Continuous low doses of far ultraviolet C (far-UVC) light can stop the flu and other airborne viruses from spreading in indoor public locations, according to a new study published in Scientific Reports.
Researchers at the Center for Radiological Research at Columbia University Irving Medical Center (CUIMC) found that overhead far-UVC light in hospitals, doctors’ offices, schools, airports, airplanes, and other public spaces is a low-cost solution that could ease influenza pandemics.
Scientists have known for decades that broad-spectrum UVC light, which has a wavelength of between 200 to 400 nanometers, or 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,” said study leader David J. Brenner, PhD, the Higgins Professor of Radiation Biophysics at the Vagelos College of Physicians and Surgeons and director of the Center for Radiological Research at Columbia.
Several years ago, Brenner and his colleagues hypothesized that a narrow spectrum of ultraviolet light called 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,” he said. “But because viruses and bacteria are much smaller than human cells, far-UVC light can reach their DNA and kill them,”
Influenza virus spreads from person to person mainly through fine liquid droplets, or aerosols, that become airborne when people with flu cough, sneeze, or talk. The new study was designed to test if far-UVC light could efficiently kill aerosolized influenza virus in the air, in a setting similar to a public space.
In their earlier studies, Brenner’s team demonstrated that far-UVC light was effective at killing MRSA (methicillin-resistant S. aureus) bacteria, a common cause of surgical wound infections but not harm human or mouse skin.
At a price of less than $1,000 US per lamp—a cost expected to decrease if the lamps were mass produced—far-UVC lights are relatively inexpensive. “
And unlike flu vaccines, far-UVC is likely to be effective against all airborne microbes, even newly emerging strains,” Brenner added.