Keys so as to avoid catching COVID-19 through the air you breathe
COVID-19 infections are increasing around the world, even after nine months after the first case was discovered. And now, it shows a virulent behavior with spikes, even in areas where the coronavirus seemed already under control.
During all the time that the pandemic has been active, not only have the secondary effects of the disease, its different symptoms and repercussions been discovered, but also new forms of contagion.
Recently, David Shukman — BBC Science editor — wrote an article about the danger and risks people take of being contaminated with COVID-19 in places with poor air circulation, as they are potentially risky for infections.
“Staying in a place with poor air circulation for a long time can be risky. With the return to classes and offices in many countries, preventing the spread of the coronavirus inside buildings has become a key issue”, explains Shukman.
Washing your hands, wearing a mask and maintaining social distancing are the primary rules to reduce the risk of being infected by the SARS-CoV-2 coronavirus that causes COVID-19.
“But scientists and engineers say that we must also think about the air we breathe”, explains Shukman, especially as many countries begin to “normalize” their daily routines at work and in schools, which begin to incorporate millions of children who were sheltered for months and now begin to experience the return to classes in the midst of the pandemic.
Keys to avoid airborne infections
In his report, Shukman lists five aspects that are key to avoid being infected by air currents and testing positive for COVID-19.
1. If it’s a poorly ventilated place, stay away
When you walk into a room and the air feels stale or stuffy, something is wrong with the ventilation. Not enough fresh air is getting in and that increases the chances of becoming infected with coronavirus.
Recent research shows that in confined spaces there may be “airborne transmission” of the virus, as small particles of the pathogen remain in the air.
Therefore, it is important to be aware of the quality of the air you breathe indoors.
So, if a place is stuffy, turn around and walk away, says Dr Hywel Davies, technical director of the UK Collegiate Institution of Building Services Engineers.
For this reason — Davies says — clean airflow is vital. “If someone is infected in a building and enough air gets in from outside, any infectious material that is spreading is diluted. The risk of other people getting infected is being reduced.
2. Watch the air conditioning
From offices to stores, air conditioning is welcome on hot days, but it is important to know what type of appliance we have.
The simplest, known as split air conditioner, takes air from a room, cools it and then expels it out again, that is, they only recycle the air inside.
In other words, it is recirculating the air. This is not a problem if you visit a place quickly. But it can be a risk if you are in the place for several hours“, adds Shukman.
A study of a restaurant in China, published by the Centers for Disease Control and Prevention of the United States, showed that this type of air conditioning plays a key role in the spread of the coronavirus.
There was a ‘presymptomatic’ customer at the facility, that is, someone who was infected but did not realize it because he had not yet developed symptoms.
Scientists believe that he released the virus as he breathed and spoke. The pathogen was spread by air currents from the split. The result was that nine other people became infected.
That is why Davies insists on the importance of fresh air: “If there had been a good supply of outside air, it is very likely that fewer people would have been infected”.
3. Find out about the ‘proportion of fresh air’ in any given place
In a modern building where the windows are sealed, how can you get enough fresh air?
The most common is to have a ventilation system in which stale air is extracted from the rooms and channeled to a treatment unit, often located on the ceiling.
In these places, fresh outside air is brought inside and it combines itself with the air from inside. What you breathe is a mixture of that. So, given the risk of coronavirus infection, the professional advice is to maximize the supply of fresh outside air.
“Having 100% outside air or close to 100% is a good thing”, says Professor Cath Noakes of the University of Leeds in the UK. The more fresh air, the lower the risk that the virus will circulate around the building again”, he adds.
The precise combination is often in the hands of building managers, and the downside of running 100% fresh air is the cost, as incoming air must be heated in winter and cooled in summer, processes that require energy, and that costs money
4. Check the filters
Although a modern ventilation system should have filters, they are not foolproof. American researchers studied something that happened at the Oregon Health and Science University Hospital. There, they found that the filters caught traces of coronavirus, but some particles were able to ‘escape’ from the filters.
Professor Kevin van den Wymelenberg, who led the project, believes that when the filters are cleaned, this could reveal whether someone working in the building is infected.
In South Korea, a telephone operator company located in an office building detected that one person was capable of infecting more than 90 by that detail. If the filters had been checked more frequently, the presence of the virus could have been detected earlier.
Van den Wymelenberg says the information in the filters can “show us where to attack and when” to fight infections.
5. Be careful with drafts
Any expert in the field says it: fresh air is the key. But a specialist in modeling the movement of air adds that “it is not that simple”.
Nick Wirth used to work on Formula 1 car design and now advises supermarkets and food processing companies on how to manage airflow to keep people safe from COVID-19.
He warns that if someone is sitting next to an open window and they are infected, they could transmit the virus to others in the direction the wind is blowing.
“If you open a window, where will the air go? You don’t want people in a direct line of that airflow”, explains Wirth.
“More fresh air is generally better, but if it flows horizontally and is full of viruses, it could have unintended consequences”, he adds.
In this regard, Professor Cath Noakes says that the benefits of a large amount of fresh air that dilutes the presence of the virus will outweigh any risks.
In her opinion, an open window could lead to more people getting the virus, but in smaller and less risky amounts.
“It is not surprising that there are disagreements: there are still many things we do not know about this coronavirus. But the air we breathe will be part of any effort to make buildings safer”, emphasizes Shukman.
