Ultraviolet (UV) rays kill the new coronavirus. They can also kill or damage human cells. However, Japanese researchers from Hiroshima University have found that lower-wavelength UV rays (in the form of far-UVC light) can kill the virus without harming humans.
Regular UV light has a wavelength of 254 nm and can irradiate human tissue, harming eyes and skin. However, UVC light, at wavelength of 222 nm, is just as germicidal as regular UV light but cannot penetrate the eyes or skin. Light in the range of 207-222 nm is called far-UVC.
In the study, published in the American Journal of Infection Control, the researchers applied UV light to lab samples containing the SARS-CoV-2 virus using a Care222 krypton-chloride excimer lamp from Ushio. This lamp provides 222-nm UV rays. After 30 seconds of exposure, the light killed 99.7% of the viral particles. A June 2020 study from Columbia University also found that far-UVC light set between 207 and 222 nm could kill up to 90% of coronaviruses and other pathogens in 8 minutes.
Because far-UVC light isn’t harmful, it could be used not only to sterilize work areas in hospitals. To stop seasonal viruses, it also could be used in “overhead far-UVC lamps” hung in public spaces. According to the Hiroshima University researchers, far-UVC also destroys the H1N1 influenza virus.
Disclaimer: This article does not provide medical advice. Do not take action based solely on this article and always consult with an appropriate healthcare professional. This article is purely for informational purposes.