The use of ultraviolet light (UVC) AND Ultraviolet Germicidal Irradiation (UVGI) as a disinfectant has been an accepted medical practice since the middle of the 20th century.
Ultraviolet light transmitted at short wavelengths breaks down the DNA of microorganisms such as coronaviruses, stopping them from reproducing or transmitting further. UVC light does not penetrate the atmosphere, so it has to be replicated in manufactured devices that will emit radiation in controlled doses for set durations.
Light As A Medical Treatment
As early as 1845, scientists had discovered that microorganisms such as bacteria and viruses were adversely affected by exposure to direct light. From that point onwards, medical professionals realised that this was a productive new method in the fight against infectious disease.
Bacteria could be neutralised by unfiltered sunlight, with varying results according to the rays’ strength and the duration of exposure. Simplistically, it explained why colds and influenza were more common during the darkness of winter, and less prevalent in the sunny summer months. Covid-19 transmission rates throughout 2020 have mirrored the same seasonal pattern.
Further research showed that light spectrums ranged through different wavelengths and that shorter wavelengths were much more effective in neutralising viruses and bacteria.
The Discovery of UVGI
In the 1930s, following research that proved that infectious diseases like tuberculosis and measles could be transmitted through the air in small droplets, an American scientist called William F. Wells was the first to propose the use of ultraviolet germicidal irradiation (UVGI) to disinfect the air and surfaces.
Later that decade, Duke University Hospital in North Carolina trialled the use of high-intensity ultraviolet germicidal irradiation (UVGI) to disinfect hospital environments, including operating rooms. Postoperative wound infection rates were immediately reduced from nearly 12% to less than 0.25% as a result.
Other departments and hospitals quickly replicated the procedures used at Duke and reported equally positive results, expanding its use into infant wards to prevent respiratory cross-infections for newborns.
Over the years, more intensive research has found that microbial sensitivity is another variable to be considered, adding to the strength of dosage and the duration of exposure to UVGI.
This means that some viruses will be disabled more quickly by UVGI than others. For example, SARS-Cov-2 requires a greater level of exposure than the HCov-OC43 virus that can cause the common cold.
UVGI became less commonplace as a treatment protocol once antibiotics became more accessible, but a resurgence of drug-resistant tuberculosis in the 1980s saw it being utilised successfully once more.
The global pandemic has accelerated renewed interest in applying UVGI devices to control the person-to-person transmission of airborne pathogens, such as Covid-19.
The technique has nearly a century of successful application behind it, and its time has come again.
Designed and developed to deliver a 22mJ\cm2 dose over a three-metre radius in just 15 minutes, our Muv-X Room steriliser achieves a 6-log kill rating (99.9999% ‘kill’ rate) in disabling all viruses and killing harmful bacteria.
That can make all the difference when you’re responsible for protecting people in public settings from potential exposure to the risk of infection from Covid-19.