hudebnik: (Default)
hudebnik ([personal profile] hudebnik) wrote2023-02-14 07:20 am
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When, where, and why do you wear a mask?

Three years after the first cases of COVID were reported in the US, I'm still wearing a face mask to the grocery store, and most times that I'm indoors with people other than immediate family. In grocery stores here in Queens, I see a significant number of other people wearing masks, but the majority of people aren't. In Manhattan, I think the fraction of people wearing masks is smaller. And of course, when I travel to Republican-leaning parts of the country, it's almost zero. I'm wondering how people reach their conclusions on when and where to mask.

Rationally, one should wear a mask when the expected benefits outweigh the expected costs. If I'm in a grocery store, I generally keep my mask on because I'm in close quarters with lots of strangers (high benefit) and there's no particular reason to take it off (low cost). If I'm in a restaurant, ditto... except that I can't eat or drink through a mask, so I take it off when the food arrives, because the cost of wearing it has just increased considerably. If you believe that COVID was never a real threat to begin with, just a political stunt to discredit The Former Guy, then obviously you perceive little or no benefit to masking. Regardless of your own beliefs, if you live surrounded by people who believe that, then the social cost of masking is elevated, so you're less likely to mask than if you were surrounded by other people masking.

My workplace renovated in 2020-2022 to put the desks farther apart and to upgrade ventilation systems. And there's a fairly small, fixed set of people who sit within (say) thirty feet of me, which is less of a contagion concern than would be a constantly-changing set of people near me. So I usually take off my mask at my desk: the cost of wearing it is low, but the perceived benefit is low too. Likewise, in a team meeting, there are at most ten people in a room, with good ventilation, and it's the same ten people every time, so I usually don't mask there. I mask to go to the bathroom, because the set of people who might be there is much larger. I mask for vocal-ensemble rehearsals, because although the set of people is small and sorta-fixed, they're singing, which entails breathing in one another's faces (and we know for certain that several super-spreader events in 2020 were choir rehearsals or concerts).

If I'm on a commercial airplane, or in an airport, or on a train, or in a train station, I definitely mask, because I'm in close quarters with lots of other people, who may have recently arrived from all different corners of the country or even the world. In addition, airplanes and trains are notorious for poor ventilation, so I'm breathing the same air as all these strangers for possibly hours on end. The expected benefit of masking is quite high, and the cost low unless I'm eating or drinking.

What do "low" and "high" mean? In reality, I don't even know in what units to measure either of them, much less can I say with confidence that one of them is absolutely more than the other in a particular situation. In practice, I (and I think most people) measure these things relative to other parts of my life: I wear a mask in the situations where it carries more benefit and less cost, and not in the situations where it carries less benefit and more cost. I work at home four days a week, my wife works at home two days a week, and we both are seldom indoors with strangers, so we mask whenever we're in that unusual situation.

But suppose I had a job in, say, fast food, that required me to be indoors and face-to-face with not only co-workers but customers, five days a week, eight hours a day, facing a different stranger every minute. The absolute level of contagion risk, and therefore the absolute benefit of masking, would be higher than I ever face in my daily life... but it would be "normal", the baseline level of risk against which I compare other situations, so I suspect I wouldn't mask up for it routinely. Likewise, people who live in Manhattan are routinely in crowds of strangers much more often than I am, so crowds of strangers become "normal" and not worth the extra step of masking. Ironically, the people in society who face the highest absolute risk of contagion are probably less likely to wear masks than people who face less, simply because that high absolute risk of contagion is a large portion of their lives and is therefore normalized.

Why wouldn't I mask up for an eight-hour shift behind the counter at a fast-food joint? Or even part of it, if wearing a mask for a long time irritates my ears or my nose or whatever? Rationally, every minute that I'm wearing a mask reduces my risk of catching or transmitting an airborne pathogen, so more masking is better than less, unless I'm doing something like eating or drinking that raises the cost of masking. But I have no basis for telling myself that this minute is higher-risk than that minute. It's cognitively easier to divide my life into "high-risk" and "low-risk" activities -- again, not absolutely but relative to one another. If I've already decided that wearing a mask for the whole eight-hour work day isn't worth the cost, that tells me I've classified it as "low-risk", so there's no point wearing a mask for any of it. This is not rational, but it's how human minds handle risk.

I haven't said anything about "six-foot social distancing." Many of the same considerations apply to it. If you live someplace like Manhattan, six-foot social distancing may be physically impossible in much of your life, so you don't do it, which tells you that you've classified its benefits as low enough to be outweighed by the cost, which probably (and irrationally) makes you less likely to do it even when you could. But the "six-foot" rule isn't based on sound science. There's a rule of thumb in epidemiology that divides pathogen spread into "aerosol" (particles smaller than 10 microns, which can hang in the air for minutes or hours and travel a long distance), "droplet" (particles larger than 10 microns, which typically fall to the ground within a few seconds and a few feet), and "contact" (self-explanatory). It was demonstrated early in the COVID pandemic that it was usually spread by particles larger than 10 microns, hence the 6-foot recommendation. Unfortunately, the rule of thumb is wrong: there was never any experimental evidence whatsoever that particles larger than 10 microns fall to the ground within seconds and feet. As this fascinating Wired article explains, the rule of thumb arose when one researcher in the 1960's misunderstood and conflated two unrelated results by a different researcher; it was published, widely accepted, and never experimentally tested. In fact, there's pretty good evidence that, under certain circumstances, particles as large as 100 microns (including those that carry COVID) can hang in the air for minutes, and travel much farther than 6 feet.

Still, you're safer in a wooded park with no other humans within a hundred yards of you than you are in a crowd in Penn Station. As a bonus, the park is much more pleasant.
conuly: (Default)

[personal profile] conuly 2023-02-14 01:49 pm (UTC)(link)
As this fascinating Wired article explains, the rule of thumb arose when one researcher in the 1960's misunderstood and conflated two unrelated results by a different researcher; it was published, widely accepted, and never experimentally tested.

By the time I was ten, I'd formulated a rule of thumb that basically states "the more times you hear something repeated without any sort of actual citation or evidence, the greater the chance that it's just garbage" and, I gotta say, the first time I read that wired article I was incensed to find out that this is yet another situation covered by my rule.
dewline: Self-portrait, outdoors while masked (Mask)

[personal profile] dewline 2023-02-14 10:48 pm (UTC)(link)
The mask in the image is one I've left in the closet for months because the science left it behind. Still, I continue to mask up in most of my public travels. I have family in long-term care that I visit regularly.

I am not interested in homicide or suicide. What vexes me is that so many others I see in public seem to have just shrugged. I want the mask protections back in the public spaces, and have written to my MP, my MPP and my city councillor and several others representing neighbouring and not-so-neighbouring wards about this.

As for your comments on fast-food work...can we extend this to retail work in general? Yes, I know claustrophobes in retail. I also know immuno-compromised people who work in retail too. How best to protect both groups, hm?
matildalucet: (Default)

[personal profile] matildalucet 2023-02-14 10:49 pm (UTC)(link)
I mask in stores because who knows what my fellow shoppers are carrying, or whether workers actually have usable sick leave. I mask at music rehearsals and don't play winds indoors away from home, even if my friends make other choices. That's partly to protect myself and my husband AND partly to protect my friends in case my chronic congestion is actually covid that I don't know about yet. It is tiresome and my reading glasses fog up, and I'm still doing it for now. I never have to mask for longer than a couple of hours at a time (with one recent nine hour exception, which made me realize how easy I've had it).

Other than stores, my main source for germs is my husband, who commutes by public transit and works at a hospital. He masks those places. He has eaten in restaurants. I've done it once or twice since this whole thing started and try to avoid it if I possibly can. I could be overreacting. The pleasure of eating out is less than the anxiety of unmasking.

Nowadays I'm wondering if this is just how the rest of my life will be, at least during traditional cold and flu season.
siderea: (Default)

[personal profile] siderea 2023-02-15 07:41 am (UTC)(link)
You might want to get a portable CO2 meter for indoor settings. This is being used, particularly by folks in the UK, as a proxy for exhalate.

I am still pretty conservative about masking, both because the cost to me is so low - I tolerate it well and need not do it long - and I perceive the risk as higher than most people do. I don't mask in restaurants because I don't go in restaurants - except to pick up takeout, which I do wearing an N95. The issue isn't infection, in my case, it's that I can't tolerate sitting for long. Same reason I don't go to concerts or movies.

So my decision to be pretty hardcore about masking is a pretty easy one.