The tight fit of the mask to the face and the use of two masks instead of one significantly reduces the likelihood of human contact with the coronavirus, according to the results of laboratory experiments.
The federal Centers for Disease Control and Prevention (CDC) experimented with masks in January.
The results of one experiment showed that the medical mask blocked 42 percent of the particles from the simulated cough, while the sheet mask blocked 44.3 percent.
If they are used together, then such a combination retains 92.5 percent of the phlegm particles from the cough.
In another experiment, researchers tried to simulate the spread of COVID-19 while breathing when one or two people were properly wearing masks.
In the first scenario, when only one aerosol source wore a mask, they found that coronavirus exposure decreased 82.2 percent with a double mask, and 62.9 percent with a tightly fitted and tied single surgical mask.