Thread by @covidschoolsCA

Now is the time to improve ventilation in Canada's schools!

We at #Masks4Canada @covidschoolsCA have compiled a primer, best practices + success stories to help YOU drive advocacy. Feedback welcome!
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Author: @spaiglass h/t @DavidElfstrom @caruzycki (mistakes mine)

THREAD: /1

A #COVID19 infected individual releases infectious particles by talking, coughing, sneezing, laughing, etc., “Aerosol transmission” acknowledges airborne spread of the virus. It has different PH implications than droplet transmission.

Img: Dr. Butler, nationalacademies.org/event/08-26-20…
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Important: The virus is NOT naked in the air. It is encased in droplets or smaller aerosols (10-1000X bigger than virus). Aerosol size impacts efficacy of masks + air purifiers, *and* how deeply particles penetrate the respiratory tract.

Adapted from: docs.google.com/document/d/1fB…
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Earlier this week, Canada acknowledged aerosol-based transmission of #COVID19.

Signals that we CANNOT rely only on strategies such as excessive surface cleaning (droplet model). We must now include masks, ventilation, air filtration (see blow).

cbc.ca/news/health/co…
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Bookmark this FAQ on protection from #COVID19 aerosol transmission. Written by infectious aerosol experts presenting at the highly-regarded @theNASEM. Well-written + regularly updated.

docs.google.com/document/d/1fB…
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Protection from airborne #COVID19 includes strategies such as:
🚫Avoiding Crowds, Indoors, Poor ventilation, Prolonged Close Contact, Talking/yelling/singing
✅Being Outdoors, Wearing Masks, Improving Ventilation or Air Cleaning by Filtration

Source: docs.google.com/document/d/1fB…
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Ventilation is dilution of indoor air w/ fresh air. Can be natural (doors, windows) or mechanical (central HVAC). Mechanical useful when natural not possible (low temp., no windows, pollution). Portable air cleaners can filter recirculated air.

Source: docs.google.com/document/d/1fB…
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How much ventilation is enough?
The @WHO recommends 6 “air changes per hour” (or 6 ACH) using natural and/or mechanical ventilation.



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CO2 meters are an affordable way to measure vent. rates in a classroom (start <$200 USD). Rate at which excess CO2 in a room decays => how quickly air is refreshed in a room.

How-to by @jljcolorado: medium.com/@jjose_19945/h…

Ventilation calculator: docs.google.com/spreadsheets/d…
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@HarvardChanSPH has published a 5-step guide to check ventilation rates in classrooms:
1. Measure class dimension
2. Check instruments are working
3. Measure outdoor air vent rate
4. Compare results to target
5. If needed, supplement air cleaning

schools.forhealth.org/ventilation-gu…
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Schools have differing needs for ventilation upgrades and funds. **One size does not fit all.**

Measuring vent. in all classrooms will identify which need portable units, retrofits, + which should be closed.

@PHLschools in US is doing this now:

https://twitter.com/covidschoolsCA/status/1323753563185709056?s=20

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NYC also did this in early Sep. Schools closed for one week + ventilation inspectors measured all classrooms.
nbcnewyork.com/news/local/doe….

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Germany is currently investing ~$500M (!) in vent. systems for public buildings, inc. universities + schools. Funds are available for CO2 sensors; individual grants < 100K euros for upgrades.

bbc.com/news/world-eur…

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In Canada, Ontario providing $700M of Fed-Prov $ for infrastructure projects in schools. This includes ventilation upgrades.

Project CVRIS-EDU (Deadline: Nov 18!)
See memo B20 here:
efis.fma.csc.gov.on.ca/faab/B_Memos_2…

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In Toronto, @tdsb bought 6,000 HEPA portable units w/ $6M of $6.9M Prov funds allocated over the summer. This initiative prioritized poorly-ventilated classrooms:

https://twitter.com/covidschoolsCA/status/1320155361207373829?s=20

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Conditions on how funds can be spent + systematic measurements will ensure more schools are equipped with basics (e.g. portable HEPA units) - i.e. be equitable.

It will avoid expensive solutions for the few, at the expense of the many 👇🏾

granderie.ca/board/news/stu…

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While summer was the ideal time for upgrades, we must hasten now to improve ventilation in schools that need it.

This is part of ensuring that schools are maximally protected through the Winter.

For more see this guide from @HarvardChanSPH:
schools.forhealth.org

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