How harmful is UV?
Generally, the shorter the wavelength, the more biologically damaging UV radiation can be if it reaches the Earth in sufficient quantity. UV-A, although it is the least energetic form of UV radiation, reaches the Earth in greatest quantity. Most UV-A rays pass right through the ozone layer. UV-B radiation is potentially very harmful. Fortunately, most of the sun’s UV-B radiation is absorbed by ozone in the stratosphere. UV-C radiation is potentially the most damaging because it is very energetic. Fortunately, all UV-C is absorbed by oxygen and ozone in the stratosphere and never reaches the Earth’s surface.
Generally, the shorter the wavelength, the more biologically damaging UV radiation can be if it reaches the Earth in sufficient quantity. UV-A, although it is the least energetic form of UV radiation, reaches the Earth in greatest quantity. Most UV-A rays pass right through the ozone layer. UV-B radiation is potentially very harmful. Fortunately, most of the sun’s UV-B radiation is absorbed by ozone in the stratosphere. UV-C radiation is potentially the most damaging because it is very energetic. Fortunately, all UV-C is absorbed by oxygen and ozone in the stratosphere and never reaches the Earth’s surface.