Stop it With the Plexiglass – How to Open Schools (and Other Places)
San Diego Unified enlisted a group of UC San Diego scientists to help officials understand the coronavirus threat and create a plan to safely reopen schools. Now, some of those same people are changing the worldwide conversation about how we understand the virus.
Joe Leventhal, a City Council candidate, recently had to clean up a comment he made about why he would be a better representative than his opponent, Marni Von Wilpert. In part, he had told the Union-Tribune, it was because he was a parent and she was not.
She was offended.
“Let me be clear: Women, like all candidates, should be valued for our skills, knowledge, and experience,” she wrote.
He replied that he was talking about his own experience.
“I believe we’re leaving our children behind, parents should have options for in-person, distance or hybrid learning, and the union that continues to push for schools to be indefinitely closed is also supporting my opponent, something I believe impacts her position on schools too,” he wrote.
The union he’s talking about, the San Diego Education Association, has received much of the heat from people anxious to see schools open. It’s been hot enough that the union did its own poll and found that a majority of respondents endorsed the district’s cautious approach to reopening. But the pollster did not single out just parents about their views.
Even if a majority of residents is supportive of cautious re-opening strategies, nobody denies that the current state of things is awful. Principals who worked for years to build a community of support and accountability and resources are watching it all evaporate. Enrollment is plummeting, and attendance numbers are unavailable. Tech problems and complaints are pervasive, and parents across the region are exasperated. We have no idea how many kids are lost right now.
Teachers tell me they want to be back in classrooms. I believe them. But they are worried. They have seen how sick kids get, how an outbreak of the flu or colds or lice can take down not only big parts of classrooms but teachers too. They know how easily germs spread in schools.
It makes sense that they want to see a plan.
When The New York Times came to San Diego to profile a school district that had re-opened, Cajon Valley Elementary School District, the reporters wrote about how tenuous the opening was: “But at a moment where many communities feel abandoned by their schools, Cajon Valley’s ability to partially reopen its buildings with the support of both families and teachers is a testament to the importance of an easily overlooked commodity during the pandemic: trust.”
To earn trust, you need to demonstrate that you understand the threat. San Diego Unified wisely signed up a group of scientists from UC San Diego to help with this. And now, some of those same people are changing the conversation worldwide about how we understand the virus that has paralyzed our lives.
What they have found is that we share the virus when we share the air. And the more we can do to clean and circulate air, the more we can live.
I don’t underestimate the logistics involved in re-opening schools, but trust isn’t going to be earned with a deadline and a bunch of rules packed into a big binder sent to principals across the city.
First, school district leaders need to demonstrate in simple terms that they understand what is happening and what they are going to do to keep their employees and the public healthy.
Ironically, I think one of the best ways to do that is start with cigarettes.
I. Watch Cigarettes Burn
I used to smoke cigarettes. I used to work at bars where smokers would blow smoke right in my face for hours at a time.
Now, decades later, I have an almost violent physical reaction when I smell them.
And it is astonishing how easy it is to smell cigarettes. You can be on the other side of a large room and the moment someone lights up, you can smell it.
In cigarette smoke, we have the perfect analogy for what these scientists are learning about SARS-Cov-2. There’s a quiet revolution happening among scientists, led in part by people in San Diego, who are concluding that the virus spreads primarily in the air.
Cigarette smoke disburses through air exactly the way aerosols do. What are aerosols?
Well, when you speak or cough or sing or yell, a spectrum of stuff comes out of your mouth. There are big droplets sometimes called (wonderfully) “ballistic droplets.” The scientists who wrote this FAQ could not have described it better for a person like me than this: “They fly ballistically (like a projectile) through the air, as in the famous ‘Angry Birds’ video game.”
That I can picture.
Ballistic droplets measure at a whopping 100 millionths of a meter. They are what led to the six-foot rule for social distancing because they usually fall to the ground within six feet.
But then there are aerosols, which are smaller particles of saliva or respiratory fluid. They can travel longer distances and stay in the air for hours – like cigarette smoke.
That is how the virus is spreading as well. People, gathering indoors, are spreading it to one another mostly by speaking, singing, yelling or coughing – and not just right next to each other. The superspreader events public health officials have tracked make clear that the virus can linger and spread just like cigarette smoke – yes, it’s more concentrated right next to the smoker, but it can quickly become airborne and travel great distances.
Unfortunately, unlike smoke, we can’t smell the virus. But it’s traveling in exactly the same way from a person who is infected and shedding it – likely blowing it out in the highest concentrations right before they even feel symptoms of the disease set in.
“The closer you get, the higher the concentration of the smoke, and the virus. But it still has the ability to disburse all over the space, and that is what people struggle with. They can’t see small particles. They don’t understand why they stay airborne. So it’s not the tangible experience you have with a smoker,” said Shelly Miller, a professor of mechanical engineering at the University of Colorado who has long studied the interplay between urban outdoor air pollution and control of airborne infectious diseases.
This week, along with several colleagues across the country, UC San Diego’s Kim Prather, the distinguished chair in atmospheric chemistry and distinguished professor at Scripps Institution of Oceanography and the Department of Chemistry and Biochemistry, and Robert Schooley, the chief of the Division of Infectious Diseases at UC San Diego Health, published a letter in the journal Science.
The letter has a simple but radical message:
Viruses in aerosols (smaller than 100 μm) can remain suspended in air for many seconds to hours, like smoke, and be inhaled. They are highly concentrated near an infected person, so they can infect people most easily in close proximity. But aerosols containing infectious virus (2) can also travel more than 2 m and accumulate in poorly ventilated indoor air, leading to superspreading events (3).
The most profound implication of this is that advising people to stay six feet from each other – indoors – is not only false assurance but perhaps deeply misleading. Like cigarette smoke, the concentrations of SARS-Cov-2 are very high right next to someone and many of the larger droplets coming out of their faces will fall to the ground but many others will fly almost immediately across the room.
What it means is we actually have a clear target for addressing the threat:
It’s all about the air. For those who manage public facilities, especially the ones we want to see open, like schools, they must completely focus on the air.
The best air is outdoors.
II. Go Outdoors
We pushed smokers outside for a reason. Non-smoking sections of restaurants or airplanes were bogus. Yes, you didn’t have to sit right next to someone smoking but the smoke was unbothered by our dividers.
But outdoors, aerosols dissipate rapidly. Think of squeezing three drops of food coloring into a glass of water. Now do it off a pier into the ocean. The aerosols are lost and whatever settles can be torched by the UV light from the sun.
We have not seen major outbreaks from the numerous protests or outdoor churches or crowded beaches in the summer. What’s more, we saw something beautiful: After infections spiked this summer and California regressed into another lockdown, officials allowed outdoor spaces to flourish.
Many of our streets transformed into outdoor dining plazas. And we settled into a welcome equilibrium: Economic activity and trust increased and transmission of the virus decreased. The outdoors provided hope.
One study of 110 cases found the odds of transmitting COVID-19 in a closed environment 18.7 times greater compared with an open-air environment. Another review of 1,245 cases in China found only two of the cases could be linked to an outdoor experience.
YMCAs operated camps outside all summer. The city of San Diego put on its Junior Lifeguard program without a hitch. Thousands of soccer players, lacrosse players, softball players pack local parks every day and nothing happened to them. Though the county refuses to provide information we want about its tracing of outbreaks, it has not cited any outdoor event or location as the site of one of the hundreds of outbreaks it has identified.
Everything we can do outside, we should do outside. It can be very difficult to imagine school outside but we need to creatively try. It should be the first question of the flow chart.
- Can you do it outside? If not, are you sure? If you’re sure, have you really thought about ways you maybe could? If you have really thought about ways maybe you could and you can’t, then move to the next level.
III. Stop it With the Plexiglass
There was an initial, understandable reaction to COVID-19: the sneeze-guardification of everything.
Suddenly plexiglass was everywhere. At the grocery stores. At the casinos dividing poker players. Voice of San Diego’s offices got some. And of course, it was in the schools that had opened, sometimes around every desk. The mania led to a plexiglass shortage.
It even became a national political issue. Sen. Kamala Harris insisted that plexiglass be placed between her and Vice President Mike Pence in their debate Wednesday.
It has all gone too far.
Plexiglass works for actual sneeze guard situations – like if Pence leaned over and coughed right onto the plexiglass, Harris might have been glad it was there. His ballistic droplets would be stopped, and some guy with Windex would wipe them away hours later.
But, again, think of the cigarette. Imagine Pence lit a cigarette during the debate (that would be quite a thing!). The plexiglass wouldn’t stop the smell from immediately hitting Harris or the moderator or most of the audience. Same with the aerosols. If he had COVID-19, especially if he were in that danger zone the day or two before he felt major symptoms, then those flying little spaceships of virus wouldn’t even notice the plexiglass as they filled the room.
If Harris and debate organizers were really concerned about safety, they would not put in plexiglass. They would move the debate outside, wear masks or cancel it.
But some configurations of plexiglass could not only be ineffective. They could be harmful.
Prather, the professor of atmospheric chemistry, told me that if you are dividing up a big facility with a ton of plexiglass, you could be making it more dangerous.
“Some air flow simulations show the air can go down the other side of the barrier and become trapped. If someone is sitting there, they will inhale these potentially infectious aerosols,” she said.
Imagine a restaurant that has completely enclosed a booth with plexiglass. A sick person in there may actually leave a pool of the aerosols and the plexiglass could have disrupted the ventilation of the building enough to prevent it from clearing out.
Again, if you can’t be outside, ventilation is the next best thing. Don’t get in its way!
Miller went further and told me that school districts that are budgeting big dollars for sanitation and plexiglass need to rethink it.
“It is a huge waste of money to spend resources on plexiglass instead of air cleaners and ventilation and good three-ply surgical masks,” she said. And while you’re at it, don’t go crazy with the Windex.
“Do not spend extra on cleaning services. There is no indication transmission is happening from surfaces from any study of outbreaks of this disease.”
If you can’t be outside, you have to clean the air inside. The district has been taking this advice and installing filters in its HVAC systems.
So if you can’t be outside, maybe can you be half outside? Francis Parker, the elite private school, was architecturally designed for many of the classes to have massive open walls and windows to the outside. It’s a dream of accidental foresight.
But if that’s not possible, every window should be open, and the air should be flowing.
And if you must be inside, even if you’re apart or separated by plexiglass, you need to wear face coverings.
IV. Masks: Sorry, You Have to
When Francisco Escobedo, the superintendent of Chula Vista Elementary School District, announced the district would begin opening its schools Oct. 26, he said masks would not be mandatory.
Within two days, he had changed that and postponed the re-opening.
Indecisiveness about masks bedeviled districts in the springtime and over the summer. But if you are unclear about masks, you are unclear about the threat. And if you’re unclear about the threat, you cannot generate trust among employees and parents.
Masks are vital not only as your last protection but as important mitigation even if you get the virus.
Schooley, the chief of infectious diseases at UC San Diego Health, appeared at a press conference where he and the others presented their letter about the significance of this new understanding of aerosols and the spread of SARS-Cov-2.
He said there is a lot of evidence that the severity of the disease you experience is a function of how much of the virus you are exposed to. If you are next to a sick person for an extended period of time, listening to them while they spew droplets all around you, wearing a mask could save your life.
“Wearing a mask decreases the amount of virus you’re likely to be exposed to. And it will decrease the likelihood that a patient will end up with a very serious case of the disease,” Schooley said.
If you have to be inside, if you’ve exhausted all efforts possible to improve ventilation and air filtration, then you have one last stop to control the virus: your own face.
Miller was the author of a study analyzing an outbreak at the Skagit Valley Chorale in Skagit Valley, Washington. It was a notorious case early in the pandemic’s spread across America.
One day in March, the chorale had a rehearsal. Only 61 of its 122 members attended. Out of that group, 53 people became infected. Two of them later died.
There’s only one person who was suspected of bringing the new coronavirus to the rehearsal, so even if that person sent one of those big, “ballistic” droplets into the mouth or nose of someone nearby, the others must have gotten it from the tiny aerosols.
They got it from sharing the air. The air was not ventilated well. It was not filtered well, and the people weren’t wearing masks.
This is how the virus spreads – these superspreader events: inside, with poor ventilation, loud talking or singing and no masks.
And social distancing won’t actually help you if you are inside a place like this. Plexiglass won’t either.
“The minute you get three or six feet from someone plexiglass does nothing to prevent you from aerosol transmission. You either get a mask or leave the space,” said Miller.
V. How to Open Schools
One thought may be that schools should stay closed indefinitely – until there’s a radical change in the virus’ threat to us. Maybe that means wait until there’s a vaccine or proven treatment.
But we need to consider the possibility that there will never be a vaccine or that it will be of limited effectiveness or that it is five more years away. Are we prepared to keep schools closed for five years? Forever?
The wealthiest parents are not. Private schools and districts like Poway Unified have started gingerly opening and adapting.
In a new poll of California residents commissioned by EdSource, one in four parents (24 percent) said they were considering moving their child from public school to a private, parochial or charter school.
The districts that are still not open can take this new understanding of the virus and apply it. They can move whatever can go outside, outside. They can identify the rooms with the worst ventilation and close them off. For the rooms with good ventilation, they can add air filters and fans.
And they can tell everyone: masks or stay home. Some of them are already in that frame of mind. Sharon Whitehurst-Payne, a school board member running for re-election on San Diego Unified’s board, recently said at a debate she is worried about kindergartners and would have them back, if it were up to her, right away.
“For me personally, this is my bias, because I’m so pro-Ks right now, and wanting them to get established, I would just bring all of them back, one class in the cafeteria, one outside in the courtyard and one in another large place because I want them back,” she said.
The key is to imagine that every class has a little cigarette smoker in it. What would you do to make sure the smoke cleared out as best it could?
You’d be outside. You’d ventilate if you were inside. And you’d put a mask on him so he couldn’t smoke.