The discoverers of the hepatitis C virus, awarded the Nobel Prize in Medicine
October 6, 2020XXVII Danone Institute Award for Scientific Career Dr. Carles Martí Henneberg
October 6, 2020
He was one of the 239 signatories of the letter that urged the WHO to recognize that the coronavirus is transmitted by air and not only by droplets or surfaces. "Not doing so is a tremendous mistake," he says, "and people don't know how to protect themselves." Aerosol physics leaves no room for doubt for specialists in this field, like this researcher from Zaragoza. That is why he advises making a social effort to carry out outdoor activities every day you can, continuously ventilate offices and schools and spend ten minutes checking if the mask fits properly.
The Zaragoza researcher José Luis Jiménez, professor at the University of Colorado in Boulder (USA), has participated in the letter published yesterday in 'Science' and which summarizes the conclusions of a workshop carried out by the National Academies of Sciences, Engineering , and United States Medicine in which it was seen that "the evidence on aerosol transmission of SARS-CoV-2 is overwhelming."
He does not stop communicating it by land, sea, air and Twitter. How important are aerosols in the transmission of coronavirus?
It is a disease that is transmitted mainly through the air and most infections (at least 75%) occur by inhalation of aerosols, infected particles that float in the air and that we breathe.
"At least 75% of infections are due to inhalation of infected aerosols floating in the air"
How does this aerosol contagion occur?
The virus is released into the air in a much larger ball of saliva or respiratory fluid. Aerosols float in the air and infect you when you breathe them. It is known that when we breathe, few respiratory particles come out. What really makes many come out is that we speak, due to the vibration of the vocal cords and the pronunciation.
"We see politicians who take off their masks to speak and it is the other way around, that is when they should put them on, especially if they are going to speak loudly or shout. When speaking, 10 times more aerosols are expelled than when breathing. When shouting or sing, 50 times more"
The easiest place to get infected is a choir in a closed place. Or a bar with a lot of people and very loud music where you have to shout. It would be a good idea to travel quietly on trains.
However, the WHO does not recognize that it is the main route of transmission of this disease.
They don't understand the aerosol evidence. It is a historical reluctance. They think that close contagion is explained by the ballistic droplets of saliva or respiratory fluid that, when one speaks, coughs or sneezes, fall to the ground, so distancing is enough. But it is an error based on 110th century science. We aerosol physicists know that's not how it works. When you move away, the reason why you are not infected is because the aerosols are dispersed in the air: it is the same as if you are next to a smoker who is exhaling smoke, the smoke is very concentrated and you breathe it; and if you move further away, you breathe less and less smoke. Many doctors have been denying that diseases are transmitted through the air for 2 years. They only admit it in very contagious ones, such as measles or chickenpox. For them, what shows that SARS-CoV-XNUMX is not airborne is that it is not very contagious. And this makes no head or tail. The draft that the Centers for Disease Control and Prevention (CDC) posted a few days ago on the internet and then removed says exactly what I say, but they are complex organizations and under pressure.
"When you directly share the air in a room, there is no longer any safe distance"
What evidence do we have?
Physicist Richard Feynman said: "If something doesn't agree with experiments, it's wrong. It doesn't matter who says it or how many years they've been thinking about it." The drops do not agree with physics, with simulations, they cannot explain why there are so many infections indoors and so few outside. There is a database with more than a thousand cases of superspreading – when one person infects many – and there is only one case outdoors. You have to focus your efforts indoors. When you directly share the air in a room, there is no longer any safe distance. Our group has studied the case of superspreading of the Skagit Valley choir, in the United States, which is impossible to explain by droplets, it can only be explained by aerosols.
What happened in that choir?
It is the most extreme case that we have studied. After two and a half hours of singing in a closed room, there was one infected person and 52 of the 60 were infected. One of the infected people was 14 m behind the source of the infection. Others, 8, 10 m. The air was trapped in the room spinning as everyone sang and everyone inhaled the aerosols exhaled by the infected person.
Could it have been avoided?
To reduce the risk of contagion, layers of protection must be made: the simulations indicate that if they had worn masks, rehearsed half as long and ventilated or filtered the air, instead of 52, 5 would have been infected. And if the test If it had been done outdoors, we thought that no one would have been infected. Outside the aerosols are dispersed into the air.
