UV light can kill virus without harming humans

In the scramble for an effective vaccine for Covid-19 comes a heart-warming US study that claims a strand of ultraviolet (UV) radiation can effectively kill the lethal virus.

Since UV radiation is safer to, the finding may lead to development of a disinfection system for occupied public spaces, including hospitals.

The study has been published in the American Journal of Infection Control. Going into specifics, it says that Ultraviolet-C (UVC) light with a wavelength of 222 nanometres (nm) effectively kills the SARS-CoV-2 virus, and it may not penetrate the human skin. According to researchers, including experts from the Hiroshima university in Japan, previous studies involving 222 nm UVC had thus far only looked at its potency in eradicating seasonal coronaviruses that are structurally similar to the novel coronavirus, but not the SARS-CoV-2 itself.

In this particular study, the researchers spread a 100 microliter solution containing the coronavirus onto a nine-centimetre sterile polystyrene plate. Following this, they allowed it to dry in a biosafety cabinet at room temperature before placing the Far-UVC lamp 24 centimetres above the surface of the plate. The research showed that 99.7 per cent of the SARS-CoV-2 viral culture was killed after a 30-second exposure to 222 nm UVC irradiation.

In the study, the researchers further noted that at this wavelength of 222 nm, UVC cannot penetrate the outer, non-living layer of the human eye and skin.

Citing the limitation of the study, the researchers said they had only investigated the efficacy of 222 nm UVC in lab conditions.

"We did not evaluate this technology in a real-world setting, such as a surface counter-top," the scientists noted.

They suggested further evaluation of the safety and effectiveness of 222 nm UVC irradiation in killing SARS-CoV-2 viruses in real-world surfaces.

(To download our E-paper please click here. The publishers permit sharing of the paper's PDF on WhatsApp and other social media platforms.)

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