Indian public sector banks had 'worst phase' under Manmohan, Rajan: Sitharaman

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.

New Delhi, April 6: India recorded the highest number of 704 positive cases of coronavirus in the past 24 hours, said the Union Ministry of Health and Family Welfare on Monday.

With these new cases, the total number of COVID-19 positive cases in India have now climbed to 4,281.

Total deaths stand at 111 including 28 new deaths. So far, 318 COVID-19 patients have been cured across the country.

Mumbai, Mar 28: Doctors in Mumbai have not been spared by the novel coronavirus. As Mumbai’s count for Covid-19 cases went up to 58, an octogenarian doctor from Saifee Hospital passed away on Friday. He was a suspected case of coronavirus with co-morbid conditions like diabetes and had a pacemaker implanted, said a press release from the state health department.

As per a statement from Saifee Hospital, he underwent a CT scan at Saifee Hospital and was diagnosed positive for Covid-19. The surgeon was transferred to the special isolation facility at PD Hinduja Hospital where he subsequently died. Behranwala’s close relatives had come down from England and were under quarantine.

In a statement, Saifee Hospital, where Behranwala underwent CT scan, said, "All containment and surveillance measures have been implemented to ensure the safety of our staff patients and visitors. Saifee Hospital reiterates that the Hospital is fully operational," said Dr Vernon Desa, Director (Medical governance and clinical compliance) Saifee Hospital.

In the second case, an Andheri-based doctor, aged 53, has been tested positive along with his 43-year-old wife and 20-year-old daughter. The family doesn’t have a travel history. The doctor reportedly came in contact with the virus through a patient. MCGM has taken samples of 60 patients who came in contact with the doctor. "As of now, no patient from his contact has tested positive," Assistant Commissioner, Vishwas Mote.

Another doctor who practiced at Vakola tested positive after he came in contact with a person having travel history to Italy, later tested positive. The doctor has been admitted at Raheja hospital and samples of his close contact have been taken.