Skip to main content

New story in Health from Time: When it Comes to Homemade Masks, the Number of Layers Matters, Study Says



With medical grade masks still in short supply and badly needed at hospitals and other care centers, many Americans have turned to a variety of other options to help slow the spread of COVID-19, from hand-sewn facial coverings to bandanas and everything in between. But it turns out that when it comes to preventing viral transmission, not all masks are created equal, according to a new study.

In the study, published Thursday in the journal Thorax, researchers pitted three kinds of facial coverings against one another: a single-layer “no sew” mask, a two-layer variety made to specifications from the U.S. Centers for Disease Control and Prevention (CDC), and a three-layer surgical mask. Using LED lights, a high-speed camera and a healthy volunteer willing to have their nose repeatedly ticked with a tissue, each variety of facial covering was tested to see which best contained droplets generated from speaking, coughing and sneezing, with the idea that better containment suggests better efficacy in terms of curbing transmission.

“The COVID-19 pandemic and the need for community face masks has raised questions about whether you can just throw a scarf over your face, or whether you should use a better designed cloth mask,” says Raina MacIntyre, a professor of global biosecurity at the University of New South Wales Sydney, and one of the study’s authors.

The result? The surgical mask did the best job overall, but the two-layer CDC mask was still “significantly better” at containing droplets than the single-layer covering. However, the researchers added, “even a single-layer face covering is better than no face covering.”

The results were somewhat unsurprising. Surgical masks are made of multi-layered polypropylene with a water-resistant outer layer, and they’re regulated based on their ability to catch droplets, MacIntyre explains. And the researchers knew from prior studies that cloth masks with more layers generally perform better. “In truth you probably need at least 3 layers,” says MacIntyre. Other factors, like the material, design, fit, and how frequently a mask is washed, also make a difference.

This new study follows a similar effort last month, which found that commercially available cone-style masks and quilted, multi-layer homemade masks that were properly fitted did the best job of containing respiratory droplets, while “loosely folded face masks” and bandanas “provide minimal stopping capability for the smallest aerosolized respiratory droplets.”

Still other studies have the need for facial coverings abundantly clear. Research published in June found that mask mandates in U.S. states were associated with faster declines in daily COVID-19 case growth, estimating that mask rules prevented up to 450,000 cases through late May. A different study, also published in June, predicted that the U.S. could avoid more than 30,000 coronavirus-related deaths though October if at least 95% of people wear masks in public, while another study found that mask wearing could reduce transmission risk from about 17% to roughly 3%.

Of course, the comparative efficacy of various types of facial coverings doesn’t matter if people aren’t covering their faces to begin with. While some cities and states have issued mandatory mask rules, many have not, and the Trump Administration has been reluctant to issue a national mandate. The issue has been politicized across the U.S., perhaps best illustrated by Georgia governor Brian Kemp’s July 16 lawsuit challenging Atlanta’s mask rules and other restrictions despite a worsening outbreak across the state.

Still, most registered U.S. voters now support statewide mask mandates, according to a Politico poll released Wednesday. For those committed to wearing face coverings in order to help keep themselves and others safe, it’s important to know that just tucking your face into your t-shirt might not cut it.

“The main message is that the design of your cloth mask matters—more layers is better than just one layer,” says MacIntyre. She recommends making masks with a water-resistant fabric, like polyester, for an outer layer, as well as having at least three layers and ensuring a good facial fit. “Most importantly,” she adds, “always use a clean mask and wash your used mask daily.”

Labels:

Popular posts from this blog

New story in Health from Time: Here’s How Quickly Coronavirus Is Spreading in Your State

The novel coronavirus pandemic is a global crisis, a national emergency and a local nightmare. But while a great deal of the focus in the U.S. has been on the federal government’s response, widely criticized as slow and halting , the picture on the ground remains very different in different parts of the country. A TIME analysis of the per capita spread of the epidemic in all 50 states and Washington, D.C. found considerable range in the rate of contagion, and, in some parts of the country, a significant disparity compared to the national figure. The U.S., unlike nations such as South Korea and now Italy , has yet to show signs of bringing the runaway spread of the virus under control. However, while no single state is yet showing strong signs of bending the curve , some are faring much worse than others. The following graphic plots the rise in the total confirmed cases of COVID-19 per 100,000 residents in each state, plotted by the day that each state reported its first case.
Read more

New story in Health from Time: We Need to Take Care of the Growing Number of Long-term COVID-19 Patients

On July 7, 2020, the Boston Red Sox pitcher Eduardo Rodriguez tested positive for the new coronavirus. He was scheduled to start Opening Day for the Sox, but the virus had other plans— damaging Rodriguez’s heart and causing a condition called myocarditis (inflammation of the heart muscle). Now the previously fit 27-year old ace left-hander must sit out the 2020 season to recover. Rodriguez is not alone in having heart damage from SARS-CoV-2, the virus that causes COVID-19. In a new study done in Germany, researchers studied the hearts of 100 patients who had recently recovered from COVID-19. The findings were alarming: 78 patients had heart abnormalities, as shown by a special kind of imaging test that shows the heart’s structure (a cardiac MRI), and 60 had myocarditis. These patients were mostly young and previously healthy . Several had just returned from ski trips. While other studies have shown a lower rate of heart problems—for example, a study of 416 patients hosp
Read more

New story in Health from Time: U.S. Inmates ‘Mistakenly’ Received COVID-19 Stimulus Checks. Now, the IRS Wants That Money Back

(BOISE, Idaho) — Hundreds of thousands of dollars in coronavirus relief payments have been sent to people incarcerated across the United States, and now the IRS is asking state officials to help claw back the cash that the federal tax agency says was mistakenly sent. The legislation authorizing the payments during the pandemic doesn’t specifically exclude jail or prison inmates, and the IRS has refused to say exactly what legal authority it has to retrieve the money. On its website, it points to the unrelated Social Security Act, which bars incarcerated people from receiving some types of old-age and survivor insurance benefit payments. “I can’t give you the legal basis. All I can tell you is this is the language the Treasury and ourselves have been using,” IRS spokesman Eric Smith said. “It’s just the same list as in the Social Security Act.” Read more: ‘A Double Whammy.’ Those Who Most Need The $1,200 Stimulus Checks May Wait the Longest To Get Them Tax attorney Kell
Read more