Researchers at MIT in the US have used a high speed imaging camera to show that a sneeze carrying the Covid-19 virus can travel up to 8m. This is four times the distance previously predicted and has significant implications for social distances and the design of equipment.
While MIT has suspended its operations on campus, research critical to understanding and limiting the spread of Covid-19 continues This includes the research group of Associate Professor Lydia Bourouiba in the Department of Civil and Environmental Engineering.
Her team at the Edgerton Center at MIT is using a high-speed imaging video camera (left) to accurately measure how far a sneeze travels.
The Phantom v2512 camera is on long-term loan from manufacturer Vision Research in New Jersey and can capture the movement of the 5 micron particles in a cough or sneeze at thousands of frames per second.
The V2512 camera uses a proprietary CMOS sensor with a 28 micron pixel size and 12bit colour depth to capture images at 25,700 fps at 1280 x 800 or 1 million fps at 256 x 32 and 265ns minimum resolution. Data is stored in up to 288Gbytes of RAM and there is 25 Gpixel/s of throughput via 10Gb Ethernet interfaces to an 8TB CineMag data storage system.
The recent work at the lab showed that the droplets from a cough spread 4 to 5m (13 to 16 feet) and a sneeze can spread droplets up to 8m (26 feet). The results were published in the Journal of the American Medical Association in a paper titled “Turbulent Gas Clouds and Respiratory Pathogen Emissions: Potential Implications for Reducing Transmission of Covid-19.”
“Whereas previous modeling might have suggested that 5-micron droplets can travel only a metre or two—as we’ve heard about the new coronavirus—her work suggests these same droplets can travel up to 8 metres when taking into account the gaseous form of a cough,” said the lab.