New York —

This type of ultraviolet ray is particularly effective in destroying the genetic material of microorganisms such as viruses and bacteria, preventing their replication.

At the epicenter of the pandemic in the United States, the iconic New York City will begin this week to apply a system to disinfect its subway cars and buses: UVC light.

This type of ultraviolet ray is particularly effective in destroying the genetic material of microorganisms such as viruses and bacteria, preventing its replication.

Since its discovery in 1878It has become a basic method of sterilization, being used every day in hospitals, airplanes, offices and even in food factories.

It is also essential for drinking water disinfection process Some parasites are resistant to chemical antiseptics such as chlorine.

And today, with the emergence of the new coronavirus in the world, UVC light has once again become relevant.

In China, for example, this technology is applied to buses every night to disinfect them, while robots have been cleaning hospital floors with this light. Even banks have disinfected money with this method.

But what are its advantages and what risks does it entail?

Types of radiation

There are three types of UV radiation.

The first is ultraviolet A (UVA), which constitutes the largest amount of radiation reaching Earth. It is capable of penetrating the skin, being the cause of the appearance of wrinkles and blemishes in people.

Then there is the ultraviolet B (UVB), which can damage skin DNA, causing sunburn and potentially cancer.

And finally there is the ultraviolet C (UVC), which is the most harmful. It has a shorter and more energetic wavelength of light than the others, making it especially harmful to humans.

This last type of radiation is absorbed by the ozone layer so it never reaches the Earth’s surface.

There are robots that apply this ultraviolet light to clean floors in hospitals and airports. (Photo: .)

However, scientists have been able to take advantage of it.

Although there is still no conclusive research to confirm that UVC light eliminates SARS-CoV-2, yes there is evidence that it does it with other coronaviruses like the which causes the SARS, whose outbreak originated in 2002.

The infectious diseases specialist and dean of the Faculty of Medicine and Science of the San Sebastián University (Chile), Carlos perez, He explains that this suggests that it also works in the case of the current pandemic.

“It can be extrapolated. This light is very intense and produces irreversible alterations in molecular structures, particularly in its genetic material, ”he tells BBC Mundo.

“We know that it is capable of eliminating living organisms on inanimate surfaces where it is applied, such as bacteria, fungi and viruses,” he adds.

But for this technique to be effective and harmless to people, experts caution that it should be handled with caution.

Skin irritation and eye damage

Since its discovery, UVC light has become a basic method of sterilization, being used in hospitals, airplanes, offices and even in food factories. (Photo: .)

“UVC is highly unpleasant, we shouldn’t be exposed to it”, told BBC Future Dan Arnold, who works at the UV Light Technology company that provides disinfection equipment in the UK.

“UVB can take hours to burn, but UVC does it in seconds. If your eyes are exposed … do you know that gritty feeling you have if you look at the sun? It is thus multiplied by 10 and only after a few seconds, “he explained.

So, to use this technology safely, Special equipment and trained personnel who understand how to apply it are necessary.

Hence the scientists’ surprise when in late April the President of the United States, Donald trump, suggested the possibility of irradiating the bodies of covid-19 patients with ultraviolet light to heal them or “simply powerful light.”

The idea was widely rejected and criticized by various health authorities.

Even the World Health Organization (WHO) She was emphatic in pointing out that ultraviolet lamps should not be used to disinfect hands or other skin areas.

“UV radiation can cause skin irritation and damage the eyes,” said the WHO.

“UV radiation can cause skin irritation and damage the eyes,” said the WHO. (Photo: .)

“You have to be very careful,” says Carlos Pérez.

“It is important that there are no people around and that it is applied by certified personnel and with special equipment. Here we are not talking about sunlight, this is different. It is much more intense, it is harmful to the skin and other tissues, such as the eyes ”, he warns.

In order to reduce the risk of this mechanism, researchers at Columbia University in the United States are trying to develop a new type of UVC (called far UVC) that would be less dangerous to handle.

This would have a shorter wavelength than normal UVC and could be applied in public places more easily.

In any case, the doctor Carlos Pérez says that this technology in no case replaces direct surface cleaning or other disinfection methods.

“It can be a good measure if it is applied efficiently, but it is complementary because it does not clean. It is necessary to continue with direct cleaning with disinfecting solutions ”, indicates.

Thus, in the midst of the pandemic that until May 11 has already caused more than 280,000 deaths in the world, this technology is beginning to emerge as one more way to help curb the disease.

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