WASHINGTON Study :
A high-quality cloth mask consisting of three layers could allow filtration as high as 90 percent. Crucially, that accounts for incoming particles as well as outgoing ones.
including masks made of cloth, are highly effective in protecting the people who wear them as well as those around them, according to a new study from Linsey Marr, a leading aerosol scientist at Virginia Tech University.
“Filtration works both ways,” Marr said. “If it works for source control,” she said during a media presentation on Monday — that is, if the mask filters out particles coming from the wearer’s mouth .
“it’s going to work pretty well for exposure reduction to protect the wearer also.”
Testing 11 different types of face coverings (nine cloth masks made from coffee filters, cotton and other materials, a surgical mask and a face shield), Marr and co-author Jin Pan found that many of the materials they “challenged” with particles meant to simulate the coronavirus exhibited a 75 percent filtration capacity.