BEIJING, April 1 (Xinhua) — Dan Arnold works for ULTRAViolet Technologies, a company that provides disinfection equipment to hospitals, pharmaceutical companies and food manufacturers across the UK, according tomedia reports, as the global crisis of new coronaviruses heats up. Whether UV rays can kill the new coronavirus has also become a hot topic, and recently, Arnold received some unusual advice, many people asked: Can UV rays kill the new coronavirus?


Arnold says only one type of ultraviolet light can kill the new coronavirus, but the process is very dangerous and poses a serious threat to human health. Has we been asked why we don’t install a UV light at the entrance to a supermarket? Customers stand under the ULTRAviolet light for a few seconds, and then go in to play the role of sterilization. I do not support such a proposal.

The idea of using ultraviolet light to disinfect skin, clothing or other objects has proved very popular in the Internet’s sweeping “health advice.” A university in Thailand has even allegedly built an ultraviolet channel through which students can disinfect it.

So is it a good idea to kill the new coronavirus with ultraviolet light? Is it true that the new corona virus hates the sun and that the sun will kill it immediately? Simply put, the idea is wrong.

Dangerous UV rays

Sunlight contains three types of ultraviolet light, the first of which is long-wave ultraviolet (UVA), which is the vast majority of the sun’s rays reaching the earth’s surface, can penetrate the depths of the skin, is believed to be the cause of skin aging 80%, causing wrinkles and old age spots.

The second is medium-wave ultraviolet (UVB), which destroys DNA in the skin, causing sunburn and eventually skin cancer. Long-wave UV and medium-wave UV rays are well known for their harmful effects on humans, and most good-quality sunscreens are resistant to both types of UV rays.

The third is short-wave ultraviolet (UVC), a relatively fuzzy part of the spectrum that is made of shorter, more energetic wavelengths of light, and is particularly good at destroying genetic material, whether human or viral. Fortunately, most of us are less likely to be exposed to short-wave UV rays, which are filtered by the Earth’s atmospheric ozone layer long before they reach human skin.

As it turns out, at least scientists have found that the use of short-wave UV rays can kill certain microorganisms, and since the discovery of short-wave UV rays in 1878, man-made short-wave UV rays have become a major method of disinfection and are used in daily disinfection facilities in hospitals, airplanes, offices and factories. Crucially, short-wave UV rays can be used for drinking water disinfection treatment, some parasites are resistant to chemical disinfectants such as chlorine, so the use of short-wave UV sterilization is more significant.

Although no specific studies have been made so far on how short-wave UV rays affect the new coronavirus, studies have shown that it can be used to treat other coronaviruses, such as SARS. Ultraviolet radiation distorts their genetic structure and prevents viral particles from replicating.

Therefore, some countries now use high-dose short-wave ultraviolet microviolet new coronavirus sterilization treatment, some public transport vehicles have blue short-wave ULTRAviolet radiation, the robot that emits short-wave ultraviolet light is responsible for cleaning the ground in the hospital, the bank has been using short-wave ultraviolet light for many years to disinfect the coin.

At the same time, UV equipment suppliers are now on record, with some increasing production to meet orders, and Arnold says UV technology is now used in all disinfection equipment.

An important warning!

Arnold said: “Short-wave UV rays are really annoying, people should n’go, if exposure to medium-wave UV rays for a few hours before sunburn, then short-wave UV rays can burn the body in just a few seconds, if your eyes are exposed to the sun, do you know that the feeling of staring at the sun?” It only takes a few seconds to cause serious eye damage. “

In order to use short-wave UV rays safely, people often need to receive professional training to operate the equipment properly.

Can sunlight kill the new corona virus?

Does medium and long-wave UV rays have a bactericidal effect? If it acts like short-wave UV rays, does that mean that people can put virus-containing substances in the sun to sterilise?

The simple answer is: it’s possible, but people can’t rely on this approach. In developing countries, sunlight is already a popular method of sterilizing water, and the World Health Organization (WHO) even recommends using sunlight to disinfect water. The technique involves pouring water into a transparent glass or plastic bottle and sunbathing in the sun for six hours, a technique that is considered effective. Because long-wave UV rays in sunlight react with dissolved oxygen, creating unstable molecules such as hydrogen peroxide, the active ingredient of many household disinfectants can destroy pathogens.

Sunlight does not react with water and can still be used to disinfect the surface of an object for longer duration than you think. The problem is that we don’t know exactly how long it will last, because scientists are still in the early stages of studying the new coronavirus. A study of SARS (a close relative of the new coronavirus) found that exposure to the virus for 15 minutes under long-wave UV rays had little effect on the infection of the virus, but the researchers did not expose the SARS virus to medium-wave UV rays, which are known to do more damage to genetic material.

Instead, other viruses may provide important clues, such as flu. When scientists analyzed hospital records in Brazil, they found a sharp increase in flu cases during the wildfire season, presumably due to more smoke from forest fires, reducing the concentration of ultraviolet rays in the sun.

Another study showed that the longer influenza virus particles are exposed to sunlight, the higher their concentration, and the less likely they are to remain contagious. The study looked at influenza virus particles suspended in the air, not attached to the surface of a surface.

The above studies show that the use of sunlight to disinfect the surface of the object is not obvious. First, it is not clear how long it will take for UV exposure to make the new coronavirus inactive, nor does it know how much dose is needed. Even if they do, the amount of UV rays in the sunlight changes depending on the time of day, the weather, the season, and the latitude of people’s lives, so this is not a reliable method of effective sterilization.

Ultimately, it is self-evident that the use of any kind of ULTRAviolet light to disinfect the skin can cause damage and increase the risk of skin cancer. Once the virus enters the body, no amount of ultraviolet light will have any effect on whether you are infected.