Rains lash parts of Saudi Arabia; severe weather claims 14 lives

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.

Jammu, Jan 15: Fresh landslides kept the Jammu-Srinagar National Highway shut for the third consecutive day on Wednesday, leaving over 5000 vehicles stranded.

"There were four fresh landslides in Digdol and Panthiyal belts on the highway in Ramban district. The traffic on the highway remained closed for the third day today", a police officer told PTI.

On Monday, heavy rains triggered shooting of stones in Moumpassi, Digdole and Panthiyal areas, forcing a suspension of the traffic, the official said.

Snowfall in Kashmir side of the highway, including Jawahar Tunnel, since Sunday has resulted in blockade of the highway.

"No fresh traffic was allowed from Nagrota in Jammu for Kashmir", he said.

As a result of the blockade of the highway, over 5000 vehicles remained stranded at various places en route from Lakhanpur in Kathua district to Banihal belt of Ramban district and also on the Kashmir side.

New Delhi, Jul 3: India reported the highest ever single-day spike of 20,903 COVID-19 cases in 24 hours on Friday, said the Union Ministry of Health and Family Welfare.

With these new cases, India's coronavirus tally has risen to 6,25,544 cases of which 2,27,439 patients are active cases while 3,79,892 patients have been cured/discharged/migrated.

379 more deaths due to COVID-19 were reported in the country in the last 24 hours, taking the number of deaths due to the infection to 18,213.

As per the Health Ministry, Maharashtra -- the worst-affected state from the virus -- has a total of 1,86,626 cases including 8,178 fatalities while Tamil Nadu has 98,392 coronavirus cases in the state inclusive of 1,321 fatalities.

Delhi has reported 92,175 cases so far inclusive of 2,864 patients succumbing to the virus.

The Indian Council of Medical Research on Friday said that the total number of samples tested till July 2 is 92,97,749 of which 2,41,576 samples were tested on Thursday.