Read this from the BBC.
“You would literally be frying people,” says Dan Arnold, laughing in disbelief.
Arnold works for UV Light Technology, a company that provides disinfecting equipment to hospitals, pharmaceutical companies and food manufacturers across the UK. Recently, as the global anxiety about Covid-19 has reached extraordinary new heights, he’s found himself fielding some unusual requests.
“We had an enquiry from a private individual about our equipment, saying ‘Well, why can't we just get one of your UV lights and put it up on the exit to the supermarket – people can stand under it for a few seconds before they go in’,” he says.
Among the abundant “health” advice currently swarming around the internet, the idea that you can disinfect your skin, clothing or other objects with UV light has proved extremely popular. In Thailand, a college has reportedly even built a UV tunnel that students can walk through
to disinfect themselves.
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So is this a good way to protect yourself from Covid-19? And is it true that since “the new coronavirus hates the sun”, sunshine will immediately kill it, as some reports on social media have claimed?
In short: no. Here’s why.
Sunlight contains three types of UV. First there is UVA, which makes up the vast majority of the ultraviolet radiation reaching the Earth’s surface. It’s capable of penetrating deep into the skin and is thought to be responsible for up to 80% of skin ageing, from wrinkles to age spots.
Next there’s UVB, which can damage the DNA in our skin, leading to sunburn and eventually skin cancer (recently scientists have discovered that UVA can also do this). Both are reasonably well known, and can be blocked out by most good sun creams.
Both UVA and UVB damage the skin — but nothing is as damaging as UVC (Credit: Getty Images)
There is also a third type: UVC. This relatively obscure part of the spectrum consists of a shorter, more energetic wavelength of light. It is particularly good at destroying genetic material – whether in humans or viral particles. Luckily, most of us are unlikely to have ever encountered any. That’s because it’s filtered out by ozone in the atmosphere long before it reaches our fragile skin.
Or that was the case, at least, until scientists discovered that they could harness UVC to kill microorganisms. Since the finding in 1878, artificially produced UVC has become a staple method of sterilisation – one used in hospitals, airplanes, offices, and factories every day. Crucially, it’s also fundamental to the process of sanitising drinking water; some parasites are resistant to chemical disinfectants such as chlorine, so it provides a failsafe.
Though there hasn’t been any research looking at how UVC affects Covid-19 specifically, studies have shown that it can be used against other coronaviruses, such as Sars
. The radiation warps the structure of their genetic material and prevents the viral particles from making more copies of themselves.
As a result, a concentrated form of UVC is now on the front line in the fight against Covid-19. In China, whole buses are being lit up by the ghostly blue light each night
, while squat, UVC-emitting robots have been cleaning floors
in hospitals. Banks have even been using the light to disinfect their money
A bus is disinfected using UVC in Shanghai, China (Credit: Getty Images)
At the same time, UV equipment suppliers have reported record sales
, with many urgently stepping up production to fill their orders. Arnold says UV Light Technology has run out of all of its equipment already.
But there’s a major caveat.
UVC is really nasty stuff – you shouldn't be exposed to it – Dan Arnold
“UVC is really nasty stuff – you shouldn't be exposed to it,” says Arnold. “It can take hours to get sunburn from UVB, but with UVC it takes seconds. If your eyes are exposed… you know that gritty feeling you get if you look at the sun? It’s like that times 10, just after a few seconds.”
To use UVC safely, you need specialist equipment and training. The World Health Organization (WHO) has issued a stern warning against people using UV light to sterilise their hands
or any other part of their skin.