[CharlesWayneCT]

If you are on an airplane with a person not in the end stages of Ebola, you are actually more likely to die of a plane crash, than you are to die of Ebola.

But for some reason, people are not refusing to fly on airplanes.

[smoky415]

Our key findings are as follows. The turbulent multiphase cloud plays a critical role in extending the range of the majority of pathogen-bearing drops that accompany human coughs and sneezes. Smaller droplets (less than 50 mm diameter) can remain suspended in the cloud long enough for the cough to reach heights where ventilation systems can be contaminated (4–6 m). A droplet of diameter dD10 mm evaporates in 0.027 s, during which it would fall a distance of approximately 0.08 mm at a settling speed of approximately 3 mm s􀀀1. It would thus clearly remain suspended in a cough or sneeze cloud metres away from the cougher. Indeed, the cloud model presented in this study predicts that the range of droplets of diameter d 6 100 mm would be extended by a factor of 5 to more than 200 as d decreases from 100 to 10 mm. Moreover, following fallout from the cloud, such small droplets or their associated droplet nuclei can be resuspended by ambient air currents that usually have speeds of the order of 1 cm s􀀀1 (e.g. Melikov & Kaczmarczyk 2012). The ambient conditions also influence the buoyancy of the cloud and so the range of contamination of its suspended droplets. Changing the buoyancy from summer to winter indoor conditions can result in a variation of the range of deposition of the order of metres for the relatively large droplets (diameter d > 50 mm) to dozens of metres for the smallest droplets and droplet nuclei (diameter d < 10 mm). We note also that droplet evaporation can enhance the cloud buoyancy, increasing its vertical momentum and thus the chances of the cloud reaching the ceiling and contaminating the ventilation system.