Athira returns home as Ayisha after High Court upholds her right to follow Islam

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.

Follow latest updates on the Covid-19 pandemic here

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.

Bengaluru, Jan 9: Some BJP workers created a ruckus on Wednesday at a college here while seeking support for the amended Citizenship Act by raising slogans like 'Go back to Pakistan' outside the campus on Wednesday, as girl students opposed a pro-CAA banner on the wall of their institution.

A video of the incident went viral on social media.

A group of BJP workers, supporters of local party leader M M Govindaraj, had put up a poster "India Supports CAA" on the wall of Jyothi Nivas College near Koramangala.

This was opposed by girl students, who said they would not allow any such poster to be put up on the college property.

The BJP workers then tried to shout down the students.

"You are not concerned about citizenship, you are concerned about yourself. You should be concerned about India first. You are not an Indian then," a BJP worker is heard screaming at the girls in the video.

They also questioned the students if they had valid reasons to oppose the Citizenship Amendment Act and sought to know whether they wanted an argument or a debate.

The BJP workers purportedly told the girls that they were only the students of the college and not the owner.

"What's your problem madam with the CAA? Are you the owner of the college?" they asked.

Amid the heated argument, the BJP workers resorted to sloganeering like 'We want CAA' and "Go back to Pakistan', as seen in another video shot by the students.

BTM Layout Congress MLA Ramalinga Reddy visited the college on Thursday after learning about the incident and spoke to its management.

Later, he told reporters that the campus should not be allowed for any political activities.

"Any signature campaign whether in favor or against it (CAA) should be done outside the campus," Reddy said.

He cautioned the pro-CAA protesters he will not let any violent incidents like the one at Jawaharlal Nehru University in New Delhi happen at the city college.

Reddy's daughter Sowmya Reddy, who is the Jayanagar MLA, tweeted, "A few videos & photos of outside #JyotiNivascollege are being circulated on social media."

"MLA Ramalinga Reddy & I have spoken to cops and the Prinicipal about this incident. Spoke to DCP South East Bengaluru and she said that Koramangala cops went there immediately & they are picketing even now," she added.

Bengaluru, Jun 5: The Karnataka government has asked all its departments and authorities to avoid during all official transactions the nomenclature "Dalit" for members belonging to the Scheduled Castes.

"All the departments and authorities of government of Karnataka are requested that (use of name Dalit) for all official transactions, matters, dealings, certificates, among others," the official circular said.

The Constitutional term Scheduled Caste in English and its appropriate translation in other national languages should alone be used for denoting the persons belonging to the Scheduled Castes/ Scheduled Tribes notified in the presidential orders issued under Article 341 of the Constitution, the circular said.

The circular issued on May 20 notes instructions issued by the Central government in 2018, with reference to the order of the High Court of Madhya Pradesh, Gwalior Bench.

"That the Central government/state government and its functionaries would refrain from using the nomenclature "Dalit" for the members belonging to Scheduled Castes and Scheduled Tribes as the same does not find mentioned in the Constitution or any statute," the order had said.

Pointing out that the Central government had earlier issued instructions that the words "Harijan" and "Girijan" should not be used, the circular said accordingly the Karnataka government also had issued a Government Order in 2010.