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	Ultraviolet - Wikipedia, the free encyclopedia
		UV radiation is often used in visible spectrophotometry to determine the existence of fluorescence a given sample.
		Ultraviolet radiation is used for very fine resolution photolithography, a procedure where a chemical known as a photoresist is exposed to UV radiation which has passed through a mask.
		UV detectors which are sensitive to UV light in any part of the spectrum respond to irradiation by sunlight and artificial light.
	en.wikipedia.org /wiki/UV_radiation (3408 words)

	EPA SunWise: UV Radiation
		UV intensity tends to be highest during the summer months.
		At higher latitudes the sun is lower in the sky, so UV rays must travel a greater distance through ozone-rich portions of the atmosphere and, in turn, expose those latitudes to less UV radiation.
		UV intensity increases with altitude because there is less atmosphere to absorb the damaging rays.
	www.epa.gov /sunwise/uvradiation.html (526 words)

	EO Library: Ultraviolet Radiation Fact Sheet
		Ultraviolet (UV) radiation that reaches the Earth’s surface is in wavelengths between 290 and 400 nm (nanometers, or billionths of a meter).
		Yet UV radiation at different wavelengths differs in its effects, and we have to live with the harmful effects as well as the helpful ones.
		Radiation at the longer UV wavelengths of 320-400 nm, designated as UV-A, plays a helpful and essential role in formation of Vitamin D by the skin, and plays a harmful role in that it causes sunburn on human skin and cataracts in our eyes.
	earthobservatory.nasa.gov /Library/UVB (600 words)

	Ultraviolet Radiation CDFS-199-98
		UV radiation causes premature aging of the skin (wrinkles, dryness, and age spots), cataracts (a permanent clouding of the eye), and immunosuppression (lowered resistance to infection).
		UV exposure is also a risk factor in the development of pterygium, a fleshy growth that invades the corner of the eye; and degeneration of the macula lutea, the small yellowish area lying slightly to the side of the center of the retina that constitutes the region of maximum visual acuity.
		The maximum UV radiation level occurs when the sun reaches its highest point in the sky (solar noon), and decreases until it is about 50 percent of this level three hours before or after the sun reaches its peak.
	ohioline.osu.edu /cd-fact/0199.html (2975 words)

	Climate Prediction Center - Stratosphere: UV Index: Nature of UV Radiation
		UV-A radiation is needed by humans for the synthesis of vitamin-D; however, too much UV-A causes photoaging (toughening of the skin), suppression of the immune system and, to a lesser degree, reddening of the skin, and cataract formation.
		However, the amount of UV radiation reaching the surface at these larger solar zenith angles is much less than at smaller solar zenith angles.
		Showing how the UV dose rate varies throughout the day, Figure 4 represents a typical mid-summer, diurnal curve of erythemally weighted UV dose rates at 20øN, 40øN, and 60øN with the same amount of ozone overhead.
	www.cpc.ncep.noaa.gov /products/stratosphere/uv_index/uv_nature.shtml (733 words)

	UV Radiation
		The Impact of Ultraviolet-B Radiation on the Motility of the Freshwater Epipelic Diatom Nitzchia Lineariz.
		The UV quantity absorbed by these compounds allows a comparison with the absorption characteristics of natural waters and, thus, is a key parameter to determine the role of photoenhanced toxicity in water.
		Since UV-A constitutes a larger fraction of sunlight at the earth surface and in the water column, photolysis by UV-A may increase the toxic risk of aromatic compounds in the marine environment.
	www.fsl.orst.edu /geowater/fishbiblio/Conservation/UV_Radiation.htm (3977 words)

	Ozone Depletion FAQ Part IV: UV Radiation and its Effects
		There seems to a correlation between melanomas and brief, intense exposures to UV (long before the cancer appears.) Melanoma incidence is correlated with latitude, with twice as many deaths (relative to state population) in Florida or Texas as in Wisconsin or Montana, [Wayne] but this correlation does not necessarily imply a causal relationship.
		The artificial UV sources do not have the same spectrum as solar radiation, however, while the filtering experiments do not necessarily isolate all of the variables, even when climate and humidity are controlled by growing the plants in a greenhouse.
		Many experiments have been carried out to determine the response of various marine creatures to UV radiation; as with land plants the effects vary a great deal from one species to another, and it is not possible to draw general conclusions at this stage.
	www.faqs.org /faqs/ozone-depletion/uv (6001 words)

	Measurements of UV Radiation
		When expressed on a relative (percentage) basis, the increases in erythemal UV radiation are seen to correlate closely with ozone reductions, whether the latter stem from natural fluctuations and seasonal cycles, or from systematic long-term depletion.
		The corresponding increases in erythemal UV radiation are estimated to be 130%, 22%, 7%, 4%, and 6%, respectively.
		Clouds generally reduce surface UV irradiances, although the magnitude of this effect is highly variable depending on cloud amount and coverage, cloud cell morphology, particle size distributions and phase (water droplets and ice crystals), and possible in-cloud absorbers (esp. tropospheric ozone).
	www.gcrio.org /UNEP1998/UNEP98p7.html (1910 words)

	Skin Diseases; Sun, UV Radiation; Protection
		The wavelengths of the solar radiation involved are in the ultraviolet (UV) spectrum - from 200-400 nm.
		The increased incidence of cutaneous malignancy from sun exposure and increased UV radiation (UVR) caused by thinning of the stratospheric ozone is now a major health concern.
		UV-B radiation also contributes to the development of melanoma skin cancer and perturbs the body's immune system in ways that can reduce immunity to infectious agents, although magnitude of the impacts cannot yet be estimated.
	www.nutramed.com /skin/uvradiation.htm (1198 words)

	UV Radiation (Site not responding. Last check: 2007-10-01)
		Ultraviolet radiation (or UV) is electromagnetic energy with wavelengths between.2 and.4 microns.
		The sun emits UV radiation as well as radiant energy at other wavelengths, such as the visible.
		UV-A (.32 to.4 microns): The amount of UV radiation at the surface remains fairly constant throughout the year.
	profhorn.aos.wisc.edu /wxwise/AckermanKnox/chap2/uv_radiation.html (213 words)

	Dictionary of Cancer Terms - National Cancer Institute
		UV radiation that reaches the Earth's surface is made up of two types of rays, called UVA and UVB rays.
		Radiation therapy given by injecting a radioactive substance into the bloodstream or a body cavity, or by swallowing it.
		UV rays are invisible rays that are part of the energy that comes from the sun.
	www.cancer.gov /dictionary/db_alpha.aspx?expand=u (1994 words)

	UV Radiation
		The response of organisms to UV radiation depends to a great extent on the spectral composition of the radiation - the wavelengths to which the organisms are exposed.
		Underwater UV and temperature exposures of organisms will depend on interactions between CDOM, temperature, and UV at the ecosystem level, while the response of organisms to a given exposure level will depend largely on the interactive effects of temperature and UV at the molecular level.
		While the higher energy shorter wavelength UV is the most damaging, the absorption and scattering of these shorter wavelengths by ozone and other substances in the atmosphere cause very little of this shorter wavelength UV to reach the Earth’s surface.
	www.users.muohio.edu /willia85/uv_radiation.html (676 words)

	Biodiversity: students speak out; Where Have All the Frogs Gone? UV Radiation and Amphibian Declines by Adrienne Howse
		UV Radiation and Amphibian Declines by Adrienne Howse
		Ultraviolet radiation is a prominent factor in some decline situations, so more attention to date has been focused on this agent.
		Species in which ultraviolet radiation negatively affects their mortality rate, such as the boreal toad and cascade frog, were found to have low levels of photolyase activity.
	www.actionbioscience.org /biodiversity/howse.html (1359 words)

	UV Radiation
		All energies that move at the speed of light are collectivelly referred to as electromagnetic radiation or 'light'.
		Ultraviolet-B(UV-B) is a section of the UV spectrum, with wavelengths between 270 and 320nm.
		One undisputed effect of long-term sun exposure is the premature aging of the skin due to both UV-A, UV-B and UV-C. Even careful tanning kills skin cells, damages DNA and causes permanent changes in skin connective tissue which leads to wrinkle formation in later life.
	www.nas.nasa.gov /About/Education/Ozone/radiation.html (1014 words)

	Ultraviolet Radiation
		Ultraviolet (UV) radiation is defined as that portion of the electromagnetic spectrum between x rays and visible light, i.e., between 40 and 400 nm (30—3 eV).
		Exposure guidelines for UV radiation have been established by the American Conference of Governmental Industrial Hygienists and by the International Commission on Non-Ionizing Radiation Protection.
		Handheld meters to measure UV radiation are commercially available, but expert advice is recommended to ensure selecting the correct detector and diffuser for the UV wavelengths emitted by the source.
	hps.org /hpspublications/articles/uv.html (722 words)

	Impact of UV Radiation on Bacterioplankton Community Composition -- Winter et al. 67 (2): 665 -- Applied and ...
		The potential effect of UV radiation on the composition of coastal marine bacterioplankton communities was investigated.
		Early studies of the attenuation of UV radiation (22) indicated that the UV range of the solar spectrum is attenuated within
		UV radiation induces DNA damage via the formation of cyclobutane and pyrimidine-pyrimidone dimers (21, 27).
	aem.asm.org /cgi/content/full/67/2/665 (4890 words)

	TEMIS -- UV radiation monitoring
		An important issue closely related to the ozone concentrations in the atmosphere is the intensity of the UV radiation that reaches the Earth's surface.
		UV index forecasts are derived from assimilated ozone measurements by SCIAMACHY.
		The clear-sky UV index and the erythemal UV daily dose are based on the CIE action spectrum for the susceptibility of the caucasian skin to sunburn (erythema).
	www.temis.nl /uvradiation (312 words)

	NOAA ARL Interagency Program on Ultraviolet Radiation
		In fact, detailed measurements of UV are one method by which scientists keep track of the total amount of ozone contained in the atmosphere.
		A central UV calibration facility (CUCF) has been established in Boulder, Colorado, where new UV standards provided by the National Institute for Standards and Technology are used to calibrate network instruments.
		The EPA intramural research focuses on the interactive effects of climate change and UV radiation on nutrient and carbon cycles in coastal waters of the Southeast and the role of UV exposure in amphibian deformities and declines through laboratory and field studies.
	www.arl.noaa.gov /research/programs/uv.html (2295 words)

	What are the effects of UV radiation?
		The photochemical effects of UV radiation can be exacerbated by chemical agents including birth control pills, tetracycline, sulphathizole, cyclamates, antidepressants, coal tar distillates found in antidandruff shampoos, lime oil, and some cosmetics.
		Exposure guidelines for UV radiation have been established by the American Conference of Government Industrial Hygienists and by the International Commission on Nonionizing Radiation Protection.
		Hand-held meters to measure UV radiation are commercially available, but expert advice is recommended to ensure selecting the correct detector and diffuser for the UV wavelengths emitted by the source.
	hps.org /publicinformation/ate/q211.html (897 words)

	UV & Ozone - NIWA Science (Site not responding. Last check: 2007-10-01)
		The UV index is a standard measurement of erythemal (sun-burn causing) UV intensity that gives a more objective measure than the old “time to burn” (which cannot account for skin tone).
		The aim of the UV Atlas project is to produce maps and time series of parameters describing the UV radiation environment over New Zealand since 1960.
		A suite of radiation sensors from the USDA (Department of Agriculture) was installed at Lauder on 20 November 2001.
	www.niwascience.co.nz /services/uvozone/index.html (692 words)

	Prevent Blindness America - UV Safety
		UV rays are an invisible form of radiation that causes sunburn.
		Yes, everyone (including children) is at risk for eye damage from UV radiation that can lead to vision loss.
		Both a wide-brimmed hat or cap and UV absorbing eyewear will reduce the amount of UV you are exposed to.
	www.preventblindness.org /safety/UVFAQ.html (367 words)

	UV radiation and skin cancer
		Extensive clinical and epidemiological evidence indicates that exposure to the ultraviolet (UV) component of sunlight is the main causative factor in the development of skin cancers [4-7].
		It is believed that decreases in stratospheric ozone (which shields the earth from short wavelength UV) [8], socio-economic factors that permit more time for outdoor leisure activities, and current societal standards which consider tanned skin attractive account (at least in part) for the recent increases in cutaneous malignancies by increasing cutaneous UV exposure [9].
		Although UV-A accounts for almost 95% of UV radiation to reach the surface of the earth, it accounts for less than 25% of the associated skin cancer risk [11].
	murray.francis.com /repair/3-UVcancer.htm (1409 words)

	Changes in UV radiation in the Arctic - Weatherhead
		UV effects on ecosystems are widespread, affecting individual species-particularly at the base of the food chain-as well as the relative abundance of species.
		Certain phytoplankton, for instance, are especially sensitive to UV, and reductions in their populations impact not only the individual species, but also organisms that compete with or feed on these populations.
		Higher UV levels can be particularly damaging to these larvae, and a reduction in the number of larvae reaching maturity can mean dramatic impacts for the fishing industry.
	www.arctic.noaa.gov /essay_weatherhead.html (751 words)

	Surface UV radiation - NIWA Science
		Determine if recently identified upward summertime trends in UV are slowing in response to the expected recovery of the ozone layer, or whether they are continuing as a result of a climate change induced delay in Antarctic ozone hole recovery.
		Relate UV measurements in New Zealand to those in other locations where UV is thought to be intense to determine the risk for New Zealand in relation to other locations.
		Develop and test radiative transfer models to map past, present and predicted future changes in ozone to changes in surface UV irradiance, and improve the accuracy of these models by incorporating other important factors affecting surface UV, such as clouds.
	www.niwascience.co.nz /rc/prog/ozone/intro/surface (522 words)

	[No title]
		From a biological viewpoint, UVB radiation is by far the most significant part of the terrestrial ultraviolet spectrum and the levels of radiation in this waveband reaching the surface of the Earth are largely controlled by ozone, a gas which comprises approximately one molecule out of every two million in the atmosphere.
		Radiation detectors used for monitoring solar UVR are commonly designed (Robertson 1972, Berger 1976) to have a spectral sensitivity which is a close match to the action spectrum for ultraviolet-induced erythema (see figure 7).
		The radiation dose recorded by these instruments is in units of 'minimal erythema dose', or MED, where one MED can be thought of as equivalent to that amount of solar exposure that produces a just perceptible reddening of unacclimatized white skin 24 h after exposure.
	www.ciesin.org /docs/001-503/001-503.html (11230 words)

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