Face masks slow spread of COVID-19; types of masks, length of use matter.
The use of face masks to help slow the spread of COVID-19 has been widely recommended by health professionals. This has triggered studies exploring the physics of face mask use and disease transmission, as well as investigations into materials, design, and other issues affecting the way face masks work.
In Physics of Fluids, by AIP Publishing, investigators looked at research on face masks and their use and summarized what we know, to date, about the way face masks filter or block the virus. They also summarize design issues that still need to be addressed.
One key aspect of face mask function involves the size of fluid droplets expelled from the nose and mouth when a person talks, sings, sneezes, coughs, or even simply breathes. Larger droplets, with sizes around 5-10 microns, are the most common. These droplets are still quite small, however. To compare, a human hair is about 70 microns in diameter.
Even smaller droplets, those below 5 microns, are possibly more dangerous. These can become aerosolized and remain suspended in air for long periods. Among the many types of masks in use (cloth masks, surgical masks, and N95 masks), only N95s can filter out aerosol-sized droplets.
The performance of face masks worn for many hours, such as by health care or other essential workers, impact how effective overall mask wearing can be. Thermal comfort is an important issue, especially in hot and humid environments.
The investigators found face masks made of hybrid polymer materials could filter particles at high efficiency while simultaneously cooling the face. The fibers used in these special masks are transparent to infrared radiation, allowing heat to escape from beneath the mask.
“There could be some relation between breathing resistance and the flow resistance of the face mask which will need to be studied for a face mask-wearing interval,” said author Heow Pueh Lee. “Also, the environmental condition in the compartmental space within the face mask will need to be more accurately quantified using miniaturized sensors and the development of human replicas for such studies.”
The investigators also reviewed epidemiological studies aimed at discovering whether face masks reduce the effective reproduction number. If the reproduction number drops below 1, the epidemic stops spreading. One study used COVID-19 data from New York state.
“The results suggest that the consistent use of efficient face masks, such as surgical masks, could lead to the eradication of the pandemic if at least 70% of the residents use such masks in public consistently,” said author Sanjay Kumar. “Even less efficient cloth masks could also slow the spread if worn consistently.”
Reference: “The perspective of fluid flow behavior of respiratory droplets and aerosols through the facemasks in context of SARS-CoV-2” by Sanjay Kumar and Heow Pueh Lee, 24 November 2020, Physics of Fluids.
DOI: 10.1063/5.0029767
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14 Comments
Yeah right what a crock of BS
President Donald Trump claims that 85% of people who wear masks catch Covid-19
It is true that nearly three-quarters of study participants reported that they had worn a mask or cloth face covering while in public in the two weeks preceding their COVID-19 diagnosis.
The research in question was conducted by the CDC and published in the U.S. COVID-19 mortality report on Sept. 11, 2020.
Did CDC Report ‘Majority’ of People Who Contracted COVID-19 Wore Masks?
U.S. President Donald Trump amplified misunderstanding when he claimed on live television that “85% of the people that wear masks catch [COVID-19].”
https://www.snopes.com/fact-check/cdc-report-majority-wore-masks/
Still not wearing a mask
Complete and utter nonsense.
Until society at large expects a price for sociopathic behavior, such as not wearing a mask during a pandemic.
We’ll get a significant % of people not bothering to protect themselves or others.
BS propaganda. Cases are rising higher since people started wearing masks. People who wear masks are more likely to be infected with COVID why is it that a fart can still make it to people’s noses even when it has any least 2 layers of protection.
https://thefederalist.com/2020/11/23/many-studies-find-that-cloth-masks-do-not-stop-viruses-like-covid/
https://www.i24news.tv/en/news/coronavirus/1606040660-danish-study-questions-efficacy-of-mask-wearing
Misleading headline. Masks, even according to this article, need to be made of specific materials , largely unavailable to the general public, and fit well — good luck with that one!!! Also, I would guess that this ‘study’ was done in a lab, not in real-world conditions. What is “possible”, and what is most likely in real-world conditions are two very different things.
THE article fails to state masks cannot filter anything smaller than .5 microns said virus is apparently .1 microns at best while Covid 19 has yet to be characterized and identified scientifically hence no valid test exists FURTHER demonstrated by the numbers of false POSITIVES ASSOCIATED WITH A PCR test THAT is not a diAgnostic per its founder. suggest referring to CDC website for data surrounding the basis of cOVID claims APPARENTLY GENERATED FROM “STOCK” VIRUS SAMPLES THUS NO VALID TEST EXISTS NOR DO ANY CLAIMS OF A VACCINE
HOPEFULLY THE AUTHOR OF THE ARTICLE WILL DO SOME MORE RESEARCH AND DISCUSS ACTUAL SCIENCE
The comments section is a glaring example of why the US is failing so miserably at curbing the spread of this virus. Americans are far too proud of their ignorance and selfishness. Get over yourselves, people. Even if masks are not 100% effective, it can’t hurt and basic logic (not to mention a variety of studies) would indicate that masks are one of the easiest ways to achieve a significant reduction in the spread of this disease.
But you lot are too cool, can’t be bothered, and clearly don’t give a damn who you harm – even if it’s yourselves.
Way to be so cool.
Oh wait, you’re not cool. You’re ignorant and you like to see (disease-ridden) hot air from your stupid faces.
I agree with Pablo. People, please have some faith in the scientists and the professionals. Stop worrying about all of this “impingement on your freedoms”. It’s a freakin’ MASK! How about we all wear one, whenever we can for 1 month and see where it gets us.
We all wear seatbelts now…oh actually that’s not true. Some people find it to be an “impingement on their freedoms”. Smart folks wear a seatbelt because it’s proven to save lives. Is a seatbelt 100% effective in every situation during an MVI? No. However, most of the time, they help.
It doesn’t need to be a political statement. Its just ppe. Workers wear ppe, everyday at work because it helps mitigate potential for negative impacts.
Swallow your pride, and try to show some respect for your fellow citizens, if not for yourself.
Wearing a mask can’t hurt. Not wearing one, has greater potential for injury.
The stupidity in this comment section is EXACTLY why, in about a month, we are gonna see despair that people would not believe could happen in this country. Hospitals are already becoming maxed out in regards to beds and medical professionals, there will be NO ONE, NOWHERE to go for help when you can’t breathe! We seriously need to fix the pollution problem asap, brain cells are in short supply and this whole situation leads me to believe the neurotoxins we spew into our environment are having a tremendous affect. I really have no other way to wrap my head around the ignorance that’s infected our society. Please ask yourself, if masks are not effective in REDUCING risk why in the world would medical personnel be insisting on wearing them?? Have you seen what they wear to go into a room w a covid patient?? That should be a clear in indicator that a mask is warranted!!
Find the cure for cov19 and get back to normal life, face masks will not stop the virus, if it’s a plague then we better start designing environment suits before the human race is wiped out.
… the only issue I find is the fact that the first line of defense are:
– masks,
– distancing,
– hand washing,
etc…
… For the love of the dear God, we are in 2020…
… If we were attacked by the aliens, something like 4 of July or what ever, we would have a chance. ( more of a sarcastic comment, just in case that some north pole people thing this is a real point) …