People exercising outdoors during the coronavirus lockdown should apply social-distancing rules that are stricter than those officially recommended, a new study suggests.

Researchers at KU Leuven and at the Eindhoven University of Technology created simulations showing how those working out outdoors could be exposing themselves to the new coronavirus (Covid-19) even when staying 1.5 metres apart.

The simulations show that the respiratory droplets of someone potentially infected with the virus could come into contact with anyone located behind them by travelling through what he referred to as a slipstream.

“When you are moving —running, cycling, walking— you are actually creating an area behind you that is often called a slipstream, or a wake,” Study Coordinator Bert Blocken told The Brussels Times.

Blocken said that slipstreams could be described as something similar to a vacuum or drag effect which occurred when the regular airflow was disturbed by someone who was in motion.

“When people speak, exhale, cough or sneeze they generate droplets, and while the largest droplets tend to fall to the ground first, the smaller ones can remain in the air a bit longer, so it is important that a person who is behind another does not walk into this cloud of droplets,” Blocken said.

While slipstreams can sometimes be as long as 10 to 15 metres, Blocken said that they remained quite narrow and noted that respiratory droplets tended to evaporate quite quickly.

“The recommended distance of 1.5 metres is very effective when people are moving slowly, but the situation is different when it comes to the active movement in sports,” he said.

Source
Gabriela Galindo
The Brussels Times