Dozens of Shia mourners detained, cops burst teargas shells to foil Muharram procession

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.

Chennai, Apr 25: Civic authorities on Saturday turned down a plea for exhuming the body of a doctor who died of COVID-19 here and burying it in another cemetery, citing health experts' view that it was unsafe to do so. Citing a request from the wife of the deceased doctor to allow exhumation and then re-burial at a cemetery in Kilpauk, the Greater Chennai Corporation said it sought a report from a committee of public health experts to ascertain the feasibility of entertaining her plea.

The spouse of the doctor had appealed to the GCC on April 22 to exhume and bury again her husband's body. She had said that burial in the Kilpauk cemetery here was her husband's last wish and he had conveyed it to her before he was put on a ventilator.

The report of experts has said that "it is not safe" to exhume and again bury the body of a COVID-19 victim and hence "it is not possible to accept her request," the GCC said in an official release. On April 19, a city-based 55-year-old neurosurgeon died of coronavirus and his burial at the Velangadu crematorium here was marred by violence.

A mob which falsely feared that the burial may lead to the spread of contagion had attacked the corporation health employees and associates of the deceased doctor. The doctor's wife and son also had to leave the burial ground in view of the violence.

The body was brought to Velangadu as people of Kilpauk area had opposed his burial there. Over a dozen men involved allegedly in violence were arrested and remanded to judicial custody. Later, in a video message, the surgeon's wife had said that it was her husband's last wish to be interred at the Kilpauk cemetery as per Christian rituals

Chief Minister K Palaniswami and DMK president M K Stalin had spoken to her on Wednesday over the phone and condoled her husband's death.

New Delhi, May 19: In a fresh blow to saffronite journalist Arnab Goswami, the Supreme Court of India today rejected his plea seeking transfer of the investigation of a case, filed against him for defaming Congress interim president Sonia Gandhi, to the CBI. The court also refused to quash the FIRs filed against him.

Goswami, editor-in-chief of Republic TV, has been booked in connection with a TV show on the gathering of migrants outside Bandra railway station on April 14. This apart, multiple FIRs have been filed against him for his show on Palghar lynching. In that show, he had posed certain questions on the incident to Congress President Sonia Gandhi, following which Congress workers lodged complaints against him in various states.

Extending Goswami’s interim protection from arrest by three weeks, the Supreme Court said, “Right of a journalist under 19 1 (a) higher…Free citizens can’t exist if news media can’t speak.”

During the earlier hearing, Senior Advocate Harish Salve, appearing for Goswami, had urged the court to transfer the probe to an agency like CBI. He said the “nature of the” second FIR against Goswami over a show on the migrant gathering outside Bandra station on April 14 “shows that it’s arm-twisting tactic”. 

“They are trying to stifle an unpleasant voice. This is a political party targeting a journalist. All complainants are members of one political party. They have a problem with the government. They want to teach this journalist a lesson,” he added.

Objecting to Salve’s plea to transfer the case to the CBI, Maharashtra government counsel, Senior Advocate Kapil Sibal, had said, “CBI investigation will go into your hands”. 

Sibal denied that Goswami was being harassed and said he was only asked relevant questions. He said Goswami should “stop this communal violence and communal mongering”.