86 astatine ← radon → francium Xe ↑ Rn ↓ Uuo Periodic table - Extended periodic table
General
Name, symbol, number	radon, Rn, 86
Chemical series	noble gases
Group, period, block	18, 6, p
Appearance	colourless
Standard atomic weight	(222) g·mol−1
Electron configuration	[Xe] 4f14 5d10 6s2 6p6
Electrons per shell	2, 8, 18, 32, 18, 8
Physical properties
Phase	gas
Melting point	202 K (−71. Astatine (ˈæstətiːn is a Radioactive Chemical element with the symbol At and Atomic number 85 Francium (ˈfrænsiəm formerly known as eka-caesium and actinium K, is a Chemical element that has the symbol Fr and Xenon (ˈzɛnɒn or) is a Chemical element represented by the symbol Xe. Ununoctium (ˌjuːnəˈnɒktiəm or /ˌʌnəˈnɒktiəm/ also known as eka-radon or element 118, is the temporary IUPAC name for This is a typical display of the periodic table of the elements and contains the symbol and Atomic number of each element Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of Chemical elements, sorted by name Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of chemical elements by symbol, including the A table of Chemical elements ordered by Atomic number and color coded according to type of element In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in History Noble gas is translated from the German noun de ''Edelgas'' first used in 1898 by Hugo Erdmann to indicate their extremely low level of reactivity In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In the Periodic table of the elements, a period is a horizontal row of the table A block of the Periodic table of elements is a set of adjacent groups The respective highest-energy electrons in each element in a block belong to the same Atomic History Noble gas is translated from the German noun de ''Edelgas'' first used in 1898 by Hugo Erdmann to indicate their extremely low level of reactivity A period 6 element is one of the Chemical elements in the sixth row (or period) of the periodic table of the elements, including the Lanthanides See also Electron configuration The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass To help compare different orders of magnitude, the following list describes various Mass levels between 10&minus36&thinsp kg and 1053&thinspkg Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) In Atomic physics and Quantum chemistry, electron configuration is the arrangement of Electrons in an Atom, Molecule, or other Xenon (ˈzɛnɒn or) is a Chemical element represented by the symbol Xe. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus. In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties This page is about the physical properties of gas as a state of matter The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic 15 °C, −96 °F)
Boiling point	211. The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 3 K (−61. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic 85 °C, −79. The Celsius Temperature scale was previously known as the centigrade scale. 1 °F)
Critical point	377 K, 6. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 In Physical chemistry, Thermodynamics, Chemistry and Condensed matter physics, a critical point, also called a critical state The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic 28 MPa
Heat of fusion	3. The standard Enthalpy of fusion (symbol \Delta{}H_{fus} also known as the heat of fusion or specific melting heat, is the amount of 247 kJ·mol−1
Heat of vaporization	18. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required 10 kJ·mol−1
Specific heat capacity	(25 °C) 20. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity 786 J·mol−1·K−1
Vapor pressure P/Pa 1 10 100 1 k 10 k 100 k at T/K 110 121 134 152 176 211
Atomic properties
Crystal structure	cubic face centered
Oxidation states	0
Electronegativity	2. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. The oxidation number of a central atom in a coordination compound is the charge that it would have if all the Ligands were removed along with the Electron pairs " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons 2 (Pauling scale)
Ionization energies	1st: 1037 kJ·mol−1
Atomic radius (calc. The ionization potential, ionization energy or EI of an Atom or Molecule is the Energy required to remove an Electron The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material )	120 pm
Covalent radius	145 pm
Miscellaneous
Magnetic ordering	non-magnetic
Thermal conductivity	(300 K) 3. The covalent radius, r cov is a measure of the size of Atom which forms part of a Covalent bond. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. 61 m W·m−1·K−1
CAS registry number	10043-92-2
Selected isotopes
Main article: Isotopes of radon iso NA half-life DM DE (MeV) DP 210Rn syn 2. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to There are thirty four known Isotopes of Radon ( Rn) The most stable isotope is 222Rn which is a Decay product (daughter product of Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides In Chemistry, natural abundance (NA refers to the abundance Isotopes of a Chemical element as naturally found on a planet Half-Life (computer-game page here It's already listed in the disambiguation page Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. The decay energy is the Energy released by a Nuclear decay. The energy difference of the Reactants is often written as Q: where Q In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 4 h Alpha 6. The hour (symbol h) is a unit of Time. It is not an SI unit but is accepted for use with the SI Alpha decay is a type of radioactive decay in which an Atomic nucleus emits an Alpha particle (two protons and two neutrons bound together into a particle 404 216Po 211Rn syn 14. Polonium (pəˈloʊniəm is a Chemical element with the symbol Po and Atomic number 84 discovered in 1898 by Marie and Pierre Curie 6 h Epsilon 2. Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the 892 211At Alpha 5. Astatine (ˈæstətiːn is a Radioactive Chemical element with the symbol At and Atomic number 85 965 207Po 222Rn trace 3. Polonium (pəˈloʊniəm is a Chemical element with the symbol Po and Atomic number 84 discovered in 1898 by Marie and Pierre Curie In Analytical chemistry, a trace element is an element in a sample that has an average Concentration of less than 100 Parts per million atoms 8235 d Alpha 5. A day (symbol d is a unit of Time equivalent to 24 Hours and the duration of a single Rotation of planet Earth with respect to the 590 218Po 224Rn syn 1. Polonium (pəˈloʊniəm is a Chemical element with the symbol Po and Atomic number 84 discovered in 1898 by Marie and Pierre Curie 8 h Beta 0. In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted 8 224Fr
References
This box: view • talk • edit

Radon (pronounced /ˈreɪdɒn/) is the chemical element that has the symbol Rn and atomic number 86. Francium (ˈfrænsiəm formerly known as eka-caesium and actinium K, is a Chemical element that has the symbol Fr and Recommended values for many properties of the elements together with various references are collected on these data pages A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton Radon is a colorless, naturally occurring, radioactive noble gas that is formed from the decay of radium. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. History Noble gas is translated from the German noun de ''Edelgas'' first used in 1898 by Hugo Erdmann to indicate their extremely low level of reactivity Radium (ˈreɪdiəm is a radioactive Chemical element which has the symbol Ra and Atomic number 88 It is one of the heaviest substances that are gases under normal conditions and is considered to be a health hazard. The most stable isotope, ²²²Rn, has a half-life of 3. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides Half-Life (computer-game page here It's already listed in the disambiguation page 8 days and is used in radiotherapy. Radiation therapy (or radiotherapy) is the medical use of Ionizing radiation as part of Cancer treatment to control Malignant While having been less studied by chemists due to its radioactivity, there are a few known compounds of this generally unreactive element.

Radon is a significant contaminant that affects indoor air quality worldwide. Indoor Air Quality (IAQ deals with the content of interior air that could affect health and comfort of building occupants Radon gas from natural sources can accumulate in buildings and reportedly causes 21,000 lung cancer deaths per year in the United States alone. The United States of America —commonly referred to as the ^[1] Radon is the second most frequent cause of lung cancer, after cigarette smoking, and radon-induced lung cancer is thought to be the 6th leading cause of cancer death overall.

History and etymology

Radon is the third discovered radioactive element (after radium and polonium). Radium (ˈreɪdiəm is a radioactive Chemical element which has the symbol Ra and Atomic number 88 Polonium (pəˈloʊniəm is a Chemical element with the symbol Po and Atomic number 84 discovered in 1898 by Marie and Pierre Curie It was discovered in 1898 by Friedrich Ernst Dorn. Friedrich Ernst Dorn ( 27 July 1848 &ndash 16 December 1916) was a German Physicist who was the first to discover that ^[2][3][4] In 1900 he reported some experiments in which he noticed that radium compounds emanate a radioactive gas which he named as Radium Emanation (Ra Em). ^[5][6] But before that, in 1899, Pierre and Marie Curie observed that the "gas" emitted by radium remained radioactive for a month. ^[7] That year, Robert B. Owens with Ernest Rutherford noticed variations when trying to measure radiation from thorium oxide. Robert "Bobby" Bowie Owens (1870 &ndash 1940 was a US Ernest Rutherford 1st Baron Rutherford of Nelson, OM, PC, FRS (30 August 1871 – 19 October 1937 was a New Zealand Physicist Thorium (ˈθɔːriəm is a Chemical element with the symbol Th and Atomic number 90 ^[8] Rutherford noticed that the compounds of thorium continuously emit a radioactive gas which retain the radioactive powers for several minutes and called this gas "emanation" (from Latin "emanare" - to elapse and "emanatio" - expiration),^[9] and later Thorium Emanation (Th Em). In 1901 he demonstrated clearly that the emanations are radioactive, but credited the Curies for the discovery of the element. ^[10] In 1903, similar emanations were observed from actinium by André-Louis Debierne^[11][12] and were called Actinium Emanation (Ac Em). Actinium (ækˈtɪniəm is a radioactive Chemical element with the symbol Ac and Atomic number 89 which was discovered in 1899, the earliest André-Louis Debierne (Paris July 14, 1874 - August 31, 1949, Paris was a French Chemist and the discoverer of the element

Several names were suggested for these three gases: exradio, exthorio and exactinio in 1904;^[13] radon, thoron and akton in 1918;^[14] radeon, thoreon and actineon in 1919,^[15] and eventually radon, thoron and actinon in 1920. ^[16] The likeness of the spectra of these three gases with those of argon, krypton and xenon, and their observed chemical inertia lead Sir William Ramsay to suggest in 1904 that the "emanations" might contain a new element of the noble gas family. Sir William Ramsay (2 October 1852 &ndash 23 July 1916 was a Scottish chemist who discovered the Noble gases and received the Nobel Prize in ^[13]

Apparatus used by Ramsay and Whytlaw-Gray to isolate radon. M is a capillary tube where approximately 0. 1 mm³ were isolated. Rn mixed with H₂ entered the evacuated system through siphon A; mercury is shown in black.

In 1910 Sir William Ramsay and Robert Whytlaw-Gray isolated it, determined its density, and determined that it was the heaviest known gas. Sir William Ramsay (2 October 1852 &ndash 23 July 1916 was a Scottish chemist who discovered the Noble gases and received the Nobel Prize in Robert Whytlaw-Gray (1877 &ndash 1958 was a Chemist, born in London England. This page is about the physical properties of gas as a state of matter ^[17] They also wrote that "L'expression l'émanation du radium est fort incommode," (the expression of radium emanation is very awkward) and suggested the new name niton (Nt) (from the Latin "nitens" meaning "shining") in order to emphasize the property of gas to cause the phosphorescence of some substances,^[17] and in 1912 it was accepted by the International Commission for Atomic Weights. In 1923, the International Committee for Chemical Elements and IUPAC chose for the names: radon (Rn), thoron (Tn), and actinon (An). The International Union of Pure and Applied Chemistry ( IUPAC) (aɪjuːpæk or ay-yoo-pec) is an international Non-governmental organization Later, when isotopes were numbered instead of named, the name of the element took the name of the most stable isotope, radon - while Tn became ²²⁰Rn and An ²¹⁹Rn). As late as the 1960s the element was also referred simply as emanation. ^[18]

The first synthesized compound of radon was obtained in 1962 and is radon fluoride. Radon difluoride ( is a compound of Radon, a Noble gas. Radon reacts readily with Fluorine to form a solid compound but this decomposes on attempted vaporization ^[19]

The first major studies of the health concern occurred in the context of uranium mining, first in the Joachimsthal region of Bohemia and then in the Southwestern United States during the early Cold War. For other places called Joachimsthal see Joachimsthal (disambiguation Jáchymov (ˈjaxɪmof in German originally Thal, later Sankt Joachimsthal Bohemia (Čechy; Bohemia Czechy is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands, currently the The Southwestern area of the United States could be defined as the states west of the Mississippi River, with the qualification of a certain northern limit such as the 37 Cold War is the state of conflict tension and competition that existed between the United States and the Soviet Union (USSR and their respective allies from the Because radon is a product of uranium, uranium mines may have high concentrations of radon and its highly radioactive daughter products. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. Many uranium miners in the Four Corners region contracted lung cancer and other pathologies as a result of high levels of exposure to radon in the mid-1950s. The Four Corners is a region of the United States consisting of southwest Colorado, northwest New Mexico, northeast Arizona and southeast Lung cancer is a Disease of uncontrolled Cell growth in tissues of the Lung. The increased incidence of lung cancer was particularly pronounced among Native American and Mormon miners, because those groups normally have low rates of lung cancer. Native Americans in the United States are the indigenous peoples from the regions of North America now encompassed by the continental United States TalkMormon#Latter Day Saint vs Latter-day Saint --> Mormon Safety standards requiring expensive ventilation were not widely implemented or policed during that period.

The danger of radon exposure in dwellings was discovered in 1984 with the case of Stanley Watras, an employee at the Limerick nuclear power plant in Pennsylvania. The Limerick Generating Station in Pennsylvania is located next to the Schuylkill River in Limerick Township, Montgomery County, Pennsylvania The Commonwealth of Pennsylvania ( often colloquially referred to as PA (its abbreviation by natives and Northeasterners is a state located in the Northeastern Watras set off the radiation alarms on his way into work for two weeks straight while authorities searched for the source of the contamination. A Geiger counter, also called a Geiger-Müller counter, is a type of Particle detector that measures Ionizing radiation. They were shocked to find that the source was astonishingly high levels of radon, around 100,000 Bq/m³ (2,700 pCi/L), in his house's basement and it was not related to the nuclear plant. The becquerel (symbol Bq) is the SI derived unit of radioactivity. A CURIE (short for Compact URI) is an abbreviated URI expressed in CURIE syntax and may be found in both XML and non-XML grammars A basement is one or more floors of a building that are either completely or partially below the Ground floor. The risks associated with living in his house were estimated to be equivalent to smoking 135 packs of cigarettes every day. Tobacco Smoking is the inhalation of smoke from burned dried or cured leaves of the Tobacco plant most often in the form of a Cigarette. A cigarette ( French "small Cigar " from cigar + -ette) is a product consumed through Smoking and manufactured ^[20] Following this event, which was highly publicized, national radon safety standards were set, and radon detection and ventilation became a standard homeowner concern.

Isotopes

Main article: Isotopes of radon

Radon has no stable isotopes. There are thirty four known Isotopes of Radon ( Rn) The most stable isotope is 222Rn which is a Decay product (daughter product of Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides There are 34 radioactive isotope that have been studied. These range from an atomic mass of 195 to 228. The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass The most stable isotope is ²²²Rn, which is a decay product of ²²⁶Ra. In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide Radium ( Ra) has no stable Isotopes A standard Atomic mass cannot be given It has a half-life of 3. Half-Life (computer-game page here It's already listed in the disambiguation page 823 days and decomposes by alpha particle emission into ²¹⁸Po. Alpha particles (named after and denoted by the first letter in the Greek alphabet, α consist of two Protons and two Neutrons bound together into a Polonium (pəˈloʊniəm is a Chemical element with the symbol Po and Atomic number 84 discovered in 1898 by Marie and Pierre Curie Among the decay daughters of this decay chain is also the highly unstable isotope ²¹⁸Rn. The naturally occurring ²²⁶Ra is a product of the decay chain of ²³⁸U. In Nuclear science, the decay chain refers to the Radioactive decay of different discrete radioactive decay products as a chained series of transformations Uranium-238 (U-238 is the most common isotope of Uranium found in nature Hereby is this decay series (with half-lives):

²³⁸U (4. 5 x 10⁹ yr) → ²³⁴Th (24. Thorium-234 is an Isotope of Thorium with 90 Protons and Electrons and 144 Neutrons. 1 days) → ²³⁴Pa (1. Protactinium ( Pa)Standard atomic mass 23103588(2 u The element has no stable isotopes 18 min) → ²³⁴U (250,000 yr) → ²³⁰Th (75,000 yr) → ²²⁶Ra (1,600 yr) → ²²²Rn (3. Uranium-234 is an isotope of Uranium. In Natural uranium and uranium ore 234U occurs as an indirect Decay product of 238U Thorium-230 (230Th is a Radioactive Isotope of Thorium which can be used to date Corals and determine Ocean current 82 days) → ²¹⁸Po (3. 1 min) → ²¹⁸At (1. 5 s) → ²¹⁸Rn (35 ms) → ²¹⁴Pb (26. Lead ( Pb) has four stable Isotopes - 204Pb 206Pb 207Pb 208Pb and one common Radiogenic isotope 8 min) → ²¹⁴Bi (19. Standard atomic mass 20898040(1 u Isotopes of Bismuth (Bi occurring within the radioactive Disintegration chains of Actinium 7 min) → ²¹⁴Po (164 µs) → ²¹⁰Pb (22. Polonium ( Po) has 33 known isotopes, all of which are radioactive. Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly 3 yr) → ²¹⁰Bi (5. Standard atomic mass 20898040(1 u Isotopes of Bismuth (Bi occurring within the radioactive Disintegration chains of Actinium 01 days) → ²¹⁰Po (138 days) → ²⁰⁶Pb (stable). Polonium ( Po) has 33 known isotopes, all of which are radioactive. Lead ( Pb) has four stable Isotopes - 204Pb 206Pb 207Pb 208Pb and one common Radiogenic isotope

There are three other isotopes that have a half life of above 1 hour: ²¹¹Rn, ²¹⁰Rn and ²²⁴Rn. The ²²⁰Rn isotope is a natural decay product of the most stable thorium isotope (²³²Th) for which was named “thoron”. Thorium (ˈθɔːriəm is a Chemical element with the symbol Th and Atomic number 90 It has a half-life of 55. 6 seconds and also emits alpha radiation. Similarly, ²¹⁹Rn is derived from the most stable isotope of actinium (²²⁷Ac) — for which it was named “actinon” — and is an alpha emitter with half-life of 3. Actinium (ækˈtɪniəm is a radioactive Chemical element with the symbol Ac and Atomic number 89 which was discovered in 1899, the earliest 96 seconds.

Characteristics

At standard temperature and pressure, radon forms a monoatomic gas with a density of 9. In Physical sciences standard conditions for temperature and pressure are Standard sets of conditions for experimental measurements to allow comparisons to be made In Physics and Chemistry, monatomic is a combination of the words "mono" and "atomic" and means "single Atom. 73 kg/m³,^[21] about 8 times the surface density of the Earth's atmosphere, 1. 217 kg/m³,^[22] and is one of the heaviest gases at room temperature and the heaviest of the noble gases (excluding ununoctium). Ununoctium (ˌjuːnəˈnɒktiəm or /ˌʌnəˈnɒktiəm/ also known as eka-radon or element 118, is the temporary IUPAC name for At standard temperature and pressure radon is a colorless gas, but when it is cooled below its freezing point (202 K ; −71 °C ; −96 °F) it has a brilliant phosphorescence which turns yellow as the temperature is lowered, and becomes orange-red at the temperatures air liquefies (below 93 K ; −180 °C). In Physical sciences standard conditions for temperature and pressure are Standard sets of conditions for experimental measurements to allow comparisons to be made Freezing Point (Chinese 冰點 Bīngdiǎn is a news journal in the People's Republic of China which has been the subject of controversy over its criticism Yellow is the Color evoked by light that stimulates both the L and M (long and medium wavelength Cone cells of the Retina about equally The colour orange occurs Red is any of a number of similar Colors evoked by light consisting predominantly of the longest wavelengths of Light discernible by the human eye in the wavelength Upon condensation, radon also glows because of the intense radiation it produces.

Natural radon concentrations in Earth's atmosphere are so low that radon-rich water in contact with the atmosphere will continually lose radon by volatilization. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Volatilisation is the process whereby a dissolved sample is vaporised Hence, ground water has a higher concentration of ²²²Rn than surface water, because the radon is continuously produced by radioactive decay of ²²⁶Ra present in rocks. Groundwater is Water located beneath the Ground surface in Soil pore spaces and in the Fractures of lithologic formations For Water masses on the surface of the world ocean see Surface water (ocean. Radium (ˈreɪdiəm is a radioactive Chemical element which has the symbol Ra and Atomic number 88 Likewise, the saturated zone of a soil frequently has a higher radon content than the unsaturated zone because of diffusional losses to the atmosphere.

Radon is a health hazard as exposure can cause lung cancer - in fact it is the second major cause of lung cancer after smoking. Lung cancer is a Disease of uncontrolled Cell growth in tissues of the Lung. ^[23] Radon as a terrestrial source of background radiation is of particular concern because, although on average it is very rare, this intensely radioactive element can be found in high concentrations in many areas of the world, where it represents a significant health hazard. Background radiation is the Ionizing radiation emitted from a variety of natural and artificial Radiation sources Radon-222 has been classified by International Agency for Research on Cancer as being carcinogenic to humans. The International Agency for Research on Cancer ( IARC, or CIRC in its French Acronym) is an intergovernmental agency forming part of the World Health The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation The contribution to background radiation from radon is so large that it received special attention in the neutrino detection experiments (see Kamioka Observatory). Neutrinos are Elementary particles that travel close to the Speed of light, lack an Electric charge, are able to pass through ordinary matter almost The is a Neutrino Physics Laboratory located underground in the Mozumi Mine of the Kamioka Mining and Smelting Co

Radon commercialization is regulated, but it is available in small quantities, at a price of almost $6,000 per mililitre. ^[24] Because it is also radioactive and is a relatively unreactive chemical element, radon has few uses and is seldom used in academic research.

Chemistry

An electron shell diagram for radon. Note the eight electrons in the outer shell. The octet rule is a simple chemical Rule of thumb that states that Atoms tend to combine in such a way that they each have eight Electrons in An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus.

Radon is a member of the zero-valence elements that are called noble or inert gases. In Chemistry, valence, also known as valency or valency number, is a measure of the number of Chemical bonds formed by the Atoms History Noble gas is translated from the German noun de ''Edelgas'' first used in 1898 by Hugo Erdmann to indicate their extremely low level of reactivity In English to be inert is to be in a state of doing little or nothing This page is about the physical properties of gas as a state of matter It is inert to most common chemical reactions (such as combustion, for example) because the outer valence shell contains eight electrons. An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus. This produces a stable, minimum energy configuration in which the outer electrons are tightly bound. ^[25] Nevertheless, due to periodic trends, radon has a lower electronegativity than the element above it, xenon, and thus is relatively more reactive. Periodicity is the quality of occurring at regular intervals or periods (in Time or Space) and can occur in different contexts A Clock marks " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons Xenon (ˈzɛnɒn or) is a Chemical element represented by the symbol Xe.

Because of this price and its radioactivity, experimental chemical research is seldomly done on this element and as a result there are very few reported compounds of radon, all either fluorides or oxides. Fluoride is the reduced form of Fluorine. Both organic and Inorganic compounds containing the element fluorine are considered fluorides An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element Radon can be oxidized by a few powerful oxidizing agents. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state such as F₂ thus forming radon fluoride. Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 Radon difluoride ( is a compound of Radon, a Noble gas. Radon reacts readily with Fluorine to form a solid compound but this decomposes on attempted vaporization ^[26][27] Among the few other reported compounds of radon are radon oxides. An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element ^[28]

Occurrence

See also: Radium and radon in the environment

The average concentration of radon in the atmosphere is about 6×10^-20 atoms Rn for each molecule in the air (or about 150 atoms in each mL of air). This is a subpage of Environmental radioactivity. Radium Radium in quack medicine See the story of Eben Byers for details of one very nasty case ^[29] It can be found in some spring waters and hot springs. A spring is a point where Groundwater flows out of the ground and is thus where the Aquifer surface meets the ground surface A hot spring is a spring that is produced by the emergence of geothermally heated Groundwater from the earth's crust. ^[30] The towns of Boulder, Montana, and Misasa; Bad Kreuznach, Germany, as well as the country of Japan boast radium-rich springs which emit radon. Boulder is a town in and the County seat of Jefferson County, Montana, United States. is a town located in Tōhaku District, Tottori, Japan. It is also home to the official treasure of Sanbutsuji and the Okayama Hospital Bad Kreuznach is the capital of the district of Bad Kreuznach, Rhineland-Palatinate, Germany. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. For a topic outline on this subject see List of basic Japan topics. Radon emanates naturally from the ground all over the world, particularly in regions with soils containing granite or shale. Granite (ˈɡrænɪt is a common and widely occurring type of intrusive, Felsic, igneous rock. Shale (also called mudstone) is a fine-grained Sedimentary rock whose original constituents were Clay minerals or Muds It is characterized by However, not all granitic regions are prone to high emissions of radon. Radon emitted from the ground has been shown to accumulate in the air if there is a meteorological inversion and little wind. ^[31] In some caves, increased radon concentration was observed. ^[32]

Radon is found in some petroleum. Because radon has a similar pressure and temperature curve as propane, and oil refineries separate petrochemicals based on their boiling points, the piping carrying freshly separated propane in oil refineries can become somewhat radioactive due to radon decay particles. Residues from the oil and gas industry often contain radium and its daughters. Petroleum ( L petroleum, from Greek πετρέλαιον, lit Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Radium (ˈreɪdiəm is a radioactive Chemical element which has the symbol Ra and Atomic number 88 The sulfate scale from an oil well can be very radium rich, while the water, oil and gas from a well often contains radon. The radon decays to form solid radioisotopes which form coatings on the inside of pipework. In an oil processing plant the area of the plant where propane is processed is often one of the more contaminated areas of the plant as radon has a similar boiling point as propane. Propane is a three- Carbon Alkane, normally a gas but compressible to a liquid that is transportable ^[33]

Radon, along with other noble gases krypton and xenon, is also produced during the operation of nuclear power plants. Krypton (ˈkrɪptən or /ˈkrɪptɒn/ from kryptos "hidden" is a Chemical element with the symbol Kr and Atomic number 36 Xenon (ˈzɛnɒn or) is a Chemical element represented by the symbol Xe. Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions A small fraction of it leaks out of the fuel, through the cladding and into the cooling water, from which it is scavenged. It is then routed to a holding tank where it remains for a large number of half-lives. It is finally purged to the open air through a tall stack which is carefully monitored for radiation level.

²¹⁰Pb is formed from the decay of ²²²Rn. Here is a typical deposition rate of ²¹⁰Pb as observed in Japan as a function of time.

Radon collects over samples of radium 226 at the rate of around 0. 001 cm3/day per g of radium. The radon (²²²Rn) released into the air decays to ²¹⁰Pb and other radioisotopes, the levels of ²¹⁰Pb can be measured. Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly The rate of deposition of this radioisotope is dependent on the weather. Here is a graph of the deposition rate observed in Japan. For a topic outline on this subject see List of basic Japan topics. ^[34] In the early part of the 20th century in the USA, gold which was contaminated with lead-210 entered the jewelry industry. The United States of America —commonly referred to as the This was from gold seeds which had held radon-222 which had been melted down (after the radon had decayed). The daughters of the radon are still radioactive today. ^[35]

In 1971, Apollo 15 passed 110 kilometers above the Aristarchus plateau on the Moon, and detected a significant rise in alpha particles thought to be caused by the decay of radon-222. Aristarchus is a prominent lunar Impact crater that lies in the northwest part of the Moon's near side The presence of radon–222 (²²²Rn) has been inferred later from data obtained from the Lunar Prospector alpha particle spectrometer. The Lunar Prospector mission was the third selected by NASA for full development and construction as part of the Discovery Program. Alpha particles (named after and denoted by the first letter in the Greek alphabet, α consist of two Protons and two Neutrons bound together into a ^[36]

Depending on how houses are built and ventilated, radon may accumulate in basements and dwellings. The highest average radon concentrations in the U. S. are found in Iowa and in the Appalachian Mountain areas in southeastern Pennsylvania. The State of Iowa ( is a state in the Midwestern region of the United States of America. The Appalachian Mountains ( often called the Appalachians, are a vast system of mountains in eastern North America. ^[37] Some of the highest readings ever have been recorded in the Irish town of Mallow, County Cork prompting local fears regarding lung cancer. Mallow ( Irish Magh Eala "valley of the swans" is the "Crossroads of Munster " and the administrative capital of north County Iowa has the highest average radon concentrations in the nation due to significant glaciation that ground the granitic rocks from the Canadian Shield and deposited it as soils making up the rich Iowa farmland. ^[38] Many cities within the state, such as Iowa City have passed requirements for radon resistant construction in all new homes. Iowa City is a city in Johnson County, Iowa, United States. It is the principal city of the Iowa City Iowa Metropolitan Statistical Area which A recent study has noted that the counties surrounding Three Mile Island have the highest radon concentrations in the United States and that this may be the cause of the increased lung cancer noted in the region. Three Mile Island Nuclear Generating Station is a civilian Nuclear power plant located on an island (Three Mile Island in the Susquehanna River near Harrisburg ^[39]

The European Union recommends that action should be taken starting from concentrations of 400 Bq/m³ (11 pCi/L) for old houses and 200 Bq/m³ (5 pCi/L) for new ones. The European Union ( EU) is a political and economic union of twenty-seven member states, located primarily in After publication of the North American and European Pooling Studies, Health Canada has proposed a new guideline that lowers their action level from 800 to 200 Bq/m³ (22 to 5 pCi/L). Health Canada ( French: Santé Canada) is the department of the government of Canada with responsibility for national Public health ^[40] The United States Environmental Protection Agency (EPA) strongly recommends action for any house with a concentration higher than 148 Bq/m³ (4 pCi/L),^[41] and encourages action starting at 74 Bq/m³ (2 pCi/L). A CURIE (short for Compact URI) is an abbreviated URI expressed in CURIE syntax and may be found in both XML and non-XML grammars A CURIE (short for Compact URI) is an abbreviated URI expressed in CURIE syntax and may be found in both XML and non-XML grammars EPA radon risk level tables including comparisons to other risks encountered in life are available in their citizen's guide. ^[42] The EPA estimates that nationally 8% to 12% of all houses are above their maximum "safe levels" (four picocuries per liter- the equivalent to roughly 200 chest x-rays). The U. S. Surgeon General and EPA recommend all homes be tested for radon.

Applications

Medical

It has been claimed that exposure to radon gas mitigates auto-immune diseases such as arthritis. Arthritis (from Greek arthro-, joint + -itis, inflammation plural arthritides is a group of conditions involving damage to the Joints of the body ^[43] As a result, in the late 20th century and early 21st century, some "health mines" were established in Basin, Montana which attracted people seeking relief from health problems such as arthritis through limited exposure to radioactive mine water and radon. Basin is a Census-designated place (CDP in Jefferson County, Montana, United States. The practice was controversial because of the "well-documented ill effects of high-dose radiation on the body. "^[44]

Radioactive water baths have been applied since 1906 in Jáchymov, Czech Republic, but even before radon discovery they were used in Bad Gastein, Austria. For other places called Joachimsthal see Joachimsthal (disambiguation Jáchymov (ˈjaxɪmof in German originally Thal, later Sankt Joachimsthal The Czech Republic ( ˈt͡ʃɛskaː ˈrɛpuˌblɪka short form in Česko ˈt͡ʃɛskɔ also called Czechia, Bad Gastein is a spa town in Austria, situated in the middle of the National Park Hohe Tauern, at 1000 metres above Sea level. Austria (Österreich ( officially the Republic of Austria (Republik Österreich Hot radium-rich spring releasing radon is also used in traditional Japanese onsen in Misasa, Tottori prefecture. For a topic outline on this subject see List of basic Japan topics. An is a term for Hot springs ' in the Japanese language, though the term is often used describe the bathing facilities and inns around the hot springs is a town located in Tōhaku District, Tottori, Japan. It is also home to the official treasure of Sanbutsuji and the Okayama Hospital Drinking therapy is applied in Bad Brambach, Germany. Bad Brambach is a municipality in the Vogtlandkreis district in Saxony, Germany. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Inhalation therapy is carried out in Gasteiner-Heilstollen, Austria, in Kowary, Poland and in Boulder, Montana, United States. Austria (Österreich ( officially the Republic of Austria (Republik Österreich Kowary Lesser Poland Voivodeship Kowary (Schmiedeberg im Riesengebirge is a town in Jelenia Góra County, Lower Silesian Voivodeship, in south-western Poland (Polska officially the Republic of Poland Boulder is a town in and the County seat of Jefferson County, Montana, United States. The United States of America —commonly referred to as the In the United States and Europe there are a few "radon spas," where people sit for minutes or hours in a high-radon atmosphere in the belief that low doses of radiation will invigorate or energize them. A destination spa is a short term residential/lodging facility with the primary purpose of guiding individual spa-goers to develop healthy habits

In addition personal testimonies of arthritis relief and other benefits, there is some (very limited) scientific evidence for this belief, known as hormesis. Radiation hormesis (also called Radiation homeostasis) is the Hypothesis that chronic low doses of Ionizing radiation are beneficial stimulating repair However, the general scientific community finds it unsubstantiated. There is no known biological mechanism by which such an effect could occur. In addition, it conflicts with the internationally recognized standard that there is no safe threshold for radiation exposure and that exposure should be limited to that "as low as reasonably achievable" (ALARA). The linear no-threshold model ( LNT) is a model of the damage caused by Ionizing radiation which presupposes that the response is Linear (i Radiation protection, sometimes known as radiological protection, is the science of protecting people and the environment from the harmful effects of Ionizing radiation

The radon gas which is used as a cancer treatment in medicine is obtained from the decay of a radium chloride source. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled Radium chloride, RaCl2 was the first Radium compound to be prepared in a pure state and was the basis of Marie Curie 's original separation of In the past, radium and radon have both been used for X-ray medical radiography, but they have fallen out of use as they are radiotoxic alpha radiation emitters which are expensive and have been replaced with iridium-192 and cobalt-60 since they are far better photon sources. Radium (ˈreɪdiəm is a radioactive Chemical element which has the symbol Ra and Atomic number 88 X-radiation (composed of X-rays) is a form of Electromagnetic radiation. Radiography is the use of ionising Electromagnetic radiation to view objects Alpha decay is a type of radioactive decay in which an Atomic nucleus emits an Alpha particle (two protons and two neutrons bound together into a particle Iridium-192 (symbol Ir192 m) is an Isotope of Iridium. The "m" denotes that it is a Metastable isomer. Cobalt-60 (60Co is a Radioactive isotope of Cobalt, with a Half life of 5

Scientific

Radon emanation from the soil varies with soil type and with surface uranium content, so outdoor radon concentrations can be used to track air masses to a limited degree. This fact has been put to use by some atmospheric scientists. Because of radon's rapid loss to air and comparatively rapid decay, radon is used in hydrologic research that studies the interaction between ground water and streams. Hydrology (from Greek Yδωρ hudōr, "water" and λόγος logos, "study" is the study of the movement distribution and quality of A stream is a body of Water with a current, confined within a bed and stream-banks Any significant concentration of radon in a stream is a good indicator that there are local inputs of ground water. Radon is also used in the dating of oil-containing soils because radon has a high affinity of oil-like substances.

Radon soil-concentration has been used in an experimental way to map buried close-subsurface geological faults, because concentrations are generally higher over the faults. Similarly it has found some limited use in geothermal prospecting. Some researchers have even looked at elevated soil-gas radon concentrations, or rapid changes in soil or groundwater radon concentrations, as a predictor for earthquakes. An earthquake is the result of a sudden release of energy in the Earth 's crust that creates Seismic waves Earthquakes are recorded with a Seismometer ^[45] Results have been generally unconvincing but may ultimately prove to have some limited use in specific locations.

Radon is a known pollutant emitted from geothermal power stations, though it disperses rapidly, and no radiological hazard has been demonstrated in various investigations. The trend in geothermal plants is to reinject all emissions by pumping deep underground, and this seems likely to ultimately decrease such radon hazards further.

Testing and mitigation

ASTM E-2121 is a standard for reducing radon in homes as far as practicable below 4 picocuries per liter (pCi/L) in indoor air. ASTM International ( ASTM) originally known as the American Society for Testing and Materials is an international Standards organization that develops and publishes ^[46][47] Radon test kits are commercially available. The kit includes a collector that the user hangs in the lowest livable floor of the house for 2 to 7 days. The user then sends the collector to a laboratory for analysis. The National Environmental Health Association provides a list of radon measurement professionals. ^[48] Long term kits, taking collections for up to one year, are also available. An open land test kit can test radon emissions from the land before construction begins. The EPA and the National Environmental Health Association have identified 15 types of radon testing. ^[49] A Lucas cell is one type of device. A Lucas cell is a type of Scintillation Particle detector. It is used to grab a gas sample filter out the radioactive particulates through a special filter and then

Radon levels fluctuate naturally. An initial test might not be an accurate assessment of your home's average radon level. Transient weather can affect short term measurements. ^[50] Therefore, a high result (over 4 pc/l) justifies repeating the test before undertaking more expensive abatement projects. Measurements between 4 and 10 pc/l warrant a long term radon test. Measurements over 10 pc/l warrant only another short term test so that abatement measures are not unduly delayed. Purchasers of real estate are advised to delay or decline a purchase if the seller has not successfully abated radon to 4 pc/l or less.

The National Environmental Health Association administers a voluntary National Radon Proficiency Program for radon professionals consisting of individuals and companies wanting to take training courses and examinations to demonstrate their competency. ^[51] A list of mitigation service providers is available. ^[52] Indoor radon can be mitigated by sealing basement foundations, water drainage, or by sub-slab de-pressurization. Radon Mitigation is any process used to reduce Radon concentrations in the breathing zones of occupied buildings In severe cases, mitigation can use air pipes and fans to exhaust sub-slab air to the outside. Indoor ventilation systems are more effective, but exterior ventilation can be cost-effective in some cases.

Modern construction that conserves energy by making homes air tight exacerbates the risks of radon exposure if radon is present in the home. Older homes with more porous construction are more likely to vent radon naturally. Positive-pressure ventilation systems can be combined with a heat exchanger to recover energy in the process of exchanging air with the outside, and it should be noted that simply exhausting basement air to the outside is not necessarily a viable solution as this can actually draw radon gas into a dwelling. Homes built on a crawl space can benefit from a radon collector installed under a radon barrier (a sheet of plastic that covers the crawl space).

Precautions

0

4

0

Radon is the invisible, radioactive atomic gas that results from radioactive decay of some forms of uranium that may be found in rock formations beneath buildings or in certain building materials themselves. Radon is probably the most pervasive serious hazard for indoor air in the United States and Europe, probably responsible for tens of thousands of lung cancer deaths per year. There are relatively simple tests for radon gas, but these tests are not commonly done, even in areas of known systematic hazards. Radon is a very heavy gas and thus will tend to accumulate at the floor level. Building materials can actually be a significant source of radon, but very little testing is done for stone, rock or tile products brought into building sites. The half life for radon is 3. 8 days, indicating that once the source is removed, the hazard will be greatly reduced within a few weeks. However annually thousands of people go to Radon contaminated mines for purposeful exposure to help with the symptoms of arthritis without any serious health effects. Arthritis (from Greek arthro-, joint + -itis, inflammation plural arthritides is a group of conditions involving damage to the Joints of the body

Radon presents significant risks since it is a colorless and odorless gas and therefore not readily detectable by a human. This page is about the physical properties of gas as a state of matter The radiation decay products ionize genetic material, causing mutations that sometimes turn cancerous. An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Radon exposure is the second major cause of lung cancer after smoking. ^[23] Radon gas levels vary by locality and the composition of the underlying soil and rocks. For example, in areas such as Cornwall in the UK (which has granite as substrata), radon gas is a major problem, and buildings have to be force-ventilated with fans to lower radon gas concentrations. Cornwall ( Kernow ˈkɛɹnɔʊ is the most southwesterly county of England, on the Peninsula that lies to the west of the River Tamar The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Granite (ˈɡrænɪt is a common and widely occurring type of intrusive, Felsic, igneous rock. The United States Environmental Protection Agency (EPA) estimates that one in 15 homes in the U. S. has radon levels above the recommended guideline of 4 picocuries per liter (pCi/L) (148 Bq/m³). A CURIE (short for Compact URI) is an abbreviated URI expressed in CURIE syntax and may be found in both XML and non-XML grammars The becquerel (symbol Bq) is the SI derived unit of radioactivity. CM3 redirects here If you were looking for the 3rd game in the Cooking Mama series abbreviated as CM3 see here. ^[41] Iowa has the highest average radon concentration in the United States; studies performed there have demonstrated a 50% increased lung cancer risk with prolonged radon exposure above the EPA's action level of 4 pCi/L. The State of Iowa ( is a state in the Midwestern region of the United States of America. ^[53][54]

Radon is a terrestrial source of radiation that is of particular concern because, although on average it is very rare, this intensely radioactive element can be found in high concentrations in many areas of the world, where it represents a significant health hazard. Radon is a decay product of uranium, which is relatively common in the earth's crust, but generally concentrated in ore-bearing rocks scattered around the world. Radon seeps out of these ores into the atmosphere or into ground water, and in these localities it can accumulate within dwellings and expose humans to high concentrations. The widespread construction of well insulated and sealed homes in the northern industrialized world has led to radon becoming the primary source of background radiation in some localities in northern North America and Europe. Some of these areas, including Cornwall and Aberdeenshire in the United Kingdom have high enough natural radiation levels that nuclear licensed sites cannot be built there — the sites would already exceed legal radiation limits before they opened, and the natural topsoil and rock would all have to be disposed of as low-level nuclear waste. Cornwall ( Kernow ˈkɛɹnɔʊ is the most southwesterly county of England, on the Peninsula that lies to the west of the River Tamar Aberdeenshire (Siorrachd Obar Dheathain is one of the 32 unitary Council areas in Scotland. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Low-level waste (LLW is a term used to describe Nuclear waste that does not fit into the categorical definitions for high-level waste (HLW spent nuclear fuel (SNF transuranic

Radiation exposure from radon is indirect. Radon has a short half-life (4 days) and decays into other solid particulate radium-series radioactive nuclides. In Nuclear science, the decay chain refers to the Radioactive decay of different discrete radioactive decay products as a chained series of transformations These radioactive particles are inhaled and remain lodged in the lungs, causing continued exposure. People in affected localities can receive up to 10 mSv per year background radiation. ^[55] Radon is thus the second leading cause of lung cancer after smoking, and accounts for 15,000 to 22,000 cancer deaths per year in the US alone. Lung cancer is a Disease of uncontrolled Cell growth in tissues of the Lung. Tobacco Smoking is the inhalation of smoke from burned dried or cured leaves of the Tobacco plant most often in the form of a Cigarette. ^[56] The general population is exposed to small amounts of polonium as a radon daughter in indoor air; the isotopes ²¹⁴Po and ²¹⁸Po are thought to cause the majority^[57] of the estimated 15,000-22,000 lung cancer deaths in the US every year that have been attributed to indoor radon. ^[58]

The general effects of radon to the human body are caused by its radioactivity and consequent risk of radiation-induced cancer. As an inert gas, radon has a low solubility in body fluids which leads to a uniform distribution of the gas throughout the body. ^[59] Radon gas and its solid decay products are carcinogens. The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation The greatest health risks come from exposure to the inhaled solid radon gas decay products that are produced during the radioactive decay of radon gas. Two of these decay products, polonium-218 and 214, present a significant radiologic hazard. Polonium (pəˈloʊniəm is a Chemical element with the symbol Po and Atomic number 84 discovered in 1898 by Marie and Pierre Curie ^[60] Once the radioactive decay products are inhaled into the lung, they undergo further radioactive decay, releasing small bursts of energy in the form of alpha particles that can either cause DNA breaks or create free radicals. Alpha particles (named after and denoted by the first letter in the Greek alphabet, α consist of two Protons and two Neutrons bound together into a Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell ^[60]

It is not known whether radon can cause health effects in other organs besides the lungs. The effects of radon, which is found in food or drinking water, are unknown.

Predicted fraction of homes exceeding the EPA's recommended action level of 4 pCi/L

The largest single source of radiation exposure to the general public is naturally-occurring radon gas, which comprises approximately 55% of the annual background dose. The largest natural contributor to public radiation dose is radon, a naturally occurring, radioactive gas found in soil and rock. ^[61] If the gas is inhaled, some of the radon particles may attach to the inner lining of the lung. These particles continue to decay, emitting alpha particles which can damage cells in the lung tissue. ^[41] The death of Marie Curie at age 66 from leukemia was likely caused by prolonged exposure to high doses of ionizing radiation. Curie worked extensively with Radium, which decays into Radon,^[62] along with other radioactive materials that emit beta and gamma rays. In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions

In the United Kingdom, residential radon is, after cigarette smoking, the second most frequent cause of lung cancer deaths; 83. 9% of deaths are attributed to smoking only, 1. 0% to radon only, and 5. 5% to a combination of radon and smoking. ^[63] Radon-induced lung cancer is thought to be the 6th leading cause of cancer death overall. Based on studies carried out by the National Academy of Sciences in the United States, radon is the second most common cause of lung cancer after cigarette smoking, accounting for 15,000 to 22,000 cancer deaths per year in the U. The National Academy of Sciences (NAS is a corporation in the United States whose members serve Pro bono as "advisers to the nation on science S. ^[64] The Surgeon General of the United States has reported that over 20,000 Americans die each year of radon-related lung cancer. Overview The Surgeon General is nominated by the US President and confirmed via majority vote by the Senate. ^[65] The United States Environmental Protection Agency (EPA) recommends homes be fixed if an occupant's long-term exposure will average 4 picocuries per liter (pCi/L) (148 Bq m⁻³) or higher. A CURIE (short for Compact URI) is an abbreviated URI expressed in CURIE syntax and may be found in both XML and non-XML grammars ^[66] Beginning with the late 1980s, this led to activists forming campaigns to raise awareness of radiation resulting from radon. ^[67]

The most elaborate case-control epidemiologic radon study performed by R. William Field and colleagues demonstrated a 50% increased lung cancer risk with prolonged radon exposure at the EPA's action level of 4 pCi/L. R William Field is an American Academic Scholar and Professor in the Department of Occupational and Environmental Health and Department of ^[68] Iowa has the highest average radon concentrations in the nation and a very stable population which added to the strength of the study. Pooled epidemiologic radon studies^[69][70] have also shown an increased lung cancer risk from radon below the EPA's action level of 4 pCi/L.

Radiation from radon has been attribuited to increase of lung cancer among smokers too. This is because the daughters of radon often become attached to smoke and dust particles and are then able to lodge in the lungs. ^[71] It is unknown whether radon causes other types of cancer, but recent studies suggest a need for further studies to assess the relationship between radon and leukemia. Leukemia or leukaemia (Greek leukos λευκός, "white" aima αίμα, "blood" is a Cancer of the Blood ^[72][73] Radon is a common problem encountered during uranium mining as it is a radioactive gas. Uranium mining is the process of extraction of Uranium Ore from the ground Inhalation of radon gas caused sharp increases in lung cancers among uranium miners employed in the 1940s and 1950s. ^[74][75][76]

Bernard Cohen has been a staunch opponent to the so called Linear no-threshold model (LNT) which postulates that there is no safe threshold for radiation exposure. Bernard Leonard Cohen is Professor Emeritus of Physics at the University of Pittsburgh. The linear no-threshold model ( LNT) is a model of the damage caused by Ionizing radiation which presupposes that the response is Linear (i His debates in academic periodicals and published correspondence with R. William Field, Brian J. R William Field is an American Academic Scholar and Professor in the Department of Occupational and Environmental Health and Department of Smith (assistant professor of biostatistics, University of Iowa), Jerry Puskin (from the U.S. Environmental Protection Agency), Sarah Darby, and Sir Richard Doll and others regarding his radon-related ecologic studies are legendary. Biostatistics (a Portmanteau word made from biology and statistics sometimes referred to as biometry or biometrics) is the application of Statistics Professor Sarah Darby is a British epidemiologist. In recent years her research has concerned evaluating the beneficial effects of giving up smoking Sir William Richard Shaboe Doll CH OBE FRS ( 28 October 1912 &ndash 24 July 2005) was a British ^[77][78] He offered many rewards ($10,000) if people could provide evidence that the inverse association he found between radon (county averages) and lung cancer (county averages) was due to some factor other than failure of the linear-no threshold theory. Puskin, Smith, Field and others have claimed that his findings are due in part to his inability to control for the inverse association between smoking and radon. ^[79][80]

Indeed Bernard Cohen's assertions appear to have gained further support recently. Bernard Leonard Cohen is Professor Emeritus of Physics at the University of Pittsburgh. The results of a methodical ten year long case controlled study of residential radon exposure in Worcester County, Massachusetts, found an apparent 60% reduction in lung cancer risk amongst people exposed to low levels (0-150 Bq/m³) of radon gas; levels typically encountered in 90% of American homes. ^[81] The study paid close attention to the cohort's levels of smoking, occupational exposure to carcinogens and education attainment. In Statistics and Demography, a cohort is a group of subjects &mdash most often humans from a given population &mdash defined by experiencing an event (typically The study was also notable for carefully placing radon monitors for one year, close to where people spent the most time in their homes. Co-author Joel H. Popkin said, "We were certainly not looking for a hormetic effect,". . . "Indeed, we were stunned when the data pointed to that conclusion in such a strong way. ^[82]

See also

• International Radon Project
• Lucas cell
• Radon mitigation
• Radiation Exposure Compensation Act
• Radiohalo

Notes

References

• Field, RW; Steck DJ, Smith BJ et al. (June 2000). "Residential radon gas exposure and lung cancer: the Iowa Radon Lung Cancer Study". American Journal of Epidemiology 151 (11): 1091–1102. Oxford Journals. PMID 10873134. Retrieved on 2007-08-11.

External links

• [3]
• ATSDR - Case Studies in Environmental Medicine: Radon Toxicity U. S. Department of Health and Human Services (public domain)
• [4]
• UK site with Radon information and risk reports for UK addresses
• Iowa Radon Lung Cancer Study
• Minnesota radon project
• Los Alamos National Laboratory - Radon
• USGS Periodic Table - Radon
• EPA Iowa Radon Study
• World Health Organization International Radon Project
• Radon Occurrence and Health Risks
• WebElements.com - Radon
• U.S. Environmental Protection Agency — Indoor Air Radon
• Ask TreeHugger: What Do Radon Tests Mean?
• Radon Removal
• Radon Occurrence and Health Risk
• Eastern Regional Radon Training Center
• Present status of national standards. NIST.