Muslim girls allegedly forced to remove scarves for II PU exam at Canara College

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.

Udupi, Jun 28: A student appearing for the Secondary School Leaving Certificate (SSLC) exams in Kaup taluk of Udupi district has tested positive for the novel coronavirus (COVID-19) infection.

Officials of the Department of Public Instruction (DPI) and Udupi District Health and Family Welfare Department have confirmed the report. 

The 16-year-old girl had appeared for the Kannada and Mathematics exams on June 25 and 27 respectively. 

Her throat swabs were sent for testing on June 27 after her father tested covid-19 positive. Today she too obtained positive report.  

The student is unlikely to appear for the science paper on June 29.

Meanwhile, health officers have ruled out the possibility of subjecting other students to covid-19 test as all necessary precautions such as physical distancing and usage of sanitization were taken in the examination centre.

New Delhi, Jul 8: India has reported a spike of 22,752 COVID-19 cases in the last 24 hours, taking the country's coronavirus tally to 7,42,417 on Wednesday, informed the Union Ministry of Health and Family Welfare.

Out of the total cases reported, 4,56,830 patients have been cured/discharged from the disease while one patient has been migrated, the Health Ministry informed.

It added that there are 2,64,944 active cases in the country.

482 deaths reported in the last 24 hours due to COVID-19 in the country, taking India's death toll to 20,642.

According to the Union Health Ministry, Maharashtra continues to be the worst affected state reporting 2,17,121 coronavirus cases and 9,250 fatalities.

Tamil Nadu -- the second worst-affected state from COVID-19 -- has a total of 1,18,594 cases and 1,636 deaths due to coronavirus.

While Delhi has a total of 1,02,831 COVID-19 cases including 3,165 deaths.

The Indian Council of Medical Research on Wednesday informed that a total of 1,04,73,771 samples tested for COVID-19 up to July 7. Of these, 2,62,679 samples were tested on Tuesday.