Ultraviolet

Ultraviolet (UV) radiation is light (i.e., electromagnetic radiation) of a wavelength shorter than that of visible light, but longer than that of soft X-rays. The name means "beyond violet" (from Latin ultra, "beyond"), violet being the color of visible light of shortest wavelength. UV itself can be subdivided into near UV (200-380 nm wavelength) and extreme or vacuum UV (10-200 nm).

Ultraviolet light is the cause of [skin cancer]?s such as melanoma. The radiation ionises DNA molecules in skin cells, causing mutations which can result in cancerous growths. As a defence to this the body tan?s when exposed to moderate (depending on [skin type]?) levels of radiation by releasing the brown pigment melanin?. This helps to block UV and prevent damage to the vulnerable skin tissues deeper down.

Uses

[Fluorescent lamp]?s work by producing UV light by the stimulated emission of low-pressure mercury gas. A phosphorescent? coating on the tubes absorbs the UV and turns it in to visible light.