Wearing cap, mask Adityanath sweeps outside Taj Mahal

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.

New Delhi, May 23: The nationwide lockdown will no longer help India in its fight against COVID-19, and in its place community-driven containment, isolation and quarantine strategies have to be brought into play, leading virologist Shahid Jameel said.

The recipient of Shanti Swarup Bhatnagar Prize for Science and Technology also stressed that testing should be carried out vigorously to identify coronavirus hotspots and isolate those areas.

"Our current testing rate at 1,744 tests per million population is one of the lowest in the world. We should deploy both antibody tests and confirmatory PCR tests. This will tell us about pockets of ongoing infection and past (recovered) infection. This will provide data to open up gradually and let economic activity resume," Jameel told PTI in an interview.

He stressed that testing has to be dynamic to continuously monitor red, orange and green zones and change these based on that data.

About community transmission of COVID-19 in India, Jameel said the country reached that stage long ago.

"We reached community transmission a long time ago. It's just that the health authorities are not admitting it. Even ICMR's own study of SARI (severe acute respiratory illness) showed that about 40 per cent of those who tested positive for SARS-CoV-2 did not have any history of overseas travel or contact to a known case. If this is not community transmission, then what is?" he posed.

Lockdown bought India time in its fight against coronavirus, but continuing it is unlikely to yield any further dividend, Jameel said.

"Instead, community-driven local lockdowns, isolations and quarantines have to come into play. Building trust is most important so that people follow rules. A public health problem cannot be dealt with as a law-and-order problem."

The nationwide lockdown, initially imposed from March 25 to April 14, has been extended thrice and will continue at least till May 31. The virus has claimed 3,720 lives and infected over 1.25 lakh people in the country so far.

Jameel has expertise in the fields of molecular biology, infectious diseases, and biotechnology. He is the CEO of Wellcome Trust/Department of Biotechnology's India Alliance and is best known for extensive research in Hepatitis E virus and HIV.

He said COVID-19 will eventually be controlled through herd immunity, which is acquired in two ways – when a sufficient fraction of the population gets infected and recovers, and with vaccination.

"It is estimated that for SARS-CoV-2 at least 60 per cent of the population would have to be infected and recovered, or vaccinated. This will happen over the course of the next few years," Jameel said.

Herd immunity is reached when the majority of a population becomes immune to an infectious disease, either because they have become infected and recovered, or through vaccination. When that happens, the disease is less likely to spread to people who aren't immune, because there just aren't enough infectious carriers.

"India has 1.38 billion people, a population density of about 400/sq km and a healthcare system ranked at 143 in the world. If we allow 60 per cent people to get infected quickly in the hopes of herd immunity, that would mean 830 million infections," Jameel said.

"If 15 per cent need hospitalization that means about 125 million isolation beds (we have 0.3 million). If five per cent need oxygen and ventilatory support, this amounts to about 42 million oxygen support and ICU beds; we have 0.1 million oxygen support beds and 34,000 ICU beds. This would overwhelm the healthcare system causing mayhem," he said.

Jameel said if the population level mortality is 0.5 per cent that would mean 40 lakh deaths. "Are we prepared to pay this price for herd immunity in the short term? Clearly not," he said.

He said it is unlikely that a vaccine would be available by the end of the year.

"Even then, we don't know yet how long it would give protection – weeks, months, one year, a few years? I don't think we will return to pre-coronavirus days for at least the next 3-5 years. This is also a chance to evaluate if we want to return to those unsustainable, environment-damaging ways. COVID-19 is a timely warning to reform our way of living," he said.

Jameel said it is hard to predict but plausible that COVID-19 would return in second or third wave.

"Later waves come when we don't understand the disease and become lax. A comparison to Spanish Flu is not entirely valid because in 1918 no one knew what caused it. No one had seen a virus till the mid-1930s as the electron microscope needed to view those was invented in 1931," he said.

"Today we know a lot more about the pathogen, its genetic makeup, how it transmits and how to prevent it. We need to be sensible and follow expert advice," he said.

If there is any scientific evidence linking deforestation, rapid urbanisation, climate change with pandemics like COVID-19, he said zoonotic viruses -- those that jump from animals to humans -- happen so when wild animal–human contacts increase.

"Deforestation destroys animal habitats bringing them closer to humans. When you cut forests, bats come to roost on trees closer to human habitations. Their viruses in secretions/stool get transmitted to domestic animals and on to humans. This happened clearly with Nipah virus outbreak in Malaysia in 1997-98 from fruit bats to pigs to humans," he said.

"COVID-19 possibly arose in wet animal markets due to dietary habits that bring all kinds of live and dead wild animals in close contact with humans," Jameel added.

Hyderabad, Mar 31: Six people from Telangana who attended a religious congregation in Delhi's Nizamuddin died due to the novel coronavirus, the state government said on Monday.

"Coronavirus has spread among some of those who attended a religious prayer meeting from March 13 to 15 at Markaz in Nizamuddin area in Delhi," according to an official release. "Among those who attended were some persons from Telangana."

Two of the six died at the Gandhi Hospital, one each in two private hospitals, and one each in Nizamabad and Gadwal towns, the statement said, without mentioning the time of their deaths.

The special teams under the collectors have identified the persons who came in contact with the deceased and they are shifted to the hospitals, it said.

Police and paramilitary personnel cordoned off a major area in Nizamuddin West in south Delhi on Monday and over 200 people have been kept in isolation in hospitals after several people who took part in a religious congregation there showed symptoms of coronavirus.

The Telagana government asked those who participated in the prayers to inform the authorities. It will conduct tests and offer treatment to them free of cost, according to the release.

The government also requested the people to alert if they come to know about those who participated in the prayers.

Earlier a separate government release said a person died of COVID-19 in Telangana, taking the toll to two and the total number touched 77 after six fresh cases were reported on Monday.

As many as 13 patients who underwent treatment for the virus were discharged on Monday, a media bulletin on COVID-19 issued by the state government said.

A techie, the first COVID-19 case in Telangana, has been discharged recently. The state now has 61 active cases, the bulletin said.

Chief Minister K Chandrashekar Rao had on Sunday said barring a 76-year-old person, who had other ailments, the other patients were doing well.

Rao had said 25,937 people were under surveillance and being watched by 5,746 teams and they would be out of watch after completing their mandated 14-day quarantine period. He had said all those who are under observation would be out of vigil by April 7 if there are no fresh suspected cases.

"From March 30, their time is nearing completion. After that, they do not need to be under any surveillance. By April 7, we will have a situation of zero... We pray God that we should not get new cases,"