Before I retired, as a physician I spent much of every day masked up in an operating room, where they are used to prevent droplet contamination of surgical wounds and offer some protection against breathing in pathogens from infected wounds or bodily secretions. I would never think of going without a mask in an operating room.
As a public health and public policy measure for the general public, both outdoors and indoors, the benefits are not so clear-cut. For one thing, SARS-CoV-2 — the name of the coronavirus that causes COVID-19 — is known to spread by aerosols where the particle size is too small to be trapped by most masks, rather than larger droplets for which the masks are designed. It has been difficult to devise studies that distinguish droplet from aerosol transmission.
A recent large peer-reviewed study with 77 references found some protection, but the authors concluded, “…it is becoming more difficult to justify the use of single-use (personal protective equipment) items by the general public” (Liao M etal,: A technical review of face mask wearing in preventing COVID-19 transmission, Current Opinion in Colloid & Interface Science 2021, 52:101417).
Another study found a 50% reduction in viral transmission from wearing masks, but the authors concluded, “Importantly, medical masks (surgical and even N-95 masks) are not able to completely block the transmission of virus droplets/aerosols even when completely sealed” (https://journals.asm.org/doi/10.1128/mSphere.00637-20).
Another article on the benefit of masks noted, “The high risk of bias in the trials, variation in outcome measurement, and relatively low compliance with the interventions during the studies hamper drawing firm conclusions and generalising the findings to the current COVID-19 pandemic” (https://pubmed.ncbi.nlm.nih.gov/33215698/).
The compassionate arguments made by Steven Koski in The Bulletin on Sept. 8 would be quite reasonable and convincing if there were no downside to mask wearing. But there are downsides.
Masks are known to trap allergens and pathogens near our mouth and nose, possibly increasing risk for allergic reactions or infection. Masks obviously can inhibit expression and understanding, and the ability to recognize and communicate with each other.
I believe we should continue to use masks to protect vulnerable populations in nursing homes and hospitals, but a mask requirement for the general population is harder to justify, given the downsides and uncertain benefits.
We must remember that the great majority of COVID-19 cases are asymptomatic and do not result in serious illness, hospitalization or death. Masks may be particularly harmful for children in schools, where they prevent children from hearing and understanding each other and their teachers (www.theatlantic.com/ideas/archive/2021/09/school-mask-mandates-downside/619952/). And the risk of serious illness for children is much lower than for older people. As of Sept. 1, CDC data shows 633,785 COVID-19 deaths to date in all ages, but only 326 in children 5 to 18 years of age.
I would argue that a much better alternative is to urge vaccination. The vaccines are not foolproof or risk-free, but they are effective in markedly reducing the risk of serious illness and death (www.cdc.gov/coronavirus/2019-ncov/vaccines/effectiveness.html?s_cid=11504:delta%20variant%20vaccine%20effectiveness:sem.ga:p:RG:GM:gen:PTN:FY21).
And the sooner we achieve herd immunity, whether by vaccination or by natural disease, the sooner we can put this nightmare behind us.