Safe UV light may sterilise high-risk Covid-19 environments

UVC light is a subtype of one of the three types of electromagnetic radiation with wavelengths shorter than visible light rays.

London: A new research adds to the growing body of evidence that ultraviolet C (UVC) lighting can be a new solution to kill aerosolised Covid-19 in enclosed environments such as hospitals and long-term care facilities.

Computational modelling has shown that low dose far-ultraviolet C (UVC) lighting can be used to disinfect in-room air, increasing disinfection rates by 50-85 per cent compared to a room’s ventilation alone, the study published in the journal Scientific Reports, reported.

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Unlike typical UVC — which has been used to kill microorganisms for decades, but is extremely harmful to humans, potentially causing cataracts or skin cancer — evidence has shown that far-UVC is safe to use around people.

“In indoor environments where it may not be possible to socially distance, aerosolised coronavirus released through breathing increases the chance of spreading the disease,” said study author Liang Yang from the Cranfield University in the UK.

Infection controls focus on a combination of personal hygiene and the correct use of personal protective equipment, which has been in short supply in many countries.

This research has shown that far-UVC lighting could provide an alternative, safe and inexpensive way to mitigate SARS-CoV-2 transmission.

“We found that far-UVC illumination in poorly ventilated spaces can be as effective as N95 masks in preventing transmission,” the researchers wrote.

“With detailed and accurate computational fluid dynamics modelling, we were able to track and eliminate the airborne transmission of pathogens,” they noted.

UVC light is a subtype of one of the three types of electromagnetic radiation with wavelengths shorter than visible light rays.

At 100 to 280 nanometres (nm), UVC has a shorter wavelength than UVA and UVB. Human-safe far-UVC falls in the 207 to 222 nm range and can be produced by special bulbs and lamps and used to disinfect pathogens.

“Far-UVC is safe because it has the unique property of interacting more readily (and loses energy more rapidly) than lower wavelength UVC but is not energetic enough to reach living human cells,” the authors wrote.

Researchers are now hoping to uncover new sources of funding for further investigation and to address outstanding issues necessary to expedite far-UVC light into service.