The Real MaskCoy - the real purpose of a mask
Many people argue about how many layers a mask needs to be, and how high the filtering properties should be. But ".. the reality is that for most people in low-risk settings, just about any mask will provide benefit. Remember, the real power of masks come from everyone wearing them. " (Joseph Allen, a professor of exposure assessment science at the T.H.Chan School, The Boston Globe, Dec 17, 2020)
Rather than argue about what type of masks to wear, how many layers, filtering properties etc, everybody should just put on a mask that they like whatever type it is, and that will already help tremendously in stopping the spread. Why so, you may ask?
When an infected person is coughing and is wearing a mask, the person facing him has a much smaller chance of catching the virus. Even a single-layer mask blocks 50-97% of forward emissions. (1)(2) This is source control - wearing a mask or face covering to block droplets at the source of the spread -- emissions from the nose and mouth of an infected person coughing, sneezing or talking. (CDC: "Masks are primarily used for source control", "Source Control versus Respiratory Protection: What is the difference?")
When an infected person is coughing and is not wearing a mask but the person facing him is wearing a mask (but not the N95 respiratory protection tightly sealed), the person facing him has a much higher chance of catching the virus. A Danish study found that surgical masks do not significantly offer protection of the wearer (3), while a researcher at the University of Hong Kong estimates 20% protection. (4)
While the jury is still out about whether masks (other than the N95 worn tightly sealed and that is reserved for medical workers) protect the wearer and if so, to what extent, pretty much all health experts agree that masks are very effective as source control, irregardless of the type of mask. The more layers the better, but even 1 layer will block about 50-97% of droplets at the source. (1) Since many people may carry the virus without knowing it, it is important that everybody wears a mask to stop spreading viruses unknowingly to others. Rather than argue about what type of masks to wear, everybody should just put on a mask or face-covering that they like and feel comfortable with, and that will help tremendously in stopping the spread. For masks, more is better than perfect.
That's why we say, "My mask protects you, your mask protects me." The most effective way of protecting yourself is to make sure that everybody around you in close proximity (especially in enclosed spaces) is wearing a face covering that covers his/her nose and mouth. It matters less what kind of mask he or she is wearing. A comfortable mask is best, so people will keep the mask on rather than removing it frequently.
Of course, don't forget distancing, hand-washing and opening the windows frequently if in shared enclose spaces for a long time! (see other blog)
(1) American Institute of Physics, Dec 22, 2020.
(2) Data Evaluation and Learning for Viral Epidemics (DELVE), UK, Report on Face Masks for the General Public, July 7, 2020
(3) New York Times, Nov 18, 2020
(4) Factcheck.org "Danish Study...", Nov 25, 2020