Via Columbia University Irving Medical Center: New Type of Ultraviolet Light Makes Indoor Air as Safe as Outdoors. Excerpt:
A new type of ultraviolet light that is safe for people took less than five minutes to reduce the level of indoor airborne microbes by more than 98%, a joint study by scientists at Columbia University Vagelos College of Physicians and Surgeons and in the U.K. has found. Even as microbes continued to be sprayed into the room, the level remained very low as long as the lights were on.
The study suggests that far-UVC light from lamps installed in the ceiling could be a highly effective passive technology for reducing person-to-person transmission of airborne-mediated diseases such as COVID and influenza indoors, and lowering the risk of the next pandemic.
“Far-UVC rapidly reduces the amount of active microbes in the indoor air to almost zero, making indoor air essentially as safe as outdoor air,” says David Brenner, PhD, director of the Center for Radiological Research at Columbia University Vagelos College of Physicians and Surgeons and co-author of the study. “Using this technology in locations where people gather together indoors could prevent the next potential pandemic.”
The study was published March 23 in the journal Scientific Reports, a Nature journal.
“Far-UVC light is simple to install, it’s inexpensive, it doesn’t need people to change their behavior, 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 says.
What is far-UVC light?
Disinfecting indoor air with far-UVC light is a new approach to safely and efficiently destroy airborne viruses in occupied spaces, including the viruses that cause COVID and influenza.
Scientists have known for decades that a type of ultraviolet light known as UVC light rapidly kills microbes, including bacteria and viruses. But conventional germicidal UVC light cannot be used directly to destroy airborne viruses in occupied indoor spaces because it is a potential health hazard to the skin and eyes.
About a decade ago, Columbia University scientists proposed that a different type of UVC light, known as far-UVC light, would be just as efficient at destroying bacteria and viruses but without the safety concerns of conventional germicidal UVC.
Far-UVC light has a shorter wavelength than conventional germicidal UVC, so it can’t penetrate into living human skin cells or eye cells. But it is equally efficient at killing bacteria and viruses, which are much smaller than human cells.
In the past decade, many studies around the world have shown that far-UVC is both efficient at destroying airborne bacteria and viruses without causing damage to living tissue. But until now these studies had only been conducted in small experimental chambers, not in full-sized rooms mimicking real-world conditions.
