There are many different forms of masks and coverings. But are they all the same in preventing the spread of the Covid-19 coronavirus? [+] In the picture, Ashley Haas (left), Ashley Haas and Heather Aboff appear in SoHo, New York City wearing their clothes. (Photo by Gotham/GC)
Although for different reasons, people may end up wearing them on their faces at the same time. Both can have multiple types and designs. Not all people are created equal. Some (masks, not pizza) are better at blocking droplets that may flow from your nose and mouth than others. In fact, according to a study just published in the journal Science Advances, in some cases, some masks actually make the situation worse, causing more droplets to be ejected into the air.
Yes, you heard it right. Wearing some masks may be worse than nothing. That¡¯s not the case with songs recorded by Alison Krauss, so how can a mask be worse than wearing nothing but a smile on the face? When you cough, sneeze, talk, sing, gasp, and say “Oh Pizza”, shouldn’t the mask block everything that flows out of your mouth and nose? Shouldn’t the mask help stop your dirty nose and mouth from spreading the Covid-19 coronavirus to others?
In this study, a team from Duke University (Emma P. Fischer, Martin C. Fischer, David Grass, Isaac Henrion, Warren S. Warren, and Eric Westman) created a “spitting on the ground” where some people talk to the box. “image. The study used a terrible laser beam to do this. The laser beam produced a piece of light in front of a hole in the black box. Therefore, in essence, the experiment is not just a black box.
Next, the research team asked a person to put his or her mouth in the hole and repeat the phrase “keep healthy, people” five times. Therefore, anything coming out of a person’s mouth, whether it is a small droplet or a fragment of a hot dog, will subsequently hit the light sheet, causing the light to scatter. In other words, any droplets or particles will scatter the sheet from it. The phone camera took this chart, which will allow the researcher to quantify what was spit out of the person¡¯s mouth.
The person repeated this process many times, first without any mask, and then wearing 14 different types of masks. This person didn’t wear 14 masks at the same time, which seemed ridiculous. Instead, this person tries one at a time. The research team established a relative drop meter number table, where 1.0 represents the number of droplets that hit the bed sheet when a person is not wearing a mask, and 0.0 represents what happens when the best mask is used. Again, remember that this is just a version of each of the 14 different types of masks that one person has tried.
N95 masks outside New York University Langone Health Hospital during the coronavirus pandemic. … [+] (Photo by Noam Calais/Getty Images)
There is no doubt that the best mask is obviously the N95 mask without an exhalation valve. After all, this is the kind of clothing that medical staff should wear, assuming that their healthcare facilities actually provide adequate protection. These masks are designed to prevent droplets and viruses from flowing or flowing in from any direction, and to protect the wearer and everyone else. Experiments conducted with this mask essentially hold the paper together, with very few scattered points recorded. In fact, such a mask is not perfect. However, they serve as the standard for this experiment, and the relative droplet count is essentially zero.
Surgical masks, just like the masks worn by medical staff in Hong Kong, China, were completed in the test… [+] Second place. (Qin Louyue/Photo by China News Service, Getty Images)
The second place player is not surprising. Compared with the N95 mask, the relative droplet count of the three-layer surgical mask has a larger change, ranging from 0 to 0.1. These masks are also medical grade and can act like a boxer (underwear instead of Mike Tyson). They can hide most things inside, but from time to time they will let some things slip outside.
Ranked third and fourth are polypropylene masks: cotton-polypropylene-cotton masks and 2-layer polypropylene apron masks. Their relative droplet count is about 0.1, slightly higher than that of surgical masks.
The fifth to eleventh finishers included four different two-layer cotton pleated masks and one single-layer cotton pleated mask. These fall within the relative drop count range of zero to 0.4. So they caused some sheets to move around.
The seventh type is another N95 mask: a mask with an exhalation valve. This records relative drop counts ranging from 0.1 to 0.2. When using an N95 mask, first check whether it has an exhalation valve that bypasses the filter. The N95 mask with this valve is a bit like those one-way perspective windows. It only provides comprehensive protection in one direction. Although a mask can protect you, you may eventually expose yourself to others. Let me rephrase it. You can still let other people touch anything that might come out of your mouth and nose.
This valve allows air to pass through the mask from the wearer’s mouth and nose without passing through the main filter. Although this may make it easier to exhale, at the same time, it may also allow the virus to enter the other side. If the sole purpose of the mask is to protect you from possible influences in the air, then this exhalation valve may be fine. One example is the use of building materials in the construction of the Temple of Justin Bieber. But such a mask will not protect others from your injury like an N95 mask without an exhalation valve. This is why medical staff do not tend to use N95 masks with exhalation valves.
The ninth place is a single-layer Maxima AT mask with an average relative droplet count of 0.2, and its range is not higher than 0.3.
The 12th place is the knitted mask. Not surprisingly, the range of this mask is very large, from about 0.1 to a relative drop count of just under 0.6. Knitted masks often resemble politicians¡¯ speeches and are riddled with defects. The hole can let a lot of things pass through the other side.
Then there are two masks, which may actually be worse than not wearing a mask at all. In the 13th position, the bandana ranges from 0.2 to 1.2. This indicates that, in some cases, applying Axl Rose to the nose and mouth may allow more droplets to pass through than with the naked nose and mouth. how can that be? How can a large handkerchief produce more water droplets? Well, the answer is to cut reality.
Depending on its arrangement, construction, and positioning, the handkerchief may actually cut larger droplets into more and smaller droplets. Think about the last time you tried to push a piece of Parmesan through a screen window (because who hasn’t tried it). Smaller droplets are worse than large droplets because they can float in the air for longer and may pass through the human respiratory tract more easily.
The last finisher explained why you might not want to be fleeed when buying a mask. The wool mask ranks 14th on the list, even worse than wearing nothing. Experiments have shown that you can still create considerable storms while wearing a wool mask. The average relative droplet count is 1.1. This means that, on average, people wearing wool masks produce more droplets than when their noses and mouths are fully exposed. This may not necessarily apply to all wool masks. Nonetheless, just like bandannas can do in some cases, this woolen mask turns big problems into more small problems. This is not good.
Of course, this research is far from perfect and has many limitations. It did not test all possible versions of different masks and how they are worn. For example, not all N95 masks with exhalation valves and knitted or wool masks are not necessarily the same. The publication did not provide a detailed description of each mask and how to wear each mask. And, who knows what will happen, different faces and ways of speaking wear masks.
In addition, spraying droplets does not necessarily mean that you are spraying the virus. Each droplet may not be enough to infect other people’s Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2). Of course, “Everyone, stay healthy” is not the only thing you say to other people. For example, what would happen if you were to say something like “this is how it is”? Therefore, please wear a mask full of salt to get all the research results.
Nonetheless, all this reminds people that public health advice has its nuances and related details. It is not enough to cover the face. Covering your face with sweat, chocolate, pizza sauce, or shame is not enough. Just using any mask will not work. For example, don’t wear Lone Ranger masks or masks that don’t really block the flow of things from the nose and mouth appear at Costco. Even if you seem to be covering your nose and mouth, you may not adequately protect others. Therefore, be cautious when buying masks. Choose the correct mask. After all, you don¡¯t say, “Give me some pizza, any kind of pizza,” do you?
I am a writer, journalist, professor, system modeler, computing and digital health expert, avocado eater, and entrepreneur, but not always in this order. Currently, I am
I am a writer, journalist, professor, system modeler, computing and digital health expert, avocado eater, and entrepreneur, but not always in this order. Currently, I am a professor of health policy and management at the School of Public Health of the City University of New York (CUNY), an executive director of PHICOR (@PHICORteam), a professor at the Johns Hopkins Carey School of Business, and the founder and CEO of Symsilico. My previous positions include serving as Executive Director of the Global Obesity Prevention Center (GOPC) at Johns Hopkins University, Associate Professor of International Health at the Johns Hopkins Bloomberg School of Public Health, Associate Professor of Medicine and Biomedical Informatics at the University of Pittsburgh, Quintiles Transnational Senior manager of Montgomery Securities, engaged in biotechnology equity research, and co-founded a biotechnology/bioinformatics company. My work includes developing calculation methods, models, and tools to help health and healthcare decision makers on all continents (except Antarctica), and I have received various sponsors such as the Bill and Melinda Gates Foundation, NIH, AHRQ, etc. Support, CDC, UNICEF, USAID and Global Fund. I have written more than 200 scientific publications and three books. Follow me on Twitter (@bruce_y_lee), but don¡¯t ask me if I know martial arts.
Post time: Jun-22-2021
