Far-ultraviolet C (far-UVC) light can kill flu viruses and placing it in spaces like hospitals, airports, and schools could reduce the incidence of flu infections, according to a new study.
The far-UVC light does not damage human tissues. It has been known for a while now that broad spectrum UVC light has the power to kill bacteria and viruses by breaking molecular bonds.
This light is also used to sterilize surgical equipment. However conventional germicidal lamps using broad-spectrum UVC light are not safe for humans to be around. They can cause skin cancer and cataracts in the eyes with prolonged exposure.
“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.” said study leader David J. Brenner, director of the Center for Radiological Research at Columbia University Irving Medical Center.
However, this study did not use broad-spectrum UV light, it used far-UVC light, which is a narrow spectrum of radiation.
“This type of UV is also effective against illnesses and 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,” Brenner said in the study.
Far-UVC safe for humans
Until recently conventional UV-light was only really practical when people were not around. The Columbia team came up with a possible solution about five years ago. Light on the far end of the UV-C spectrum, known as far-UVC, has very short wavelengths. The researchers, led by Brenner, suspected it can penetrate and destroy microscopic bacteria and viruses. They discovered that it cannot travel through the protective outer layers of human skin or eyes.
“We wanted to get all the benefits of UV light in terms of killing microbes, but none of the health hazards. We haven’t seen any biological damage to skin cells or eye cells, whereas with conventional UV light we’ve always seen lots of biological damage,” Brenner said.
Earlier studies have shown that exposure to far-UVC light does indeed appear to be safe. In their new study, Brenner and his colleagues released aerosolized particles of the H1N1 seasonal flu virus into a test chamber and exposed them to very low doses of far-UVC light. The light inactivated the viruses with about the same efficiency as conventional germicidal UV light. A control group of bacteria not exposed to light remained active.
Brenner and his colleagues have thus shown that UVC light can effectively kill airborne influenza.
Deadly flu bouts
In the US, this year has been accompanied with an especially deadly flu season. It is forecast to be more deadly than the Swine Flu of 2009-2010, killing about 4,000 people a week.
Researchers continue to work to better understand and explain flu and are working on more effective and accessible treatments. The study on far-UVC light very low doses can inactivate flu viruses, but the results still need to be recreated and explored in a variety of settings.
However, this finding can be a powerful tool if it is confirmed that this type of light can kill flu viruses without causing any human harm. This could mean that overhead lights could be placed in medical facilities, public spaces, and even homes which would act to wipe out exposed viruses, stopping them from spreading and infecting new people.