Ultraviolet B
One of the three types of invisible light rays (together with ultraviolet A and ultraviolet C) given off by the sun. Although ultraviolet C is the most dangerous type of ultraviolet light in terms of its potential to harm life on earth, it cannot penetrate earth's protective ozone layer. Therefore, it poses no threat to human, animal or plant life on earth. Ultraviolet A and ultraviolet B, on the other hand, do penetrate the ozone layer in attenuated form and reach the surface of the planet. Because ultraviolet A is weaker than ultraviolet B, scientists long blamed ultraviolet B as the sole culprit in causing skin cancer in persons with a history of sunburn and repeated overexposure to ultraviolet radiation. Recent research, however, has also implicated ultraviolet A as a possible cause of skin cancer. In addition to natural light from the sun, artificial light from tanning lamps contains ultraviolet A and ultraviolet B. Electric arc lamps can also generate ultraviolet light to heat furnaces for melting and to enable motion-picture projectors to show movies. Though ultraviolet light can damage health, it can also maintain or improve health. When ultraviolet light strikes human skin, it triggers the production of vitamin D, which promotes the growth of bones and teeth.

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ultraviolet B -'bē n UVB

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(UVB) ultraviolet radiation with wavelengths between 290 and 320 nm; this constitutes less than 1 per cent of the ultraviolet radiation reaching the earth's surface. UVB causes sunburn and a number of damaging photochemical changes within cells, including damage to DNA, leading to premature aging of the skin, premalignant and malignant changes, and a variety of photosensitivity reactions; it is also used therapeutically in the treatment of skin disorders.

Medical dictionary. 2011.

Look at other dictionaries:

  • ultraviolet-B — ultravioletinis B spektras statusas T sritis Standartizacija ir metrologija apibrėžtis Ultravioletinės spektro srities (ultravioleto srities vidurys) dalis, esanti nuo 280 nm iki 315 nm. Ši sritis iš dalies patenka į saulės spinduliuotės spektrą …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • ultraviolet-B — ultravioletinis B spektras statusas T sritis fizika atitikmenys: angl. ultraviolet spectrum B vok. Ultraviolett B, n rus. спектр В ультрафиолетового излучения, m pranc. ultraviolet B, m …   Fizikos terminų žodynas

  • ultraviolet B — /ʌltrəˌvaɪələt ˈbi/ (say ultruh.vuyuhluht bee) noun a form of ultraviolet light which causes sunburn of the skin and which can damage the cornea and lens of the eye. Abbrev.: UVB Compare ultraviolet A …   Australian English dictionary

  • ultraviolet B — electromagnetic radiation with a wavelength of between 280 and 320 nanometers, radiant component of sunlight which causes sunburn and skin cancer, UVB …   English contemporary dictionary

  • ultraviolet B — noun : UVB herein …   Useful english dictionary

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  • Ultraviolet radiation — Invisible rays that are part of the energy that comes from the sun. Ultraviolet radiation can burn the skin and cause skin cancer. Ultraviolet radiation is made up of three types of rays ultraviolet A, ultraviolet B, and ultraviolet C. Although… …   Medical dictionary

  • Ultraviolet A — One of the three types of invisible light rays (together with ultraviolet B and ultraviolet C) given off by the sun. Although ultraviolet C is the most dangerous type of ultraviolet light in terms of its potential to harm life on earth, it cannot …   Medical dictionary

  • Ultraviolet C — One of the three types of invisible light rays (together with ultraviolet A and ultraviolet B) given off by the sun. Although ultraviolet C is the most dangerous type of ultraviolet light in terms of its potential to harm life on earth, it cannot …   Medical dictionary

  • ultraviolet spectrum B — ultravioletinis B spektras statusas T sritis Standartizacija ir metrologija apibrėžtis Ultravioletinės spektro srities (ultravioleto srities vidurys) dalis, esanti nuo 280 nm iki 315 nm. Ši sritis iš dalies patenka į saulės spinduliuotės spektrą …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

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