A dramatic new visualization shows exactly why it's a good idea to wear a face mask to prevent the spread of the new coronavirus.
Without a mask, droplets produced during coughing can travel up to 12 feet (3.7 meters), the visualization revealed, but with a mask, this distance is reduced to just a few inches in the best cases.
The simulation, which was described today (June 30) in the journal Physics of Fluids, also reveals that some cloth masks work better than others at stopping the spread of potentially infectious droplets.
"The visuals used in our study can help convey to the general public the rationale behind social-distancing guidelines and recommendations for using face masks," study lead author Siddhartha Verma, an assistant professor at Florida Atlantic University's College of Engineering and Computer Science, said in a statement.
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To simulate a cough, the researchers connected a mannequin's head to a fog machine (which creates a vapor from water and glycerin), and used a pump to expel the vapor through the mannequin's mouth. They then visualized the vapor droplets using a "laser sheet" created by passing a green laser pointer through a cylindrical rod. In this setup, simulated coughs appear as a glowing green vapor flowing from the mannequin's mouth.
The researchers then placed several types of non-medical masks on the mannequin head to test their effectiveness at blocking these "coughs." These included a homemade mask stitched with two layers of cotton fabric used for quilting (with 70 threads per inch), a single-layer bandana, a loosely folded cotton handkerchief and a non-sterile cone-style mask sold in pharmacies.
They found that, with no mask covering, the simulated coughs traveled up to 12 feet in 50 seconds.
The homemade stitched cotton mask — with its multiple layers and snug fit — reduced the spread of the droplets the most, although there was some leakage at the top of the mask between the nose and the cloth material. When the mannequin wore this mask, droplets traveled only about 2.5 inches (6.35 centimeters) forward from the face. The cone-style mask also worked well, with droplets traveling just about 8 inches (20 cm) from the face.
However, the single-layer bandana (made from an elastic T-shirt material) and folded handkerchief were less effective. Droplets leaked through the mask material and traveled more than 3.5 feet (1 m) with the bandana and more than a foot (0.3 m) with the handkerchief.
Still, "although the non-medical masks tested in this study experienced varying degrees of flow leakage, they are likely to be effective in stopping larger respiratory droplets" from dispersing, the authors wrote in their paper.
"Promoting widespread awareness of effective preventive measures [for COVID-19] is crucial at this time as we are observing significant spikes in cases of COVID-19 infections in many states, especially Florida," Verma said.
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Originally published on Live Science.
Second, I would like to have seen a visualization of a hand/handkerchief/elbow sneeze as well, as this should be an acceptable option for people that can't wear masks (e.g., asthma).
Third, all of those visualizations make me concerned about a massive spike in conjunctivitis (pink eye) and other ocular issues as every mask appears to result in blow-back into the cougher's eyes. Yes, pink eye is less serious than COVID, but it's also highly contagious and I don't know what other ocular risks would come from those germs.
Finally, if I am regularly coughing or sneezing I would probably not be going out regardless. The bigger issue being discussed is the value of a mask in regular activities without coughing or sneezing or exercising or singing, but simply walking near people in a store or restaurant and just breathing.
With todays tech couldn't A real human with the virus wear A mask and breath through the mask while being measured? Also A cough from the virus infected person would give you distance and volume that could also be measured.
This report makes it sound like something done on youtube not in A Scientific Lab.
I think these insights might be extended to strong additional recommendations for social distancing and minimizing face-to-face conversations (even through masks) with anyone not in one's household. We must not be emitting "spit" or vapor into anyone else's space while this plague is with us.
something like this addresses some of your questions. At least you can see why a human looks like expelling droplets
it doesn't show masks, but it's looking at different elements
Nowhere in the Constitution does it cover a situation like we have right now. The Founders could have never foreseen such a virus, or the results from it. The Constitution is a roadmap for the formation of new laws to cover situations which are not mentioned in this document. No one could have looked into a Crystal Ball and received revelation that the COVID-19 would hit the World population as hard as it has. While it isn't the worst epidemic or pandemic in World History, it is still a deadly virus, especially for those with compromised health conditions. Also it is obvious this virus is easily spread from one person to another, as well as from animal-Human contact.
Requiring masks to be worn in public is not unconstitutional, because it is covered under the General Welfare Clause of our Constitution. Lawmakers have the duty and responsibility to introduce and pass legislation which affect the whole of the population. Wearing of masks has been proven to curb the spread of COVID-19 in the general population, and the wearing of R-95 or more effective mask have been proven to protect medical workers from the virus. So why is there so much opposition from the conservative side of the isle concerning Covid-19?
Partly it has to do with the principle of freedom of choice. But this principle falls flat because NOT wearing a mask is a danger to everyone they come in contact with. It has been shown non-medical masks, protect others more than they do wearers of the mask. To go into public and be potentially responsible for making other sick is irresponsible
The other part is, we conservatives have identified huge errors in both domestic and foreign policy, many of which have no Historical, Scientific, or Political facts or president to back the laws being made, or Treaties being entered into. In fact many decisions made by our government blatantly violate the Constitution and principles of the Founding Fathers. Therefore we keep a watchful eye on politicians and Bills introduced in Congress, as well as Treaties being approved by the Senate.
I am a strict Jeffersonian Conservative Constitutionalist, who relies on facts, to make pragmatic decisions about the issues.
If you have any regard for the health and safety of others, WEAR A MASK!
What if it's windy?