Director of the Nucleic Acid Observatory in Boston. Speaking for myself unless I say otherwise.
I don't understand either. It's common within the contra world (ex, from one of the central organizations) to claim that these policies are needed by 30% of people, but as far as I can tell this is a massive overestimate.
My guess is that this comes from having a strong desire to be welcoming and open to all, and the people convincing dances to adopt the policies not being clear about the scale of the request they're putting on the attendees. And probably some sense that there's no amount of minor inconvenience to some people that outweighs preventing harm to other people.
All the cases I can think of were for valved masks in situations that required everyone to be wearing unvalved masks; is that also what you're thinking about?
If there's another serious pandemic, wearing a slightly larger mask isn't going to cost many weirdness points.
I don't know, I felt too awkward to wear a big brightly colored respirator during COVID, even taking into account that I'm a weird guy (I walk around barefoot in cities, I post here) and I was making substantial sacrifices to avoid infection (isolating with my household for over a year). If it were clearly much worse than COVID I think it would be different, but in some cases (ex: a stealth pathogen) there might be a large difference between how worried I was and how I expected others to view it.
The first one on this page, the ElastoMask Pro, filters bidirectionally. I have one and like it, very breathable, good deal. Though it's one of the worst for intelligibility.
The best is to try them on and see how well they fit your particular face. But very roughly the bigger the distance between your chin and the bridge of your nose is the bigger a mask you need.
Aren't those less effective at protecting other people than using a mask without a valve?
Yes. On the other hand they have less condensation, are easier to breathe in, and are generally much easier to find in higher protection factors (I'm not aware of any valveless 99%+ efficacy masks)
I think cost much more than doubles: at the beginning of covid high-quality masks were essentially not available at all. If you imagine something like uncontained SARS I expect this would be even worse.
You're can substitute your own value for "what would I pay not to die", but unless your expected number of remaining life years is really low I doubt this changes much?
What was the rationale behind cleaning the air above people's heads - was eye safety the main concern for you?
To clean the air between the people you need UVC on the ceiling pointed down, and you need a lot of lamps. This isn't something we'd be able to set up in a hall we don't own. Additionally, the efficacy of UVC is proportional to the distance the rays traverse, so we're getting a lot more benefit from an emitter aimed above people than we would from downward facing ceiling-mounted ones.
Eye safety is something we're thinking about, but the risk is at close range. With all of the options we're considering the lamps are at least five feet from anyone's eyes, which is more than enough for safety.
Did you also do any prior modeling of the space before the setup?
We did a little modeling on the UV setup, yes!
Added something to the end of the post based on a survey I did a few years ago.