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UV-C radiation, as a method of eliminating the coronavirus, is recommended, among others by the World Health Organization and the Chief Sanitary Inspectorate. It is an effective solution for the neutralization of harmful viruses, bacteria and other microorganisms. The method of UV-C irradiation, known for many years, is widely used in hospitals and public places in many countries. In response to the coronavirus pandemic, new virucidal devices using UV-C radiation have appeared on the market.
UV-C lamps that purify the air in rooms where people may stay, effectively reduce the risk of infection. According to Jamie Childress, a Boeing Research & Technology engineer, the UV-C irradiation technology will also find widespread use in disinfecting the interior of passenger planes.
How UV-C radiation works
The technology of air and surface sterilization is based on the viral and bactericidal effect of UV-C radiation, which is part of the light spectrum with a wavelength of 100 to 280 nm. Although naturally generated by the sun, UV-C does not reach Earth due to the protective ozone layer. Artificial UV-C sources are mercury lamps, halogen lamps, lasers and special LED lamps. One of the problems with the use of such UV-C sources is the carcinogenic effect of this radiation on human skin and, as with the entire UV range, its harmfulness to the eyes. This imposes specific requirements on the design of safe sterilizers, especially for home use.
UV-C radiation is particularly effective in eliminating viruses from exposed surfaces and air. Viruses contain nucleic acids, DNA or RNA (as in the case of the COVID-19 coronavirus) that, when infected – entering human or animal cells – cause permanent genetic changes in the victim’s cell. UV-C acts directly on DNA and RNA, changing their chemical structure and, as a result, inactivating the infectivity of viruses.
Washing hands with soap or wiping contaminated surfaces with chemical disinfectants effectively eliminate viruses, however, these methods are very ineffective in the fight against viruses that are suspended in the air in microdroplets. And it is precisely the “clouds” of such suspensions, created as a result of coughing or breathing by people infected with the virus, that are the most dangerous for people in the vicinity. The commonly required wearing of masks is one way to prevent inhalation of droplet virus suspensions, but it would be more effective to systematically sterilize the inhaled air by flow-through UV-C irradiation.
Many decades of research have shown that the UV-C sterilization method is one of the most effective and simplest ways to ensure effective air decontamination or drinking water treatment. Disinfection with UV irradiation is safely used in medical facilities and laboratories.
According to the New York Times, this very method is used to decontaminate hospital rooms where there are patients with deadly infections such as Clostridium Difficile. The same journal reports that in 2014, UV-C was an effective weapon during the Ebola epidemic.
According to the World Health Organization: “Airborne microbial diseases are one of the major challenges for global public health. Typical examples are influenza in seasonal and pandemic forms, and airborne bacterial diseases such as tuberculosis, which are increasingly emerging in multi-drug resistant forms. ”
The COVID-19 coronavirus is currently the greatest epidemiological risk for all of mankind. In the absence of effective drugs and a specific vaccine, the key question has become: How to reduce the risk of infection in rooms where people stay.
There are quite effective methods of disinfecting rooms by ozonation. Their main disadvantage is the need to leave the ozonated room and ventilate thoroughly after using harmful gas. So how do you effectively remove viruses while people are indoors, whether at work or at home?
American researchers from Columbia University conducted detailed tests on the effectiveness of flow devices with a UV-C lamp, which showed that this type of devices, meeting basic safety conditions, effectively eliminated viruses from rooms without harmful effects on people staying in them.
Based on the latest research results, several companies around the world have started producing UV-C flow devices on a mass scale. In the USA, devices generating UV-C radiation are produced by, for example, Bio Tech UV, on the European market examples are the German company IST or the Polish-American brand Sayoli.
How does the flow-through UV-C lamp work?
Innovative solutions allow the use of flow devices with a built-in UV-C lamp, which allows for continuous disinfection of the air. The special construction has been designed in such a way that it is not necessary to leave the room while the sterilizer is operating.
The air contaminated with pathogens is sucked through the inlet openings and then goes to the disinfection chamber. Inside, it is exposed to concentrated high-energy UVC radiation, instantly eliminating viruses and bacteria. The disinfected air leaves the device through the exhaust vents. Air movement is forced thanks to the use of a fan for continuous operation, characterized by a low noise level.
The lamp emitting UV-C radiation is covered with a special reflector, so the light is not emitted to the outside. Thus, even during operation, the device is completely harmless to eyesight or skin.
Types of flow-through UV-C sterilizers
The flow-through UV-C lamps are manufactured in various sizes and equipped with lamps and fans of various capacities.
Small portable models can be taken with you as a personal “antivirus shield”. Large stationary models will clean the air of pathogens not only around us, but also in larger rooms, such as offices, classrooms and courtrooms.
Where can sterilizers with a built-in UV-C lamp be used?
Leading American epidemiologist, Dr. Russell Olmsted, recommends the use of UV-C radiation sterilization devices, including flow devices with a built-in lamp. In the USA, devices of this type are already widely used, incl. in waiting rooms and offices. In Europe, along with the growing awareness of them, they are also gaining popularity and can be found in medical offices, hairdressing and beauty salons, restaurants and hotel rooms.
There are no restrictions as to the time of staying near the lamp or the distance that should be kept when the device is working, so they will be used wherever people meet on a daily basis, where customers are received.
Flow sterilizers can work continuously, quietly, consuming a small amount of electricity, reducing the risk of infections in service points, workplaces, but also in private homes and vehicles.
The recommendations and directives of the Ministry of Health, the State Sanitary Inspection and the Polish Association for the Development of Medical Sterilization and Disinfection show that in Poland, every medical and service facility is obliged to ensure the safety of each patient and client, including by using available sterilization devices. Flow-through UV-C sterilizers may become one of the most important, effective and most desirable methods of ensuring such safety.
EU funding for UV-C sterilizers
The necessity to supply service points with devices for purifying the air from pathogens has been noticed by local authorities. In order to improve the operation of businesses as well as possible and to try to facilitate their return to the level of functioning from before the pandemic, marshal offices are successively launching subsidy programs for the purchase of such devices.
An example is the new program: “Investment Support Fund. Equipping retail outlets with air filtering devices. Scheme designed for micro-enterprises. ”, In which a micro-entrepreneur from the Kujawsko-Pomorskie voivodeship could receive up to PLN 2 from the Marshal’s Office for the purchase of a sterilizer. Similar programs are under preparation in other Polish provinces.
SOURCES:
https://www.tandfonline.com/doi/pdf/10.1080/02786821003762411
https://www.ist-uv.com/en/technology/steritube-air-sterilisation
https://biotechuv.com/pages/the-uvc-light-technology
https://sayoli.eu/covid19/