Sunlight is a natural disinfectant, and it has been known for years that sunlight can kill germs. Sunlight is made up of a form of electromagnetic radiation called ultraviolet light (UV light). Interestingly, ultraviolet light has actually been used for years to disinfect objects and to prevent infection. Ultraviolet light-wave radiation works by damaging the genetic material of germs, to prevent them from replicating.
Now, researchers at the National Biodefense Analysis and Countermeasures Center have exposed viruses in simulated saliva to UV light (at a strength equivalent to a sunny day), and found that 90% of the viruses including Covid virus were inactivated. This is only one small study but it is promising.
Scientists are now testing to see if ultraviolet light can be used to sterilize surfaces in elevators, public transportation, hospitals, and other indoor spaces in order to limit the spread of Covid.
Are there risks from ultraviolet light? Direct UV light can cause skin or eye damage, so it should only be used on surfaces, and not directly on our bodies or around our eyes.
UV light being used to disinfect a hospital room: