The Cognitive Revolution · Sunday, August 16, 2026
Vivian Belenky explained that far UVC light (222 nm) is germicidal because it's absorbed by the DNA and RNA of pathogens, as well as proteins. For humans, a 20-micron thick layer of dead skin cells absorbs the light, preventing it from reaching living cells and thus causing damage.
“So, on a chemical biological level, um, the special thing about far UVC is that it is absorbed by the DNA and RNA of pathogens, as well as by essentially all proteins.”
“And this is, uh, very important because the fact that it has so heavily absorbed by proteins is the thing that makes it much safer than other germicidal UVC wavelengths.”
“So, essentially, you know, it's not good for living cells to be exposed to UVC of any wavelength. Um, you know, but the difference is that human cells have a 20-micron thick layer of dead skin cells that are chock full of proteins that essentially absorb all far UVC.”