Background radiation is a measure of the level of ionizing radiation present in the environment at a particular location which is not due to deliberate introduction of radiation sources.
Radium is a chemical element; it has 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 1,600 years. When radium decays, it emits ionizing radiation as a by-product, which can excite fluorescent chemicals and cause radioluminescence. For this property, it was widely used in self-luminous paints following its discovery. Of the radioactive elements that occur in quantity, radium is considered particularly toxic, and it is carcinogenic due to the radioactivity of both it and its immediate decay product radon as well as its tendency to accumulate in the bones.
Radon is a chemical element; it has symbol Rn and atomic number 86. It is a radioactive noble gas and is colorless and odorless. Of the three naturally occurring radon isotopes, only 222Rn has a sufficiently long half-life for it to be released from the soil and rock where it is generated. Radon isotopes are the immediate decay products of radium isotopes. The instability of 222Rn, its most stable isotope, makes radon one of the rarest elements. Radon will be present on Earth for several billion more years despite its short half-life, because it is constantly being produced as a step in the decay chains of 238U and 232Th, both of which are abundant radioactive nuclides with half-lives of at least several billion years. The decay of radon produces many other short-lived nuclides, known as "radon daughters", ending at stable isotopes of lead. 222Rn occurs in significant quantities as a step in the normal radioactive decay chain of 238U, also known as the uranium series, which slowly decays into a variety of radioactive nuclides and eventually decays into stable 206Pb. 220Rn occurs in minute quantities as an intermediate step in the decay chain of 232Th, also known as the thorium series, which eventually decays into stable 208Pb.
Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided.
Radioactive decay 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, beta, and gamma decay. The weak force is the mechanism that is responsible for beta decay, while the other two are governed by the electromagnetic and nuclear forces.
Nuclear chemistry is the sub-field of chemistry dealing with radioactivity, nuclear processes, and transformations in the nuclei of atoms, such as nuclear transmutation and nuclear properties.
Ebenezer McBurney Byers was an American socialite, sportsman, and industrialist. He won the 1906 U.S. Amateur in golf. He died from jawbone cancer after consuming Radithor, a patent medicine made from radium salts dissolved in water.
Radithor was a patent medicine that is a well-known example of radioactive quackery. It consisted of triple-distilled water containing at a minimum 1 microcurie (37 kBq) each of the radium-226 and 228 isotopes.
Radium and radon are important contributors to environmental radioactivity. Radon occurs naturally as a result of decay of radioactive elements in soil and it can accumulate in houses built on areas where such decay occurs. Radon is a major cause of cancer; it is estimated to contribute to ~2% of all cancer related deaths in Europe.
Radium dials are watch, clock and other instrument dials painted with luminous paint containing radium-226 to produce radioluminescence. Radium dials were produced throughout most of the 20th century before being replaced by safer tritium-based luminous material in the 1970s and finally by non-toxic, non-radioactive strontium aluminate–based photoluminescent material from the middle 1990s.
Uranium tailings or uranium tails are a radioactive waste byproduct (tailings) of conventional uranium mining and uranium enrichment. They contain the radioactive decay products from the uranium decay chains, mainly the U-238 chain, and heavy metals. Long-term storage or disposal of tailings may pose a danger for public health and safety.
Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the environment, such as uranium, thorium and potassium and any of their decay products, such as radium and radon. Produced water discharges and spills are a good example of entering NORMs into the surrounding environment.
Radium-226 is the longest-lived isotope of radium, with a half-life of 1600 years. It is an intermediate product in the decay chain of uranium-238; as such, it can be found naturally in uranium-containing minerals.
Uranium tiles have been used in the ceramics industry for many centuries, as uranium oxide makes an excellent ceramic glaze, and is reasonably abundant. In addition to its medical usage, radium was used in the 1920s and 1930s for making watch, clock and aircraft dials. Because it takes approximately three metric tons of uranium to extract 1 gram of radium, prodigious quantities of uranium were mined to sustain this new industry. The uranium ore itself was considered a waste product and taking advantage of this newly abundant resource, the tile and pottery industry had a relatively inexpensive and abundant source of glazing material. Vibrant colors of orange, yellow, red, green, blue, black, mauve, etc. were produced, and some 25% of all houses and apartments constructed during that period used bathroom or kitchen tiles that had been glazed with uranium. These can now be detected by a Geiger counter that detects the beta radiation emitted by uranium's decay chain.
Radon-222 is the most stable isotope of radon, with a half-life of approximately 3.8 days. It is transient in the decay chain of primordial uranium-238 and is the immediate decay product of radium-226. Radon-222 was first observed in 1899, and was identified as an isotope of a new element several years later. In 1957, the name radon, formerly the name of only radon-222, became the name of the element. Owing to its gaseous nature and high radioactivity, radon-222 is one of the leading causes of lung cancer.
Tho-Radia was a French pharmaceutical company making cosmetics between 1932 and 1968. Tho-Radia-branded creams, toothpastes and soaps were notable for containing radium and thorium until 1937, as a scheme to exploit popular interest for radium after it was discovered by Pierre and Marie Curie, in a fad of radioactive quackery.
Doramad Radioactive Toothpaste was a brand of toothpaste produced in Germany by Auergesellschaft of Berlin from the 1920s through World War II. It was known for containing thorium, a radioactive metal, and is an example of radioactive quackery.
William John Aloysius Bailey was an American patent medicine inventor and salesman. A Harvard University dropout, Bailey falsely claimed to be a doctor of medicine and promoted the use of radioactive radium as a cure for coughs, flu, and other common ailments. Although Bailey's Radium Laboratories in East Orange, New Jersey, was continually investigated by the Federal Trade Commission, he died wealthy from his many devices and products, including an aphrodisiac called Arium, marketed as a restorative that "renewed happiness and youthful thrill into the lives of married peoples whose attractions to each other had weakened."
The history of radiation therapy or radiotherapy can be traced back to experiments made soon after the discovery of X-rays (1895), when it was shown that exposure to radiation produced cutaneous burns. Influenced by electrotherapy and escharotics—the medical application of caustic substances—doctors began using radiation to treat growths and lesions produced by diseases such as lupus, basal cell carcinoma, and epithelioma. Radiation was generally believed to have bactericidal properties, so when radium was discovered, in addition to treatments similar to those used with x-rays, it was also used as an additive to medical treatments for diseases such as tuberculosis where there were resistant bacilli.
The radium fad or radium craze of the early 20th century was an early form of radioactive quackery that resulted in widespread marketing of radium-infused products as being beneficial to health. Many radium products contained no actual radium, in part because it was prohibitively expensive, which turned out to be a grace, as high levels of radium exposure can result in radiation-induced cancer.
