Safe ultraviolet light potential to sterilize high-risk COVID-19 environments
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 to 85 percent compared to a room's ventilation alone, according to a new study published in the journal Scientific Reports. The results point to a potential new solution to kill aerosolized novel coronavirus (COVID-19) in enclosed environments such as hospitals and long-term care facilities.
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, the researchers said.
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 nanometers (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, according to the research.
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.
A radiation transport and fluid dynamics model was developed as part of the research to quantify disinfection rates within a 3-meter by 3-meter air-conditioned single occupancy private room, representative of typical environments found in hospitals and long-term care facilities.
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.
"In indoor environments where it may not be possible to socially distance, aerosolized coronavirus released through breathing increases the chance of spreading the disease,” said Liang Yang, PhD, study author and lecturer in the Centre for Renewable Energy Systems at Cranfield University, in a statement. “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 [COVID-19] transmission.”