Effect on the skin
UV radiation in general is very energy-rich and has several important meanings for humans. Probably the best known of these is the risk it poses to the skin. Here one must differentiate also again between the effect of the UV-A and the UV-B radiation.
UV-A radiation does not have such a high energetic potential and is therefore hardly responsible for sunburn. Sometimes, however, UV-A rays can lead to a so-called sun allergy or other light-induced skin rashes. The long waves do not penetrate so deeply into the skin, they only reach the dermis.
Therefore, although they lead relatively directly to a tan (this light causes a conformational change in the pigment melanin, which is responsible for coloring the skin), it lasts only a very short time and does not leave a permanent protective layer on the skin. In addition, the radiation can denature proteins in the skin and especially in the collagen fibers contained therein, causing them to lose their shape. However, these effects only become noticeable later in the form of premature skin aging and increased wrinkle formation.
In addition, UV-A light causes indirect damage to the genetic material (DNA), which over time increases the risk of a certain skin cancer, malignant melanoma. UV-B radiation is more energetic and therefore also more dangerous. Since its short waves can penetrate deeper into the skin, they are also associated with a high risk of sunburn.
In return, they also cause the pigment melanin to form in the epidermis, resulting in a delayed but long-lasting tan of the skin, which provides real protection from the sun. UV-B radiation causes direct damage to the DNA by causing strand breaks in the DNA. This in turn increases the risk of skin tumors.The extent of all these dangers increases both with the frequency and intensity of exposure to sunlight and thus UV radiation.
In order to prevent them, one should therefore not spend too much time in the direct, strong sun and always ensure sufficient UV protection with the help of textiles and/or creams or sprays. However, UV radiation does not only have bad effects for humans, quite the contrary! It is absolutely necessary, so that our body can form Cholecalciferol (Vitamin D3) from Cholesterin.
A lack of vitamin D leads to rickets, a disease that is mainly caused by a disturbance of the bone metabolism, but is also associated with muscular disorders and an increased susceptibility to infections. An influence on the condition of the central nervous system and thus on mood has also been described. As a result, many people feel more comfortable in sunlight or suffer from a so-called “winter depression” due to a prolonged lack of light.
It is also assumed that vitamin D can even protect against certain forms of cancer. Beyond that one can make oneself the energy of UV light meanwhile in many ranges use. Only some examples are black light, fluorescent lamps, disinfection and electronics.