Fake news about coronavirus and ordinary fraudsters.
There are many materials and tips on the Internet on how to fight bacteria and viruses. Some of these texts are reliable advice based on scientific research, unfortunately there is also a lot of fake news in the media and on the Internet, which only obscures the image and is misleading. In order not to spend your money on an ineffective gadget, it's worth understanding the basics of devices that are to protect us and our loved ones. Even more so when wrong products or misuse can cause more harm than good.
Let's start from the basics, what is SARS-CoV-2?
Coronavirus, as the name suggests, is a virus and for the purposes of understanding how to fight it should be enough for us. Of course, epidemiologists will point out a number of differences between COVID-19 and e.g. influenza or ebola, but from our perspective, we need a general knowledge of what viruses are and how we can neutralize them. Quoting from Wikipedia:
Viruses (Latin: "poison, venom" virus) - small infectious particles infecting all life forms, unable to multiply outside the host cell [..] The simplest viruses are made of the nucleic acid constituting their genome and the surrounding protein coat called the capsid. They contain one of two nucleic acids - RNA (RNA viruses) or DNA (DNA viruses), which contains the information needed to produce daughter particles [1].
It is worth noting that the SARS-CoV-2 virus is made of RNA, although from the point of view of UV-C radiation it does not matter much.
What is UV radiation?
Ultraviolet, ultraviolet radiation, or UV for short is an electromagnetic radiation with a wavelength of 100 to 400 nanometers (some sources give from 10 nm). UV radiation is invisible to the naked eye because its waves are shorter than visible light. At the same time, the UV wavelength is longer than the X-ray wavelength. From the perspective of fighting coronavirus and any other bacteria or virus, the key is the division of UV radiation due to its impact on the above-mentioned living organisms.
There are three types:
UV-C wavelength 100-280 nm
UV-B wavelength 280-315 nm
UV-A wavelength 315-380 nm
Bacterial and virucidal effects only have radiation with the shortest waves, i.e. UV-C. UV-A and UV-B radiation occur naturally on Earth and correspond to, among others for our tan, they are also used as radiation curing glues and gel nail polishes or fillings in dentistry. Again, however, to fight the virus we only need knowledge about UV-C radiation, because only UV-C neutralizes microorganisms, UV-A and UV-B radiation are not suitable for this. What is the short UV-C wave that effectively kills living organisms and viruses?
How to kill the virus (also SARS-CoV-2 and COVID-19 disease)?
There are many ways to disinfect and fight pathogens effectively. You can use high temperature, there are also chemicals, e.g. alcohol in high concentration or chlorine compounds, and ozonation. All these methods attack and destroy microorganisms from the outside. Ozone-free sterilizing UV-C lamps use a different method. In their case, the wavelength is about 254 nm. This wavelength without obstacles penetrates through cellular structures and fatty coatings and directly strikes RNA and DNA structures causing permanent damage. Such "pierced" protein chains cause the death of microorganisms and their permanent inability to reproduce. As a result, you can sterilize both air and the surfaces.
To better understand the effect of UV-C light on Covid-19, it is worth to look at the picture below. It illustrates how RNA structures of the virus are destroyed by UV-C light.
Is UV-C radiation better than other methods?
In the case of fighting bacteria and viruses, it is difficult to talk about better and worse methods. Much depends on the solutions available. Certainly, however, you can distinguish methods: cheaper and more expensive, faster and slower, safe and dangerous, with proven effectiveness and complete novelty. To better understand the available methods and see the benefits of UV-C radiation, it's best to read the text: 10 reasons why you should use UV-C sterilization.
[1] https://pl.wikipedia.org/wiki/Wirusy 08.05.2020