Face masks and face coverings can prevent the wearer from transmitting the COVID virus to others and offer the wearer protection. Numerous studies have shown that {Mod’s Edit: Advertising URL removed, the ‘member’ was just a shill poster of spam and has been banned with all posts deleted, but this post has been left minus the ad link because the content is pertinent. Stay safe everyone} can contain droplets expelled from the wearer. They are responsible for the majority of the transmission of bacteria and viruses. This 'source control' method reflects a shift in thinking from a 'medical' perspective to a 'public health' perspective (will it reduce community transmission and risk for everybody?).
Several people with COVID are unaware they are carrying the coronavirus. It is predictable that 40% of persons with COVID are asymptomatic but possibly able to transmit the virus to other people. In the absence of extensive screening tests, you have no way of identifying several people who are silently sharing the coronavirus in their community.
Universal face mask use can significantly reduce COVID virus transmission in the community by preventing anyone, comprising those who are unwittingly carrying the virus, from spreading it to others. Disease modeling suggests that face masks worn by significant portions of the population joined with other measures, can substantially reduce COVID case numbers and deaths.