Effective yesterday, February 1, it is a violation of federal law not to wear a mask on a public conveyance or in a transit hub, including taxis, trains and commercial trucks (The 11 page mandate is here.)
The “mask wars” are a major source of disagreement and politicizing science during the current pandemic, but my interest here is not of clashes between pro-and anti-mask culture warriors, but the clashing recommendations among science policy officials and scientists wearing their policy hats. A recent Washington Post editorial by Joseph Allen, (director of the Healthy Buildings program at the Harvard T.H. Chan School of Public Health), declares “Everyone should be wearing N95 masks now”. In his view:
there’s no reason any essential worker — and, really, everyone in the country — should go without masks that filter 95 percent. The masks I’m referring to, of course, are N95s. These are cheap — pre-pandemic they cost about 50 cents — and easy to manufacture. Yet our country has failed to invoke the Defense Production Act to produce enough masks for health-care workers and other essential workers. That needs to change, as my colleagues at Harvard Medical School have written.
To see the true power of masks as a public health tool, we have to examine them in the context of everyone wearing them, where the power of each mask doubles. That’s because the particles have to pass through the material twice — once after being emitted and again before someone breathes them in. Take the example of two 70 percent efficient masks, which combine to reduce 91 percent of particles. Not bad. But two N95s result in greater than a 99 percent reduction in exposure. Think about that for a minute. We could reduce exposure by 99 percent for what should be $1 a mask. (Prices are higher now because of the failure to produce an adequate supply.)[i]
Wow. The cheapest I have found N95 masks going for is $3.95—provided you buy in quantity of 100. Generally, they’re around $5. Other high-filtration (hi-fi) masks, e.g., KN95 go for around half that—still prohibitive for 1-time uses.
Doctor Abraar Karan and colleagues have been calling for a “national hi-fi mask initiative” in the U.S. (Stat News Jan. 7, 2020), averring that the pandemic would be over in 4 weeks were everyone to wear N95s in public areas. It would be worth it, they say, for the government to provide monthly stocks of hi-fi masks to everyone in the country, especially with the new mutant Covid-strains we’re seeing. [ii] Anderson Cooper and Dr. Sanjay Gupta echoed this call in one of those town-halls the other day, questioning the new head of CDC, Dr. Rochelle Walensky, along with Dr. Anthony Fauci. Cooper asked, with a straight face: “Does the Biden administration plan on sending every household N95 or equivalent masks?” Restraining a chuckle, Fauci said “I’m not sure that that will happen”. Walensky’s reply to this is that it wasn’t entirely clear to her that the reason people weren’t wearing masks is lack of access to them. Sure, but that’s very different from lack of access to hi-fi masks being the reason they’re mostly out of reach. N95 masks can only be extended for around 2 days even with life-extending contrivances, which individuals would not have available[iii].
Gupta asked Walensky two questions: first, should people be wearing high filtration (hi-fi) masks, such as N95s, in order to slow the spread of Covid-19? And, second, is the reason the CDC doesn’t recommend the public wear N95s that they have to be reserved for healthcare providers? Remarkably, Wolensky says no to both.
CDC Director Dr. Rochelle Walensky: Yeah, it’s a really good question and one we get a lot. I have spent a reasonable amount of time in an N95 mask and they’re hard to tolerate all day every day. … I worry that if we suggest or require that people wear N95’s, they won’t wear them all the time. They’re very hard to breathe in, when you wear them properly.
The question, of course, was whether the public should wear hi-fi masks to slow the spread of Covid-19, for example on public conveyances, not whether recommending them would have the effect of decreasing the use of any masks. Besides, perhaps pointing out the advantages of hi-fi masks would cause more people to wear some kind of mask. They could use the information to upgrade their cloth masks (considered the weakest of the lot, even aside from the problem of infrequent washings causing bacteria build-up). The public should not be presumed incapable of making the kind of decisions they make every day about trade-offs of risks and benefits, maybe wearing the hi-fi mask in crowded situations—which for most people would rarely be all day—and less protective masks for other times. Even those pressing for N95s deny you’d need them for running outdoors, for example. In answering factual questions, especially ones they get all the time (which suggests people really want to know) CDC should provide the best information—in this case, about the efficacy of different masks, and we now have a number of studies on this–and not give obfuscating answers that are described as having been designed to avoid or ensure some behavior. “It is just for your own good that we’re not recommending them!” Going down that road makes us wonder what else they’re not being frank about.[iv]
The other possibility that springs to mind, of course, is that the CDC worries that if it recommended (not required) hi-fi masks, the public would urge that there be an effort to provide them at a reasonable cost. Why can’t they be manufactured for the 50 cent pre-pandemic rate?
As for denying that CDC is reserving N95s for healthcare providers, this is at odds with the CDC site itself, in several places. For example, under the CDC guide to choosing a mask
DO NOT choose masks that are intended for healthcare workers, including N95 respirators or surgical masks
N95 Respirators Not for Use by the General Public
The Centers for Disease Control and Prevention (CDC) does not recommend that the general public wear N95 respirators to protect themselves from respiratory diseases, including coronavirus (COVID-19). Those are critical supplies that must continue to be reserved for health care workers and other medical first responders, as recommended by current CDC guidance.
Weaving in and out of the discussion is an equivocation between not recommending the public do X and recommending the public refrain from doing X. Officials should be honest in admitting a shortage remains; and that they do not see a way to restore the 50 cent price-tag.[v]
The CDC recommendation for cloth masks, starting last spring was primarily intended to reduce the emission of virus-laden droplets (“source control”), especially relevant for asymptomatic or presymptomatic people with Covid-19. That was OK as a stop-gap measure, but we want to protect ourselves too. The electrostatic charges found in N95 caliber masks enable trapping aerosols, which we know go beyond 6 feet and can travel across a room.
Some say the general public cannot be expected to conduct the “user seal check” to test the fit of hi-fi masks, but it’s not clear why not. They’re worn by our government representatives in DC.
The push for high filtration (hi-fi) masks has been growing in Europe (Washington Post, January 20, 2021):
Germany on Tuesday night made it mandatory for people riding on public transport or in supermarkets to wear medical style masks: either N95s, the Chinese or European equivalent KN95 or FFP2s, or a surgical mask.
It follows a stricter regulation from the German state of Bavaria this week that required N95 equivalents in stores and on public transport. Austria will introduce the same measures from Monday.
Meanwhile in France, the country’s health advisory council on Monday discouraged the wearing of inefficient cloth and homemade masks, also arguing they may not offer sufficient protection against the more highly transmissible coronavirus variants.
… Markus Söder, the state premier of Bavaria, said that the decision to require [hi-fi masks] there was “very simple.”
“If the virus becomes more dangerous, the mask has to get better,” Söder said. He said he thought it was “absolutely necessary” to have a higher level of protection on public transport and in retail and work places. …
In the U.S., we not only lack affordable hi-fi masks, there has been little attempt at standards for mask adequacy. Dr. Nahid Bhadelia, an infectious disease physician at Boston Medical Center, says the U.S. needs a national effort to get hi-fi masks to the public, beginning with releasing a standard for the masks that are available.(The source is here.)
It’s unconscionable that we have the largest use of PPE by American public in history and the quality of these masks is not being moderated, standardized or regulated. (Dr. Nahid Bhadelia, Twitter, Jan 26, 2021, as quoted in this article.)
The new Feb. 1 mask law allows that wearing an N95 would satisfy the ruling; however aside from blocking face shields [by themselves], bandanas, masks with exhalation valves and masks that don’t fit properly, there are no specific standards. The edict says passengers and operators must wear their masks at all times except “for brief periods, such as to eat, drink or take medications”. But Covid-19 transmission doesn’t take food break, and when my neighbors have their masks off (as well as the rest of the time), I’d like hi-fi protection.
What do you think? Please share your comments. Check back for updates (which I’ll indicate in the title with (i), (ii), etc.).
[i] Without a federal standard, he recommends N95, then the KF94 from Korea, and next the KN95 from China, ideally one with a NIOSH certificate.
[ii] A measurement called the Fitted Filtration Efficiency corresponds to the concentration of particles behind the mask expressed as a percentage of the particle concentration in the chamber air. The overall percentage of FFE, measured in a number of positions, is calculated as 100 × (1 − behind the mask particle concentration / ambient particle concentration). (JAMA Dec. 2020)
[iii] When I wear the hi-fi mask, I get more life out of it with one of those blue masks over it which are around 25 cents).
[v] There is something called a Thermoplastic Elastomer mask that comes up to hi-fi standards, for $15, and is deemed more comfortable than N95s. It still requires purchasing filters, but is sure to get you noticed, especially with goggles, which I’ve also taken to wearing.