As the global pandemic has largely left the news cycle I think it is wise to reflect on how people interact with science on a daily basis in the media and how ineffective science communication can shape public discourse. Masks, lockdowns, and vaccines were the largest topics of discourse over the course of the last 2 years. Arguments were had in the media on a near daily basis about these and about how effective, necessary, and safe all these were. But government controlling the movement of people and Anti-vaxxers have been in and out of the news cycle for years. Masks are a relatively new topic for a lot of people, and I believe that the science of masks didn’t really get into the collective psyche. Here I will be debunking some of the myths surrounding masks and exploring how different masks work.
“I’m getting less oxygen!”
A common complaint about masks is that they restrict breathing, and this is somewhat true. It can cause someone to put more effort into breathing, and for some people with certain medical conditions this can be a real issue. It was also recommended that children under 13 shouldn’t be made to wear mask. Unfortunately this leads to some incorrect conclusions. One of the most pervasive myths is that masks trap carbon dioxide or stop you getting as much oxygen. Many people report feeling out of breath wearing masks, so it is a reasonable conclusion to come to, that these masks are someone giving you less oxygen.
This proposed ability to select for simple gasses with a 25 cent surgical mask is however, not possible. The range of pore diameter in a standard surgical mask is 10 to 50 micrometers¹, while the molecular size of carbon dioxide and oxygen are 0.33 nanometers and 0.30 nanometers. This makes the holes in the masks more than 50,000 times larger than an oxygen molecule, while a carbon dioxide molecule is 1.1 times as big. But if masks don’t block oxygen, why are people feeling bad after wearing them? Unfortunately a big part of it is mental health. Pandemics are scary, and putting on a mask, especially at the beginning, made it more real. Anxiety and panic attacks can look like a lot of different things and the high levels of anxiety surrounding masks² can cause people to connect breathlessness and tiredness, and other symptoms of anxiety, with the physical properties of the mask, rather than how they feel about them.
“How can a piece of cloth stop a virus, but my underpants don’t stop a fart?”
This is a surprising good question, though it is usually brought up by someone arguing in bad faith. The explanation is relatively simple, like above, the things we are talking about filtering are orders of magnitude apart in size, so they cannot be compared. However, in this case, they are largely right. Masks don’t outright filter and trap virus particles and a lot makes it through, into the environment.
So why then do we wear masks? For one, it’s a numbers game. When fighting a new disease, the number of virus particles in your body matters and will determine how sick you get and how much you spread it. Masks stop some virus, and that can prevent infections. Myths like this are particularly pervasive because they contain partial truths, but this question misses the point. Implicit in the phrasing is an implication that it is a binary. Masks either stop covid, or they don’t, and if they don’t they’re useless. The issue is, when people bring this up, they are largely arguing with well intentioned “pro-maskers” who often imply the opposite side of the binary, that masks do stop covid. This makes it very easy for the anti-masker to “win” the debate, because all they have to prove that they don’t stop all covid particles, which is of course true.
People don’t have a very good intuition of the physics of masks. One can think of it has just a tiny sieve, but matter interacts different at that small a scale. An N-95 mask for example has very tight knit nanofibres that can capture a wide range of sizes of particle, but for some particles, like water droplets, it utilise electro static charges within the fibres to induce slight polarity in the droplets to then adsorb the droplet.
“Even the scientists admit masks don’t work.”
A Danish paper found that recommending people wear surgical masks did not produce a “statistically significant result” and concluded that in their data, masks were comparable to lesser forms of protection. This was touted by many as irrefutable evidence that facemasks are effectively useless. There are however many limitations with this study. There was no blind study, data was collected via self reporting, and the trial only looked at the mask wearer’s themselves testing positive, when it is known from other studies that masks are better at protecting people from the wearer.³ Possibly most importantly the study was done where there was already other preventative measures in place. Absence of proof is not proof of absence and this study is far from conclusive, which the scientists involved are all too eager to point out.
There is quite a large disconnect between what scientists publish and what gets disseminated to the general public. It is hard to blame scientists for this issue as scientists are, by and large, not writing for lay people when they publish an article in an academic journal. They are writing for other scientists, but in the age of information, it’s not only scientists who have access to them. Explaining new science is often left up to reporters, or sometimes, science communicators act as a middle man, making mask discourse (or any science discourse) a bizarre game of telephone.
If someone didn’t have a good understanding of the science of masks or scientific methods in general, then the first time they heard facts about masks were through fairly strict mask mandates, made by decidedly not science-educated politicians. In some cases this allows some people to conflate the (poorly represented) scientific facts with the politics of the government espousing them.
There will of course always be fringe groups with outlandish claims and a disregard for science, but facts and figures can be presented better than a ream of figures listed off on the 9 o’clock news every night. Science can be more accessible.
¹ Du, W., Iacoviello, F., Fernandez, T. et al. Microstructure analysis and image-based modelling of face masks for COVID-19 virus protection. Commun Mater 2, 69 (2021). https://doi.org/10.1038/s43246-021-00160-z
² Szczesniak D, Ciulkowicz M, Maciaszek J, Misiak B, Luc D, Wieczorek T, Witecka KF, Rymaszewska J. Psychopathological responses and face mask restrictions during the COVID-19 outbreak: Results from a nationwide survey. Brain Behav Immun. 2020 Jul;87:161-162. doi: 10.1016/j.bbi.2020.05.027. Epub 2020 May 7. PMID: 32389696; PMCID: PMC7204728.
³ Efficiency of surgical masks as a means of source control of SARS-CoV-2 and protection against COVID-19. Int. Res. J. Pub. Environ. Health 7(5):179-189.