(PTI) Respiratoey droplets travel between eight to 13 feet before they start to evaporate or escape, without wind and depending on the ambient condition, according to researchers who suggest that physical distancing greater than six feet may be essential to prevent Coronavirus transmission.
Researchers from the Indian Institute of Science noted that it is well established that the Coronavirus transmitted via respiratory droplets that infected people eject when they talk, cough or sneeze.
The research team developed a model for the early phase of a Coronavirus like pandemic using the evaporation and aerodynamics characteristics of respiratory droplets.
The research was published in the journal Physics of Fluids, modelled the pandemic dynamics with a reaction mechanism, wherein each reaction has a rate constant obtained by calculating the droplet collision frequency.
The researchers then compared the droplet cloud ejected by a COVID-19 infected person to the one by a healthy person.
The normal size of the water droplet, it's lifetimes are, the distance it travels, therefore all important factors that we calculated using conservation of mass, momentum, energy and species, said Swetaprovo Chaudhuri from the University of Toronto in Canada.
The model could be used to estimate approximately how far the droplets can travel, how long they can survive, said Chaudhari, one of the authors of the research.
He added the actual situation could be complicated by air-recirculation, wind, turbulence and other effects.
Without complicated situations like wind and depending on the ambient condition, we found droplets travel between eight to 13 feet before they evaporate or escape, said Abhishek Saha, a co-author, from the University of Calfornia, San Diego in the US.
This findings shows that social distancing at perhaps greater than six feet is essential, according to the researchers. The initial size of the longest surviving drolets is in the range of 18-50 microns, meaning face masks can indeed help, they said.
Though this model is not claiming to predict the exact spread of Coronavirus, but our research shows that droplet evaporation time is highly sensitive to the some factors such as relative humidity and ambient temperature, said Satpathy Basu, study co-author, from IISc.