Ultraviolet light can be a double-edged sword. On the one hand, it is characterized by being highly mutagenic, that is, it is capable of changing the composition of human DNA, deforming its chain and causing alterations that are especially reflected in the skin, such as spots, wrinkles and even cancer. However, in the search for alternatives to fight COVID-19, Japanese scientists have discovered a type of ultraviolet light that kills the coronavirus without producing harmful effects.
Experts from the University of Hiroshima found that ultraviolet light radiation with very specific characteristics can eliminate 88.5 percent of coronavirus molecules in just 10 seconds of exposure, while after 30 seconds 99.7 percent are eliminated.
In the lab, the researchers used 222 nanometer wavelength ultraviolet light on SARS-CoV-2 cultures and found good results 10 to 30 seconds after exposure. Longer lapses failed to kill the remaining coronavirus cells, but they believe this minimal surviving would not pose a health risk.
The study, published in the American Journal of Infection Control, points out that UV lamps currently on the market radiate 254 nanometers, a wavelength that is harmful to human skin and eyes, so it can only be used to disinfect empty spaces.
But, they say, an irradiation of 222 nanometers “has a very limited depth of penetration into the skin or eyes and is also an efficient antimicrobial technology. Therefore, a 222 nanometer UVC disinfection system could be used in occupied public spaces, including a hospital room occupied by patients and frequented by healthcare workers and possibly visitors. ”
And although experts point out that more studies are still required to evaluate the safety and efficacy of this type of UV light in inhabited environments, “our results suggest that this technology could be used for the prevention and control of infections against COVID-19, not only in unoccupied spaces but also in occupied spaces ”.