29 January 2022

Wear your mask

The pandemic is an insidious threat -- you cannot sense its presence -- and there's no instrumental means of detection (unlike other common insidious threats like electricity and methane).  All the indicators are lagging indicators; we can know where it was, not where it is.

What that means is you do not know -- you cannot know -- what your risk is.  It is by-definition impossible to know what your risk is.  (Remember that while it's statistically unlikely that you personally happen to be standing next to the person who was so startlingly fortunate as to have the "lethal as MERS" Omicron mutation occur during their initially asymptomatic infection, that's not a statement about your risk.  It's a statement about how likely that event is in the population, given a certain set of assumptions.  Your risk? inherently unknown.  Assume that the person next to you is shedding.)

Your single best means of avoiding death is to get (and keep getting) vaccinated.  This is not enough to prevent spread, and spread is how the disease gets worse.  So vaccination is not sufficient unto your civic duty.  You must also avoid infection.

Your single best means of avoiding infection -- and you want to avoid infection, because infection increases your risk -- is to wear a mask.  

Today, in the current state of the plague, wear a mask means a half-face respirator with a full gasket seal, no exhaust valve, and P100 filters.  (You're not a health-care professional with a need to dispose of your mask. You're going outside absolutely as little as possible -- which means you don't, unless necessary to avoid material harm -- you're bagging your mask in an impermeable plastic bag when you get home, and since it's a respirator, you can take the filters off and wash it from time to time.  Slather it with hand-sanitiser more frequently than that.  Yes, this costs more up front, but given that you're going to need it for at least the next year, your total cost is less this way.)

If you leave the house, you do it with the mask on.  It stays on the whole time you're out of the house.

When can we stop wearing masks everywhere?

When the disease is extirpated.

Given full population vaccination, universal mask use, and time, the disease will be extirpated.

Yes, there's a whole lot of public support required to get there; it's not as simple as always wearing your mask.  Yes, there are a bunch of evil people on Team Virus who think freedom means they are free to commit contagion.  At a minimum, don't be like that.  Wear your mask.

Duty requires.


JReynolds said...

I too would like to live in a world where COVID is extirpated.

However, we're living in a world where arseholes can convoy their trucks to Ottawa, piss on the Tomb of the Unknown Soldier, wave Nazi flags and cause havoc. All in the name of their 'freedom'. While the authorities don't want to bring the full hammer of the state's power down upon them (hate speech, whatever the 'shouting fire in a crowded theatre' law might be to combat lies in the media[1]).

I look forward to a Canada where the vax rate is over 95%. Then we might actually get somewhere, and ICUs could empty out.

[1] I don't even know if such a law exists. If it did, this would also be prone to abuse. So keep Nazis down, dammit.


Graydon said...


It's not (and never was) a freedom of expression issue; it's a public health, and thus common defence, issue.

Any time someone entrusted with the civil power wants to notice that there's a whole lot of bioterrorism going on and suppress it on those grounds, the legal machinery is just sitting there to do so.

Breaks the white supremacy loot-sharing agreement, hard, which is where about half the reluctance comes from (the other half comes from "real civil power can tax, we're pretty sure that's wrong" mammonism). But it's not going to be especially optional, by-and-by; especially if we wind up with something substantially more lethal, or someone figures out that the ten year survival rate from what we've got is small, or similar.

(Canada does a terrible job of excess death statistics; there's a couple of years of lag before they're publicly available.)

Anonymous said...

Incidentally, it takes about 7mm of spacers (the trusty box of washers supplies ISO 7093 in M10 (twice) and M8) to disable the outflow valve on a 3m 6000 Series. Probably should have thought of that earlier.

Graydon said...


That's a good fix!

I like the COVID-specific respirators; the "speaking diaphragm" really is helpful, one sounds like one's underwater but not a long way away under water. But whatever comes to hand, absolutely.

Moz said...

You're making rules that can only be followed by the rich again.

Easier way to defeat the exhale valves is paper tape. You can even cut little circles of it if you like. You should also wear eye protection because those mucous membranes are also happy places for coronaviruses.

But the question is ... will you die sooner because you get no aerobic exercise than you will if you run or cycle with exhale valves active? I mean "statistical you" on a population level. The argument is well-established in public health circles that bike riding adds to your life... so that half hour ride to the shops is worth more than half an hour in extra QALYs.

It's also not as simple as P100 or die. Partly from a "what if everyone did that" and as we saw early on in the pandemic, the answer is that only the rich get masks and not all of them. Just like vaccines. But also partly because of the restrictions imposed by masks. No valves means no hard work, sure, but even with a "nothing that makes you breathe heavily" restriction on everyday life, the difference between a P100 mask and a P95 one is significant. So you're asking people who are infirm in some way (the 90% of Canadians who are overweight, say), to slow down their public activities even further for a small marginal gain.

It was interesting reading the debate / discussion from Aotearoa on this issue, as they switched from "cloth masks are ok, even pulling your t shirt up is acceptable" to "N95 masks are the minimum standard". One big issue was the cost - that adds $1 or so per person to the cost of leaving the house, and not everyone can afford it. That flows from "not everyone can afford to store their mask in a safe place and care for it appropriately". And not everyone is in a position to enforce "if your mask is dirty or damaged you can't go outside" on their kids, even if they wanted to.

Also, when there's not snow on the ground even half face masks are very hot. A wear a full face one for some outdoor activities, and once it's over about 30°C that means half an hour working, half an hour inside in the cool.

Zeborah said...

@Moz N95 is not the minimum standard in Aotearoa, though it's certainly popular.

Originally the requirement was "something that covers your nose and mask". Within the last week it's switched to "something that's actually a mask" for the general public, which includes N95, surgical masks, and cloth masks. For people working at the frontlines in roles that have a government vaccine mandate (health, education, etc), the requirement is for a "medical grade" mask - either N95 or surgical mask, and most such workers I see are wearing surgical masks.

The government is actually currently hesitating on recommending N95s to the general public because a branch of public health people influential with government reckon that it's too hard to teach people how to fit them properly, though I don't see in what way this differs from any other mask (and indeed my N95s almost naturally give me a brilliant fit). Despite this they're popular enough they're pretty much sold out nationwide until new stocks arrive, because a branch of public health people influential on social media are going, "Yeah nah, these are good actually, here's how to fit-test them, also see this research that you can safely rotate them so stick them in paper bags labelled for the day of the week and have at it."

I don't honestly see the need to wear them outside, though this may depend on ambient population density: I do put mine on when I get near to people at the bus stop for example. I can also see the desire to avoid cross-contamination but I deal to that with hand-san and soap-and-water.

Moz said...

I suspect my dislike of the surgical masks coloured my recollection. Those are designed for, and quite effective at, stopping medical people spitting on patients. The research I saw said they're almost as useless as a cloth mask at preventing covid getting in.

I'm reduced to medical-grade N95 "duck" masks ATM because workshop ones haven't been available since the start of the pandemic. The medical ones are $AUS2 each in a box of 50! But the workshop ones are mostly still going after 2 years (box of 20) because they're much more robust than the medical ones. Which are still designed to be single use.

Graydon said...

Modern respirators with no exhaust valves work fine when exercising. The art -- or at least the material science -- has advanced like whoa. I don't really notice having the thing on; two-can respirators have far more surface area than you need to breathe comfortably. The newer designs are much better at keeping the wet off your face. (I can and have slept in mine.) Heat, well, let's say I've had different experiences.

Surgical masks are heavily constrained by being disposable; they have to hit a price point, and all else follows from that. If you're spending ~100 AUD for fifty, that's thereabouts of a respirator and P100 cartridges which (presuming you're not going to do anything really dusty like sanding) ought to out-last the fifty. And the cartridges are about 20 AUD for a pair hereabouts; the long-term total cost is much lower.

The state is obviously obliged to provide these things and equally obviously should be engaged in direct production of these things. That this is not seen as obvious is a problem; that there are a heap of idiots who don't want to solve the problem (people getting sick) so much as they want to maintain some sort of control is also a problem. This is not a reason not to mask.

Omicron is the spreadingest disease in human history; it might be as infectious as measles, and it's well-documented that you can get measles from walking through air someone with measles walked through an hour before. It's an "everything for air quality" situation; HEPA filters anywhere indoors, masks any time you're around strangers. Mothball the restaurants and theatres until extirpation.

An inability to get the ideal outcome from the political machinery isn't a reason not to be careful on a personal scale.

Graydon said...


There are two reasons to wear the thing outside; if Omicron (or one of the Omicron variants) really is as contagious as measles, we're going to find out after a lot of people got sick from contact outside, on the one hand, and there's absolutely no indication there _isn't_ outside spread now. Just the outside spread wouldn't sustain the pandemic on previous rates but we don't actually know what it is right now.

The other reason is that people do terrible, no good, rotten risk assessment. Wearing your mask only when you feel like you're at risk is not an effective policy because most people are optimists. It works a lot better to do simple rules like "mask on outside the home".