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Ultraviolet ( UV) light is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and ...
May 31, 2024 · ultraviolet radiation, that portion of the electromagnetic spectrum extending from the violet, or short-wavelength, end of the visible light range to the X-ray region. . Ultraviolet (UV) radiation is undetectable by the human eye, although, when it falls on certain materials, it may cause them to fluoresce—i.e., emit electromagnetic radiation of lower energy, such as visible
- The Editors of Encyclopaedia Britannica
- Ultraviolet radiation is the portion of the electromagnetic spectrum extending from the violet, or short-wavelength, end of the visible light range...
- Ultraviolet radiation is produced by high-temperature surfaces, such as the Sun’s, in a continuous spectrum and by atomic excitation in a gaseous d...
- No, ultraviolet radiation is undetectable by the human eye. Many insects, however, are able to see ultraviolet radiation.
- Ultraviolet radiation is useful as both a research tool and a sterilizing technique. It can also be used in fluorescent lamps, which are a more ene...
- The three basic skin cancers, basal- and squamous-cell carcinoma and melanoma, have been linked to long-term exposure to ultraviolet radiation and...
Mar 9, 2016 · Solar emissions include visible light, heat and ultraviolet (UV) radiation. Just as visible light consists of different colours that become apparent in a rainbow, the UV radiation spectrum is divided into three regions called UVA, UVB and UVC. As sunlight passes through the atmosphere, all UVC and most UVB is absorbed by ozone, water vapour ...
- Everyone is exposed to UV radiation from the sun and an increasing number of people are exposed to artificial sources used in industry, commerce an...
- Ozone is a particularly effective absorber of UV radiation. As the ozone layer gets thinner, the protective filter activity of the atmosphere is pr...
- The three types of UV radiation are classified according to their wavelength. They differ in their biological activity and the extent to which they...
- Time of year and time of day UV levels vary mainly with the height of the sun in the sky and in mid-latitudes are highest during the summer months...
- Overview
- Health Effects
- People at Particular Risk
- Protective Measures
- Who Response
Ultraviolet radiation (UVR) can neither be seen nor felt. While some people are exposed to artificial UVR sources (e.g. in medicine, industry and for disinfection and cosmetic purposes), everyone is exposed to solar UVR. Solar UVR levels are influenced by several factors: 1. Sun elevation: the higher the sun in the sky, the higher the UVR level. UV...
Small amounts of UVR are beneficial to health and play an essential role in the production of vitamin D. However, excessive exposure to UVR is associated with negative health consequences as UVR is carcinogenic to humans.
Children and adolescents are particularly vulnerable to the harmful effects of UVR due to their skin and eye structure. Sunburns in childhood lead to a higher risk of skin cancer in later life. Also, a larger amount of UVR can reach and damage their retina. Fair-skinned people suffer more from sunburn and have a higher risk of skin cancer than dark...
Skin cancer is highly preventable. WHO recommends the following measures to protect against excessive exposure to UVR. 1. Limit time in the midday sun. 2. Seek shade. 3. Wear protective clothing. 4. Wear a broad brimmed hat to protect the eyes, face, ears and neck. 5. Wear wraparound-style sunglasses that provide 99 to 100% UV-A and UV-B protection...
WHO aims to reduce the burden of disease resulting from exposure to UVR. It encourages research, develops guidance and disseminates information tools about effective UVR protection interventions related to the public, occupationally exposed workers and patients. The Global Solar UV index (UVI), an information tool that describes the level of solar ...
Aug 10, 2016 · ULTRAVIOLET LIGHT FROM OUR SUN. The Sun is a source of the full spectrum of ultraviolet radiation, which is commonly subdivided into UV-A, UV-B, and UV-C. These are the classifications most often used in Earth sciences. UV-C rays are the most harmful and are almost completely absorbed by our atmosphere. UV-B rays are the harmful rays that cause ...
Aug 24, 2023 · Ultraviolet (UV) radiation is one part of the electromagnetic spectrum of radiation that reaches Earth from the sun. It is a form of light energy situated on the spectrum just beyond visible light.
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