Madhya Pradesh CM Shivraj Singh Chouhan tests covid positive

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.

Hyderabad, Feb 10: All India Majlis-e-Ittehadul Muslimeen (AIMIM) chief Asaduddin Owaisi continued his tirade against PM Modi and Amit Shah against Citizenship Amendment Act (CAA), National Population Register (NPR) and National Register of Citizens (NRC). "We are ready to take bullets in our chests but we will not show our papers.

We are ready to take bullets in our chests as we love our country," Owaisi said further.

Mumbai, Feb 26: Observing that the violence in Delhi is akin to a "horror film" depicting the grim reality of the 1984 anti-Sikh riots, the Shiv Sena on Wednesday said the "bloodbath" has brought disrepute to the national capital like never before while US President Donald Trump was in India with the "message of love".

The editorial in party mouthpiece 'Saamana' lamented that Trump was welcomed in Delhi while there was bloodbath on the streets.

It further said that the violence could potentially spread the message that the Central government has failed to maintain the law and order situation in Delhi.

"Violence has erupted in Delhi. People are on the streets equipped with canes, swords, revolvers, blood is being spilled on the roads. Some horror film-like situation is being witnessed in Delhi, which depicts the grim reality of the 1984 riots," the Sena said.

It further said the BJP was still blaming the Congress for the deaths of hundreds of Sikhs in the violence that was erupted after assassination of then Prime Minister Indira Gandhi.

It needs to be unravelled who is responsible for the current riots in Delhi, the Sena said while referring to the "language of threats and warning used by some BJP leaders".

"The national capital was burning at a time when Prime Minister Narendra Modi and visiting US President Trump were holding talks.

"It does not augur well that Trump was welcomed in Delhi with the horror film of violence, bloodbath on the streets, screams of people, and tear gases. Trump saheb came to Delhi with a message of love, but what unfolded before him? 'Namaste' in Ahmedabad and violence in Delhi. Never before Delhi was defamed like this," the editorial said.

Trump had begun his February 24-25 India visit from Ahmedabad in Gujarat.

Seventeen people have died so far and over hundred were injured in the violence that has gripped several parts of north east Delhi over the Citizenship Amendment Act (CAA) since Sunday.

Attacking the Central government over reports that the violence was timed with Trump's visit, Sena said, "the Union Home Ministry has alleged that a conspiracy was hatched to defame India internationally by triggering the violence during Trump's visit to the national capital.

"The Home Ministry not knowing about the conspiracy behind the violence over the CAA is detrimental to national security. There is no problem in controlling the riots with the same courage with which Article 370 and 35A were scrapped," the editorial said.

It further said the anti-CAA protest at Shaheen Bagh in Delhi was yet to be called off yet despite the Supreme Court appointing mediators.

"It is being said that the violence sparked off after some BJP leaders talked the language of threats and warning. So, did someone want the peaceful agitation (at Shaheen Bagh) to acquire the present form of riots? (They) could have waited for at least Trump to leave the country," the Sena said.

The Uddhav Thackeray-led party also questioned the timing of the riots, which are occurring days after the results of the Delhi assembly polls.

"It is mysterious that the violence broke out days after the BJP lost the Delhi assembly elections. The BJP lost and now this is the condition of Delhi," the Sena said.

The Uddhav Thackeray-led party, a former ally of the BJP, now shares power in Maharashtra with the NCP and the Congress.