So wait…do masks help or what?? And what do I have around the house to make a good one?
When trusted sources of information like the Surgeon General say opposite things a month apart, what to believe?
Here’s what we KNOW:
- A N95 Mask properly worn, as well as a variety of DIY mask materials, is very protective for you as well as others.
- Covering your nose and mouth with your sleeve or ANY mask, even a bandanna tied around your face, is incredibly important to reduce the spread of this virus, especially from infected people who feel well.
- There is widespread confusion and poor quality information over what materials work best for DIY masks, but some recent good studies answer the question about what materials you have at home and how well they work.
It turns out that now that we ‘officially’ should wear masks, so today let’s explore two things: why the message changed, and now that masks are ‘in’ again, what are REALLY the best materials to make a DIY mask at home?
Here are two opposite messages from the Surgeon General Jerome Adams, one month apart:
February 29: AGAINST members of the public wearing face masks:
April 4: Shows how to make a cloth mask out of a T-shirt and says people SHOULD mask up when outside.
Of course saying masks won’t help contradicts virtually all evidence about how covering the mouth and nose are important methods to reduce the spread of infectious diseases transmitted through droplets — I think a lot of people noticed right away the discrepancy between the established knowledge that even covering your mouth with your sleeve is protective against spreading flu and other droplet infections, but wearing a mask for coronavirus would not help? Even during plague 600 years ago people DIY’d masks because some protection was better than NO protection:
I was disappointed when agencies we normally trust for good information gave out misleading information about using masks. Now, credit where credit is due — I honestly think most people really are trying the best they can, and especially when you look at how quickly people raided hospital storerooms and Amazon inventories of masks in the first couple of weeks (along with the toilet paper), I understand why our leaders could be tempted to discourage people from getting masks. They were justifiably panicked about the sudden severe shortage of masks for health care workers, who did indeed need to be prioritized, and they could truthfully say that ‘there was no evidence to support masks specifically protecting us from THIS coronavirus” (because it was new and there was no information specifically about this new virus). But I bet that did not do much to decrease demand for masks (maybe it did, but I doubt it), and there is certainly a large body of evidence that masks are protective in droplet and airborne driven pandemic infections generally, which I think most people realized. I just saw an interview with the CDC director Robert Redfield who sidesteps the direct question about why they gave out wrong mask advice in an interview. He doesn’t even address it when asked directly (after all, what could he really say), just diverts attention to the current advice.
Now that the official position is reversed, I fear previously trusted agencies like the Surgeon General (who in fairness normally gives good advice) will lose credibility because of it. Even with good intentions, dishonesty breeds distrust and though perhaps understandable, a very disappointing experience. I would face-palm, but I’m trying not to touch my face.
Since we now recognize that the lion’s share of infections likely result from asymptomatic people walking around feeling fine, shedding lots of virus into the environment in exhaled or coughed droplets, it is interesting to think how many infections might have been prevented by people wearing any kind of mask at all if they had been advised to way back when all we were hearing is ‘masks won’t help.’
Infected people without symptoms are only about 50% as infective as ‘sick’ infected people, but may account for up to 80% of the total infections simply because there are so many more infected people who don’t show many symptoms, and who keep wandering around at will shedding virus instead of feeling sick and lying in bed at home. This is where the new antibody tests being released are going to make a big difference.
So if a mask DOES help but there aren’t any, and if we really do want to reserve manufactured masks for health workers (as we MUST until the supply is abundant again), what kind of masks can we use or make?
Scott Segal, chairman of anesthesiology at Wake Forest Baptist Health launched a research project a couple of weeks ago to study the effectiveness of the materials used in homemade masks. They focused mainly on materials that would be commonly available in the home and that were already being shared as DIY mask solutions online.
Not surprisingly, some of the materials they examined performed much better than others:
1. Tightly woven fabrics with a 180 thread count or more: Fabrics like batik or quilter’s cotton, not knits (which have bigger holes). In Segal’s study, Quilter’s cotton filtered out up to 79% of small particles including viruses — that’s better than regular surgical masks, which Segal said filter out 65% of particles in their study (N95 masks filter 95%). Thicker ‘Jersey’ t-shirts performed well, as did dish towels in his and another study at Stanford, but cheap thin cotton did badly.
2. Use TWO LAYERS. You can put one layer of thicker cloth like a piece of flannel between thinner cloths.
3. Use a ‘Light Test’ if you are unsure of the thread count: if you hold it up to the sun or a lamp and see lots of light, that’s not a good sign. If it lets in light its more likely to let in/out virus particles.
4. Wash your masks frequently and don’t handle the front of the mask when you take it off (and wash your hands afterwards)
5. Make sure it’s not so thick you can’t make it through a trip to the supermarket before you have to pull it off, gasping for breath!
6. Consider alternative materials such as a vacuum cleaner bags or a piece of an air filter from your home AC system: Vacuum bags ranked higher than dish towels, but remember that some items like these (such as air filters) may be made of fiberglass or other materials so they should be sandwiched between fabrics.
7. An interesting possible adjunct is Salt: I found a fascinating 2017 study looking at options for fast, effective DIY mask production as pandemic preparedness by modifying the surface of the fibrous filtration layer within masks with a continuous salt film). The Study showed how soaking a fabric in salt significantly increased material’s efficiency at trapping and killing viral particles.
Since the Surgeon General’s video shows him using a t-shirt to make a mask, but since some thin cotton fabrics like those in cheap t-shirts performed very poorly in Segal’s tests (“Some cotton fabrics filter less than 25% of air particles”), Segal sent an email to the Surgeon General to share these preliminary results and as mask use trends upward, hopefully the Surgeon General’s office can use this data and engage similar studies to offer more specific guidance on DIY masks.
Last, but possibly most important: Don’t Get Cocky.
My cousin proof-read this for me, and this was her favorite part — because she had just been in the grocery store and 5 people, all wearing masks, were crowding and jostling her in total disregard of social distancing guidelines, probably because they felt safe masked.
“No mask is as good as social distancing,” Segal says, and expressed concern that “once people start wearing masks they might relax social distancing.”
Public Health expert Deborah Birx, assisting the White House’s coronavirus response team, expressed similar concerns last week: “The most important thing is the social distancing and washing your hands, and we don’t want people to get an artificial sense of protection because they’re behind a mask.”
And they are right — no mask is as good as literally staying out of the virus’ reach. So mask up, get creative and make yourself a good one. But don’t get cocky — the mask is there almost more to protect other people from you as it is to protect you from them. And remember — no mask is perfect, and even the best mask is only as effective as how well it’s worn. Even an N95 mask worn perfectly blocks 95% of particles, not 100%, so maintain your social distance and quarantine even as you sport this spring’s new masks:
