In a paper called “Filtration Performance of FDA-Cleared Surgical Masks,” the scientists tested five surgical mask brands. Four of the five masks allowed 15 percent or more of 100-nanometer (virus-sized) to 1 micron-sized particles through. Two of the five allowed more than half of those particles through.
Surgical masks were designed to stop sweat and large droplets of saliva from falling into a patient during surgery not protect against viruses to the wearer. People who think they are effective are wrong but the need education not a justification to not wear a mask at all
