In my view, it is good to see that the CDC has gotten on board with wearing non-medical masks when in public with its updated guidance: "CDC recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies) especially in areas of significant community-based transmission." (emphasis in original). In this article, I provide rationale and tips that support use of non-medical face masks by the general population when in public around other people, and call for people to wear non-medical face masks as a statement that they are making changes necessary to help their community win this fight against the COVID pandemic (see. e.g. https://www.thecureis.us/, and see my article on doing our part to fight this pandemic).
Wearing non-medical face mask has a number of possible benefits and little downside. Such masks are inexpensive and unlike medical masks, even in this pandemic they are easy to make at home (see numerous YouTube videos on this topic) and easy to find for purchase on web sites such as Etsy.com. As far as tips on how to use a home made mask, although the World Health Organization (WHO) is apparently not yet on board with the CDC's guidance and use of non-medical face masks by the general public, they provide helpful tips on how to put on and take off, a non-medical face mask here.
People who resist wearing non-medical masks, often argue either that there is not strong scientific data to support that this practice reduces viral spread, or cite the fact that masks other than N95 masks, have pores that are too large to stop viral particles from passing through. While the latter is technically true, the fact is that much larger droplets/mucus are likely responsible for at least some, if not most of the spread of the virus between people (See this peer-reviewed article on PLOS), and hand made masks can capture at least some if not most of these larger droplets. This recent article on the importance of viral dose at infection is further support, I believe, for wearing non-medical masks in public, which would be much better than nothing at stopping large mucus droplets in both directions. Furthermore, since many individuals with Coronavirus infection lack symptoms (See CDC), and there is evidence and a general agreement I believe among most experts (E.g. See WHO cite above for example), that people who are infected should wear a face mask to help stop the spread to others, it is actually extremely logical that we all should wear masks when around strangers in public to help protect them, if not ourselves.
Regarding scientific data to support non-surgical masks in public, over a week ago, I published a post on LinkedIn that cited this Boston Globe article from some public health expert PhDs, which was a call for the general public to wear non-medical face masks. Separately, the authors were kind enough to send me some of the cited studies eluded to in their article, which they admit are not pristine, but generally support that non-medical face masks can help prevent the spread of viruses. Here is one article on the peer-reviewed online journal PLOS that studied N95, surgical, and home-made tea cloth masks, and found some protection from home made mask. The authors conclude: "Although this could imply that individual subjects may not always be optimally protected, from a public health point of view, any type of general face mask usage can still decrease viral transmission. ... It is also clear that home-made masks such as teacloths may still confer a significant degree of protection, albeit less strong than surgical masks or FFP2 masks." The paper also provides cites to studies that they conclude suggest that population-wide use of face masks in Asia helped to decrease the transmission of SARS and influenze.
I propose yet another reason for wearing masks in public: As a sign that we are informed and concerned about this pandemic, that we are taking precautions against its spread, and willing to do whatever we need to do, including change our own habits, for the greater good of our community. In my local community here in the Chicago area, the former pro athlete Bo Jackson, has launched a campaign called TheCureIsUs that is a call out for people to take these actions. I wrote an article on LinkedIn and on my Amp site to promote a similar message, which I now refer to as "getting back to 'normal'" (with important quotes around "normal," which refers to each of us taking action to help our society move forward in our new normal). There is some Western society resistance to wearing face masks in public and some stigma to this (e.g., See Boston Globe article and see this article about the tension of requiring masks at an outdoor market in Vancouver). However, there is evidence as discussed above, that such widespread use in Asia has decreased viral transmission in certain countries.
In sum, there is little downside and likely upside in wearing non-medical masks in public. Let's overcome our Western resistance to this, and wear non-medical masks in pubilc to show that we are in this fight together, and taking action now to get back to "normal". The cure is us!
PLOS cite in document
van der Sande, et al., "Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population" PLoS One. 2008; 3(7): e2618. Published online 2008 Jul 9. doi: 10.1371/journal.pone.0002618
Cites from CDC guidance on non-medical wearing face coverings:
Rothe C, Schunk M, Sothmann P, et al. Transmission of 2019-nCoV Infection from an Asymptomatic Contact in Germany. The New England journal of medicine. 2020;382(10):970-971.
Zou L, Ruan F, Huang M, et al. SARS-CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients. The New England journal of medicine. 2020;382(12):1177-1179.
Pan X, Chen D, Xia Y, et al. Asymptomatic cases in a family cluster with SARS-CoV-2 infection. The Lancet Infectious diseases. 2020.
Bai Y, Yao L, Wei T, et al. Presumed Asymptomatic Carrier Transmission of COVID-19. Jama. 2020.
Kimball A HK, Arons M, et al. Asymptomatic and Presymptomatic SARS-CoV-2 Infections in Residents of a Long-Term Care Skilled Nursing Facility — King County, Washington, March 2020. MMWR Morbidity and mortality weekly report. 2020; ePub: 27 March 2020.
Wei WE LZ, Chiew CJ, Yong SE, Toh MP, Lee VJ. Presymptomatic Transmission of SARS-CoV-2 — Singapore, January 23–March 16, 2020. MMWR Morbidity and mortality weekly report. 2020;ePub: 1 April 2020.
Li R, Pei S, Chen B, et al. Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV2). Science (New York, NY). 2020.