People across america are wearing Masks For Coronavirus in an effort to curb transmission of the coronavirus. But there isn’t enough data to know for sure whether such cloth masks can prevent an infected person from spreading the virus to someone else, experts say.
Inside the face of evidence that the coronavirus may spread by talking and breathing, on top of coughing or sneezing, the U.S. Centers for Disease Control and Prevention recommended April 3 that people cover their faces with cloth or fabric when going out in public areas.
Cloth may cut down on some large respiratory droplets from a cough or sneeze, but it’s unclear whether it will also catch smaller droplets called aerosols which can be released by just breathing or talking.
Cloth masks, as well as surgical masks, are designed to protect others from virus spread from the mask wearer, not the opposite. Those infected with the virus which induces COVID-19 can transmit it to others before they begin showing symptoms (SN: 3/13/20). If the masks are worn as a general habit, they try to prevent people who are unaware they are sick from unwittingly transmitting the virus to others. Wearing a mask is not intended to be a substitute for social distancing, handwashing and other efforts.
Scientists and journalists share a core belief in questioning, observing and verifying to achieve the reality. Science News reports on crucial research and discovery across science disciplines. We must have your financial support to make it happen – every contribution is important.
But you can find few studies evaluating the effectiveness of Masks For Coronavirus at preventing respiratory diseases from spreading, researchers through the U.S. National Academies of Sciences, Engineering and Medicine wrote within an April 8 letter towards the White House Office of Science and Technology Policy.
People who do exist suggest that fabric masks may capture large respiratory droplets, like those from a cough or a sneeze. Those made from various kinds of cloth use a wide-ranging capacity to filter virus-sized particles, with a trade-off between filtration and capacity to breathe.
In a single study, a mask that used 16 layers of handkerchief fabric managed to filter out 63 percent of 300-nanometer-sized particles. (The coronavirus is between 50 to 200 nanometers in diameter.) But that mask was harder to breathe with in contrast to thick, tight-fitting N95 respirators, often found in hospitals, that can block minuscule particles. Wearing a cloth mask using that many layers will be uncomfortable and may “cause some to pass through out,” they wrote inside the letter.
See all of our coverage in the 2019 novel coronavirus outbreak
Surgical masks are somewhat less mysterious. Those Face Masks For Coronavirus may help reduce transmission of influenza and seasonal coronaviruses that induce common colds from individuals with symptoms, researchers report April 3 in Nature Medicine. Researchers quantified the volume of virus exhaled by participants both with and without a surgical mask over thirty minutes.
Those masks significantly reduced the volume of detectable influenza virus in respiratory droplet particles, as well as the volume of seasonal coronaviruses in aerosols.
Regardless of how well they work, the success of cloth or surgical masks at protecting others is dependent upon whether people wear the gear properly – including keeping it in place – and ensuring it doesn’t get too wet. Moisture, such pqcish from breathing, can trap virus in a mask and make it a strong way to obtain contamination when the wearer takes them back.
Even though the evidence for fabric masks is sparse, health officials should still persuade folks to use face masks, other researchers write in an April 9 analysis within the BMJ. Limited protection could still save lives. “As with parachutes for jumping away from aeroplanes, it is time to act” without waiting for evidence, the authors say.