Going Airborne Accelerates Virus Transmission
Getting a sense of scale from viruses to aerosols to droplets
Virus transmission — WHO’s on first…
It is now December. We have exceeded 330,000 American deaths from COVID-19. Amid this resurgence of the SARS-CoV-2 virus we have heard of yet another possible route of infection: airborne virus. Sounds like the special forces of pathogens: highly trained and lethal viruses who insert themselves behind their host’s front lines by parachuting in on incredibly tiny droplets called aerosols.
What do we know about how this pandemic virus infects us? The World Health Organization (WHO) has acknowledged two primary routes of coronavirus infection so far.
First is what they call respiratory droplets which are droplets we exhale that are greater than 5 µm in diameter (that Greek letter mu means “micro” or one millionth so 5 micrometers or 5 millionths of a meter — I’ll show you exactly how small that is shortly). Droplets larger than 5 µm travel a limited distance before settling to the ground or onto whatever happens to be in its path. In this case, if a person is within…
