London, May 20: The current physical distancing guidelines of 6 feet may be insufficient to prevent COVID-19 transmission, according to a study which says a mild cough in low wind speeds can propel saliva droplets by as much as 18 feet.
Researchers, including those from the University of Nicosia in Cyprus, said a good baseline for studying the airborne transmission of viruses, like the one behind the COVID-19 pandemic, is a deeper understanding of how particles travel through the air when people cough.
In the study, published in the journal Physics of Fluids, they said even with a slight breeze of about four kilometres per hour (kph), saliva travels 18 feet in 5 seconds.
"The droplet cloud will affect both adults and children of different heights," said study co-author Dimitris Drikakis from the University of Nicosia.
According to the scientists, shorter adults and children could be at higher risk if they are located within the trajectory of the saliva droplets.
They said saliva is a complex fluid, which travels suspended in a bulk of surrounding air released by a cough, adding that many factors affect how saliva droplets travel in the air.
These factors, the study noted, include the size and number of droplets, how they interact with one another and the surrounding air as they disperse and evaporate, how heat and mass are transferred, and the humidity and temperature of the surrounding air.
In the study, the scientists created a computer simulation to examine the state of every saliva droplet moving through the air in front of a coughing person.
The model considered the effects of humidity, dispersion force, interactions of molecules of saliva and air, and how the droplets change from liquid to vapour and evaporate, along with a grid representing the space in front of a coughing person.
Each grid, the scientists said, holds information about variables like pressure, fluid velocity, temperature, droplet mass, and droplet position.
The study analysed the fates of nearly 1,008 simulated saliva droplets, and solved as many as 3.7 million equations.
"The purpose of the mathematical modelling and simulation is to take into account all the real coupling or interaction mechanisms that may take place between the main bulk fluid flow and the saliva droplets, and between the saliva droplets themselves," explained Talib Dbouk, another co-author of the study.
However, the researchers added that further studies are needed to determine the effect of ground surface temperature on the behaviour of saliva in air.
They also believe that indoor environments, especially ones with air conditioning, may significantly affect the particle movement through air.
This work is important since it concerns safety distance guidelines, and advances the understanding of the transmission of airborne diseases, Drikakis said.
Comments
Sure he will pay for such barbaric henious act, just a matter of wait and watch.
Retaliate kill him and supportng RSS leader in same manner.
Uncultured barbarian act...!! Culprit should be hanged in order to put end to these ruthless act.
Shourya diwas part 2 by VHP? India is becoming famous in negative sense day by day, all credit to right extremist hindu groups!
Give them more power, we will become next Taliban, Nazi!!!
That whole area of Indian subcontinent (India, Pakistan, Bangladesh, Sri Lanka etc) is still pretty much brutally primitive. Not only that they have not achieved much in materialistic standards in seven decades of independance but in terms of behavior also, the people on the ubcontinent have remained to be quite primitive !
RSS should be happy today, as one of their cadre has done them proud. RSS has made animals out of humans. This is what RSS wants in India. Great. Bharat Mata ki Ja
Love jihad is a very dangerous practice which is now spreading in whole of India. Though the murder of a lab on the name of love jihad in Rajasthan can not be justified but those responsible for this practice must be identified and sent in jail with exemplary punishment.
Check the original video. The cries of the poor helpless man are still haunting me. How can somebody be so ruthless? Comparing this scumbag to an animal is an insult to whole of animals. As lynching was a common phenomenon by the so-called fully tolerant, totally peace loving Hindus, I felt perhaps it should be the work of few uncivilized religious bigots. Now I wonder the difference between Hindus and the other peace loving religion. If Hindus have muscle power, money power, position and the required resources, they can be one of worst sects or an ideal competitor for the other peace loving religion in this world.
@Bhageeraha Bhaira,
What you said is applicable to all. Many so called "peace lovers" killed poor peopel.
Many Hindus got killed by muslim terrorists. Then no news.
Mr Kumar! Killing is not intolerance. This is terrorism. The word ‘Intolerance’ can be used if someone doesn’t tolerate the smell of your body.
Intolerance... Attack on muslims increasing
Shocking incident
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