UV RADIATION. “The other lethal radiation is the high-energy fraction of ultraviolet light (short-wavelength UVB and shorter UVC) in the short-wavelength tail of solar radiation that consists mostly of visible light. UVB is mostly absorbed by a diffuse layer of ozone (O3) in the stratosphere and UVC is scattered to harmlessness by O2 and N2 molecules (which makes Earth’s sky appear blue).”
https://www.sciencedirect.com/science/article/pii/S0012825219302636?via=ihub