In my town, there are huge Orwellian road signs at the hiking trailheads that read, “Wear a Mask, Save Lives!”. I do wear my mask because they tell me to, but I also roll my eyes because the science on mask use is nowhere near that settled. Now two new studies stir that proverbial unsettled pot into a nice frothy mess. Let’s dive in.
What Type of Masks?
The masks I’m discussing here are the surgical or cloth masks that you can easily buy. We’re not reviewing whether n-95 respirators work, as the science is more convincing that those do help reduce the spread of a respiratory virus like SARS-CoV2.
The Old Science on Mask Use
The concept that wearing masks can save lives in a respiratory virus pandemic goes back decades. Hence, this is not even close to a new subject. I’ve already reviewed that research and suffice it to say that it didn’t demonstrate that mask use prevented the spread of respiratory viruses.
The Crazy Running “Study”
This one was literally some guys at a university engineering department screwing around with a computer model of how droplets would spread with runners in different positions. It never studied whether anyone could get infected because it never involved any real virus. It was also never published or even placed on a pre-print server, just released to the press. However, it did produce some seriously cool graphics that freaked out millions. Some people I observed were so frightened that they dramatically reduced their outdoor trips. That reduction in outdoor activities likely hurt more people than it helped.
Silly New Science
I have also reviewed a new population-based computer model that purported to prove that mask use saves lives (1). The problem is that the model is conjecture multiplied by more conjecture and divided by uncertainty. Basically, by slightly altering a few key variables in this mask use model, you can get it to prove that masks are bad, good, or do nothing. Hence, this study didn’t help settle the issue.
The Brand New Computer Model on Droplets
This is a study that is published, on how small water droplets can pass through cloth and surgical masks (2). It’s a computer model like the runner study above, but it’s actually been peer-reviewed, unlike that model. Here the scientists used a complex simulation of coughs and water droplets. Basically, masks helped keep small water droplets (which can carry the virus) in for the first cough. However, in repetitive coughs, the water droplets just went right around the mask. This of course is not new information, as a better study was done by NIOSH years ago that also concluded that cloth masks wouldn’t work (3). Also, keep in mind that this is another computer model where no actual infections were measured.
The Brand New Small Town Study
This one isn’t really a peer-reviewed study as much as it is some data presented as an opinion piece in a German Labor Institute publication (4). The authors noted that the German city of Jena was the first to institute mask use and in that city, COVID-19 cases dropped by as much as 40%. You know you’re in trouble with this paper when the analytical method is described as “A Synthetic Control”. What the heck is that? A fancy way of saying that there were a slew of reasons why the COVID-19 cases may have gone down, but we used a bunch of math to convince you it was the masks. Let’s just look at a few:
- The testing rate in Germany wasn’t constant during this time, meaning testing determines case numbers
- Jena is a highly educated university town and home to several German research societies, so they were much more likely to comply with social distancing measures that were also imposed at the same time
- The “control” group (no mask use) they used was “synthetic”, meaning it didn’t actually exist. So the study didn’t take one town that was identical to Jena and at the same time tell them all not to wear masks and then make sure all other variables like testing levels, social distancing metrics from cell phones, and other closures were identical.
There are also other problems called “confounders”(6). These are other things that are dramatically different about Jena that all could have impacted the COVID positive rate:
- On March 17th, far before other German cities, Jena closed all restaurants and fitness clubs
- On March 20th, Jena put a curfew that restricted visiting any public place other than for shopping or a physician’s visit
- On March 24th, the mayor declared that all of Germany was a high-risk area and everyone who entered Jena had to quarantine for two weeks
This fits with what a UK scientist, Antonio Lazzarino, said in the London Times about this paper, “This is a non-experimental study, so causal inference cannot be claimed,” and “There are too many assumptions” (5).
The Public Wants Certainty
The public believes that science=certainty. However, science is really a long slog of uncertainty trying to prove certainty. Meaning that it can take decades in medicine to prove one simple issue like masks reduce the spread of COVID-19. So far, we are a VERY long way away from proving that issue. In fact, most of the careful research done before the pandemic began has shown that mask use doesn’t work. In the past few months, a bunch of far lower quality studies have been slapped together with spit and toilet paper and thrown out there or rushed through journals just to get something published. Regrettably, the quality of this new research is poor, which gets us no closer to definitively answering this question.
The upshot? The science on this issue of mask use is far from settled! Hence, I give you permission to roll your eyes when you see Orwellian signs in your community. In the meantime, I’ll continue to wear a mask where they tell me I should and know that nobody really has any solid idea whether my mask, or anyone else’s mask, is helping anyone.
(1) Imperial College of London. Report 9: Impact of non-pharmaceutical interventions (NPIs) to
reduce COVID-19 mortality and healthcare demand. https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-COVID19-NPI-modelling-16-03-2020.pdf Accessed 5/29/20.
(2) Dbouka T, Drikakisb D. On respiratory droplets and face masks. Physics of Fluids. Volume 32, Issue 6. DOI: 10.1063/5.0015044
(3) Rengasamy S, Eimer B, Shaffer RE. Simple respiratory protection—evaluation of the filtration performance of cloth masks and common fabric materials against 20-1000 nm size particles. Ann Occup Hyg 2010 Jun 28;54(7):789-98
(4) IZA Institute of Labor Economics. Face Masks Considerably Reduce COVID-19 Cases in Germany: A Synthetic Control Method Approach. IZA DP No. 13319, June 2020
(5) The London Times. Facemasks slow spread of coronavirus by 40 per cent, study shows. https://www.thetimes.co.uk/article/facemasks-shown-to-cut-spread-of-covid-19-9r92zfpb8. Accessed 6/19/20.
(6) Zeit Online. Warum Jena? https://www.zeit.de/gesellschaft/2020-04/mundschutzpflicht-atemschutzmaske-coronavirus-infektionsschutz-jena Accessed 6/25/20.