Dear @tdsb, @TDSBDirector ; I know the province has screwed you over. But we're all in this together, and here are some immediate, low-cost steps within your power to reduce the spread of Covid-19 in schools. Given high community spread in Toronto, speed is of the essence. /1

First, pls accept the premise that Covid-19 is spread significantly by aerosols, small fluid droplets that float in the air like smoke. While transmission by fomites (particles on surfaces you touch) is possible, this has not been shown to be the dominant mode of spread. /2

This means that while all the effort put into sanitizing is not for nothing, it's not enough to make schools safe. Aerosols *build up* in poorly ventilated rooms. (For an up-to-date overview of evidence for aerosol spread, see this recent presentation: https://twitter.com/CyrusMaher/status/1313998343232602112) /3

Things that make me crazy: Seeing only 2 of 5 windows in my kid's classroom open on a beautiful afternoon. Seeing unmasked kids at my kid's school sitting around a tiny table working on projects together (outside yes, but outside isn't magic). /4

More things that make me crazy: Hearing that windows get closed when kids say they're cold. Hearing that doors get closed because of noise. Seeing zero effort made to eat lunch outside./5

Step 1: Implement a strong windows-and-doors open policy for classrooms with natural ventilation. All windows open all the way all the time. It's cool outside? Put on a sweater. No exceptions. We'll deal with winter when we get there./6

Step 2: Work to rearrange schedules if necessary so all classes can eat lunch outside. It's complicated for some schools with limited space, but unmasked eating indoors is a high-risk activity./7

Step 3: You are now responsible for making sure kids maintain distance at school. Deal with it! If kids are outside and unmasked, they should not be closer than 2m. If they are working together on projects and are going to be getting close, mask up. But limit this please. /8

Step 4: Roll out an emergency air filtration project, or allow parents to step up. I know equity's an issue. Many parents would gladly donate money to a central fund if they knew action would *also* be taken in their school. Many would also volunteer to help other schools. /9

Air filtration does not have to be a $1000 units per room. You can build perfectly viable air filter using furnace filters strapped to box fans. The aerosol scientists are all over this. Here are tests of effective filtering rates of different designs. https://twitter.com/JohnSemmelhack/status/1313855226844151808 /10

There is no reason in the world for easy, cheap, effective measures like these not to be taken. *The board needs to make it clear to local schools that these steps are not only permitted, they are encouraged and expected.* There are many people of good will ready to help. /11

Resources on aerosols and Covid-19: https://twitter.com/jljcolorado/status/1301367221076152320
Selecting air cleaners for classrooms:
https://twitter.com/j_g_allen/status/1314537564565635072
General risk reduction advice:
https://twitter.com/j_g_allen/status/1314540916015853570 /12

Here's where I tag trustees: @MacLeanWard2 @harpreetgill__ @NunziataPatrick @trusteemammo @alexandralulka @christonks @RobinPilkey @shelleylaskin @Steph4schools @ChrisMoiseTO @rchernoslin @AlexBrownWard12 @JamesX_Li @trixiedoyle @jenniferstoryTO @aarts_michelle @ParthiKandavel

@Zakir4TDSB @MannaWongTDSB @YaliniR_Ward21 @Anu_Sris @FirdausShallo
And some others who may wish to amplify:
@pothen @yonanestel @Sue_Innovates @DFisman @sbearbergman