"The virus is transmitted mainly by aerosol". 

Researchers have published in the journal Science consistent evidence that inhalation of the SARS-CoV-2 virus is the main route of transmission of COVID-19. So the virus is transmitted mainly by aerosol.

The head of the research group Kimberly Prather and his collaborators, from the University of California at San Diego, defend that the sanitary recommendations should be modified and that greater importance should be given to protection against airborne transmission of the virus.

In the United States, several scientists agree that the virus remains floating in the air for a long time and they have already changed their recommendations.

They advise and request the authorities to provide recommendations to promote outdoor activities and on the importance of improving indoor air quality through ventilation and purification, thus improving the protection of workers in companies and citizens in consumer and leisure environments.

All this in addition to the already recommended use of a mask, social distancing and the maximum hygiene that we must maintain at all times.

The United States Centers for Disease Control (CDCs) have already updated, as of October 5, 2020, their recommendations. They emphasize that the virus remains in the air for minutes or hours and therefore the disease can be contracted mainly in closed spaces and with inadequate ventilation.

These latest findings and the CDCs' recommendations contradict the WHO version, which tells us that the virus is transmitted mainly through droplets of saliva.

In the middle of this year, in July, a total of 239 scientists from 32 different countries, highlighted the evidence showing that small particles can infect and demanded that the WHO change its guidelines and recognize that the coronavirus is transmitted by air (aerosol).

The following month, in August, another study found evidence that the spread of the SARS-CoV-2 virus from patients infected with COVID-19 becomes viable up to a distance of almost 5 meters, also affirming the airborne transmission of the disease. .

All this is confirmed when cases are seen in events or places with a high density of people in which a few infected infect dozens of people.

The big difference between the main form of transmission recognized by the World Health Organization and the findings of these research groups is that to stop SARS-CoV-2 new recommendations and measures would have to be adopted, mainly in closed settings.

WHO insists that:

“The transmission of the virus occurs at a short distance, through droplets of saliva or particles loaded with viruses, which are expelled by coughing / sneezing and that can infect other people if they impact against their mouth or their eyes."

This is not considered as aerosol transmission and implies that it is essential to avoid contagion only to maintain social distance and use a mask.

When we talk about air transmission, it is different. In this way, it is recognized that the virus also spreads through very small particles that behave like aerosols. These are released simply by talking, breathing, coughing, and sneezing, and are then suspended in the environment.

In these circumstances, the need arises for any closed environment to find some way to keep the air clean, through ventilation and / or air purification, although in these same environments all people use a mask.

The use of Ozone generators that emit low concentrations of O3 gas is gaining strength, not exceeding 0.05 ppm. These devices can be used continuously and, according to a very recent study, Ozone in low concentrations is totally safe for the human body and completely inactivates the coronavirus particles.

Portable air purifiers also regain importance in places where there is difficulty in ventilating. The use of purifiers equipped with high-efficiency HEPA filters is recommended. HEPA filters have the ability to retain aerosols in percentages greater than 99.95%.

The aerosol expert José Luis Jiménez, from the University of Colorado, in an interview with ABC in September this year, cited the main recommendations to avoid contagion by airborne transmission. 

It tells us that we should prioritize the use of open spaces and with a mask. In case of having to be in closed spaces with other people, we should be where there are fewer people and for a short time.

This is due to the fact that in most of the closed premises there is little ventilation, most do not have a central ventilation system or that allows to renew the air from the outside, and in autumn / winter seasons it is practically impossible to stay with the doors open. To this is added that people in the premises generally remove their masks at some point, wear them poorly adjusted or made of non-approved fabrics.

From Ozone Specialists, with more than 10 years of experience in the commercialization of these equipment, we are in line with these latest studies. We strongly recommend treating the air in closed spaces, as well as permanent ventilation or filtration of the air, to guarantee interpersonal safety. In this way, without a doubt, we will be able to reduce the rate of common infections as much as possible and win or at least take advantage of this pandemic while there is no safe vaccine for the world population.

06/10/2020 - By Juliana Tieppo; PhD in Physiological Sciences from UFRGS and Universidad de León - ES