We want to thank Dr. Rich Davis, D(ABMM), MLS (@richdavisphd), he is the Clinical Microbiology Laboratory Director at Providence Sacred Heart Medical Center in Spokane, WA, who conducted this study. Check it out!
Two simple demos:
What does a mask do? Blocks respiratory droplets coming from your mouth and throat.
First demo: Dr. Davis sneezed, sanged, talked & coughed toward an agar culture plate with or without a mask. Bacteria colonies show where droplets landed. A mask blocks virtually all of them. (Graphic 1&2)
What about keeping your distance?
Second demo: He set open bacteria culture plates 2, 4 and 6 feet away and coughed (hard) for ~15 seconds. He repeated this without a mask.
As seen by number of bacteria colonies, droplets mostly landed <6 ft, but a mask blocked nearly all of them. (Graphics 3&4)