Scientists: Aerosols play an important role in coronavirus contamination

Researchers at the Royal Netherlands Academy of Arts and Sciences (KNAW) believe that more consideration should be given to aerosols as a risk of covid contamination. Indeed, “more and more” model studies show that they play an important role in the pandemic.

The World Health Organization also recognized the role of aerosols last Friday. Much to the relief of researcher Daniel Bonn from the University of Amsterdam. “We have been saying this for a long time.”

Tiny particles in the air

Aerosols are tiny particles that can linger in a room for a few minutes. Everyone produces aerosols, for example by coughing and sneezing, but also by talking. A number of viruses, such as measles, spread strongly through these aerosols. For a long time this was not clear to Covid, but now it does appear to be a possibility.

Researcher Bonn shows how aerosols work:

There is no hard evidence for the role of aerosols, Bonn admits. “But there are a lot of things you can’t explain quantitatively if you don’t include this aerosol contamination.”

We do not yet know how important the role of aerosols is in the pandemic. “There are more and more model studies that indicate this is an important part.” He cites practical examples, such as contamination in choirs or a restaurant in Guangzhou, where people were infected while keeping their distance last year.

Adjust policy

What does this new vision mean for the fight against the virus? According to Bonn, this is clear: “Ventilate, ventilate, ventilate”.

Science journalist Jop de Vrieze also believes things should be done differently. “Now we put on a face mask when entering a public space. As soon as we are inside and can keep enough distance, we remove it. If you assume aerosol contamination, you may indeed suffer consequences after half a day next to a colleague. . “

De Vrieze also sees consequences for people’s home visits: most regular homes aren’t very well ventilated, so keeping a distance may not be enough.

Researcher Bonn calls for more research on the ventilation of certain spaces, such as schools, gymnasiums, restaurants and airplanes. “Wherever there are a lot of people, you want the ventilation capacity to be large enough.”

Mouth plugs

The type of masks we use now may also need to be adjusted. “Normal masks and surgical masks don’t hold enough if you leave aerosols,” says De Vrieze. “You really need an FFP2 mask for this.”

The ‘double mask’, where you put two masks on top of each other, can also help. “The Americans are already doing it. We think it’s a strange sight, but it makes sense: one mask works like a filter for your mouth, and the other makes sure it seals the edges well.”