How far can air droplets travel from person infected with coronavirus (COVID-19)?

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DETROIT – Scientists from several countries have learned more about how far droplets from people infected with the coronavirus (COVID-19) can travel in the air.

Now, 239 researchers from 32 countries are calling on the World Health Organization to be more clear about how the virus can spread and what measures might contain it.

The letter “It is time to address airborne transmission of COVID-19″ was published in a scientific journal and signed by scientists from the United States, Europe, China, Australia and the Middle East.

The letter says studies “have demonstrated beyond any reasonable doubt that viruses are released during exhalation, talking and coughing in micro droplets small enough to remain aloft in the air and pose a risk of exposure.”

How is that different from what we already knew? It’s now accepted that large droplets from infected people can travel about six feet in the air.

Scientists argue there is also evidence that much smaller droplets can hang in the air for longer periods of time, especially indoors.

That means ventilation is much more important in terms of dispersing the virus, as illustrated in a graphic that accompanies the letter.

Scientists recommend bringing more outdoor air inside and minimizing recirculating air, particularly in public buildings, work places, schools, hospitals and nursing homes.

They also recommend using high efficiency air filters and germ-killing ultraviolet lights and avoiding overcrowding, particularly in public transportation and public buildings.

The WHO has not yet responded to the letter, but last week, acknowledged the challenges of COVID-19.

“It is just six months ago that we actually learned about this cluster of cases of pneumonia originating in Wuhan and none of us could have, I think, imagined when we woke up on the first of January that six months along this is where we are going to be grappling with this pandemic,” WHO Chief Scientists Dr. Soumya Swaminathan said. “We’ve learned a lot.”

Scientists said measures such as hand washing and social distancing are still recommended, but additional measures are needed to protect against airborne transmission.

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