Ask an expert: Are masks inspected? And which type should I wear?
Editor’s note: Today, we introduce a new column, “Ask an expert,” by epidemiologist and Cal Poly Professor Dr. Aydin Nazmi.
He’ll answer your questions about COVID-19, in addition to other topics such as risk mitigation, vaccines, herd immunity and how social disparities can affect health care.
Send your questions to aydin@epi-intel.com.
Question: Please explain the science behind masks that are of any and all varieties; worn in every fashion; untested and uninspected; handled and laid down; taken off to speak or eat; linked to respiratory problems; not required for children and those with compromised health; and previously discouraged until May 2020?
Steve King, Carpinteria
Answer: We know cloth face coverings (“masks”) work. Scientific evidence that masks prevent transmission of airborne viral infections is rock solid.
Studies since at least the early 20th century, around the time of the 1918 flu pandemic, have consistently shown that masks, when properly made and regularly worn by the public, are effective in preventing the spread of infection. Countries where mask use is common, or was adopted early and aggressively in the current pandemic, have been much less scathed by COVID-19.
Mr. King’s question about testing and inspection of masks is a good one. Medical grade masks are tested, inspected and certified by the International Organization for Standardization (ISO) and/or the FDA to certain specifications, and this information should be available on the box. If a box of masks does not contain this information, you can assume it is not certified, but this does not necessarily mean it will be ineffective at reducing spread of COVID-19. Indeed, homemade masks, though less effective at containing viruses compared to medical grade masks, are suitable and recommended for community use.
Mr. King brings up another important point: Why were masks not recommended until several months after the pandemic began?
In the United States, this can be boiled down to three main reasons.
First, key authorities severely underestimated this virus, thinking the incidence of COVID-19 in the U.S. would remain relatively low, as it did with SARS and MERS, which infected 27 and two people, respectively.
Second, illusions of the apocalypse led to toilet paper rationing, and if people started hoarding masks, healthcare workers would suffer shortages. Not a great reason to undersell masking, but in the context of our nation’s utter pandemic disarray, fair enough.
Finally, acceptance and social norming of mask wearing in America was never going to be straightforward. The politics of masks have become heated — even though their benefit is overwhelmingly clear to public health officials.
To some, mask mandates reek of tyranny. Many political leaders did not advocate mask use and some actively fought against it (then backtracked). By now, most lawmakers have come around, even proposing legislation that would provide, manufacture and distribute free masks to the public.
Now, just in case you’ve been living in a fortified bunker with no Wi-Fi, here is a brief overview on what we know about masks:
Why wear masks? COVID-19 is nefarious in that asymptomatic individuals, estimated to be up 40% of all cases, are infectious. That is, even if you feel well and have not gotten a COVID-19 test (why would you?), you are still shedding the SARS-CoV-2 virus for weeks and can give it to others. If you do feel sick and test positive, the pre-symptomatic period, up to 14 days when you feel fine, is a long time to be out in public getting other people sick.
How do masks work? By preventing your spit from getting on others, basically. Respiratory droplets (and probably even smaller aerosolized SARS-CoV-2 particles), the primary culprits in person-to-person COVID-19 transmission, travel impressive distances just by breathing and in normal conversation. God forbid you sing, laugh, scream, cough, or sneeze. Masks protect you, those around you, and seem to lead to less severe COVID-19 infections among those who do get it.
Who should wear masks? Everyone. Exceptions include children under the age of 2 years, anyone who has trouble breathing, or individuals who are otherwise severely incapacitated.
When should you wear a mask? Any time you happen to be near other humans, indoors and outdoors, especially when physical distancing is unavoidable and if proximity to others is sustained for more than a few minutes. The state of California mandates face coverings in these “high risk” situations. And yes, COVID-19 has forever altered the definition of high risk. Not sure if anybody will ever be blowing out candles on a birthday cake ever again.
What type of mask should you wear? Members of the general public are advised to wear cloth face coverings. Multiple layers of material are better than single. Masks should fit snugly and completely over the nose, mouth and chin, allow for unrestricted breathing, and be washable. Masks with one-way valves or vents are not recommended for obvious reasons. N95 and surgical masks are also effective, but the CDC recommends those only for healthcare workers, as they are in short supply. You should wash or sanitize your hands prior to putting on a mask, not touch your mask while wearing it, leave it on as long as you are around other people, and wash or sanitize your hands again after taking it off.
When do masks not work effectively? When not completely covering the mouth, nose, and chin, when worn loosely, when worn as a chin strap, when not clean, when shared or when used in place of physical distancing.
In the era of COVID-19, face coverings are essential to stemming the tide of the pandemic.
Yes, they are uncomfortable, hot and nobody likes wearing them, but they work. If you are tired of this thing and want to get back to normal as soon as possible, do your part. Mask up.
Dr. Aydin Nazmi is an epidemiologist and professor at Cal Poly SLO, where he serves as Presidential Faculty Fellow to COVID-19 Response and Preparedness. His research focuses on the intersection of health equity, policy and food systems. He recently chaired the expert panel to develop SLO County’s COVID-19 roadmap to recovery and since 2013, has served on the California Governor’s Science Advisory Board.
This story was originally published September 8, 2020 at 3:39 PM.