However, the normal mask material prevents most of the drops from spreading the virus, it is not enough at close range.
Just wearing a mask is not enough to stop the spread COVID-19 Without social distance.
In The physics of fluids, Through AIP Publishing, researchers have tested how the spread of drops of five different types of mask materials is affected when we cough or sneeze.
Each material tested dramatically reduced the number of droplets dispersed. But at a distance of less than 6 feet, enough drops to cause a potential illness still made it through many materials.
Krishna Kota, an associate professor at New Mexico State University and one of the authors of the article, said, “A mask definitely helps, but even if people are very close to each other, there is a possibility of spreading the virus or contracting.” “It’s not just a mask that will help. It’s both a mask and a distance. “
A device used by researchers to study how masks block simulated respiratory droplets carrying the COVID-19 virus. Credit: Javed Akhtar
At the university, researchers created a machine that uses an air generator to mimic human coughs and sneezes. The generator was used by the camera to blow small liquid particles, such as sneezing and coughing, into the airtight square tube through a laser sheet.
They blocked the flow of drops into the tube with five different types of mask substances – a regular cloth mask, a two-layer cloth mask, a wet two-layer cloth mask, a surgical mask and a medical-grade N-95. Masked.
Each mask occupied most of the drops, starting with the regular cloth mask, allowing about 6.ople% of the dot to go up to the n-mas mask, which closed off 100% of the drops. But at a distance of less than 6 feet, even a small percentage of the dot can be enough to make someone sick, especially if a person with Covid-19 often sneezes or coughs.
A sneeze can carry 200 million small virus particles depending on how sick the carrier is. Even if the mask blocks a large percentage of those particles, the person can escape enough to make someone sick if they are close to the carrier.
“Without a face mask, it is almost certain that many foreign drops will transfer into a sensitive person,” Kota said. “A sensitive person wearing a mask will be protected by reducing the number of foreign airborne air sneezes and cough drops that would otherwise enter a person without a mask. If possible, consideration must be given to minimizing or avoiding face-to-face or further human interactions. “
The study also did not account for leakage from the mask, whether worn properly or improperly, which could increase the number of drops entering the air.
Reference: “Can face masks close-up, face-to-face protect human aviation from aerated sneezes and cough drops? ” The physics of fluids.
DOI: 10.1063 / 5.0035072
