UltraViolett

Ultraviolet (UV) radiation is a form of electromagnetic radiation with wavelengths shorter than visible light, but longer than X-rays. It is invisible to the human eye but can be detected using special instruments. UV radiation is categorized into three main types based on its wavelength: UV-A, UV-B, and UV-C.

UV-A radiation has the longest wavelengths, ranging from 315 to 400 nanometers (nm). It is the most abundant type of UV radiation reaching the Earth's surface and is responsible for tanning of the skin. UV-B radiation has wavelengths between 280 and 315 nm. It is the primary cause of sunburn and is also linked to skin cancer. UV-C radiation has the shortest wavelengths, ranging from 100 to 280 nm. It is almost entirely absorbed by the Earth's ozone layer and does not reach the surface.

UV radiation is produced by the Sun and by artificial sources such as tanning beds and certain types of lamps. It has various applications in industry, medicine, and science, including sterilization, fluorescence, and the production of vitamin D. However, excessive exposure to UV radiation can be harmful to living organisms, causing skin damage, eye damage, and suppression of the immune system.

The ozone layer in the Earth's stratosphere plays a crucial role in protecting life on Earth by absorbing most of the Sun's UV-C and a significant portion of UV-B radiation. Depletion of the ozone layer due to human activities, such as the use of chlorofluorocarbons (CFCs), has raised concerns about increased UV radiation reaching the Earth's surface, which could have adverse effects on human health and ecosystems.