the point of the article is... the mask literally does nothing.
especially the cloth ones.
there is no science supporting the concept. none.
if you’re unsure, go into an elevator, fully dressed, with a bunch of people wearing masks.
fart.
people will smell it.
thru your cloth underwear.
thru your dense cloth pants.
and thru their cloth mask.
if masks worked, they wouldn’t smell it.
The difference from viruses in water droplets and human flatulence is chemistry. A fart is composed of about 59 percent nitrogen, 21 percent hydrogen, 9 percent carbon dioxide, 7 percent methane and 4 percent oxygen. Only about one percent of a fart contains hydrogen sulfide gas and mercaptans, which contain sulfur, and the sulfur is what causes the stink. The type of mask to filter such a gas, called a gas mask, might eliminate the sulfur smell. The problem with such masks is they all have a valve to allow you to expel air out. So, if you had garlic in your breath, the people in the elevator would smell it.
An experiment to try is to eat some garlic, put on your mask and see if people can smell the garlic in your breath.