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Undark
Undark was a trade name for luminous paint made with a mixture of radioactive radium and zinc sulfide, as produced by the U.S. Radium Corporation between 1917 and 1938. It was used primarily in watch and clock dials. The people working in the industry who applied the radioactive paint became known as the Radium Girls, because many of them became ill and some died from exposure to the radiation emitted by the radium contained within the product. The product was the direct cause of radium jaw in the dial painters. Undark was also available as a kit for general consumer use and marketed as glow-in-the-dark paint. Similar products Mixtures similar to Undark, consisting of radium and zinc sulphide were used by other companies. Trade names include: * ''Luna'' used by the Radium Dial Company, a division of Standard Chemical Company and * ''Marvelite'' used by Cold Light Manufacturing Company (a subsidiary of the Radium Company of Colorado) See also * Self-powered lighting * Radiu ...
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Undark (Radium Girls) Advertisement, 1921, Retouched
Undark was a trade name for luminous paint made with a mixture of radioactive radium and zinc sulfide, as produced by the U.S. Radium Corporation between 1917 and 1938. It was used primarily in watch and clock dials. The people working in the industry who applied the radioactive paint became known as the Radium Girls, because many of them became ill and some died from exposure to the radiation emitted by the radium contained within the product. The product was the direct cause of radium jaw in the dial painters. Undark was also available as a kit for general consumer use and marketed as glow-in-the-dark paint. Similar products Mixtures similar to Undark, consisting of radium and zinc sulphide were used by other companies. Trade names include: * ''Luna'' used by the Radium Dial Company, a division of Standard Chemical Company and * ''Marvelite'' used by Cold Light Manufacturing Company (a subsidiary of the Radium Company of Colorado) See also * Self-powered lighting * Radium ...
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Undark Luminous Paint
Undark was a trade name for luminous paint made with a mixture of radioactive radium and zinc sulfide, as produced by the U.S. Radium Corporation between 1917 and 1938. It was used primarily in watch and clock dials. The people working in the industry who applied the radioactive paint became known as the Radium Girls, because many of them became ill and some died from exposure to the radiation emitted by the radium contained within the product. The product was the direct cause of radium jaw in the dial painters. Undark was also available as a kit for general consumer use and marketed as glow-in-the-dark paint. Similar products Mixtures similar to Undark, consisting of radium and zinc sulphide were used by other companies. Trade names include: * ''Luna'' used by the Radium Dial Company, a division of Standard Chemical Company and * ''Marvelite'' used by Cold Light Manufacturing Company (a subsidiary of the Radium Company of Colorado) See also * Self-powered lighting * Radium ...
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Radium Girls
The Radium Girls were female factory workers who contracted radiation poisoning from painting watch dials with self-luminous paint. The incidents occurred at three different factories: one in Orange, New Jersey, beginning around 1917; one in Ottawa, Illinois, beginning in the early 1920s; and a third facility in Waterbury, Connecticut, also in the 1920s. After being told that the paint was harmless, the women in each facility ingested deadly amounts of radium after being instructed to "point" their brushes on their lips in order to give them a fine tip; some also painted their fingernails, face and teeth with the glowing substance. The women were instructed to point their brushes in this way because using rags or a water rinse caused them to use more time and material, as the paint was made from powdered radium, gum arabic and water. Five of the women in New Jersey challenged their employer in a case over the right of individual workers who contract occupational diseases to sue ...
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United States Radium Corporation
- The United States Radium Corporation was a company, most notorious for its operations between the years 1917 to 1926 in Orange, New Jersey, in the United States that led to stronger worker protection laws. After initial success in developing a glow-in-the-dark radioactive paint, the company was subject to several lawsuits in the late 1920s in the wake of severe illnesses and deaths of workers (the Radium Girls) who had ingested radioactive material. The workers had been told that the paint was harmless. During World War I and World War II, the company produced luminous watches and gauges for the United States Army for use by soldiers. U.S. Radium workers, especially women who painted the dials of watches and other instruments with luminous paint, suffered serious radioactive contamination. Lawyer Edward Markley was in charge of defending the company in these cases. History The company was founded in 1914 in New York City, by Dr. Sabin Arnold von Sochocky and Dr. George S. Willi ...
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Luminous Paint
Luminous paint or luminescent paint is paint that exhibits luminescence. In other words, it gives off Visible spectrum, visible light through fluorescence, phosphorescence, or radioluminescence. There are three types of luminous paints: fluorescent paint, phosphorescent paint and radioluminescent paint. Fluorescent paint Fluorescence, Fluorescent paints 'glow' when exposed to short-wave ultraviolet (UV) radiation. These UV wavelengths are found in sunlight and many artificial lights, but the paint requires a special black light to view so these glowing-paint applications are called 'black-light effects'. Fluorescent paint is available in a wide range of colors and is used in Theatrical Lighting, theatrical lighting and effects, posters, and as entertainment for children. The fluorescent chemicals in fluorescent paint absorb the invisible UV radiation, then emit the energy as longer wavelength visible light of a particular color. Human eyes perceive this light as the unusual ...
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Radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha decay ( ), beta decay ( ), and gamma decay ( ), all of which involve emitting one or more particles. The weak force is the mechanism that is responsible for beta decay, while the other two are governed by the electromagnetism and nuclear force. A fourth type of common decay is electron capture, in which an unstable nucleus captures an inner electron from one of the electron shells. The loss of that electron from the shell results in a cascade of electrons dropping down to that lower shell resulting in emission of discrete X-rays from the transitions. A common example is iodine-125 commonly used in medical settings. Radioactive decay is a stochastic (i.e. random) process ...
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Radium
Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium nitride (Ra3N2). All isotopes of radium are radioactive, the most stable isotope being radium-226 with a half-life of 1600 years. When radium decays, it emits ionizing radiation as a by-product, which can excite fluorescent chemicals and cause radioluminescence. Radium, in the form of radium chloride, was discovered by Marie and Pierre Curie in 1898 from ore mined at Jáchymov. They extracted the radium compound from uraninite and published the discovery at the French Academy of Sciences five days later. Radium was isolated in its metallic state by Marie Curie and André-Louis Debierne through the electrolysis of radium chloride in 1911. In nature, radium is found ...
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Zinc Sulfide
Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment. In its dense synthetic form, zinc sulfide can be transparent, and it is used as a window for visible optics and infrared optics. Structure ZnS exists in two main crystalline forms. This dualism is an example of polymorphism. In each form, the coordination geometry at Zn and S is tetrahedral. The more stable cubic form is known also as zinc blende or sphalerite. The hexagonal form is known as the mineral wurtzite, although it also can be produced synthetically.. The transition from the sphalerite form to the wurtzite form occurs at around 1020 °C. A tetragonal form is also known as the very rare mineral called polhemusite, with the formula . Applicatio ...
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Radium Jaw
Radium jaw, or radium necrosis, is a historic occupational disease brought on by the ingestion and subsequent absorption of radium into the bones of radium dial painters. It also affected those consuming radium-laden patent medicines. The symptoms are necrosis of the mandible (lower jawbone) and the maxilla (upper jaw), constant bleeding of the gums, and (usually) after some time, severe distortion due to bone tumors and porosity of the lower jaw. The condition is similar to phossy jaw, an osteoporotic and osteonecrotic illness of matchgirls, brought on by phosphorus ingestion and absorption. The first written reference to the disease was by a dentist, Dr. Theodor Blum, in 1924, who described an unusual mandibular osteomyelitis in a dial painter, naming it "radium jaw". The disease was determined by pathologist Dr. H.S. Martland in 1924 to be symptomatic of radium paint ingestion, after many female workers from various radium paint companies reported similar dental and mandibul ...
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Radium Dial Company
The Radium Dial Company was one of a few now defunct United States companies, along with the United States Radium Corporation, involved in the painting of clocks, watches and other instrument dials using radioluminescent paint containing radium. The resulting dials are now collectively known as radium dials. The luminous paint used on the dials contained a mixture of phosphor and radium, a product that the Radium Dial Company named ''Luna''. However, unlike the US Radium Corporation, Radium Dial Company was specifically set up to only paint dials, and no other radium processing took place at the premises. History The Radium Dial Company was started in 1917 and was in full production of painted dials by 1918. The company was a division of the Standard Chemical Company based in the Marshall Field Annex building in Chicago. In 1920 the company relocated to Peru, Illinois to closer proximity to the clock manufacturer and major customer, Westclox. By 1922 the company had moved t ...
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Self-powered Lighting
Tritium radioluminescence is the use of gaseous tritium, a radioactive isotope of hydrogen, to create visible light. Tritium emits electrons through beta decay and, when they interact with a phosphor material, light is emitted through the process of phosphorescence. The overall process of using a radioactive material to excite a phosphor and ultimately generate light is called radioluminescence. As tritium illumination requires no electrical energy, it has found wide use in applications such as emergency exit signs, illumination of wristwatches, and portable yet very reliable sources of low intensity light which won't degrade human night vision. Gun sights for night use and small lights (which need to be more reliable than battery powered lights, yet not interfere with night vision or be bright enough to easily give away one's location) used mostly by military personnel fall under the latter application. History Tritium was found to be an ideal energy source for self-luminous com ...
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Radium Dials
Radium is a chemical element with the Symbol (chemistry), symbol Ra and atomic number 88. It is the sixth element in alkaline earth metal, group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium nitride (Ra3N2). All isotopes of radium are radioactive, the most stable isotope being radium-226 with a half-life of 1600 years. When radium decays, it emits ionizing radiation as a by-product, which can excite fluorescent chemicals and cause radioluminescence. Radium, in the form of radium chloride, was discovery of the chemical elements, discovered by Marie Curie, Marie and Pierre Curie in 1898 from ore mined at Jáchymov. They extracted the radium compound from uraninite and published the discovery at the French Academy of Sciences five days later. Radium was isolated in its metallic state by Marie Curie and André-Louis ...
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