Counting underway in Gujarat, Himachal Pradesh: BJP takes early lead over Cong

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, Mar 23: The total number of COVID-19 cases in the country rose to 390 on Monday after 30 fresh cases were reported.

The figure includes 41 foreign nationals and the seven deaths reported so far.

Gujarat, Bihar and Maharahstra reported a death each on Sunday, while four fatalities were reported earlier from Karnataka, Delhi, Maharashtra and Punjab, the Union Health Ministry said.

The total number of active COVID-19 cases across the country now stands at 359, while 24 people have been cured/discharged/migrated.

New Delhi, Apr 16: The number of COVID-19 cases in India has reached 12,759, the Health Ministry said on Thursday.

According to the official data, India has 10,824 active cases and 1514 discharged and cured cases. Meanwhile, 420 people have died from the disease which originated in China.

Maharashtra has reported the highest number of cases in the country which stands at 2919, including 295 cured and discharged and 187 deaths.

With 1578 coronavirus cases, Delhi is in the second position of India's tally of corona infected people; followed by Tamil Nadu (1242) and Rajasthan (1023).

Kerala, which reported India's first coronavirus case, has 388 confirmed cases, including 295 cured and discharged and 187 deaths.

On the other hand, Uttar Pradesh and Haryana, that border the national capital, have 773 and 205 cases, respectively.

Chhattisgarh, Chandigarh and Pudducherry have reported 33, 21 and 7 cases respectively. While West Bengal has 231 coronavirus infected people, Odisha has confirmed 60 cases.

The newly carved union territories -- Ladakh and Jammu and Kashmir--- have 17 and 300 cases, respectively.

In the Northeast, 33 people were detected positive for COVID-19 in Assam, which is the worst-affected states in the region. Six corona cases were confirmed from Meghalaya, two each from Manipur and Tripura and one from Arunachal Pradesh. Nagaland remains free from coronavirus till date, said the Ministry.