Ultraviolet radiation (biology)
Giese, Arthur C. Department of Biological Sciences, Stanford University, Stanford, California.
Last reviewed:July 2018
Show previous versions
- Photobiological effects
- Action spectra
- Effects on the skin
- Clinical use
- Links to Primary Literature
- Additional Readings
Electromagnetic radiation in the wavelength range of 10 to 400 nanometers that affects biological organisms. The ultraviolet (UV) portion of the electromagnetic spectrum includes all radiations from 10 to 400 nanometers (nm); in addition, radiations as low as 4 nm are sometimes included in this range. Radiations shorter than 200 nm are absorbed by most substances, even by air; therefore, they are technically difficult to use in biological experimentation. Radiations between 200 and 320 nm are selectively absorbed by organic matter, and they produce the best-known effects of ultraviolet radiations in organisms. Radiations between 320 and 400 nm are relatively little absorbed and are less active on organisms. In general, though, ultraviolet radiation in sunlight at the surface of the Earth is restricted to the span from about 290 to 400 nm as a result of the protective effects of the Earth's ozone layer. Notably, and in contrast to x-rays, ultraviolet radiations do not penetrate far into larger organisms; thus, the effects that they produce are surface effects, such as sunburn and development of D vitamins from precursors present in skin or fur. Moreover, excessive exposure to the ultraviolet rays in sunlight can cause skin cancer (Fig. 1). See also: Cancer; Electromagnetic radiation; Radiation biology; Radiation injury (biology); Stratospheric ozone; Ultraviolet radiation; Vitamin D
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information