Cover Your Nose! Sneeze 'Gas Clouds' Travel Far Further Than Previously Thought (VIDEO)

Feel a sneeze coming on? Then you'd better cover your nose and mouth for everyone else's sake. It turns out that coughs and sneezes create gas clouds that keep potentially infectious droplets aloft for far longer than researchers previously realized.

"When you cough or sneeze, you see the droplets, or feel them if someone sneezes on you," said John Bush, one of the researchers, in a news release. "But you don't see the cloud, the invisible gas phase. The influence of this gas cloud is to extend the range of the individual droplets, particularly the small ones."

In this latest study, the scientists used high-speed imaging of coughs as sneezes. They also used laboratory simulations and mathematical modeling in order to chart coughs and sneezes. In the end, they found that smaller droplets traveled far further than larger ones, and that the gas cloud from a sneeze resembled a puff emerging from a smoke stack.

"If you ignored the presence of the gas cloud, your first guess would be that larger drops go farther than the smaller ones, and travel at most a couple of meters," said Bush in a news release. "But by elucidating the dynamics of the gas cloud, we have shown that there's a circulation within the cloud-the smaller drops can be swept around and resuspended by the eddies within a cloud, and so settle more slowly. Basically, small drops can be carried a great distance by this gas cloud while the larger drops fall out. So you have a reversal in the dependence of range on size."

The findings reveal the importance of covering up when you cough or sneeze. They also have implications for the way hospital ventilation systems are currently designed. Currently, the researchers are developing additional tools and studies in order to extend their knowledge on the subject.

"We're trying to rationalize the droplet size distribution resulting from the fluid breakup in the respiratory tract and exit of the mouth," said Lydia Bourouiba, one of the researchers, in a news release. "That requires zooming in close to see precisely how these droplets are formed and ejected."

Want to see the research for yourself? Check out the video below, courtesy of YouTube.

The findings are published in the Journal of Fluid Mechanics.