This may create enough air turbulence to push a viral particle from landing on your face and mucous membranes.

CNN: Commentary: Flu and your health on a plane

When mucous membranes dry out, they are far less effective at blocking infection.

WSJ: Where Germs Lurk on Planes

Lesions also develop in the mucous membranes of your nose and mouth and quickly turn into sores that break open, spreading the virus into your saliva.

CNN: Smallpox

Mstislav, champion of this episode, reasonably pointed out that any droplet of the pollutant we exported from the Den was destined for circulation and, ultimately, our mucous membranes.

NEWYORKER: Lostronaut