These 3 rays fall in the ‘harmful’ category because they are ionizing and their long-term exposure is very harmful to humans. They can tear our bodies apart to go inside and change our DNA. Now, in the ultraviolet range there are 3 categories of UV rays. UV-A is a wavelength of 315-400 nm. UV-B is a wavelength of 280-315 nm. And UV-C is a wavelength of 100-280 nm. UV-C has the smallest wavelength and is the most dangerous. Followed by UV-B and then UV-A.
Our ozone layer stops X-rays, gamma rays, and UV-C rays from reaching the Earth. UV-B radiation is only partially absorbed by the ozone layer. And UV-A is not absorbed at all. And it passes through the ozone layer. That’s why sunscreens protect us from UV-A and the remaining UV-B radiation. Most of the sunscreens protect you from UV-B radiation only.
That’s why you are always told to buy broad-spectrum sunscreen. A sunscreen that protects you from both UV-A and UV-B radiation. When we talk about the depletion of the ozone layer, you can understand how threatening it is, because then UV-C radiation could reach the Earth. Along with other harmful rays.
