Making the air indoors as safe as the air outdoors is key to preventing the rapid and deadly person-to-person transmission of airborne diseases like COVID – which is where ultraviolet light comes in.
In a recent joint study led by scientists from the UK and the Columbia University Vagelos College of Physicians and Surgeons, a new kind of ultraviolet light proved successful in cutting airborne microbes indoors by 98%.
Dr David Brenner, director of the Center for Radiological Research at Vagelos College, says installing far-UVC light from lamps fixed into the ceilings is technology that “could prevent the next potential pandemic.”
“Far-UVC light is simple to install, it’s inexpensive, it doesn’t need people to change their behaviour, and evidence from multiple studies suggests it may be a safe way to prevent the transmission of any virus, including the COVID virus and its variants, as well as influenza and also any potential future pandemic viruses,” Brenner said.
For decades scientists have known UVC light destroys microbes. The problem was that conventional germicidal UVC light also damages skin cells and eye cells. But the wavelength of the new far-UVC version is far shorter and cannot penetrate skin in this way.
In the study, scientists at the University of St. Andrews, University of Dundee, University of Leeds, and Columbia University trialled the technology in a massive room-sized chamber, set up with the same ventilation characteristics as an average home or office. Sprayers were used to fire microbes into the room and when the lamps were turned out 98% of them were vaporised.
“Our trials produced spectacular results, far exceeding what is possible with ventilation alone,” said Dr Kenneth Wood, lecturer in the School of Physics and Astronomy at the University of St. Andrews and senior author of the study. “In terms of preventing airborne disease transmission, far-UVC lights could make indoor places as safe as being outside on the golf course on a breezy day at St Andrews.”
The technology is a bit of a silver bullet as well. It works effectively, regardless of any variants that develop and – because it kills microbes, viruses can’t develop resistance to it.
“What’s particularly attractive about far-UVC technology as a practical method of preventing indoor disease transmission is that it will be equally good at inactivating all future COVID variants, as well as new infectious viruses that have yet to emerge, while retaining efficacy against ‘old fashioned’ viruses like influenza and measles,” added Brenner.