I’m not going to list their objections. I’m simply going to post facts, links and citations. Those of you who’ve read the anti-masker mantras and Internet memes should recognize where their errant claims are answered, below.
The key thing to remember is that the mask doesn’t have to stop particles as small as the virus. All it has to do is stop the vastly larger droplets which carry the virus as they’re expelled in speech, a cough or a sneeze. The size difference between the virus and the droplets which carry it isn’t tiny.
The actual testing of various materials was conducted by SmartAir’s “The Ultimate Guide to Homemade Face Masks for Coronavirus.”
Is it an AMA/OSHA/UL/CDC/WHO-approved testing laboratory? No.
Is it dang close with respect to both the precision and reproduction of the results? Yes.
Is it “close enough for government work?” Absolutely.
Denim, bed sheets and canvas are the best for home-made masks as they’re washable. Paper towels are not. Shop towels have always appeared to me to be too full of large holes to be effective. Perhaps they’re testing different shop towels. Who knows? I’d stick with denim and canvas.
If the coronavirus were the size of a baseball, the mucous droplet* containing it would cover 23 acres.
*Mucous droplet sizes produced by speech range between, 2e-3 to 2e-5 meters in diameter. The logarithmic mean is 2e-4 meters. The SARS-CoV-2 virus is 1e-7 meters. An O2 molecule is 3.63e-10 meters and a CO2 molecule is 3.3e-10 meters.
Mucous droplets expelled during a cough or a sneeze range in size comparable to those produced during speech to a small dog. Just seeing if you’re still with me. If so, let me know you saw the small dog. 🙂
A baseball is 7.38e-2 meters. For the droplet size, I used the logarithmic mean of 2e-4 meters.
Crunch the numbers and you wind up with a length of 1,000 feet. Squared, that’s 1 million square feet, which is 22.9568411 acres.
You’re not stopping the baseball. You’re stopping something the size of a medium-sized farm. Thus, the “trying to stop a mosquito with a chain link fence” arguments are way off on the relative sizes, as well.
My only error is that droplets are round, not square! But I’ll leave the area=pi*r^2 math to the engineers… 🙂 It’s “roughly” the size of a medium farm as compared to the baseball-sized virus.
Mechanism of Action
There’s a great deal more to it than this, and I can supply you with thousands of pages of peer-reviewed medical research, but I’ll summarize by adding:
1. Being so small, the droplets evaporate within a few tenths of a second to a couple of minutes, depending on the size of the droplet. They’ll generally shrink down to about 1e-6 meters, called a droplet nuclei, which is 10x larger than the virus itself. The droplet nuclei encapsulates the virus in a layer of mucous protein. It’s very sticky, particularly at microscopic levels. We’re talking tar and feather sticky.
2. If the droplet lands on an absorbent material (paper, cotton) before it’s fully dry, the absorbent material will draw away most of the water and protein, leaving the virus exposed. Viruses exposed to the atmosphere are quickly decomposed by oxygen. If the droplet lands on an inert substance like plastic or stainless steel, it remains well-protected in the mucous protein sheath for a period ranging from hours to upwards of five days, with the number of viable viruses dropping in a natural logarithmic decay, but none lasting a week. Oxygen will tear through the protein.
3. Only the smaller droplets (<2e-4 m) are carried away by typical air currents and Brownian motion. Larger droplets fall fairly quickly to the floor, travelling between 0 and about 3 feet away from the source, hence the 6 foot social distancing rule.
4. The keys to a good mask are:
– the choice of fabric
– pleats to increase surface area reducing both the breathing force and increasing filtration efficiency
– a very close fit to minimize internal mask volume and therefore maximize the exchange of gases
– an excellent seal around the sides achieved by proper dimensions and at least partially elastic straps
For fabric, I’d go with two layers, denim on the outside and smoother canvas next to my skin. Denim and canvas are 92% and 93% effective at 1um, the size of the SARS-CoV-2 droplet nuclei. Together, they’re 1-(1-.92)*(1-.93) = 99.44% effective at filtering that nuclei — IF your mask seals tightly around the edges.
If you find breathing a bit taxing, you’re probably limited to a one-layer pleated mask. You’re still achieving a 92% to 93% filtration rate, which, when combined with the filtration rate of the other people’s masks and social distancing, results in a far more effective solution than either the media or the anti-maskers are making things out to be.
Don’t skimp on the pleats or it will be difficult to force air through it.
Similarly, make certain the fabric fits tightly, without billowing, or it’ll be more like you’re breathing in and out of a balloon with little exchange of gases through the fabric.
5. Because of the rapidly shrinking size of expelled droplets, a mask worn at the source is roughly four times as effective as a mask worn at the destination. Together, they’re five times more effective than a mask worn only at the destination, hence the draconian-sounding edict that’s actually based on extremely well-researched and oft-proven science.
As for the need for masks, COVID-19 remains very serious. As of two days ago and out of 1,165,174 U.S. cases that resolved in either recovery or fatality, 138,358 — 11.9% — were fatal.
Some 2.3 million cases remain unresolved. Given the now widespread and more aggressive early treatment options, I strongly suspect the 11.9% fatality rate will drop.
- Hydroxychloroqine (200mg 2x/day for 5 days)
- Azythromycin (500 mg 1x/day for 5 days)
- Zinc sulfate (220 mg 1x/day for 5 days
This remains the treatment regimen most commonly cited by physicians as being highly (>98%) successful, with early and aggressive treatment resulting in the best outcomes. Some doctors are claiming 100% success with roughly 500 patients.
It’s the same treatment regimen endorsed by President Trump, after which mainstream media refused to air it. Draw your own conclusions.
Good luck, be safe, think clearly, and hopefully, I’ll catch you on the backside!