A US professor has dismissed the two-metre distance rule as not enough to give protection from Covid-19, saying it is based on old science.
The Massachusetts Institute of Technology researcher, Prof Lydia Bouroiba, said the two-metre “social distancing” recommendation is too close – and that to avoid the virus, people have to keep much farther – possibly eight metres.
“Although such social distancing strategies are critical in the current time of pandemic, it may seem surprising that the current understanding of the routes of host-to-host transmission in respiratory infectious diseases are predicated on a model of disease transmission developed in the 1930s that, by modern standards, seems overly simplified,” Prof Bouroiba says in her paper published in the Journal of the American Medical Association.
She also warns that besides the cough and sneeze droplets, people have to be wary of “turbulent gas cloud” that traps and carries within it the virus.
“The locally moist and warm atmosphere within the turbulent gas cloud allows the contained droplets to evade evaporation for much longer than occurs with isolated droplets. Under these conditions, the lifetime of a droplet could be considerably extended by a factor of up to 1,000 from a fraction of a second to minutes,” says the professor, who studies the fluid dynamics of disease transmission.