What is UV radiation (light)?
What is UV radiation (light)?
Ultraviolet Light and Your Skin Ultraviolet (UV) light is a type of radiation from the sun that we can not see. The wavelengths of UV light are shorter than the visible light that we see with or that plants and trees use to make sugars.
UV light is divided into three categories, based on wavelength–UV A, B and C.
UV-C is the shortest and is
mostly blocked by the earth’s atmosphere.
It is used artificially in germicidal lamps, the type you might see upon entering an intensive care unit of a hospital.
UV-B is the middle range UV light.
More UV light reaches the earth’s surface (and hence, our skin) during the summer months. UV-B is more damaging in the short term, and is responsible for sunburn and most of our tanning changes.
UV-A is a longer wavelength light.
It produces a more gradual pigment change in our skin, and therefore is the form of radiation used in tanning booths.
However, UV-A penetrates the skin more deeply and therefore is thought to contribute to long term skin damage and immunosuppression (or inability of our skin to fight off skin cancer).
UV-A is responsible for much of the aging effects of the sun on our skin.
The amount of UV-A light that reaches the earth is fairly constant year-round.
It produces a more gradual pigment change in our skin, and therefore is the form of radiation used in tanning booths.
However, UV-A penetrates the skin more deeply and therefore is thought to contribute to long term skin damage and immunosuppression (or inability of our skin to fight off skin cancer).
UV-A is responsible for much of the aging effects of the sun on our skin.
The amount of UV-A light that reaches the earth is fairly constant year-round.