As the world continued with changing restrictions and recommendations surrounding the coronavirus pandemic, rumors continued in late summer 2020 regarding scientific understanding behind the effectiveness of certain face coatings used to reduce COVID-19 transmission. In August, a number of news outlets reported findings from Duke University’s study claiming that they wore “neck gaiters” – stretchy, thin clothing worn around the neck to sometimes cover the face – less for transfer then complete a mask beforehand.
Our investigation found that this assertion was false and largely misreported by some media.
The claim can be traced back to a study published in Science Advances on August 7, 2020. In the course of their research, scientists set out to determine the best methods for testing how to evaluate 14 types of face coverings – not determining which one it is. most effective in protection against transmission. The study was not intended to describe as a modest manual which one masks to wear, but rather how to test their varied effectiveness. Results regarding the effectiveness of each particular face covering were merely a by-product of the study.
A simple and cost-effective method for testing the effectiveness of certain facial coatings is thought to be a crucial element in increasing the understanding of how SARS-CoV-2, the coronavirus responsible for COVID-19, is spread. To this end, the research team turned to optical imaging to “highlight marked differences in the effectiveness of different masks and mask alternatives” that may help stop the spread of respiratory droplets known to contain SARS-CoV-2 and can broadcast during “regular speech.”
Furthermore, by mid-2020 there was still much to be determined about the pathways of infection of COVID-19, the route of transmission, how to use a mask properly, and how the virus can be affected by environmental variables.
For the proof-of-concept study, which is intended to inform future research, a person wearing a mask stood inside a dark closet and spoke in the direction of a laser beam. Respiratory drops were seen as they scattered light from the laser beam capturing a camera from the phone. A simple computer algorithm then counted the drops. Mask testing included a fit N95 mask both with and without valves, surgical masks, various variations of polyester and cotton masks, as well as a bandana, and neck fleece, as well as gaiter. These were then compared to respiratory drops emitted by a person who was not wearing a face mask.
Recently, the research results concluded that the laser beam method for viewing, recording and counting respiratory drops of analyzed face coatings is a quick and easy way to test their effectiveness. But how well each mask worked was not determined —– that would require further, more specific evaluation, stricter testing mechanisms, and greater control over variables. Now other scientists can use the same laser beam method to test specifically on mask effectiveness.
A fit N95 mask was determined to be the most effective, as exactly .1% of drops were transferred. On the other hand, it was shown that larger droplets disperse in smaller dispersion, resulting in a higher droplet count than any other face covering and indeed even a face mask at all.
“We notice that talking through some masks (especially the neck fleece) seems to disperse the largest droplets into a lot of smaller droplets, which explains the apparent increase in droplet count relative to no mask in that case,” the researchers wrote. . “Considering that smaller particles carry air longer than large droplets (larger droplets sag faster), the use of such a mask can be counterproductive.”
Katherine Ellen Foley, a health and science reporter at Quartz, pointed out in a Twitter thread that the research is not without limitations. For starters, test subjects were just talking and not sitting, coughing or breathing heavily. Furthermore, the study counted the number of drops sent through each mask – a finding that is not necessarily equal to risk. In all, the study was intended to inform attempts to improve training on the proper use of masks to determine the safety and effectiveness of reuse of some masks.
“This was just a demonstration – more work is needed to investigate variations in masks, speakers, and how people wear them – but it proves that this kind of test could easily be performed by companies and others who supply masks to them. employees or patrons, ”said study judge Martin Fischer, Ph.D., a chemist and physicist and director of the Advanced Light Imaging and Spectroscopy facility, in a Duke University news release.
Then there is the argument regarding mask material. The researchers only tested gaiters made of fleece. However, different fabrics or materials – such as polyester or cotton – can affect how effective a gaiter is in reducing transmission.
Outside experts, headliners misjudged the findings by saying that it is better not to wear a mask than a neck gear. The Centers for Disease Control and Prevention recommends that people wear masks in public settings and when sitting around people outside their homes, and prove that masks are effective in reducing the transmission of COVID-19 and spraying drops when they cross the nose and mouth wear.
“If everyone wore a mask, we could stop up to 99% of those drops before they reach anyone else,” said Duke University physician Eric Westman. “In the absence of a vaccine or antiviral drug, it is the only proven way to protect others than yourself.”
