This, despite the fact that the WHO's June 5, 2020, guidance memo on face mask use states there's no direct evidence that universal masking of healthy people is an effective intervention against respiratory illnesses.
What's more, people are being urged to use cloth masks or bandanas (ostensibly to prevent shortages among health care staff), none of which conform to any kind of quality standards, and according to what little scientific evidence is available have been shown to provide only about half of what little protection you may get from a surgical mask.
SARS-CoV-2 is a beta-coronavirus with a diameter between 60 nanometers (nm) and 140 nm, or 0.06 to 0.14 microns (micrometers). This is about half the size of most viruses, which tend to measure between 0.02 microns to 0.3 microns.
Virus-laden saliva or respiratory droplets expelled when talking or coughing measure between 5 and 10 microns, and it is these droplets that surgical masks and respirators can block.
At present, there is no direct evidence (from studies on COVID- 19 and in healthy people in the community) on the effectiveness of universal masking of healthy people in the community to prevent infection with respiratory viruses, including COVID-19.
For example, N95 masks can filter particles as small as 0.3 microns, so they may prevent a majority of respiratory droplets from escaping. They cannot block aerosolized viruses, however, that are in the air itself. Additionally, many N95 masks only protect the wearer, as they have exhalation ports that allow you to exhale unfiltered air....<<<Read The Full Article Here>>>...
