1. Solar spectrum in space (thin line) and on Earth's surface (thick line).
Solar spectrum in space (thin line) and on Earth's surface (thick line). Below the spectrum is an expansion of the UV portion, showing the approximate boundaries between UV-C, UV-B, and UV-A. Also shown is the UV wavelength commonly used in the laboratory (254 nm) and the UV wavelengths incident on the Earth's surface (290 nm and longer). vis, visible; IR, infrared.
Wayne L. Nicholson et al. Microbiol. Mol. Biol. Rev. 2000; doi: /MMBR