Canadian study finds 6 feet may not be far enough for physical distancing

A study by Western University suggests the globally recommended six-foot physical distancing rule may not be enough.

The study was completed during the 2017-18 flu season and determined if someone coughs in your direction, the droplets will reach you within three seconds and continue to projectile forward well beyond the recommended six feet.

Western’s Department of Mechanical and Materials Engineering built a ‘cough chamber” to look at the airflows of a cough by a human who was naturally infected with the seasonal flu.

The chamber is a two-metre enclosed cube with an opening and chin rest in the front, which is used as an access point for study participants to cough. Within the cube, a camera and a laser are used to determine the velocity of the expelled droplets from the cough.

“Even when you are 2.5 metres (eight feet) away, the airflow in the cough can still be moving at 200 millimetres a second,” said Eric Savory, Mechanical and Materials Engineering, Western University in a news release. “That means the very fine droplets are going to remain suspended for a long time, even after four seconds.”

Savory worked with virologists at Sunnybrook Hospital in Toronto for the final analysis.

Despite the initial study being completed well before the COVID-19 outbreak, Savory is now transitioning his findings specifically to the pandemic.

He will be collaborating with other departments at the university including the Schulich School of Medicine & Dentistry and Chemical and Biochemical Engineering, to examine the pathways of COVID-19 droplets through the air and analyze different material surfaces in order to verify its survivability under different temperature and humidity conditions.