Ultraviolet light is essentially a type of radiation. It possesses more energy than radio waves or visible light, and you can be exposed to UV light through natural sunlight or other sources such as tanning beds for examples. UV lights can be used to kill germs such as bacteria and viruses. More recently, there has been discussion of the UV-C light being able to help tackle the fight against the Coronavirus. Although UV lights can kill germs, the question is – how effective is it at eliminating the Coronavirus, and how long does it take?
The UK is still fighting many cases of Coronavirus, although the infection rate is decreasing. The ‘silent killer’ as the PM states, has unfortunately taken the lives of many across the world and as we frantically work to find a cure, and an effective one at that, we still need to be careful, keep our distance and wash our hands. Hygiene is the best fighter for COVID19 at the moment, so it’s absolutely paramount you wash your hands as regularly as you can. We’ve all had to make changes in our lives, and as technology advances so do new solutions – like the UV-C light for example. Throughout this article we’ll explore how UV light works, and review studies and research whereby the lights have been in action.
The Different Types of UV Light
Before we kick things off, we need to understand that there are various types of UV light, and the UV-C light is only one out of a few. See below.
- UVA light – This light has the lowest amount of energy. You experience UVA light when you’re exposed to the sun, and it is linked to skin damage, and aging
- UVB light – The UVB light sits in the middle between the 3 UV lights – a tiny portion of sunlight contains UVB light, and it’s the main type of light that contributes to sunburns, and even skin cancers
- UVC light – As you have probably guessed, this type of light has the most energy. You’re not usually exposed to this light on a daily basis, as UVC light from the sun is absorbed in the earth’s ozone
How Does UVC Light Work To Kill Germs?
The UVC light, being the light that possesses the most energy out of the 3, is also the only effective light at killing germs too. It has the power to disinfect the air, liquids, and surfaces. It is able to kill germs such as viruses and bacteria by damaging molecules such as proteins and nucleic acids. Because of this, it means the germ is unable to perform the processes it needs to survive and eventually dies. A new study which was carried out by researchers at Columbia University Irving Medical Centre, has tested the use of UVC light at a wavelength where it’s safe for humans.
What We Know
What they found was that it killed more than 99.9% of coronaviruses that are found present in airborne droplets. The coronaviruses are similar to the SARS-CoV-2 virus that causes COVID19. This is not said to cure the Coronavirus, but based on the results, continuous airborne disinfection with UVC light has the power to significantly reduce the level of airborne viruses in indoor environments.
The researchers at Colombia University believe that exposure to the far UVC light would kill 90% of airborne viruses in around 8 minutes. To kill 95%, it takes around 11 minutes, for 99% it takes 16 minutes and 99.9% in 25 minutes.
Cranfield University are also paving the way for a new, effective solution to ill aerosolised covid19 in indoor environments, following Colombia University.
Dr Liang Yang, lecturer in marine renewable energy systems has said:
In indoor environments where it may not be possible to socially distance, aerosolised coronavirus released through breathing increases the chance of spreading the disease. Infection controls focus on a combination of personal hygiene and the correct use of personal protective equipment, which has been in short supply in many countries. This research has shown that far-UVC lighting could provide an alternative, safe and inexpensive way to mitigate SARS-CoV-2 transmission. We found that far-UVC illumination in poorly ventilated spaces can be as effective as N95 masks in preventing transmission. With detailed and accurate computational fluid dynamics modelling, we were able to track and eliminate the airborne transmission of pathogens.
Further details of the research carried out can be found here on Nature Scientific Reports.
In conclusion, UV-C light is definitely effective in reducing the risk of Coronavirus. While it may not be a universal treatment, this is something that can be integrated with latest technology in washrooms and popular hotspots to reduce the risk. Automatic soap dispensers have risen in popularity, UVC lights can now be found in electric hand dryers that further improve your personal hygiene and we won’t be surprised by other innovative designs and ideas too.