Ultraviolet (UV) radiation is a form of electromagnetic radiation that comes from the sun and man-made sources like welding torches.
Radiation is the emission of energy from any source. There are many types of radiation, ranging from very high-energy (high-frequency) radiation – like x-rays and gamma rays – to very low-energy (low-frequency) radiation – like radio waves. UV rays are in the middle of this spectrum. They have more energy than visible light, but not as much as x-rays.
There are also different types of UV rays, based on how much energy they have. Higher-energy UV rays are a form of ionizing radiation. This means they have enough energy to remove an electron from an atom or molecule. Ionizing radiation can damage the DNA in cells. But even the highest-energy UV rays don’t have enough energy to penetrate deeply into the body, so their main effect is on the skin.
There are three types of UV rays-
- UVA rays have the least energy among UV rays. These rays can cause skin cells to age and can cause some indirect damage to cells’ DNA. UVA rays are mainly linked to long-term skin damage such as wrinkles, but they are also thought to play a role in some skin cancers.
- UVB rays have slightly more energy than UVA rays. They can damage the DNA in skin cells directly, and are the main rays that cause sunburns. They are also thought to cause most skin cancers.
- UVC rays have more energy than the other types of UV rays. Fortunately, because of this, they react with ozone high in our atmosphere and don’t reach the ground, so they are not normally a risk factor for skin cancer. But UVC rays can also come from some man-made sources, such as arc welding torches, mercury lamps, and UV sanitizing bulbs used to kill bacteria and other germs.