Hundreds of scientists are sounding the alarm over the possibility that the novel coronavirus may spread through air more than once thought.
On Monday, a report by the New York Times said 239 scientists had warned the World Health Organization (WHO) that the virus can linger in the air for hours, raising the chances of exposure for people.
The researchers plan to publish their evidence in a journal next week.
WHO says Sars-CoV-2, the virus that causes Covid-19, spreads primarily through small droplets expelled from the nose and mouth of an infected person, which quickly sink to the ground.
But in an open letter to the Geneva-based agency, published on Monday in the Clinical Infectious Diseases journal, 239 scientists from 32 countries outlined evidence that - they say - shows floating virus particles can infect people who breathe them in.
In order to reduce the chances of contracting the infection from the virus-riddled droplets, proper ventilation is a must-have, and there is no alternative to wearing masks, the report says.
What does it mean for a virus to be airborne?
A virus being airborne signifies that it may be carried by the air in a viable type. For most pathogens, it is a yes-no state of affairs. HIV, too delicate to outlive outdoors, cannot be airborne. Measles is airborne, and dangerously so: It can survive in the air for as long as two hours.
For the novel coronavirus, the definition has been more sophisticated. Experts agree that the virus doesn’t journey lengthy distances or stay viable outside. But there is data that suggests it will possibly traverse the size of a room and, in a single set of experimental circumstances, remain viable for perhaps three hours.
How are aerosols different from droplets?
Aerosols are droplets, droplets are aerosols — they don’t differ besides in measurement. Scientists typically opine that droplets smaller than five microns in diameter are aerosols. By comparison, a pink blood cell is about five microns in diameter; a human hair is about 50 microns broad.
From the beginning of the pandemic, the WHO and different public well-being organizations have targeted the virus’ means to transmit via giant droplets, which are expelled when a symptomatic individual coughs or sneezes.
These droplets are heavy and fall to the ground or onto a floor that others may come into contact with. This is why public well-being businesses have advised maintaining a personal distance of no less than two metres, or six feet, from others, and frequent hand washing.
Physical distancing and washing hands
Physical distancing continues to be crucial. A person in close vicinity may be a contaminated individual, and chances are he or she will be uncovered too. Washing hands remains an important safety measure.
Wearing a hospital-grade mask
Healthcare 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.
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,” Dr Milton said.
