Jimenez explains: “We should avoid putting disinfectants in the air like ozone, hydrogen peroxide or chlorine dioxide, all of this will benefit surfaces, but not the air; it’s dangerous.”
The path of transmission of the coronavirus that most scientific evidence collected during this epidemiological year is the air path, “this does not mean that the virus travels kilometers to be infected”, rather it means that we breathe “invisible smoke (fog)” that comes out from the infected person when we are close or accumulates in Closed places, explained Spanish researcher Jos Luis Jimenez Telam, one of the most important international references on the topic.
A professor at the University of Colorado, USA, and one of the 239 scientists who asked the World Health Organization (WHO) to recognize the dominant role that aerosols play in the pandemic, Jimnez, in an interview with Tlam, outlined some key concepts for improving care in the face of the second wave facing the country.
Blam: There are three recognized forms of infection: by surfaces, by large droplets and by aerosols. What scientific evidence has been collected for each one to date?
Jose Luis Jimenez: About the three forms of infection, the CDC (the Centers for Disease Control and Prevention in the United States) said already last year and repeated it vigorously this week: Cross-surface infection is difficult and there are no confirmed cases.
The remaining two are clear evidence of airborne infection from inhalation of aerosols. There is a lot of evidence for this: cases of high infection or long-distance travel (for example in quarantine hotels like a country in New Zealand), and the fact that people without symptoms (by not coughing or sneezing) simply give off an aerosol and we Be aware that it is contagious, or that the transmission is much higher indoors than outdoors. All this can only be explained if the infection occurred through the air.
“At the start of the epidemic, it was said a lot that it was transmitted through contact with infected surfaces, so seeing disinfected surfaces gives a sense of safety that we know today as wrong.” “
Animals such as rodents have also been found infected, which can only occur through the air.
The evidence for infection with ballistic drops, large drops, is very weak; So it is a shame that one year after the outbreak of the epidemic, the World Health Organization continues to say that this is the main course of infection.
What does it mean that the virus is in the air?
JLJ It is not a ghostly definition, nor does it mean that a virus will travel miles and infect. That is, infected people come out in the form of invisible smoke that can contain the virus with the potential for infection. This smoke is respiratory aerosols, which are very small, invisible particles that remain floating in the air.
However. When do you breathe in a lot of each other’s spray? In two cases: when you are very close, especially without a mask (chin strap), or when you share air in a closed room, because the closed space traps the air that that person exhales. They are two common and recurring situations.
T: How can we reduce infection?
JLJ The first point is to understand that all people exhale this invisible smoke and that we should try not to breathe in. Risk reduction measures are not that difficult, but they have not been implemented. The first thing is to do everything you can do outdoors, at a distance and with masks. Classes, business meetings, family meetings, everything has to be done under these conditions.
The mask needs to be well fixed on our face, especially around the nose. If all the air we breathe passes through the mask, the virus can “stick” to this fabric, whereas if we wear it with holes it does not perform well.
The mask should always be used indoors or when we enter places where someone has been or someone will come later (so that we do not leave viruses).
Outdoors, for example, on the balcony or on the patio, I should use it if I am within two meters of another person.
If I am indoors, I should reduce the number of people as much as possible and ventilate, which means the air outside enters and leaves the polluted air.
To see if we are breathing well, one possibility is a measure of carbon dioxide (CO2) that will tell us how much exhaled air is there.
If it cannot be ventilated, it must be filtered; So there are specific devices like hepa filters or fan filters that can work well.
And we have to avoid two kinds of things: chemical techniques that use ions, plasma, hydroxyl and photocatalysis, because they are dangerous because they can produce toxic compounds; It is also necessary to avoid placing disinfectants in the air such as ozone, hydrogen peroxide or chlorine dioxide, all of this will benefit in disinfecting surfaces, but not for the air. It is dangerous.
T: Why do people incorporate alcohol jelly over aeration?
JLJ I think the reason for this is that at the beginning of the epidemic a lot was said to be transmitted by contact with infected surfaces, and then seeing disinfected surfaces give a sense of safety that we know today is wrong.
This fear has remained and is now very difficult to remove. Hand washing is fine, we all agree, but very diligently cleaning surfaces was not helpful. This is part of the responsibility of the World Health Organization.
– T: So, outdoors I should also wear a chin strap.
JLJ It depends, if you are in the middle of a mountain and there is no one around, then it is not necessary in principle. But if you’re walking in a city and people are passing by, or you’re in a bar or on a balcony with friends, yes. One has to imagine that the rest are smoking and that as much as one smells a cigarette, one may breathe in the aerosol that the other exhales.
– T: If I don’t have a CO2 meter, how can I make sure the place is well ventilated?
JLJ It is a problem because if you feel the current, especially in the winter, the most common thing is that people are not resisting and everything is switched off.
So, with a group, we started to insist on measuring CO2. Bearing in mind that the outdoor measurement is 400 ppm, and the ideal is that in the environment we live in, it should not exceed 700 ppm; Most of the time when you measure you find more than 1500 parts per million, and in a car it can reach 5000 parts per million.
The device is not very expensive and they can buy two at school, periodically measure classes and learn; For example, on a windless day, you may have to open three 15 cm windows, but on a windy day, 10 cm opening may be sufficient.