The rare times I’m out and about these days, I don’t see too many smiles. I don’t think that’s because everyone is terribly depressed, but people are anxious and many if not most are covering up their faces for protection from dreaded Mr. Corona. But does this make any sense, or are people just clinging to a security blanket that happens to hang from their ears?
What are they up against? The naked coronavirus is about 120 nanometers (0.12 microns) across. The virus escapes the cells it’s infected and destroyed enveloped in some of that cell’s membrane, making particles that can be twice that size. A thick beard hair is about 50 microns in diameter. So if your beard hair is as wide as football field, Mr. Corona checks in as a soccer ball at midfield (a little over 8 1/2 inches). So this is a tiny sucker you’re trying to stop.
This link provides a good guide as to what’s out there (manufactured) for masks https://healthcentricadvisors.org/wp-content/uploads/2017/04/3_MaskEnomics_Poster_2012.pdf
Masks are rated for their ability to stop 0.1 micron particles. The much prized n95 mask is rated to stop 95% of such intruders, and it goes down from there. Note how some of the more commonly seen masks aren’t even rated.
No one has published the pore size of the common bandana, but you see them everywhere. The CDC has even issued directions for homemade masks https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/diy-cloth-face-coverings.html. The CDCs lack of confidence in bandanas is illustrated by recommendations you include a coffee filter.
From my reading, these things mostly prevent you from spewing your germs to others.
So maybe wearing a mask in public is a sign of good citizenship, like washing your hands frequently. You’ll be keeping any disease laden droplets you happen to cough up to yourself and not sharing them with others. Thank you for your consideration. But don’t expect it to prevent the reverse. You’ll need an n95 or at least an ASTM Level 1-3 for that. But unless you’re a doc or nurse in an ER or ICU, you’re not swimming in an environment full of little Mr. Coronas, and really don’t need that kind of protection.
So take off that bandana and fold it up for your back pocket where it belongs. And give us a smile. We need more of that. This thing is coming to an end. Let’s start to celebrate and get ready for when we really can.