Wearing a face mask can protect yourself and others from Covid-19, but the type of material and how many fabric layers used can significantly affect exposure risk, found a new study from the Georgia Institute of Technology.
The study measured the filtration efficiency of submicron particles passing through a variety of different materials. For comparison, a human hair is about 50 microns in diameter while 1 millimetre is 1,000 microns in size.
“A submicron particle can stay in the air for hours and days, depending on the ventilation, so if you have a room that is not ventilated or poorly ventilated then these small particles can stay there for a very long period of time,” said Nga Lee (Sally) Ng, associate professor and Tanner Faculty Fellow in the School of Chemical and Biomolecular Engineering and the School of Earth and Atmospheric Sciences, according to a report by Hindustan Times.