. This won't be the first time our physical realm has been altered due

to disease. In the eighteen hundreds, for example, after cholera killed tens of thousands of Parisians, the city condemned crowded medieval neighborhoods and instead built wide avenues and parks. But the sign suggests we should be considering things like airflow and the size of a room when making decisions about what distance is a safe distance. You know, probably any researcher in any of the related fields would agree is

that the farther way you can be the better. Right, And and so you have to make some messaging decision. And I suppose about what is far and what is close. Six ft doesn't feel that far to me um, But also there I understand that there are other sort of things that go into making that decision. Right, can you open up? Would you be able to reopen any of our day to day life if we insisted on right? That becomes a lot harder at the end of the day.

It's not exactly six ft that's a rule to live by. Instead, it's more important to remember to keep your distance no matter where you are, and of course to wear a mask. That was Kristin v. Brown and that's it for our show today. For coverage of the outbreak from one around the world, visit Bloomberg dot com slash coronavirus and if you like the show, please leave us a review. And a rating on Apple Podcasts or Spotify. It's the best

way to help more listeners find our global reporting. The Prognosis Daily edition is produced by Topher foreheads Jordan Gospore, Magnus Hendrickson, and me Laura Carlson. Today's main story was reported by Kristin V. Brown. Original music by Leo Citrin. Our editors are Rick Shine and Francesco Levi. Francesco Levi is Bloomberg's head of podcasts. Thanks for listening.