Respectfully disagree dear FReeper.
Hygiene standards of 1917 are in no way comparable with 2020 standards. In 1917, major population centers still dumped raw sewage directly into their potable water source. People didnt wash their hands. Ice was in common use for retail food sales and storage.
Engineers dont get to pick and choose between which laws of physics we follow and ignore. There is no scientific proof masks prevent virus spreads; only regurgitated, non-peer reviewed junk science propaganda pushed by #EnemyOfThePeople media.
For example, a N95 standard mask protects wearer from inhaling 95% of 3 micron sized particles. #WuhanVirus is 1 micron sized. Only a HEPA filter mask with a proven air tight seal or a positive pressure supplied air breathing system followed with proper decontamination of the user afterwards is 100% effective protection against 3 micron particles.
Furthermore, the N95 one way exhalation valve does not filter exhaled breath from #WuhanVirus infected users; if an infected user is coughing up an infected lung, particles as large as 6000 microns are exhaled.
Bandannas and other non-standard face coverings as a virus filter are a cruel joke upon the non-critically thinking people; engineers should fight back against this junk science. Quite frankly, if masks could prevent the spread of a virus particle attached to water vapor, one could wear that mask below 45f dew point and not see exhaled water vapor from their breath.
As with all airborne viruses,100% of the population will eventually become exposed; herd immunity, virus mutations, and host death are the only means that slows virus transmission rates.
Cheers,
OLA