Simply wearing a mask may not be enough to prevent the spread of COVID-19 without social distancing.
In Physics of Fluids, by AIP Publishing, researchers tested how five different types of mask materials impacted the spread of droplets that carry the coronavirus when we cough or sneeze.
Every material tested dramatically reduced the number of droplets that were spread. But at distances of less than 6 feet, enough droplets to potentially cause illness still made it through several of the materials.
“A mask definitely helps, but if the people are very close to each other, there is still a chance of spreading or contracting the virus,” said Krishna Kota, an associate professor at New Mexico State University and one of the article’s authors. “It’s not just masks that will help. It’s both the masks and distancing.”
At the university, researchers built a machine that uses an air generator to mimic human coughs and sneezes. The generator was used to blow tiny liquid particles, like the airborne droplets of sneezes and coughs, through laser sheets in an airtight square tube with a camera.
They blocked the flow of the droplets in the tube with five different types of mask materials — a regular cloth mask, a two-layer cloth mask, a wet two-layer cloth mask, a surgical mask, and a medical-grade N-95 mask.
Each of the masks captured the vast majority of droplets, ranging from the regular cloth mask, which allowed about 3.6% of the droplets to go through, to the N-95 mask, which statistically stopped 100% of the droplets. But at distances of less than 6 feet, even those small percentages of droplets can be enough to get someone sick, especially if a person with COVID-19 sneezes or coughs multiple times.
A single sneeze can carry up to 200 million tiny virus particles, depending on how sick the carrier is. Even if a mask blocks a huge percentage of those particles, enough could escape to get someone sick if that person is close to the carrier.
“Without a face mask, it is almost certain that many foreign droplets will transfer to the susceptible person,” Kota said. “Wearing a mask will offer substantial, but not complete, protection to a susceptible person by decreasing the number of foreign airborne sneeze and cough droplets that would otherwise enter the person without the mask. Consideration must be given to minimize or avoid close face-to-face or frontal human interactions, if possible.”
The study also did not account for leakage from masks, whether worn properly or improperly, which can add to the number of droplets that make their way into the air.
Reference: “Can face masks offer protection from airborne sneeze and cough droplets in close-up, face-to-face human interactions? A quantitative study” by Javed Akhtar, Abner Luna Garcia, Leonardo Saenz, Sarada Kuravi, Fangjun Shu and Krishna Kota, 22 December 2020, Physics of Fluids.
DOI: 10.1063/5.0035072
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.
33 Comments
So, “science” is now admitting what most of us have been observing for the past 6+ months. Masks don’t work.
Says the guy too dumb to read the article.
(why am I not surprised)
I agree, masks with social distancing increases your protection against getting COVID 19. MASK DO HELP!!!
You’re safe, D.T. The virus will have a hard time passing your hemorrhoids.
El covid 19 es una falsa
Hay un error en tu nombre: Debe ser “Loco” en vez de “Coco”. 🙂
TODO ES UNA FALSA ESTO ES NINGUNA PANDEMIA ES UN MONTAGE PARA UNA GUERRA ABSURDA SILENCIOSA HAY QUE SER MUY TONTO PARA NO VERLO SAVEMOS QUE PAGAIS A LOS MEDIOS DE COMUNICACION Y A LOS MEDICOS Y A LOS PRESIDENTES Y GOVERNANTES LO SAVEMOS
Claro que si es “una falsa”. Y por esa “falsa”, mueren mucho mas Latinos que personas que no son Latinos. Imbecil.
I am involved with a mask that has two layers of high quality graphene oxide woven into it that reports it completely filters out droplets and particles 1000x smaller than Covid droplets and kills Covid-19 within 2 minutes of contact. Learn more at mygo2mask.com and the graphene oxide aspect should be examined by the experts. In fact, I believe SciTech Daily has looked at this or posted about it in the past.
Masks plus social distancing work a lot better than masks without social distancing. Wear your mask and stay six feet apart.
Thanks for this really negative title… of course, it will now be cited (incorrectly) by COVID-19 deniers and mask effectiveness deniers to justify their refusal to follow basic public health guidelines backed up by science (as evidenced by some of the other commenters). This, as opposed to a title more representative of the actual study findings such as, ‘Social Distancing and Masks Are Both Important For Stopping COVID_19 Spread’ or ‘Social Distancing Proven to Reduce COVID-19 Spread’.
Sure, instead, lets go with ‘Masks not enough to stop COVID-19…” and bury study author’s statement, “Without a face mask, it is almost certain that many foreign droplets will transfer to the susceptible person,” at the bottom of the article, as if there’s not millions of people in the US alone that refuse to wear masks – in large part because of changing advise about their effectiveness. Irresponsible.
I agree with Teresa.
Thd have only been telling us to wear a mask, social distance and wash your hands for the past 9 months. Were scoreddaily been.
6 feet is a arbitrary number, who ever cane up with that? By now we should all realize! more is better. Clean fresh multilayer masks and avoid crowds and 20ft distance. its extream but a pandemic is pretty extream!
This is completely irresponsible! Heed commenters advice and redact / remove this article! It gives the wrong impression for the millions of intellectually challenged people already having a hard time selecting correct information!
This article does a disservice by its title. A mask is better than nothing. There is evidence that receiving a smaller dose of the virus can result in a milder form of the virus. The mask might even prevent infection. You should publish a retraction of the erroneous title as suggested by others who made comments.
Covid 19 not real it’s a joke to try and control American people, if you can’t see this you are real dummy but you’ll soon find out
Your cavalier, arrogant attitude may cost you your own life!
So tell me what is killing so many people around the Globe young or old please educate me in what is really going down.
This is not rocket science to figure out – HEPA filtered masks which are some of the best masks available are tested at 0.3 micron particle sizes. The Covid-19 particle is 70 to 90 nanometers in size – i.e. 0.07 to 0.09 micron. When you pour water through a screen into a bucket, it slows down the flowrate of the water into the bucket. From an analogy standpoint, masks are like the screen – it will slow down the rate at which the Covid-19 particles penetrate the mask but will not stop it. Again, not rocket science – I am an engineer and do radioactive work and we understand filtration. I would honestly think that a mask with an activated carbon layer would do better at filtering virus particulate since this material is good at filtering organic compounds (e.g. a double layer mask with an outer HEPA filter media and an inner activated carbon media).
COVID19 IS A HOAX! If this nonsense is true; why do they have to stick a probe into the back wall of the sinus cavity to get a sample. If this disease is just oozing off of us wouldn’t a nose hair swab be sufficient? I’m a security guard. My Company assigned me to guard nurses at local hospitals screening people for COVID19. I worked 12 on 12 off, one day off a month, sometimes I had an hour commute. I worked all of February, March, April, May and half of June. Not once did anyone come in with the classic symptoms of COVID19.
Furthermore; John Hopkins published a paper stating that America is on par with previous years as to the average number of people who die from all causes. The paper was withdrawn or big donors to the school would stop donating. COVID19 IS A HOAX!
I see that you never let facts interfere with your opinions! all a hoax? Then why are hospital ICUs full across the country? And, no, you are wrong about the Johns Hopkins ‘study’. It was not a study – it was a non-peer reviewed article that was withdrawn. Our only hope is that the virus disproportionately people like you so that our collective IQ increases.
Give the security guard an extra day off so he may be lucky enough to smell coffee!
When wearing masks actually people reduce social distance unconsciously, so consider that overall the masks didn’t help, if didn’t make it worse.
Where’s the science about the droplets having covid
If you sneeze or cough wtf are you doing out ? Masks were to help for asymptomatic cases only which tracing proved do not spread the virus.
Yeah I bet isolating and testing is even more effective than mask wearing and social distancing.
Its comment sections like this one that have made me loose my faith in humanity and feel shame to be an American Citizen. I know nine people who are dead now. How many other flu seasons have lostceven one friend or family member to the flu? None, thats right. What killed my friends and family out of the blue this year then? And who do you reckon is behind a conspiracy theory that spans the entire globe, sguts down Europe and kills off villagers in third world countries at insane rates? No one has that reach or power, and what would the point be? Wear a mask you ignorant selfish inbreeders.Youre spreading this plague like wildfire and killing off innocent high risk people with your foolish arrogance. Also, try actually reading articles instead of running your belligerent mouths in public. I feel embarrassed for you but you don’t have the intelligence to be ashamed of yourselves. Id feel pity but you are killing people so its best you just go ahead and prove that natural selection is just God’s way of harvesting idiots.
Its comment sections like this one that have made me loose my faith in humanity and feel shame to be an American Citizen. I know five people people who are dead now.Their families, lifelong friends of mine, tell me firsthand accounts of the deceased’s horrific symptoms, their rapid and lonely disent into ICU, the gasping for air, and How many other flu seasons have I lost even one friend or family member to? None, thats right. What killed my friends and family out of the blue this year then? And who do you reckon is behind a conspiracy theory that spans the entire globe, shuts down Europe and kills off villagers in third world countries at insane rates? No one has that reach or power, and what would the point be? Wear a mask you ignorant selfish inbreeders.Youre spreading this plague like wildfire and killing off innocent high risk people with your foolish arrogance. Also, try actually reading articles instead of running your belligerent mouths in public. I feel embarrassed for you but you don’t have the intelligence to be ashamed of yourselves. Id feel pity but you are killing people so its best you just go ahead and prove that natural selection is just God’s way of harvesting idiots.
What a rinky dink looking experiment. Why is anyone listening to these charlatans?
Properly retitled, the article is “Someone Has To Cough Repeatedly Directly On You For Even A Crappy Mask To Fail”
Covid-19 deniers are on par with those that deny climate change. I read an article about a covid-19d denier that ended spending over 15 days in the ICU. He’s no longer a denier, and was still weak after a month of rehab. Conspiracy theories seem to be in pandemic mode themselves; they do little for helping us cope with the real problems we face, and can undo the social order if they’re not recognized for what they are; populist propaganda with little backing fact or proof. 25 years ago I had a farmer cousin tell me that “global warming was a myth”, and that the ocean levels rising by ice melting wouldn’t happen because “an ice cube floating in a glass of water doesn’t raise the level in the glass as it melts”… (true), but the ice sitting on solid land in Greenland and Antarctica isn’t floating, it’s sitting on land masses and melting into the oceans! Oh, you say it really isn’t happening–dream on, pilgrim, but you had better buy some hip waders if you live near the oceans!
… people say that it is bit too hard to figure out if thing work, or not…
… That is just so simple, take a look at this curve:
https://en.wikipedia.org/wiki/Control_system#/media/File:Second_order_transfer_function.svg
this is when beast is handled, well it is not exactly, but that is what is it about, and in the case of uncontrolled growth it will just jump on some rate, and if it goes down, well, it is a sign of condition that are not good for it…