Modi justifies fielding terror accused Pragya Thakur, conducting I-T raids

Global health experts on Wednesday said novel coronavirus is here to stay for more than a year and called for aggressive testing to prevent its spread.

In an interaction with Congress leader Rahul Gandhi, health experts Professor Ashish Jha and Professor Johan Giesecke talked about the COVID-19 pandemic as part of the series being aired on Congress social media channels.

While Jha exuded confidence that a vaccine will be available in a year's time, Prof Giesecke said India should practice a lockdown that is as 'soft' as possible, as a severe lockdown will ruin its economy very quickly.

"When the economy is opened up after lockdown, you have to create confidence among people," Harvard health expert Ashish Jha told Gandhi.

Jha is a professor of Global Health at TH Chan School of Public Health and Director, Harvard Global Health institute.

He said coronavirus is a '12-18 months' problem and the world is not going to be free of this till 2021.

The expert also called for the need for aggressive testing strategy for high-risk areas.

Gandhi, while interacting with the experts, said life is going to change post COVID-19.

"If 9/11 was a new chapter, this will be a new book," he remarked.

Professor Johan Giesecke, former chief scientist, European Centre for Disease Prevention and Control said India should have a 'soft lockdown'.

"The situation that India is in, I think, you should have a soft lockdown, as soft as possible," he said.

"I think for India, you will ruin your economy very quickly if you have a severe lockdown. It is better, skip the lockdown, take care of the old and the frail...," he noted.

Washington, Apr 23: Air pollution over northern India has plummeted to a 20-year-low for this time of the year, according to satellite data published by US space agency National Aeronautics and Space Administration (NASA).
The US space agency's satellite sensors observed aerosol levels at a 20-year low post the countrywide lockdown, implemented to slow the spread of the novel coronavirus.

"We knew we would see changes in atmospheric composition in many places during the lockdown," said Pawan Gupta, a Universities Space Research Association (USRA) scientist at NASA''s Marshall Space Flight Center. "But I have never seen aerosol values so low in the Indo-Gangetic Plain at this time of year," added Mr Gupta.

Acting Assistant Secretary of State for South and Central Asia Alice G Wells tweeted, "These images from NASA were taken each spring starting in 2016 and show a 20-year low in airborne particle levels over India. When India and the world are ready to work and travel again, let's not forget that collaborative action can result in cleaner air."

The data published with maps show aerosol optical depth (AOD) in 2020 compared to the average for 2016-2019. Aerosol optical depth is a measure of how light is absorbed or reflected by airborne particles as it travels through the atmosphere.

If aerosols are concentrated near the surface, an optical depth of 1 or above indicates very hazy conditions. An optical depth, or thickness, of less than 0.1 over the entire atmospheric vertical column is considered "clean." The data were retrieved by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite.

In the first few days of the lockdown, it was difficult to observe a change in the pollution signature. "We saw an aerosol decrease in the first week of the shutdown, but that was due to a combination of rain and the lockdown," said Mr Gupta.

Around March 27, heavy rain poured over vast areas of northern India and helped clear the air of aerosols. Aerosol concentrations usually increase again after such heavy precipitation.

"After the rainfall, I was really impressed that aerosol levels did not go up and return to normal. We saw a gradual decrease and things have been staying at the level we might expect without anthropogenic emissions," Mr Gupta said.

On March 25, the Indian government placed its 1.3 billion citizens under a strict lockdown to reduce the spread of COVID-19. The countrywide mandate decreased activity at factories and severely reduced car, bus, truck and airplane traffic. Every year, aerosols from anthropogenic (human-made) sources contribute to unhealthy levels of air pollution in many Indian cities.

Aerosols are tiny solid and liquid particles suspended in the air that reduce visibility and can damage the human lungs and heart.

In southern India though, the story is a little hazier. Satellite data show aerosol levels have not yet decreased to the same extent. In fact, levels seem to be slightly higher than in the past four years. The reasons are unclear but could be related to recent weather patterns, agricultural fires, winds or other factors.

"This a model scientific experiment," Robert Levy, program leader for NASA's MODIS aerosol products, said about the lockdown and its effects on pollution.

"We have a unique opportunity to learn how the atmosphere reacts to sharp and sudden reductions in emissions from certain sectors. This can help us separate how natural and human sources of aerosols affect the atmosphere," Mr Levy added.