Modi in Thimphu: Honoured to have a friend like Bhutan

The coronavirus can stay aloft for hours in tiny droplets in stagnant air, infecting people as they inhale, mounting scientific evidence suggests.

This risk is highest in crowded indoor spaces with poor ventilation, and may help explain superspreading events reported in meatpacking plants, churches and restaurants.

It’s unclear how often the virus is spread via these tiny droplets, or aerosols, compared with larger droplets that are expelled when a sick person coughs or sneezes, or transmitted through contact with contaminated surfaces, said Linsey Marr, an aerosol expert at Virginia Tech.

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Aerosols are released even when a person without symptoms exhales, talks or sings, according to Marr and more than 200 other experts, who have outlined the evidence in an open letter to the World Health Organization.

What is clear, they said, is that people should consider minimizing time indoors with people outside their families. Schools, nursing homes and businesses should consider adding powerful new air filters and ultraviolet lights that can kill airborne viruses.

What does it mean for a virus to be airborne?

For a virus to be airborne means that it can be carried through the air in a viable form. For most pathogens, this is a yes-no scenario. HIV, too delicate to survive outside the body, is not airborne. Measles is airborne, and dangerously so: It can survive in the air for up to two hours.

For the coronavirus, the definition has been more complicated. Experts agree that the virus does not travel long distances or remain viable outdoors. But evidence suggests it can traverse the length of a room and, in one set of experimental conditions, remain viable for perhaps three hours.

How are aerosols different from droplets?

Aerosols are droplets, droplets are aerosols — they do not differ except in size. Scientists sometimes refer to droplets fewer than 5 microns in diameter as aerosols. (By comparison, a red blood cell is about 5 microns in diameter; a human hair is about 50 microns wide.)

From the start of the pandemic, the WHO and other public health organizations have focused on the virus’s ability to spread through large droplets that are expelled when a symptomatic person coughs or sneezes.

These droplets are heavy, relatively speaking, and fall quickly to the floor or onto a surface that others might touch. This is why public health agencies have recommended maintaining a distance of at least 6 feet from others, and frequent hand washing.

But some experts have said for months that infected people also are releasing aerosols when they cough and sneeze. More important, they expel aerosols even when they breathe, talk or sing, especially with some exertion.

Scientists know now that people can spread the virus even in the absence of symptoms — without coughing or sneezing — and aerosols might explain that phenomenon.

Because aerosols are smaller, they contain much less virus than droplets do. But because they are lighter, they can linger in the air for hours, especially in the absence of fresh air. In a crowded indoor space, a single infected person can release enough aerosolized virus over time to infect many people, perhaps seeding a superspreader event.

For droplets to be responsible for that kind of spread, a single person would have to be within a few feet of all the other people, or to have contaminated an object that everyone else touched. All that seems unlikely to many experts: “I have to do too many mental gymnastics to explain those other routes of transmission compared to aerosol transmission, which is much simpler,” Marr said.

Can I stop worrying about physical distancing and washing my hands?

Physical distancing is still very important. The closer you are to an infected person, the more aerosols and droplets you may be exposed to. Washing your hands often is still a good idea.

What’s new is that those two things may not be enough. “We should be placing as much emphasis on masks and ventilation as we do with hand washing,” Marr said. “As far as we can tell, this is equally important, if not more important.”

Should I begin wearing a hospital-grade mask indoors? And how long is too long to stay indoors?

Health care workers may all need to wear N95 masks, which filter out most aerosols. At the moment, they are advised to do so only when engaged in certain medical procedures that are thought to produce aerosols.

For the rest of us, cloth face masks will still greatly reduce risk, as long as most people wear them. At home, when you’re with your own family or with roommates you know to be careful, masks are still not necessary. But it is a good idea to wear them in other indoor spaces, experts said.

As for how long is safe, that is frustratingly tough to answer. A lot depends on whether the room is too crowded to allow for a safe distance from others and whether there is fresh air circulating through the room.

What does airborne transmission mean for reopening schools and colleges?

This is a matter of intense debate. Many schools are poorly ventilated and are too poorly funded to invest in new filtration systems. “There is a huge vulnerability to infection transmission via aerosols in schools,” said Don Milton, an aerosol expert at the University of Maryland.

Most children younger than 12 seem to have only mild symptoms, if any, so elementary schools may get by. “So far, we don’t have evidence that elementary schools will be a problem, but the upper grades, I think, would be more likely to be a problem,” Milton said.

College dorms and classrooms are also cause for concern.

Milton said the government should think of long-term solutions for these problems. Having public schools closed “clogs up the whole economy, and it’s a major vulnerability,” he said.

“Until we understand how this is part of our national defense, and fund it appropriately, we’re going to remain extremely vulnerable to these kinds of biological threats.”

What are some things I can do to minimize the risks?

Do as much as you can outdoors. Despite the many photos of people at beaches, even a somewhat crowded beach, especially on a breezy day, is likely to be safer than a pub or an indoor restaurant with recycled air.

But even outdoors, wear a mask if you are likely to be close to others for an extended period.

When indoors, one simple thing people can do is to “open their windows and doors whenever possible,” Marr said. You can also upgrade the filters in your home air-conditioning systems, or adjust the settings to use more outdoor air rather than recirculated air.

Public buildings and businesses may want to invest in air purifiers and ultraviolet lights that can kill the virus. Despite their reputation, elevators may not be a big risk, Milton said, compared with public bathrooms or offices with stagnant air where you may spend a long time.

If none of those things are possible, try to minimize the time you spend in an indoor space, especially without a mask. The longer you spend inside, the greater the dose of virus you might inhale.

New Delhi, Jan 24: Although India's Ujjwala programme encouraged adoption of liquefied petroleum gas (LPG) for cooking among the poor, households availing the scheme have not shifted away from using highly polluting fuels like firewood, a study reveals.

The researchers, including those from the University of British Columbia (UBC) in Canada, found that additional incentives to encourage regular use of cooking gas are necessary for a complete transition to clean cooking fuel among poor rural households.

They noted that about 2.9 billion people across Asia, Africa, and Latin America burn solid fuels like firewood to meet their cooking energy needs.

This has significant negative implications for public health, the environment, and societal development, according to the researchers.

Through the Pradhan Mantri Ujjwala Yojana (PMUY), India has provided capital cost subsidies to poor women to adopt a clean-burning cooking fuel or LPG.

The researchers explained that within the first 40 months of the scheme, more than 80 million households obtained LPG stoves.

However, the full benefits of LPG adoption depend on near complete replacement of polluting fuels with LPG, according to a research-based policy brief published in the journal Nature Energy.

The scientists said this cannot be assumed solely on the basis of LPG presence in the household.

"Our research shows that Ujjwala was able to attract new consumers rapidly, but those consumers did not start using LPG on a regular basis," Abhishek Kar, a postdoc at Columbia University in the US, told PTI.

The study analysed LPG sales data for over 25,000 consumers, including PMUY beneficiaries, as well as general rural LPG consumers in Koppal district of Karnataka.

The scientists employed data covering all LPG purchases of PMUY beneficiaries through their first year in the programme.

They also assessed the general rural population's purchases during their first five years as consumers to assess the effect of experience on use.

The findings estimate that an average rural family needs to purchase five 14.2 kilogramme-cylinders annually to meet half of their cooking needs.

However, the study said just seven per cent of PMUY beneficiaries in Koppal purchased five or more cylinders annually, suggesting that the beneficiaries seldom use LPG.

The general (nonPMUY) consumers in this region use on average two times more LPG cylinders than PMUY beneficiaries, the researchers noted.

Yet, only 45 per cent of nonPMUY consumers use five or more cylinders per year -- even after several years of experience with LPG, they said.

The team assessed price and seasonal factors affecting LPG use among the general population over a three-year period.

It found that LPG consumers are sensitive to price and seasonality -- LPG cylinder refill rates are lower in the summer when agricultural activity is limited, and cash is scarce.

"There was no scheme incentives to promote use, except general LPG subsidies which is available to all, including the urban middle class," said Kar, who was a Ph.D. scholar at UBC when the research was published.

"If there is no additional income, what cost would a poor family on an already tight budget cut to pay for an extra expense on a regular basis.

"Ujjwala has started the scheme of 5 kg-cylinder in response, but the impact of that on LPG sales is still publicly unknown," he said.

These findings, the researchers noted, suggest the need for additional measures to promote regular LPG use for all rural populations.

Although the finding come from a single district in Southern India, it may also apply to other areas with similar socio-economic conditions, they said.

A more expansive evaluation of PMUY would help design targeted incentives to transform infrequent users to regular users, according to the researchers.

New Delhi, Mar 20: The four men convicted of the gang rape and murder of a Delhi woman on December 16, 2012 were hanged in the darkness of pre-dawn on Friday, ending a horrific chapter in India's long history of sexual assault that had seared the nation's soul. Mukesh Singh (32), Pawan Gupta (25), Vinay Sharma (26) and Akshay Kumar Singh (31) were executed at 5.30 am for the savage assault in an empty moving bus on the 23-year-old physiotherapy intern who came to be known the world over as Nirbhaya, the fearless one.

This is the first time that four men have been hanged together in Tihar Jail, South Asia's largest prison complex that houses more than 16,000 inmates. The executions were carried out after the men exhausted every possible legal avenue to escape the gallows. Their desperate attempts only postponed the inevitable by less than two months after the first date of execution was set for January 22.

They were hanged at 5.30 am, Director General of Prison Sandeep Goel said.

After raping and brutalising the woman, the men, one of whom was a juvenile at the time, dumped her on the road and left for dead on the cold winter night. Her friend who was with her was also severely beaten and thrown out along with her. She was so severely violated that her insides were spilling out when she was taken to hospital. She died in a Singapore hospital after battling for her life for a fortnight.

Six people, including the four convicts and the juvenile, were named as accused.

While Ram Singh allegedly committed suicide in the Tihar Jail days after the trial began in the case, the juvenile was released in 2015 after spending three years in a correctional home.

The road to the gallows was a long and circuitous one, going through the lower courts, the High Court, the Supreme Court and the president's office before going back to the Supreme Court that heard and rejected various curative petitions.

The death warrants were deferred by a court thrice on the grounds that the convicts had not exhausted all their legal remedies and that the mercy petition of one or the other was before the president.

On March 5, a trial court issued fresh death warrants for March 20 at 5.30 am as the final date for the execution.