A specific wavelength of ultraviolet (UV) light is not only extremely effective at killing the virus which causes COVID-19, but is also safer for use in public spaces, finds new research.
The study is the first to comprehensively analyze the effects of different wavelengths of UV light on SARS-CoV-2 and other respiratory viruses, including the only wavelength safer for living beings to be exposed to without protection.
The findings, which the authors refer to as a “game changer” for UV light use, could lead to new affordable, safe, and highly effective systems for reducing viral spread in crowded public spaces like airports and concert venues.
The researchers found that while the virus was quite susceptible to UV light in general, a specific wavelength of Far ultraviolet-C, at 222 nm, was particularly effective. Created by what’s known as a krypton chloride excimer lamp, fueled by molecules moving between different states of energy, this wavelength is very high energy. Therefore, it’s able to inflict greater viral protein and nucleic acid damage to the virus compared to other UV-C devices, as well as be blocked by the very top layers of human skin and eyes — meaning that it has limited to no detrimental health effects at doses that are capable of killing off viruses.
UV light disinfection can even rival the positive effects of improved indoor ventilation by providing the equivalent protection of increased air changes per hour within a room. It’s also much cheaper to install UV lights than to upgrade an entire HVAC system.