I suggested this as an alternative to mask enforcement months ago and was ridiculed on hacker news. I'm happy to see the idea come up again as it has a lot of solid science behind it.
To my knowledge masks are a low cost / lost risk way to reduce the spread, and countries that had faster uptake and higher rates of compliance in mask usage did see lower overall case counts.
The building ventilation side to me seems more like a long term solution, with lots of details to implement. How can we be confident that someone did the retrofit correctly, and tested the air pathways to make sure there isn't droplets being pushed from one table to another in a restaurant. Can we be confident that small changes to dampers, rearrangement of the dining room, other changes don't affect the conditions and are maintained over time. Building HVAC systems are hard enough to maintain as is.
This seems like a great addition to building codes, or if some standard can be developed for inspection, maintenance, testing, etc. And how can we be sure that businesses don't just try and cheat, would they be liable, can this be inspected, would the liability be collectable, etc, etc.
I think as a society we should be looking at this problem holistically, I think part of the solution is masks, and part is vaccines, and part should probably be building codes and HVAC systems in public indoor spaces to reduce a variety of airborne pathogens.
As someone who knows an HVAC inspector, they WILL cheat.
He has appalling stories.
The most appalling was him having to hold up opening a memory care facility because the HVAC was all shared when it was all supposed to be isolated. This was completely on the HVAC contractor as the plans were quite explicit about what needed to be done--which means that contractor did this before and got away with it.
People who come into these kinds of facilities are not well, and get sick with things all the time. Many of them are immune compromised. But, nope, everybody wanted the facility open and banking money--this included the local politicians, the local community, the "oversight" committee, etc.--nobody gave a damn about the fact that the HVAC would KILL PEOPLE.
So, don't hold your breath.
Or, do.
1) This isn't really true. There's not a lot of correlation between what nations/states did, and where they ended up. You can find observational papers on both sides of every question (for example, specific to masks, recently: [1]).
2) What else did nations with mask adoption do that could also explain the outcomes? Most places did many things at once, so we're going to be doing post-hoc analysis of this for years. Unfortunately, because nobody thought it appropriate to conduct actual clinical trials, we'll probably never know the answer. There are too many intermingled factors at play so we have to use models, and the modeling work so far has largely been garbage that reflects the assumptions used to create them [2].
(and before anyone says it: yes, it's entirely possible to have conducted clinical trials of masks. A cluster randomized trial, for example, could have been used to establish efficacy early in the pandemic. That we didn't even consider doing these "because it's a pandemic" is one of the biggest scientific lost opportunities of our lifetime.)
[1] https://www.medrxiv.org/content/10.1101/2021.05.18.21257385v...
[2] https://www.jclinepi.com/article/S0895-4356(21)00087-1/fullt...
There were studies done; all the way back in March 2020 there was an infographic making the rounds showing a rough estimate of percentage of particles filtered/let through by different types of cloth masks and N95/etc. If I remember right, all the cloth masks let through >50% of particles.
https://www.cebm.net/covid-19/masking-lack-of-evidence-with-...
Strapping a mask on a mannequin or to a nozzle is, of course, very different than asking people to wear them everywhere. For evidence of real-world effectiveness of a medical intervention, you do a controlled trial. We could have done some, but we did not. It is notable -- but not at all perfect -- that the only RCT conducted with masks and Covid-19 in 2020 found no significant personal protective effect:
https://www.acpjournals.org/doi/10.7326/M20-6817
It is a well-done study, and certainly limits the claims that can be made for masks, but doesn't answer every question. A good cluster RCT might have been able to address the question of whether or not masks protect others, for example.
https://www.nber.org/papers/w28734
In this paper they demonstrated an intervention in Bangladesh that increased mask usage by 30 percentage points (from ~10% to ~40%). In the follow-up paper they are doing random antibody testing between the two groups.
With masks being such a hot topic in certain regions, it would seem unreasonable to conclude that there is only correlation available.
The opinion I'm referring to and cited is in line with this one (just did a quick google search, I don't remember the original source of my assertion): https://www.sciencedaily.com/releases/2020/06/200624082657.h...
There appear to be a number of smaller studies available as well: https://en.wikipedia.org/wiki/Face_masks_during_the_COVID-19... which if cloth masks are effective it would seem to me to be reasonable to extend this to rate of adoption and a contributing factor.
I don't think you should take this one paper as some kind of definitive rebuttal on masks. You should interpret it as a reasonable summary of current evidence, as well as a not-terrible analysis of US states that poses some serious challenges to the effectiveness of mask mandates.
That said, an editorial/letter in science daily is not a rebuttal, and wikipedia is useless for politically sensitive questions. There are many papers on both sides of the issue, and it's easy to cherry-pick a set that support any particular position.
Is it the end of the discussion? No. But It's not as cut-and-dried as people make it seem. The evidence base for masks is very low-quality. The issue became political, and as with all things political today, nuance and reason were tossed out the window.
I don't see how this is much less scientific than the non-peer-reviewed paper you posted.
Both of the papers I linked to are either peer reviewed, or a pre-print in the process of review.
So not reviewed yet.
My point is that both a preprint and a letter to the editors have not gone through a rigorous review. Preprints might be submitted for peer-review but that's no guarantee that it will be published in a reputable venue.
Yes, both are text, written in the english language, shown on a webpage. Beyond that, they share no similarities.
If you cannot reliably judge the legitimacy of a pre-print in an area, then you aren't qualified to judge the legitimacy of any scientific comment in that area.
> If you cannot reliably judge the legitimacy of a pre-print in an area, then you aren't qualified to judge the legitimacy of any scientific comment in that area.
I agree, but now we are moving into the content and not just judging the book by its cover.
The short of it is that people don’t stick rigidly to the effectiveness requirement. Hence why states and countries that stop compulsion don’t see any deviation in the rate of change.
Like HCQ it works in the lab, but not in real life.
What’s disturbing is why so many people still believe they do - and why they desperately want them to work - which moves into the political and religious (“I’m pure - it’s everybody else that isn’t”) rather than the scientific.
At this stage it’s become like carrying posies to ward off the Black Death.
Total cost: $20.
Consider that during the pandemic, the good N95 masks were not even available for any price, so people were wearing flimsy cotton things that only block 20% of particulates. Opening a window with a fan works far better if you do it right and uses materials we still had in supply.
Most office buildings are giant rectangular blobs. The vast majority of people are not near a window. Most skyscrapers don't even have windows that can be opened.
Most manufacturing, processing, distribution jobs etc are in large warehouses. No windows near anybody. Same with a huge number of other blue-collar jobs like groceries and retail.
Even in buildings where windows can be opened, you're throwing potentially thousands of dollars worth of heating out the window half the year, and thousands of dollars in cooling the other half.
So don't just look around your own room, see the window, and say "hey, there's an obvious $20 solution to this, why didn't all these ventilation experts ask me?"
Did you realize that we're in a pandemic that's killing millions of people? We need to get R0 down in any way that we can. Masks aren't perfect. Vaccines aren't perfect. We need to use everything we've got.
I looked at it as a novel tech stack. Sure one could be an expert in twenty year old X, but if thrown into a brand new emergent tech Y, any engineer worth their salt would approach it with a certain degree of humility.
I did not see that happen at least in terms of what medical professionals the politicians and media brought to the fore early on.
We still haven't got functioning HVAC systems in all our hotel quarantine facilities in Australia... it seems insanely hard to grok, for some reason.
Once a few experts broke and started saying the truth that others still haven't really embraced changing science is a reflection on those experts that is morally criminal (probably not legally)
"Opening a window", some places don't even have a window to open.