[Lydia] Bourouiba, a fluid dynamics scientist at MIT, has spent the last few years using high-speed cameras and light to reveal how expulsions from the human body can spread pathogens, such as the novel coronavirus. Slowed to 2,000 frames per second, video and images from her lab show that a fine mist of mucus and saliva can burst from a person’s mouth at nearly a hundred miles an hour and travel as far as 27 feet. When the sternutation is over, a turbulent cloud of droplet-containing gas can remain suspended for several minutes, depending on the size of the droplet.
Understanding exactly how these clouds travel and disperse is critical to containing infectious respiratory diseases such as COVID-19. Many knowledge gaps remain over how it spreads. Bourouiba’s research highlights an ongoing scientific debate about how the new coronavirus moves through the air, suggesting such airborne transfer may be more likely than previously thought.
Guidance from the U.S. Centers for Disease Control and Prevention, which recommends people stay at least six feet apart from one another, likely falls short because it doesn’t take fluid dynamics into account, Bourouiba says.
Given what Bourouiba’s research shows about the extraordinary distances people can launch respiratory droplets, one of the most important things everyone can do is make sure to cover their nose and mouth when they sneeze or cough.