The research: When a person violently sneezes or coughs, he release a gas cloud filled with fluid, or droplets. Previous science suggests that small droplets don’t travel as far as large droplets (both of which get released during a sneeze) because a larger size means more momentum. But that’s not what lead author Lydia Bourouiba, an assistant professor of mathemetics at the Massachusetts Institute of Technology, and her team found. After looking at high-speed images of sneezes and coughs, as well as conducting lab experiments and mathematical models, Bourouiba found small droplets travel up to 200 times further than larger ones (think centimeters versus meters)—and suspend in the air indefinitely. Should these droplets suspend near, say, an air conditioner, they can be transmitted from building to building, she says. “This work is ongoing, but it’s the first step in understanding contact illness and disease, as well as evidence to explore the efficiency of ventilation systems in places like hospitals,” she says. What it means: You can get sick without ever coming into contact with the host. However, not all sneezes are created equal, says Bourouiba. “Even when you’re exhaling, you’re emitting the gas cloud [of droplets],” she says. The trouble is when that gas includes pathogens from a viral or bacterial infection. The bottom line: When sick, remember to cover your mouth and nose with a tissue. No tissue? Sneeze or cough into the crook of your elbow, not your hands. “Sneezing into your elbow may break up the coherence of the cloud, dividing the number of droplets and reducing their [travel] range,” Bourouiba says. More from Prevention: 10 New Ways To Avoid Getting Sick
