1/ The Delta Fredericton has central corridor air pressurization and shared washroom exhaust. Lower floors may have inadequate pressure allowing air to flow out of suites. Failure of an exhaust fan can lead to direct connection between all suites on same shaft, @ShiftNB
2/ This style of ventilation & exhaust is disproportionally prevalent in Ontario apartment building outbreaks. Before concluding fomite transmission a more detailed analysis by subject matter experts (building science) is required. @DFisman @IPACCanada docs.google.com/spreadsheets/d…
3/ More detail about the possible mechanisms from building science in this thread:
4/ And this would also apply to the Magee House residence outbreak at University of New Brunswick which has been blamed on the elevator and other surfaces, without any mention of the functioning of the elevator cab exhaust.
5/ Hotel quarantine outbreaks in AU and NZ, initially blamed on surfaces, turned out to be airborne after detailed ventilation studies were conducted, including inter-zonal pressure differences and review of security camera footage.
6/ My calls to action are:
1⃣ Ensure any quarantine or isolation accommodation is tested beforehand to be compartmentalized (if multi-unit) or "air-gapped" (like trailers) Figure from BuildingScience.com showing compartmentalization
7/
2⃣ Ensure that anyone who has an active case of COVID-19 living in a multi-unit residential building or congregated setting, that is NOT compartmentalized or air gapped, should be moved to one that IS, until the infection is resolved.
8/
3⃣ For any outbreak, immediately bring in an independent engineer or building scientist to check for ventilation & filtration effectiveness.

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More from @DavidElfstrom

10 May
1/ Public Health @cityofhamilton, to stamp this out fast, you should issue an order requiring off-site air-gapped isolation/quarantine accommodation for those with an active infection. cbc.ca/news/canada/ha…
2/ Off-site air-gapped isolation can take the form of individual trailers, or a newer hotel that has been tested for dwelling unit compartmentalization.
3/ We know from decades of building science that there is significant unintentional air transfer between suites, especially in older buildings.
Read 7 tweets
4 May
#Onted, who would be able to provide data on number of classrooms, students per classroom etc for Ontario so that I can do some capital cost and operational costs on air quality related upgrades? More than the 2015 facility condition list. edu.gov.on.ca/eng/parents/fc…
2/ I'm thinking of some per-classroom budget numbers balancing operable windows/fan, HRV, filtration, upper room UVGI, including energy costs/penalty, GHG emissions, maintenance.
3/ I can do analysis per classroom with an "average" class size or some distribution bins and then multiply through by total classrooms to arrive at a total $ figure.
Read 4 tweets
4 May
1/ HOW TO HIDE YOUR DATA
In the highlighted section from Conly's presentation last month he references no transmission events in 5544 person-hours.
Source is "Conly J et al ARIC". Here's the section of that reference: (aricjournal.biomedcentral.com/articles/10.11…) H/T @jmcrookston @CPita3 There have been an estimated 5544 person hours of continuous
2/ Okay, so reference 26 is the Alberta Health Services Rapid Review. link: albertahealthservices.ca/assets/info/pp…
3/ And here is the 5544 person hours passage from the Alberta Rapid Review. What is the source? HIMSELF, personal communication.

This intellectual dishonesty has been used to support the denial of respiratory protection to front-line health care workers.
Read 5 tweets
3 May
WHO's pandemic guidance language for health care workers regarding proper PPE is belittling and paternalistic on matters of workplace safety.

This language is like when construction workers chastise peers for wearing PPE because they think it's a sign of weakness. In general, health workers ...
Reminder once again of the fallacy of the "AGP" (aerosol generating procedure). Regular activities produce FAR MORE bioaerosols than specific medical procedures.
Same document, just above. Back to harms from acne again. This whole paragraph has Conly's fingerprints all over it. The WHO COVID-19 IPC GDG co...
Read 5 tweets
1 May
1/ I wear an N95 at locations outside of my home. I wear it to the grocery store, pharmacy and my doctor's office.

It's comfortable, doesn't hurt my ears, doesn't fog up my glasses, and easy to breathe through. I can wear it all day, anywhere. EXCEPT at the hospital! Photo of @DavidElfstrom wearing an N95 respirator and presen
2/ Many health care facilities require visitors to REMOVE their superior respiratory PPE and don a basic surgical ASTM Level 1 mask.

This practice must stop. Understanding the difference between surgical masks and N95
3/ Here's my friend Annamaria's experience this past Thursday when she went to @NGHSimcoe for her second vaccination, shared with her permission👇 When I got there, I stood in full view of the door and took
Read 14 tweets
29 Apr
U of T is making all classrooms achieve 6 ACH with #ventilation and #filtration, the same as for health care patient exam rooms. They measured air flow.
THIS should be the target for all Ontario daycare, elementary, and secondary schools too.
utoronto.ca/news/u-t-asses…
Children will be the last to be vaccinated. Schools & daycares will benefit immensely from reduced cold, flu, seasonal allergies by upgrading to 6 ACH. The time to start was a year ago. The next best time is tomorrow.
Big shout out to @ShellyMBoulder and the UC Boulder team that led the way on this last summer.
Read 4 tweets

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