Samuel Rodriguez
Even Cloth Masks May Protect Us From Coronavirus Spread:
One of the things we learned from the Joe Rogan post on coronavirus, is that it spreads by Breathing.
The other things we learned are that at least 1 more wave of it is coming by the Fall, and we won’t have a vaccine by then.
So in addition to lots of washing and hand-sanitizer, there are going to be a lot of Masks for us in the future.
So a good idea then is getting them right, and a few new studies point that out…
Efficiency Is Everything And Some Masks Fail:
Now back in that clip from the Joe Rogan Experience, Dr. Osterholm might have sounded a little skeptical about anything short of an N95 respirator.
Fortunately for us, there are other options that do fairly-well, that are supported by the new work that’s come out.
But first a few warnings:
1) Bandannas are basically useless
2) So are Scarves
3) T-Shirts are not much better
Doing the minimum of doubling them up may help a little.
But still, all the efficiency-testing that’s been done shows those items filtering only between 10 and 40 percent of what they need to.
Even disposable surgical masks are better than that.
If you can hold it up to the light and still see it coming through the fabric, it’s probably a crappy filter-material.
Masks With Valves Are Counter-Productive:
The next warning is about the “Cool Flow” masks people will undoubtedly be trying toward the summer.
The problem with those is a fully closed mask is supposed to do 2 things.
1) Protect you from other people
2) Protect other people from you
Masks with one-way check valves in them only do half that job.
Not only that, but since there is still some debate about how effective a mask can be in the hands of the average person,
#2 on that list is probably the more-likely of the two cases, so with a valved-mask you’re failing even at that.
Now that we’ve outlined the Fails, let’s get to the new studies.
Cloth Masks Vs. Coronavirus: New Studies Show Some Really Do Work!:
In two different works, one from Canada’s McMaster University, and another from U. Chicago with the Argonne National Lab,
Both found that cloth masks, even the kind you could make at home, really do filter out virus droplets and particles like coronavirus.
The second team found that sandwiched or hybrid designs were 80% effective at filtering the smallest particles and 90% effective at filtering the largest particles.
These represent the kind that would 1) Hang in the air for awhile, and 2) Fall to the ground within that 6-foot social-distancing guideline we’ve all been given.
These hybrid masks had to be made of at-least 2 layers,
With high thread-count cotton on the outside of anywhere from 180 to an even-better 600 TPI,
And either Flannel, Silk, or Polyester-Chiffon on the inside.
Even in 1918 these guys wore cotton multi-layer masks, too! -National Archives
Many Different Layers Are Better Than Just One:
The great thing about this type of design is that the Cotton stops the big particles like a coffee-filter,
And the polyester or silk stops the little ones via static-electricity.
So the smaller ones might be able to get through one layer, but their Achilles’ Heel is that they can be trapped due to their ionic charge,
Just the same way a high-end air-filter uses at least 2 different methods to do the same, one of them would be attracting charged-particles.
Still better than that is after looking back at previous mask designs,
The Canadian team reminds us data from the 60s and 70s shows by wearing a multi-layered one,
You can to reduce the amount of risk you expose other people by up-to 99%!
-Even for the fine aerosol-mists that are the hardest to stop.
(these were 4-layer cotton muslin or 2-layer tea towel, btw)
What’s great about that is past data suggest the particles doing most of the infection are still the larger droplets from that 6-foot radius we hear about,
Even though information for infection by the smallest of particles for coronavirus hasn’t been studied to produce conclusive data yet.
Succeess Or Failure. It’s All About The Fit:
But that all falls down if you’re not wearing it properly.
Remember that terrible efficiency-figure for Bandannas, Scarves and T-Shirts?
Well, your fancier multi-layer mask is almost as bad as those if you don’t wear it properly.
The US researchers found that if the fit wasn’t tight enough,
(I would imagine particularly around the bridge of the nose)
Your filtering-efficiency goes down by 60 Percent!
So for whatever mask you have, it should fit tight to the sides of your face,
A Good Mask Should Be Snug Against Every Surface Of Your Face:
And also have a thicker gasket-like area on the inside where it touches your nose,
And a small aluminum bar that can force the fabric around the contours of that part of your face.
Otherwise, you could still be doing a terrible job at filtering out any coronavirus particles at-all.
That’s why the N95 is designed the way it is, so it can make a really good seal on all surfaces of you.
So if you need to spend a little more to get it right, do it! You’ll be saving yourself and other people a lot of trouble.
3M
Proper Handling Procedures Matter Too:
And there’s still another way you can let yourself down, too!
The CDC warns us to not just wear masks, but use them in safe ways at every step of the procedure:
1) Assume your hands are dirty and wash them before putting on a mask
2) Assume all masks and hands are contaminated as soon as you put the mask on
3) Wash your hands if you touch the mask
4) Don’t reuse single-use masks
5) Only take them off and hold them via the ear-loops
6) Either dispose of single-use masks or put cloth masks in the wash immediately
7) Assume your hands got contaminated taking off the mask and wash them again, too.
Masks Are Not Magic, We Still Have To Do Everything Else Right:
So, even though masks are one of the best things we’ve got going to fight the rest of this pandemic, they’re still not magic.
As things open up, we’re still going to have to pair that with the other preventative measures at our disposal,
Like keeping our hands clean and attempting to social-distance as best we can,
Even though we’re trying to get back to something like a normal life at the same time.
We all might still try to stay home as much as possible too,
And stay at-least 6 feet apart while we’re not.
Because reducing the chances for coronavirus infection is still probably a better strategy than even the most perfect mask you could get, n95 or otherwise.
CDC
References & Links:
• Sources: U Chicago | McMaster U, Canada
• Source Studies: ACS – Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks | ACP/AIM – Cloth Masks May Prevent Transmission of COVID-19: An Evidence-Based, Risk-Based Approach
• More Coverage: CDC – How to wear face coverings | CDC – Washing them | CDC – General mask recommendations
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