Sajjan Kumar resigns from Congress, writes to Rahul

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.

The Shopping Centres Association of India (SCAI) on Monday said the sector has lost over Rs 90,000 crore in the last two months, owing to the lockdown, and market players need much more than the repo rate cut and the loan moratorium extended by the RBI.

In a statement, the industry body said that the Reserve Bank of India's (RBI) relief measures are not adequate to support the liquidity needs of the industry.

According to the SCAI, there is a common misconception that the shopping centres' industry is centred around metros and large cities with investments only from large developers, private equity players and foreign investors.

"However, the fact is that most malls are part of the SMEs or standalone developers. i.e. more than 550 are single owned by standalone developers out of the 650-odd organised shopping centres across the country and there are 1,000+ small centres in smaller cities," it said.

Amitabh Taneja, Chairman of SCAI said: "The organised retail industry is in distress and has not earned anything since the lockdown and their survival is at stake. While the extension of the loan moratorium talks about some relief on repayment but won't help the industry in liquidity."

He said that a long term beneficial plan from the government is much required to revive the sector.

"Being the most safe, accountable, and controlled environment, unfortunately, malls have not been permitted to open which will lead to job losses and might even shut shops for a lot of mall developers," Taneja said.

In its representations to the Centre and the Reserve Bank of India, the association has also pointed out that, in absence of financial package and stimulus from the RBI, over 500 shopping centres may go bankrupt, that may lead to the banking industry staring at NPAs of Rs 25,000 crore.

The industry body has put forward its recommendations and requests to the government. It had sought moratorium till March 2021 at the least in terms of repayment of bank loans, interest, EMI and so on, without levy of any penalties or penal interest.

It has also sought a one-time loan restructuring with lower rates of interest, permitted for shopping centres and a facilitative and forward-looking support provision of short-term financing options for a period of six to 12 months, at lower interest rates, to meet the increased working capital requirements.

Among other relaxations, it had also appealed for GST rebates to offset the losses on account of and for the period of closure of business.

It also said that interest rates should be brought down to "manageable levels" of 5-6% in view of the precarious financial situation.

Six months since the new coronavirus outbreak, the pandemic is still far from over, the World Health Organization said Monday, warning that "the worst is yet to come".

Reaching the half-year milestone just as the death toll surpassed 500,000 and the number of confirmed infections topped 10 million, the WHO said it was a moment to recommit to the fight to save lives.

"Six months ago, none of us could have imagined how our world -- and our lives -- would be thrown into turmoil by this new virus," WHO chief Tedros Adhanom Ghebreyesus told a virtual briefing.

"We all want this to be over. We all want to get on with our lives. But the hard reality is this is not even close to being over.

"Although many countries have made some progress, globally the pandemic is actually speeding up.

"We're all in this together, and we're all in this for the long haul.

"We will need even greater stores of resilience, patience, humility and generosity in the months ahead.

"We have already lost so much -- but we cannot lose hope."

Tedros also said that the pandemic had brought out the best and worst humanity, citing acts of kindness and solidarity, but also misinformation and the politicisation of the virus.

In an atmosphere of global political division and fractures on a national level, "the worst is yet to come. I'm sorry to say that," he said.

"With this kind of environment and condition, we fear the worst."