Indoor Dining and the Spread of Coronavirus

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Brian Lehrer: It's The Brian Lehrer Show on WNYC. Good morning everyone. New York and New Jersey are, for the moment anyway, going different routes on what to do about restaurants during the latest COVID search. Indoor dining closed again in New York City as of yesterday, but not in New Jersey, this despite New Jersey having a test positivity rate twice as high as the city's at around 11% of tests coming back positive.

The numbers I've read are that New Jersey also has around 800 ICU beds with about 700 currently occupied. That's bad. In New York, according to Gothamist, eight hospitals across the five boroughs have reached more than 90% capacity of their Intensive Care Units. Governor Cuomo warned yesterday he would declare a full shutdown if case and hospitalization rates show that a region's hospital capacity will reach 90% within three weeks. Here's the Governor.

Andrew Cuomo: At this rate, if nothing happens, we could have 11,000 people in hospitals and 3,500 deceased. If you factor out these numbers, that's what we're looking at if nothing changes. The increase in hospitalizations could overwhelm some regions if nothing changes by January. That's the trajectory we're looking at.

Brian: The Governor went on to warn--

Cuomo: What you should worry about is shutdown because if we do not change the trajectory, we could very well be headed to shutdown.

Brian: He used that dirty word "shutdown". "If Cuomo goes there," says Gothamist, "it would resemble the PAUSE order issued in March, which shuttered non-essential businesses and prohibited most gatherings. Mark Levine, a Manhattan City Council member who chairs the health committee, told Gothamist that a more drastic shelter-in-place order could be handed down within a week.

Now, Governor Murphy is also reserving the right to take further steps in New Jersey if needed, but restaurant owners continue to protest and argue that they can stay open safely with social distancing and limited capacity protocols. Here's Gianna Cerbone, a Long Island City restaurant owner, talking to CBS News.

Gianna Cerbone: This is not because you're getting sick in the restaurant. This is because we cannot control people to stay away from each other.

Brian: Is that true? Is it because we can't control people from staying away from each other or are they getting it in the restaurants? There's a lot at stake in the answer to that question. Millions of restaurant workers are unemployed. Let's not make light of that. Many of them lower wage Americans who get shut out of the economy while, let's face it, higher paid professional class employees can work from home much more often and still get paid.

We thought we would take a look at the science of COVID spread in restaurants with a guest who is an expert in the field. With me now is Dr. Donald Milton. He is a professor of environmental and occupational health at the University of Maryland School of Public Health. Now his bio page, which may have seemed obscure before COVID, now makes him look like the guy everyone wants to talk to. It says, "His work focuses on the interrelated areas of infectious bioaerosols, exhaled breath analysis, and respiratory epidemiology." Not a great conversation starter at a party until this year.

He's also known to his students for a contraption he built called a Gesundheit machine. We'll explain. Dr. Milton, thanks so much for coming on. Welcome to WNYC.

Dr. Donald Milton: Thank you for inviting me. A pleasure to be here today.

Brian: I can only imagine you at cocktail parties in the past when people said, "Well, what do you do for a living?" and you say, "Well, I'm an expert in exhaled breath analysis," and then you go, "Oh." Now--

Donald: I usually applied them with influenza stories and how influenza is present in exhale breath and fine particles floating in the air.

Brian: Yes. Excuse me. I have to go get another drink. What's a Gesundheit machine?

Donald: The Gesundheit II, as we call it, is a device. It's a big cone. A person sits in a booth where we keep the air warm and humidified, and the cone is right in front of their face. It's like a capture hood over a stove. It just pulls all of the breath that they're exhaling and any droplets they're generating as they talk or sing. It pulls them into a sampling device that sorts them and picks the bigger aerosols, bigger than five microns. Still aerosol, it's still floating in the air, and the ones that are smaller than that. It collects them so that we can analyze them for viruses.

Brian: How have you used this during COVID differently from before COVID?

Donald: Well, we've actually been using it very much in similarly to the way we've been studying influenza and other respiratory viruses now with this device for almost 15 years. We have previously shown that flu and seasonal coronaviruses can be stopped by wearing a mask using this device. One of our papers in nature medicine in April was very influential in convincing the National Academy of Sciences to recommend mask-wearing for everybody. That was done by colleagues of mine, who we provided one of these machines to and did this study in Hong Kong.

In our studies here, we've similarly shown that masks work quite well for cutting out about two-thirds of the virus people shed into the air when they're infected with influenza. We're now doing that with coronavirus. We are asking people with the virus to come into our lab and sit into the instrument. Recently, we've changed our protocol a little bit because of all of this information about singing and loud talking being really involved. We're asking people to sing. We ask people to sing happy birthday, and we ask them to shout--

Brian: While washing their hands?

Donald: Well, they're not washing their hands.

Brian: I was just kidding. Go ahead.

Donald: Right, but they sing happy birthday. We have them shout our University of Maryland cheer, "Go Terps".

Brian: I noticed, by the way, that the person who got the first coronavirus vaccine in New Jersey, which was administered this morning, is a health care worker whose birthday is today. She said it was a great birthday present, so happy birthday to anybody having a birthday today, and certainly that person who got the coronavirus. We should all sing Happy Birthday To You into Dr. Milton's Gesundheit machine. Oh, just one other thing on masks, since you brought them up, before we go to our main topic, which is restaurants.

You just described your study that got a lot of publicity in the spring about how effective masks are for the wearer in terms of not spreading it to others. Dr. Fauci and others were saying the same thing at the time and added that masks mostly protect people the wearer is breathing on, not so much the wearers themselves. Has your understanding of that evolved in terms of people wearing masks getting protection for themselves from incoming virus?

Donald: Well, it probably does protect somewhat from incoming virus. As I've said before with flu, which is where we have the most data and I think it's the most reliable data that we have, it looks like it cut out about two-thirds of the virus people were shedding into their environment. Studies of masks as protection suggests that they cut out about two-thirds of what you inhale as well. I would expect that that's about what you can expect from the mask.

That's why we don't think of them as the same class as respirators for high risk workers, like people in first responders and emergency room workers and so forth, because there when you're being exposed every day, all-day, you need something a whole lot better than cutting out two-thirds of the exposure. If most of the time you're not actually being exposed, cutting down your risk by two-thirds is nothing. When you combine that with everybody wearing masks out there, cutting out two-thirds of what they're shedding, you've cut out two-thirds of two-thirds, and it begins to really add up.

This is where I love that Swiss cheese graphic. There's no one thing that is the silver bullet here. It's adding up all these layers of things that we can do.

Brian: Have you studied, since we're going down the masks rabbit hole, how much the number of layers or specific mask materials make a difference? Because there are a lot of masks being sold on all kinds of websites that have really pretty patterns but aren't necessarily the most protective. I'm not talking about N95s or KN95s, but the kinds of masks that people typically are seen wearing on the street. Two layers, three layers, four layers, polyester versus cotton, anything you would say?

Donald: Well, I think that there are a number of publications that have come out about this showing, for example, that two layers of neck gaiter are much better than one and that what we really need are better filter materials and some standardization. I know that there is a move of foot to create some standards for consumer masks and barrier face coverings, they're called, in the proposal. I think that's going to make a big difference.

The other thing it makes a big difference is how tightly it seals around your face. For example, there's a website called Fix The Mask, which talks about this fancy rubber band device that you can put over a surgical mask and show that they can get the equivalent of practically an N95 protection by using this rubber band contraption on top of a surgical procedure mask that you can pick up at the corner pharmacy.

Brian: A friend of mine has started actually making masks with little bits of two-sided tape around the bridge of the nose, which gives you a good seal there. It doesn't let as much air in and it's also, here's a tip glasses where this is from personal experience, and there may be some actual science out there to this effect too, that it helps prevent your glasses from getting fogged.

If you've got that really good seal at the bridge of your nose and up along your cheekbones-- There's problem that a lot of people have in colder weather of their glasses getting fogged up can be largely prevented. There's a little thing. Get a little piece of tape that is of the kind that you can put on your skin, some medical tape or whatever, and that could be helpful. Okay, that's a wrap.

Donald: That's getting you to the point that it's leaking all the way around. That's where you really would want to put tape all the way around to keep it from leaking. The rubber band idea or some elastomeric mask that just has a filter that pops into it would be ideal. I think we need to get these out to lots of people. The problem with restaurants is when was the last time you ate a burger with a mask on?

Brian: It would be a neat trick. I would like to try it. All right. Restaurants, let's go there. My guest is Dr. Donald Milton, professor of public health, specifically environmental and occupational health at the University of Maryland School of Public Health. He's an expert in exhaled breath analysis among other things. Restaurants. You were quoted in a Washington Post article on Friday about an alarming indoor dining study out of South Korea that people may have heard about published in a medical journal there. The headline is about a guy who got the virus sitting more than 15 feet away from an infected but asymptomatic diner in the restaurant.

Can you describe for our listeners how they found that that happened?

Donald: Well, this was possible for a couple of reasons that they could do this in South Korea. One was that at the time, in the summer when this happened, there was very little transmission going on in South Korea, and so both South Korea and New Zealand, they've given us some really important information about transmission of the virus. Because in the background of nothing, when something happens, you can figure out what happened whereas now here, there's so much going around. You don't know where you've gotten exposed, sometimes frequently in fact.

The other thing is that they had a lot of data from using tracking apps that they are pretty much requiring people to use, a cell phone tracking. They had video cameras in the restaurant that they could see when people came and went and where they sat, and which door they entered by and left. I've seen a few people commenting about this paper saying, "Oh, well, they maybe passed in the doorway or something."

Actually, if you read the paper carefully, you'll see that the index case, the person who infected other people came in and out the back door, and the person who was sitting 21 feet away and got infected went in and out the front door. They never got close to one another.

Brian: There was a specific risk factor they found according to one version of this story that I read. Confirm this for me, if you can, that the air conditioner was blowing past the infected person toward the one who caught it. People sitting closer to the infected person but knocked down wind of the airflow did not get infected. Can that be applied to keep restaurants and other spaces safe, if you know where the wind is blowing?

Donald: Yes, tailoring the air movement so that you don't expose other people is one strategy that can be used along with other things to ensure that you aren't infecting people nearby. I do think it is possible to engineer dining facilities to make them safe. One of the things that has bothered me for years has been that our plans around how to deal with pandemics has required us to shut things down rather than figuring out how to make our buildings safe, intrinsically safe, so that during flu season it's safe, during a pandemic it's as safe as any place like that can be. Obviously, any place people are going to take their masks off is going to be risky.

Brian: Well, that's the $64,000 question, as they used to call it. Now it's if you look at the COVID relief bills, it's the $64 trillion question. Can you design restaurants to be safe from COVID rather than shut them down?

Donald: I am optimistic that we can do a lot better. It will take some work to figure out all the methods. My preferred solution is that if you had an updraft ceiling fan above every table and upper room germicidal ultraviolet light so that you're bringing the air up from the diners and zapping it killing virus before it can come down and infect other people, that I think could be quite effective. There are other things you could do as well but, in terms of expense and ease of installation, I think that probably wins the lottery.

Brian: Listeners, we can take a few phone calls for Dr. Donald Milton from the University of Maryland, an expert in exhaled breath analysis and related epidemiology on restaurants on masks. If you want, if we have time, we'll get a little into schools and subways and airplanes. 646-435-7280, 646-435-7280, or tweet a question @BrianLehrer. Dr. Milton, restaurants in New York make the case.

Mayor de Blasio has acknowledged on the show that contact tracers in New York have not traced many COVID cases back to restaurants, but some people say contact tracing data here is mostly useless unlike in other countries where people are more compliant, because people don't give up their information all that much in any case. Do you ever take on the meaning of contact tracing in New York or anywhere in the US for determining indoor dining risks?

Donald: Well, I can say that certainly over the summer here in Maryland where I was paying attention to the data, the three highest risk things that were associated with most cases were indoor restaurant dining, outdoor restaurant dining, and outdoor social gatherings like barbecues. What they all have in common is that people have their masks off and are socializing. The fact that outdoor dining was a problem is worrisome, but because it may be that--

If you're sitting along a sidewalk and you may be six feet away from the nearest table, but if the wind is blowing continuously while you're sitting there for half an hour from the table next to you towards you, it's like-- Think about if there were as a smoker over there. Would you smell the cigarette smoke? Would you inhale the cigarette smoke? Yes. It's the same thing.

Brian: That's a good analogy. That's a good test. Even outdoors, because you said outdoor dining, outdoor barbecues, you just said. I'm sure that made people's eyebrows go up like, "Wait. I thought outdoors was safe."

Donald: Outdoors with a mask on is safe but when you're around other people, if you're going to social gatherings with people outside of your bubble, it's still a risk.

Brian: Let's take a break. We have a lot of callers lined up. I'm going to get into the issue of comparing the risks in restaurants and schools, which I think you can help us do. We'll continue from there with Dr. Milton. 646-435-7280. Stay with us.

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Brian: Brian Lehrer, WNYC, with Dr. Donald Milton from the University of Maryland School of Public Health. He's an expert in infectious bioaerosols, exhaled breath analysis, and respiratory epidemiology. In other words, he's got a lot to say about indoor dining and also masks. People are really interested in some of the things that you've said about masks earlier in the segment.

By the way, people are asking for more information on those rubber bands. People are asking if we can put up diagrams of the things you were discussing. People are asking, "Well, what's the best material for today?" You talk mostly about the materials that are under development. How would you answer that caller's question, or Twitter's question?

Donald: I think that a lot of the disposable procedure masks that you can pick up at Ace Hardware and Walgreens and CVS and so forth are quite good.

Brian: Just the regular light blue, like three-layer medical masks?

Donald: Yes. Many of them are quite good. Some are better than others, but they have the advantage of they mostly are reasonably good filters and they are quite breathable. The problem is that they're so-- that the ear loop, the thing, leaves these big gaps by your cheeks and under your eyes. If you're wearing glasses, you are quite well aware of how much they leak. Getting a good seal on that is the thing.

The ones that you'll often see in medical facilities are usually not ear loops. They're often ones where they tie over the top of your head and behind your neck, and that's because pulling in those two different directions tends to flatten that out on your cheeks and get a better seal. It's really that there's the filtering material and several layers of various fabrics work pretty well. I haven't been focused on that enough to be able to say off the top of my head which fabrics are better than others, but you can look at it. I think Linsey Marr, for example, has posted a lot of stuff about that.

That Fix The Mask website that I mentioned earlier has some comparisons of different materials, and I think Linsey may have on her, one of her websites, certainly some of her Twitter posts too. You can look at those sites for information about the materials, but it's really going to be about the fit that makes a huge difference. This is one of the things that really sets a respirator apart from regular procedure masks and so forth, is that they not only filter well but they fit tight, which is their tremendous advantage and what makes them such a pain to wear. You really have trouble wearing an N95 mask for hours on end because, if it fits tight, it's uncomfortable.

Brian: We've seen those photos of nurses with marks on their faces after they get off of work. Those are some good tips. We're going to move back to restaurants. For masks, so many people are asking Linsey Marr, who's a great environmental engineer. She's been on the show, and they are if you want to check her stuff. Dr. Milton said Fix The Mask is another site. I also look at ConsumerLab, which is a good review site that includes things about masks.

Let's go to the phones. Rachel, a caterer in Douglass City, Kansas. Rachel, thank you so much for calling in. Hello from New York.

Rachel: Hi. Thank you so much. This is going to be completely outside topic and just my experience. I bought a restaurant, a catering company, in January, me and my husband, so I absolutely understand not just the desire but the need to get things going again. I'm also working as a contact tracer, and I can tell you from my personal experience that the people who are willing to eat indoors at a restaurant, and the people who are willing to fully cooperate with a contact tracing investigation, are as pretty much a circle.

Just anecdotal supporting what you've already said, but it does seem to me that basing the decision to open restaurants purely on contact tracing numbers seems like it may not be very reliable to me.

Brian: So when you say they're a circle, the people who are sufficiently not risk-averse, that they would do indoor dining at all right now, are the same people who would blow off a contact tracer and not give up their information?

Rachel: Exactly, yes.

Brian: Thank you very much. Let's see if we have anybody else in the restaurant business calling in. Screeners, help me with this. Well, maybe close is Dan, a landlord in Brooklyn. Dan, you're on WNYC with Dr. Milton. Hi, Dan.

Dan: Hi. Good morning. Dr. Milton, I wonder if you're familiar with HRV system. I'm consulting with a tenant about the install of the system that we'll bring in. It's often used in passive houses where there's not a lot of natural ventilation through windows. It brings in 100% fresh air and then heats the exhaling air with that incoming air without mixing the two. It seems like a--

Donald: Air-to-air heat exchangers, yes.

Dan: Yes.

Donald: When I upgraded the central AC in my house a few years ago, I tried to find the contractor who knew what I was talking about here in Maryland, and it was really difficult. The California now in new construction and major renovations requires air-to-air heat exchangers. I think it's a good idea because our homes tend to have very low air exchange.

This is why family big Thanksgiving dinners were such a concern to those of us trying to understand what's happening, because whereas in public buildings you hope to have something like at least two air changes an hour, and homes usually have half an air change an hour or less. It takes a long time to turn over the air in your house, which means that aerosols can linger if you have extended family over your rebreathing each other's breath all the time.

Brian: How much can at-home systems, filtration systems that you can buy air purifiers that just sit on the floor, work in your home if you know you're having people over, which of course they say we're not supposed to do at this point but sometimes people do?

Donald: Well, I think it can make some contribution. Exactly how much, we don't know, because it's also going to depend on the airflow patterns and all. If we're sitting across the table from each other and the airflow pattern is such that my breath gets to you before it gets to the filter, the filter is going to have less effect than if the airflow is directed in a way that it takes our air and cleans it before it gets to the next person. That's really difficult to achieve in a home environment.

What it will do is mean that there won't be the buildup and lingering of aerosols in the indoor environment, which is probably another issue we need to be worried about. It can help with that, but you still need to have the distance and the masks to reduce the load and the direct exposure that can happen.

Brian: The New York Times recently had an article comparing the risk of spreading the virus in restaurants and schools, and that's when it seemed weird to people. It was just last month. These things go so fast and time is so strange now. It was just last month that it seemed weird to a lot of people that schools were being closed in New York while restaurants and gyms were being kept open.

The Time's article cited a Stanford University study that found restaurants, gyms, cafes, and other crowded indoor venues likely accounted for some 8 in 10 new infections, 8 in 10, in the early months of the US coronavirus epidemic according to an analysis that used cell phone mobility data from 10 US cities from March to May. 8 in 10 in the early months from restaurants and other crowded indoor venues. Are you familiar with that study?

Donald: I'm aware of it. I haven't studied it as closely as the Korean restaurant one. That's what matters.

Brian: That was before we knew as much as we know now. The question now is with safety protocols, especially distancing, though I certainly get what you're saying, you can't eat with a mask on, how much can be prevented without shutting down?

Donald: Well, I think that this issue of schools versus restaurants is a really important one because there is tremendous social benefit to having children in schools. The social development, the education, the parents being able to work, all of these things are enormous benefits that society gets from schools. I am clearly in the camp that would say, "Let's prioritize schools and let's compensate restaurant workers, but let's close the restaurants first and the schools as a very later resort." I think that the big issue with schools is lunchtime. It's the same problem as restaurants. You got to take your mask off.

Brian: How do you explain the data from schools that seem to show younger kids spread it to their teachers and their parents and each other less than older kids?

Donald: Well, there is some suggestion of that. In household studies, children under 12, there's this nice CDC study with data from Tennessee looking at households. The kids were spreading it to adults in the households about as well as-- In fact, even better than the high school students, the younger students. There is some suggestion from the biology that after puberty, you may produce more virus, and that you may be more infectious.

In some of the population, data is suggesting-- I think a lot of it is suggesting that the big driver of the pandemic in recent months has been people 18 to 30 years old because they're out and about and mobile. When we were that age, we all believe we're invincible. Some of us still do. People in that age group frequently have asymptomatic infection. They can go around and spread it without realizing they have it.

Brian: Before you go, restaurant owners compare their plight to malls and big-box stores, which for now are mostly allowed to stay open. Can you compare those risks?

Donald: Well, my question is, can you wear a mask while you're in the big box store, and can you wear a mask when you're eating a burger?

Brian: Very simple. Since I teased this earlier, and a number of people have tweeted asking briefly, because our next guest congresswoman Kathleen Rice with some big news out of Congress related to the presidential election that just broke during the show, so we'll hold you in suspense on that for just a couple of minutes until congresswoman Rice is on. The subways, Dr. Milton, people really want to know, because there have been several international studies that have come out and indicated, "Hey, subways is a lot less risky than you think."

Donald: Yes. The one study that has gotten a lot of the press is an ecological study showing that cities with subways have lower risk than for flu, it was, I believe, than places without. It's really a population density thing. It's a little hard to understand what's going on. I don't think it really says much about if anything. In fact, the articles clearly said it did not say that within a city, people who rode public transportation were at lower risk than people who didn't or higher risk. It didn't really have anything to say about that.

What I would say again is things where people can wear masks and where mask-wearing is enforced, are going to be safer than things where mask-wearing is not possible. If people can ride the buses and subway cars wearing masks and not yelling and screaming and singing loudly, it ought to be reasonably safe. People need to wash their hands, worry about contact, but those are doable things.

Brian: For people who are tweeting us now as mask skeptics and saying, "Wait. You said in April, and Dr. Fauci said in April, that masks protect people from the wearer, but they don't do much to protect the wearer. What changed you on that?

Donald: I think that the question is how much protection do they get? It's that on a community level, if everybody is doing it, that protection adds up the fact that it's both reducing how much people are putting into the environment and how much they're getting from the environment. You add that together, the cumulative effect on us as a big group is what makes a difference.

If you focus on the individual level, the difference isn't that big. If the data shows that, on a population level, it really makes a difference. Places where people are doing this religiously have much lower rates of spread.

Brian: It really means wearing a mask is the patriotic thing to do. Some people portray it as the opposite. The ones who beat their chest about patriotism and talk about freedom, don't wear masks. Really, if you want to contribute to the wellbeing of the country as a whole, it sounds like the patriotic thing to do is wear a mask. Dr. Donald Milton from the University of Maryland School of Public Health. Thank you for so much good information. I could tell the listeners really, really, really appreciate it. I hope you'll come back.

Donald: I would love to. Thank you for inviting me today.

 

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