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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.

Langkawi, Jan 20: Malaysia will not take retaliatory trade action against India over its boycott of palm oil purchases amid a political row between the two countries, Prime Minister Mahathir Mohamad said on Monday.

India, the world’s largest edible oil buyer, this month effectively halted imports from its largest supplier and the world’s second-biggest producer in response to comments from Mahathir attacking India’s domestic policies.

“We are too small to take retaliatory action,” Mahathir told reporters in Langkawi, a resort island off the western coast of Malaysia. “We have to find ways and means to overcome that,” he added.

The 94-year-old premier of Muslim-majority Malaysia has criticised New Delhi’s new religion-based citizenship law and also accused India of invading the disputed region of Kashmir.

Mahathir again criticised India’s citizenship law on Monday, saying he believed it was “grossly unfair”.

India has been Malaysia’s largest palm oil market for the past five years, presenting the Southeast Asian country with a major challenge in finding new buyers for its palm oil.

Benchmark Malaysian palm futures fell nearly 10% last week, their biggest weekly decline in more than 11 years.

New Delhi is also unhappy with Malaysia’s refusal to revoke permanent resident status for controversial Indian Islamic preacher Zakir Naik, who has lived in Malaysia for about three years and faces charges of money laundering and hate speech in India.

Mahathir said even if the Indian government guarantees a fair trial, Naik faces the real threat of vigilante action and that Malaysia will only relocate the preacher if it can find a third country where he would be safe.

“If we can find a place for him, we will send him out.”

Washington, May 30: US President Donald Trump on Friday said that America is terminating its relationship with the World Health Organization as he blamed it and China for the deaths and destruction caused by the COVID-19 pandemic across the globe.

Stating that the funding of the WHO would now be diverted to other global public health organisations, Trump announced a series of decisions against China including issuing proclamation to deny entry to certain Chinese nationals and tightening of regulations against Chinese investments in America.

"Because they (WHO) have failed to make the requested and greatly needed reforms, we will be today terminating our relationship with the World Health Organization and redirecting those funds to other worldwide and deserving urgent global public health needs, Trump said.