Continuous low doses of far-ultraviolet C (far-UVC) light can kill airborne flu viruses without harming human tissues, according to a new study at the Center for Radiological Research at Columbia University Irving Medical Center (New York, NY).1 The findings suggest that use of overhead far-UVC light in hospitals, doctors’ offices, schools, airports, airplanes, and other public spaces could provide a powerful check on seasonal influenza epidemics, as well as influenza pandemics.
Scientists have known for decades that broad-spectrum UVC light, which has a wavelength between 200 and 400 nm, is highly effective at killing bacteria and viruses by destroying the molecular bonds that hold their DNA together. This conventional UV light is routinely used to decontaminate surgical equipment. “Unfortunately, conventional germicidal UV light is also a human health hazard and can lead to skin cancer and cataracts, which prevents its use in public spaces,” says study leader David Brenner.
Several years ago, Brenner and his colleagues hypothesized that far-UVC could kill microbes without damaging healthy tissue. “Far-UVC light has a very limited range and cannot penetrate through the outer dead-cell layer of human skin or the tear layer in the eye, so it’s not a human health hazard. But because viruses and bacteria are much smaller than human cells, far-UVC light can reach their DNA and kill them,” Brenner said.