Continuous low doses of far-UVC light have been shown to kill airborne flu viruses without harming human tissue. Far-UVC light will offer low-cost solutions to controlling airborne microbial diseases in indoor public spaces. A study conducted by the Center for Radiological Research at Columbia University Irving Medical Center (CUIMC) tested if far-UVC light could efficiently kill aerosolized influenza virus in the air, in a setting similar to a public space.
Researchers tested the efficacy of 222-nm far-UVC light to inactivate influenza A virus (H1N1) carried by aerosols in a benchtop aerosol UV irradiation chamber, which generated aerosol droplets of sizes similar to those generated by human coughing and breathing. The far-UVC light inactivated the flu viruses with about the same efficiency as conventional germicidal UV light.
Scientists have known for decades that broad-spectrum UVC light is highly effective at killing bacteria and viruses by destroying the molecular bonds that hold their DNA together. However, its widespread use in public settings is limited because conventional UVC light sources can lead to skin cancer and cataracts.“Far-UVC light has a very limited range and cannot penetrate through 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,” said professor David J. Brenner.“And unlike flu vaccines, far-UVC is likely to be effective against all airborne microbes, even newly emerging strains.”
The study used single-wavelength far-UVC light generated by filtered excilamps. Use of low-level far-UVC fixtures, which are potentially safe for human exposure, could provide the desired antimicrobial benefits without the accompanying human health concerns of a conventional germicidal lamp UVGI.
Far-UVC light Prevents MRSA Infection
Prevention of superficial surgical wound infections from drug-resistant bacteria such as methicillin resistant Staphylococcus aureus (MRSA) currently present major health care challenges. The majority of surgical site infections (SSI) are believed to be caused by airborne transmission of bacteria alighting onto the wound during surgical procedures. Far-ultraviolet C light in the wavelength range of 207–222 nm is significantly harmful to bacteria, but without damaging mammalian cells and tissues.
Because of the prevalence of the airborne bacteria route, UV exposure during surgery has long been considered as a potential modality for reducing SSI. In fact there have been multiple clinical studies, starting as far back as 1940, demonstrating that UV exposure of the wound during surgery results in markedly decreased SSI rates.
Far-UVC light in the range of 207–222 nm kills bacteria efficiently, but without the skin damaging effects associated with conventional germicidal UV exposure. Another advantage of the ability of far-UVC light to selectively inactivate microorganisms while preserving the viability of mammalian host cells and tissues, is promotion of wound healing and skin homeostasis