Monday, May 10, 2021

Safe Schools in September - Second Try

Last September, despite all the science to the contrary, school boards opened schools with "mask breaks" built in to the mornings rather than have a shorter day and let the kids go home for lunch. I left my windows open an inch, and kids complained about the cold. And then I discovered how difficult it is to teach hybrid style, with my attention split between kids in the room and kids at home and with other classes using the hallways to practice skits outside my open door, and while tethered to my laptop by my mic cord so the kids can hear me through my triple-ply mask, I could barely manage a complete thought.

So I started calling in sick. A supply teacher quietly read a book all day as I managed the class from home, where I could teach everyone at once from a warm, quiet room without any PPE blocking the sound of my voice. The marking load was insane in the quadmester system that compressed each class to 22 days,  especially with four senior courses in a row without a prep built in to the schedule. The big changes coming in the fall include having semesters again and full days. It sounds suspiciously like business as usual except with two classes per day and half of each class learning from home. I can't even picture what that will look like! Will some kids come for half the day? Will the kids there all day be eating in our classrooms? How will two classes/day but cut in half stop the spread?? When will the other two classes run: alternating days or weeks??

But now on top of what some scientific journals have argued for over a year, the CDC and WHO have made it very clear that Covid-19 is spread through aerosol transmission, which means distancing, hand sanitizer, desk-washing, and daily symptom quizzes are far less important, and masks, ventilation, eating outdoors, and testing are everything

By one account, "The CDC 100% waited to admit what scientists around the world understood more than a year ago until we had the vaccine b/c it would have been inconvenient for commerce. Instead counties shoved kids back into school and restaurants let patrons breathe in servers’ faces." That's not unlikely.

In a Globe & Mail article today, Brooke Fallis and David Fisman explain that using hospitals as a way to understand transmission didn't work because people are less contagious once they get sick enough to be hospitalized: 

"Current workplace guidelines follow hospital principles. Continuous masking is not required if distancing is observed, and masks are removed in lunchrooms. The current approach is clearly inadequate based on the indoor workplace transmission we are witnessing. . . . Primary mitigation strategies shift from two metres distancing and handwashing to ventilation and high-quality masks. Monitor ventilation using portable carbon dioxide monitors, open windows and emphasize improvements in ventilation or air filtration when ventilation systems are poor. Distancing remains important but high-quality respirators should always be worn while indoors. All breaks and meals where masks will be removed must be moved outdoors or, when outdoors is not possible, in large well-ventilated rooms with maximal distancing and small numbers of people. . . . In many of these settings, the spark is an infectious individual who has no symptoms yet."

A few days ago, the New York Times ran an article about the sunk-cost fallacy keeping people from making the right changes to policy: 

"Another key problem is that, understandably, we find it harder to walk things back. It is easier to keep adding exceptions and justifications to a belief than to admit that a challenger has a better explanation. . . . So much of what we have done throughout the pandemic — the excessive hygiene theater and the failure to integrate ventilation and filters into our basic advice — has greatly hampered our response. Some of it, like the way we underused or even shut down outdoor space, isn’t that different from the 19th-century Londoners who flushed the source of their foul air into the Thames and made the cholera epidemic worse. . . . Recently, though the organization’s documents have lagged, more of its officials have started giving advice compatible with aerosol transmission, emphasizing things like close mask fit — which matters little for droplet transmission — and ventilation — which matters even less. . . . Dr. Marr and other scientists told me the situation was very difficult until recently, as the droplet dogma reigned."

And in April, Martin Bazant and John Bush published a guideline to best limit indoor transmission in Proceedings in the National Academy of Science, explaining that they've found the 

"presence of infectious SARS-CoV-2 virions in respiratory aerosols suspended in air samples collected at distances as large as 16 ft from infected patients . . . face mask directives have been more effective than either lockdowns or social distancing in controlling the spread . . . one is no safer from airborne pathogens at 60 ft than 6 ft . . . the transmission rate is inversely proportional to [the room's ventilation outflow]. . . . Assuming 6 h of indoor time per day, a school group wearing masks with adequate ventilation would thus be safe for longer than the recovery time for COVID-19 (7 d to 14 d), and school transmissions would be rare. We stress, however, that our predictions are based on the assumption of a “quiet classroom", where resting respiration (Cq=30) is the norm. Extended periods of physical activity, collective speech, or singing would lower the time limit by an order of magnitude. . . . With mechanical ventilation (at 8 ACH) in steady state, three [unmasked] occupants could safely remain in the room for no more than 18 min. . . . it underscores the need to minimize the sharing of indoor space, maintain adequate, once-through ventilation, and encourage the use of face masks. . . . For a group sharing an indoor space intermittently, for example, office coworkers or classmates, regular testing should be done with a frequency that ensures that the CET between tests is less than the limit set by the guideline."

The implication is that the 6' rule doesn't come in to play as much as earlier thought when we're dealing with aerosol transmission, which, like cigarette smoke, fills all the nooks and crannies of a room. When we walk into a room with others, we're all in the same fishbowl together. So there should be NO mask removal once we're more than 6' away - or at least not for more than 18 minutes with only 3 people in the room!

According to Bazant and Bush, a cloth mask extends the cumulative exposure time (CET) to less than two hours, but a simple medical mask can take us to the end of the school day. So it matters what kind of masks the kids wear. Everyone should be given N95 or KN95 (which are near identical - and both protect the wearer as well as others), and schools should consider banning cloth masks. But most importantly, we need the kids to wear masks all the time. It will get tricky as everyone's at a different stage of vaccination, so it's even more important that masks are a rule until we hit a critical mass of full vaccinations in the building.

Right now, the twitter-sphere is gearing up to protests hybrid teaching in September, and I completely agree that it's a horrible way to teach, but I can't imagine what else will work. Lecce isn't about to fund double the number of teachers in order to keep class sizes low, so getting half the students to learn at home is the only option. They could tie all remote learning students to their school to automatically take out a certain number who prefer to learn from home, but they're really married to that being taught by the board (or by TVO). That decision has got Ford's fingerprints all over it. Other than that, I don't forward the complaints because I can't think of a solution that is safe and good pedagogy within the current funding.

I can live with the hybrid scheme, as awful as it is, provided the powers that be have seen the light on the importance of masks on all staff and students, all day, with eating only done outside the building. We can survive tech difficulties and speaker issues, but we have to keep fighting to make sure our kids and their families survive Covid. 

ETA: I was hoping the consensus on aerosol transmission would mean masks all day inside every building, but now one doctor is suggesting that we can open school WITHOUT MASKS at all! This will be a fun ride from now until Labour Day! 

ETA: This anti-masking presentation was viewed by my board last night. I'm losing hope! And we'll definitely NOT have hybrid learning, but nobody knows what we WILL have (here from 52:30-54:00), but we MIGHT still have quadmesters (at 1:10:20), which is a far worse idea than the hybrid system!! We're on a need-to-know basis, so hopefully we find out by September 7th!

ETA: It's been explained to me that we've never had hybrid, technically, because that means teaching kids in the room at the same time as teaching kids at home, and we're allowed to just set up info on a website for the kids at home, which DOESN'T WORK AT ALL!  I've taught in this system, and actually DID teach hybrid by projecting my screen and talking through meets so kids in the room AND at home could see everything and talk together as one class. Some teacher just "catch people up" once they're in the room, except some kids opt to work from home and then might not actually get a formal lesson, so THAT can't be the solution!!  Bottom line, it looks like we're still teaching half the class at home, and I'll be teaching a hybrid system rather than just hoping kids can follow along from home!

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