A BAHRAINI research team has debunked claims that ultraviolet (UV) lights it studied can kill the coronavirus (Covid-19).
A study by Bahrain University and the Health Ministry has found that while commercially available UV ceiling lights could kill certain bacteria and fungi – it had no effect on the coronavirus.
UV radiation can be classified into three types based on wavelength – UVA, UVB and UVC – of which UVC has the highest energy.
“Many researchers in the field believe that UVC destroys the virus by warping the genetic material and preventing the viral particles from reproduction,” the university’s academic programmes and postgraduate studies vice-president Dr Waheeb Al Nasser, who led the study, said.
“This is not true.”
The team’s findings are revealed in the research paper “The Null Effect of UVC Ceiling Light Exposure on SARS-CoV2”.
Dr Al Nasser said the study assumes relevance as adverts promoting the sale of UVC lamps that kill Covid virus have surfaced on social media.
“In this paper, we report the result of our novel experiment on the effects of UVC on the virus using a commercially available UVC source – the Krypton Disinfection lighting – which is sold and marketed for the disinfection of pathogens,” Dr Al Nasser said.
“Our findings revealed that it has no effect on the virus when it is close to the culture plate (at 4cm-5cm) or at a distance of 2m-2.9m – which is when fixed to the ceiling.
“This observation is important as the public seems to have the impression that commercial UVC ceiling light can kill the virus, while this study has proven the opposite.”
The study found that UVC light could be effective for disinfection as it destroys certain bacteria and fungus in 30 seconds when it is at 2.9m or less away from them and through one-day exposure.
The use of a ceiling fan is also important, stressed the study, “as it draws polluted air upwards leading to all floating bacteria, viruses and fungi getting zapped quickly and all surfaces in the room are disinfected”.
“The Ultraviolet Light UVC destroys the genetic material in pathogens, DNA in bacteria and fungi and RNA in viruses – hurdling them from reproducing,” he said.
“Our results revealed that when exposing UVC to bacteria and fungus there was a substantial effect – the more the UVC exposure, the smaller the microbial growth.
“Several artificial sources for producing UV radiation have been devised such as tanning booths, black lights, curing lamps, germicidal lamps, mercury vapour lamps, halogen lights, high-intensity discharge lamps, fluorescent and incandescent sources as well as some types of lasers.
“However, commercially available UVC ceiling lights had no effects on SARS-CoV2 despite claims in advertisements and catalogues.”
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