I’m almost at a loss to describe how near-perfect the substance of this document is. I actually printed it out.
I feel that the WA State approach should be held in nomination for our much-needed nation-wide standard.
I (we?) can only hope that Biden’s team is aware of this outstanding WA State effort, and that people in the medical professions like Dr. Fauci and others will also endorse and publicize it. It represents by far the best physics-based approach to assessing dining safety I’ve seen – in every detail.
The one and only thing I might add is that a tare reading should probably be made of the local ambient atmospheric (outdoor) CO2 concentration. There’s some allusion to this in the document, but it doesn’t go far enough and is a bit vague.
The requirement would then be that the CO2 concentration at the designated test location in the restaurant space should not exceed the tare (background) level by more than 50 ppm. But I’d be happy to bypass that nit and just go with 450 ppm as being the max.
The basis and details of this approach, to the credit of what was obviously the product of a very thorough and thoughtful WA State study, needs (urgently, I think) to get widespread distribution and attention.
Here’s a related item, a computational fluid dynamics (CFD) simulation carried out at Harvard last month and also published by NYT in Wednesday’s newspaper (much better online, actually), illustrating covid spread by airflow in classrooms.
They certainly appear to have reached the right conclusions/recommendations (portable HEPA filter plus exhaust fan blowing out of the window, with a cracked-open lower window for outdoor air intake), although the default placement of the filter that’s suggested (center of room) could be debated.
It doesn’t appear that they included turbulence shear/diffusion (e.g. k-epsilon model or direct) in their simulations, however.
The same principles hold for restaurants.
A corner table is a bad place to be in any case. Corners tend to be semi-stagnant accumulation zones. Restaurants should put artwork or plants in corners, not people, until the pandemic-related danger has passed. Whenever that will be.
I was encouraged to read that classrooms that re-opened to limited in-person instruction yesterday in San Diego Unified (after a year) included HEPA filters among steps taken to reduce virus transmission.
Excellent. And I agree with the quote at the end of the article:
“I don’t think this is rocket science,” says Freed, “which is why it’s mind-boggling to me that the public health officials aren’t talking to the building scientists.”
Those Safety First recommendations seem dated, lots of hygiene theater and misinformation about how the virus spreads, e.g. “some studies suggest at least 20-30 feet” when we know that for a fact, or that vaccinated people must wear masks to prevent spread from asymptomatic infections while the rate of “breakthrough” infections is less than 1 in 10,000.
The first article is also somewhat dated (updated but not completely up to date), as it draws on recommendations from the second. One line caught my attention in particular:
As we throw open our doors, we need to show guests a wide, welcoming smile — with our eyes.
Not so. If all of the staff are fully vaccinated/+14 (as they should be), they can show their guests the rest of their faces as well as their eyes (if permitted by state/local mandates). In a restaurant setting, I would think that unmasking would give patrons a feeling of confidence that all of the staff are indeed vaccinated and pose no threat to them. The restaurant could even post a sign to that effect at the door.
Restaurants should require all staff to be vaccinated, just like meat-packing plants, care homes, and other workplaces that have been common infection hotspots. That should be a state-level requirement. Actually national, but forget that in this country.
Unfortunately many employers don’t require it for everybody. e.g. in my industry it is kind of ironic that biotech/pharma has now opened their doors again but doesn’t require anything to get back to work
Not sure if I would agree - it might be a relative small probability to get infected in such a scenario but there is some indication that the risk might not be 0.01% but perhaps with the delta variant somewhere around 1-3% (but obviously it’s always a personal decision how much risk one is willing to take for different things)
For my part, I’ll continue to patronize these places – with or without that condition.
But perhaps a graceful way for restaurants and bars to help encourage vaccination would be to provide a discount to those with a card or QR code verifying their vaccination status. (E.g., one injection, 5%; two injections and 14 days, 10%.)