I hope you all had a safe and healthy 4th of July, and that you keep making safe choices to keep yourself, your loved ones and your community healthy. COVID-19 cases keep rising in the U.S., particularly in states that either don’t have face mask requirements or aren’t enforcing them. A vaccine is months away at best, so until then it’s up to us to control this pandemic as best we can using the few tools we have available. Face masks have been proven to reduce the spread of COVID-19; everyone over 2 years old should be wearing one anytime they are out in public or around people who don’t live in their household.
Now that face masks are finally catching on, there are so many to choose from. It can be hard to choose which kind is right for you. Fortunately, the AIP Physics of Fluids published a fascinating study visually comparing the effectiveness of various kinds of commonly worn face coverings.
First, a note: please save the medical grade face masks, particularly N95 respirators, for healthcare workers treating people with COVID-19. N95 face mask shortages and price gouging are putting our essential workers at serious risk. At least 735 frontline healthcare workers have died of COVID-19 to date. Many healthcare workers have had to resort to reusing single-use disposable masks in an act of desperation to protect the people who are trying to protect us. Please think twice before buying or stockpiling medical grade face masks; leave them to the healthcare workers who need them the most.
Back to the study: the researchers used a smoke generator and a simple foot pump to force smoke through a hollowed-out manikin’s mouth in a simulated cough. They shone a green laser on the smoke to make it easier to see, and recorded the distance the smoke traveled using high speed video. They repeated this experiment without a face covering and with four different types of masks.
Smoke from uncovered coughs traveled about 8 feet on average in their study, farther than the CDC’s estimate of 6 feet, although smoke from heavy coughs traveled as far as 12 feet within 50 seconds. I do think this is a potential flaw in this study, although an interesting one. If the study’s simulated coughs were too forceful and traveled farther than a typical cough, then one might assume that face masks would reduce the spread of regular coughs even more than they reduced the spread from these larger coughs.
A bandana tied around the manikin’s face reduced the spread of smoke by about half: from 8 feet uncovered to just under 4 feet. A simple folded handkerchief – similar to the no-sew method explained at the CDC’s “How to Make Cloth Face Coverings” web page – was pretty good in a pinch; some smoke leaked through, but only traveled just over 1 foot.
But the clear winner was a homemade sewn cloth mask made with two layers of quilting fabric; surprisingly, it was even more effective at blocking the spread of the smoke than a store-bought mask. The small amount of smoke that leaked out of the mask only traveled 2 1/2 inches on average, in a stunning display of the effectiveness of cloth masks.
So there you have it: simple, homemade two-layer sewn cloth masks are the most effective choice for the general public, even more than store-bought masks. The CDC has a simple tutorial to sew your own, or if you’re not crafty then a lot of online retailers are selling them. Even certain multinational conglomerates I won’t name nor link to are selling cloth masks!
Cloth face masks can be a cute and fun way to show off your personality or make a fashion statement or a political one. I happen to live in an area that has embraced face masks, and I am not exaggerating when I say that I get compliments on my cloth face masks every time I go out in public.
One last thought before I go: remember to be careful to buy or make a face mask in an appropriate size and shape for your child. Kids have smaller faces and different facial structures than adults. I had to try three different sellers before I found masks that fit my kids correctly, but it was worth it to protect my kids.
😷 Dr. B