Fear the "freely evolving turbulent puff cloud"!
It’s well worth your time to check out a great video recently published in NEJM by Dr. Lydia Bourouiba (from the MIT Fluid Dynamics of Disease Transmission Laboratory). Simply entitled “A Sneeze”, the images and videos graphically demonstrate the biological plausibility of the findings Eli describes in his recent post on presenteeism.
In her description, Dr. Bourouiba writes:
"[The video]…shows a turbulent cloud that consists of hot and moist exhaled air, mucosalivary filaments and drops, and residues from droplet evaporation (nuclei). The ejection lasts up to 150 msec and then transitions into a freely evolving turbulent puff cloud. The largest droplets rapidly settle within 1 to 2 m away from the person. The smaller and evaporating droplets are trapped in the turbulent puff cloud, remain suspended, and, over the course of seconds to a few minutes, can travel the dimensions of a room and land up to 6 to 8 m away.”