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Encyclopedia > Ionizing radiation
Radiation hazard symbol.
Radiation hazard symbol.
Ionizing radiation hazard symbol (recently introduced).
Ionizing radiation hazard symbol (recently introduced).[1]

Ionizing radiation is energetic particles or waves that have the potential to ionize an atom or molecule through atomic interactions. It is a function of the energy of the individual particles or waves, and not a function of the number of particles or waves present. A large flood of particles or waves will not cause ionization if the individual particles or waves are not energetic enough. These ionizations, if enough occur, can be destructive to biological organisms, and can cause DNA damage in individual cells. Extensive doses of ionizing radiation have been shown to have a mutating effect to future generations of the individual receiving the dose. Examples of ionizing radiation are energetic Beta particles, neutrons, alpha particles and energetic photons (UV and above). The amount of energy required to ionize an atom or molecule may widely vary. X-rays and gamma rays will ionize almost any molecule or atom; Far ultraviolet, near ultraviolet and visible light are ionizing to very few molecules; microwaves and radio waves are non-ionizing radiation. Image File history File links Radiation_warning_symbol. ... Image File history File links Radiation_warning_symbol. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Particle radiation is the radiation of energy by means of small fast-moving particles that have energy and mass. ... Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. ... ... For other uses, see Atom (disambiguation). ... 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane. ... DNA damage resulting in multiple broken chromosomes DNA repair is a process constantly operating in each cell of a living being; it is essential to survival because it protects the genome from damage. ... It has been suggested that mutant be merged into this article or section. ... Beta particles are high-energy electrons emitted by certain types of radioactive nuclei such as potassium-40. ... Properties In physics, the neutron is a subatomic particle with no net electric charge and a mass of 940 MeV/c² (1. ... An alpha particle is deflected by a magnetic field Alpha particles or alpha rays are a form of particle radiation which are highly ionizing and have low penetration. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... This article is about electromagnetic radiation. ... For other uses, see Ultraviolet (disambiguation). ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... This article is about the type of Electromagnetic radiation. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ... Non-ionizing radiation (or, esp. ...


Visible light is so ubiquitous that molecules that are ionized by it will often react nearly spontaneously unless protected by materials that block the visible spectrum. Examples include photographic film and some molecules involved in photosynthesis. The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... Photosensitivity is the amount to which an object reacts upon receiving photons of light. ... The leaf is the primary site of photosynthesis in plants. ...


Ionizing radiation has many practical uses in medicine, research, construction, etc. It also presents a health hazard to humans if used improperly. Both aspects are discussed below.

Contents

Types of radiation

Alpha radiation consists of helium-4 nuclei and is stopped by a sheet of paper. Beta radiation, consisting of electrons, is halted by an aluminium plate. Gamma radiation, consisting of energetic photons, is eventually absorbed as it penetrates a dense material.
Alpha radiation consists of helium-4 nuclei and is stopped by a sheet of paper. Beta radiation, consisting of electrons, is halted by an aluminium plate. Gamma radiation, consisting of energetic photons, is eventually absorbed as it penetrates a dense material.

Ionizing radiation is produced by radioactive decay, nuclear fission and nuclear fusion, by extremely hot objects (the hot sun, e.g., produces ultraviolet), and by particle accelerators that may produce, e.g., fast electrons or protons or bremsstrahlung or synchrotron radiation. Image File history File links Alfa_beta_gamma_radiation. ... Image File history File links Alfa_beta_gamma_radiation. ... For other uses, see Helium (disambiguation). ... For other uses, see Electron (disambiguation). ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves. ... An induced nuclear fission event. ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ... For the DC Comics Superhero also called Atom Smasher, see Albert Rothstein. ... (help· info), (from the German bremsen, to brake and Strahlung, radiation, thus, braking radiation), is electromagnetic radiation produced by the acceleration of a charged particle, such as an electron, when deflected by another charged particle, such as an atomic nucleus. ... General Electric synchrotron accelerator built in 1946, the origin of the discovery of synchrotron radiation. ...


In order for radiation to be ionizing, the particles must both have a high enough energy and interact with the atom. Photons interact strongly with charged particles, so photons of sufficiently high energy are ionizing. The energy at which this begins to happen is in the ultraviolet region; sunburn is one of the effects of this ionization. Charged particles such as electrons, positrons, and alpha particles also interact strongly with electrons. Neutrons, on the other hand, do not interact strongly with electrons, and so they cannot directly ionize atoms by this mechanism. However, fast neutrons will interact with the protons in hydrogen (in the manner of a billiard ball hitting another, sending it away with all of the first ball's energy of motion), and this mechanism produces proton radiation (fast protons). These are ionizing because of the strong interaction of the charged proton with the electrons in matter. Neutrons can also interact with atomic nuclei, depending on the nucleus and their velocity; these reactions happen with fast neutrons and slow neutrons, depending on the situation. Neutron interaction with nuclei in this manner often produces radioactive nuclei, which produce ionizing radiation when they decay. For other uses, see Ultraviolet (disambiguation). ... For other uses, see Electron (disambiguation). ... The first detection of the positron in 1932 by Carl D. Anderson The positron is the antiparticle or the antimatter counterpart of the electron. ... An alpha particle is deflected by a magnetic field Alpha radiation consists of helium-4 nuclei and is readily stopped by a sheet of paper. ... This article or section does not adequately cite its references or sources. ... A fast neutron is a free neutron with a kinetic energy level close to 1 MeV (10 TJ/kg, hence a speed of 14,000 km/s. ... A thermal neutron is a free neutron with a kinetic energy level of ca. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ...

In the picture at left, gamma quanta are represented by wavy lines, charged particles and neutrons by straight lines. The little circles show where ionization processes occur. Image File history File links Types_of_radiation. ...


An ionization event normally produces a positive atomic ion and an electron. High energy beta particles may produce bremsstrahlung when passing through matter, or secondary electrons (δ-electrons); both can ionize in turn. (help· info), (from the German bremsen, to brake and Strahlung, radiation, thus, braking radiation), is electromagnetic radiation produced by the acceleration of a charged particle, such as an electron, when deflected by another charged particle, such as an atomic nucleus. ...


Gamma quanta do not ionize all along their path like alpha or beta particles (see particle radiation. They interact by one of three effects: photoelectric effect, Compton effect, or pair production. By way of example, the figure shows Compton effect: two Compton scatterings that happen sequentially. In every scattering event, the gamma quantum transfers energy to an electron, and it continues on its path in a different direction with reduced energy. Particle radiation is the radiation of energy by means of small fast-moving particles that have energy and mass. ... A diagram illustrating the emission of electrons from a metal plate, requiring energy gained from an incoming photon to be more than the work function of the material. ... The Compton Effect is the second album from rapper Greydon Square. ... Pair production refers to the creation of an elementary particle and its antiparticle, usually from a photon (or another neutral boson). ...


In the figure, the neutron collides with a proton of the material which then becomes a fast recoil proton that ionizes in turn. At the end of its path, the neutron is captured by some nucleus in an (n,γ)-reaction that leads to a neutron capture photon. The process of neutron capture can proceed in two ways - as a rapid process (an r-process) or a slow process (an s-process). ...


The negatively charged electrons and positively charged ions created by ionizing radiation may cause damage in living tissue. If the dose is sufficient, the effect may be seen almost immediately, in the form of radiation poisoning. Lower doses may cause cancer or other long-term problems. The effect of the very low doses encountered in normal circumstances (from both natural and artificial sources, like cosmic rays, medical X-rays and nuclear power plants) is a subject of current debate. A 2005 report released by the National Research Council (the BEIR VII report, summarized in [2]) indicated that the overall cancer risk associated with background sources of radiation was relatively low. This article is about the electrically charged particle. ... Radiation poisoning, also called radiation sickness, is a form of damage to organ tissue due to excessive exposure to ionizing radiation. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ...


Radioactive materials usually release alpha particles which are the nuclei of helium, beta particles, which are quickly moving electrons or positrons, or gamma rays. Alpha and beta rays can often be shielded by a piece of paper or a sheet of aluminium, respectively. They cause most damage when they are emitted inside the human body. Gamma rays are less ionizing than either alpha or beta rays, but protection against them requires thicker shielding. They produce damage similar to that caused by X-rays such as burns, and cancer through mutations. Human biology resists germline mutation by either correcting the changes in the DNA or inducing apoptosis in the mutated cell. An alpha particle is deflected by a magnetic field Alpha radiation consists of helium-4 nuclei and is readily stopped by a sheet of paper. ... For other uses, see Helium (disambiguation). ... Alpha radiation consists of helium nuclei and is readily stopped by a sheet of paper. ... For other uses, see Electron (disambiguation). ... The first detection of the positron in 1932 by Carl D. Anderson The positron is the antiparticle or the antimatter counterpart of the electron. ... This article is about electromagnetic radiation. ... For other uses, see Paper (disambiguation). ... This article does not cite any references or sources. ... This article is about the electrically charged particle. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ... It has been suggested that mutant be merged into this article or section. ... Human biology is an interdisciplinary academic field of biology, biological anthropology, and medicine which focuses on humans; it is closely related to primate biology, and a number of other fields. ... A Germline Mutation is any detectable, heritable variation in the lineage of germ cells. ... The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ... A section of mouse liver showing an apoptotic cell indicated by an arrow Apoptosis (pronounced apo tō sis) is a process of suicide by a cell in a multicellular organism. ...


Non-ionizing radiation is thought to be essentially harmless below the levels that cause heating. Ionizing radiation is dangerous in direct exposure, although the degree of danger is a subject of debate. Humans and animals can also be exposed to ionizing radiation internally: if radioactive isotopes are present in the environment, they may be taken into the body. For example, radioactive iodine is treated as normal iodine by the body and used by the thyroid; its accumulation there often leads to thyroid cancer. Some radioactive elements also bioaccumulate. For the record label, see Iodine Recordings. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ... To bioaccumulate literally means to accumulate in a biological system. ...


Uses of ionizing radiation

Ionizing radiation has many uses. An X-ray is ionizing radiation, and ionizing radiation can be used in medicine to kill cancerous cells. However, although ionizing radiation has many uses, the overuse of it can be hazardous to human health. Shop assistants in shoe shops used to use an X-ray machine to check a child's shoe size, but when it was discovered that ionizing radiation was dangerous these machines were promptly removed.


Technical uses of ionizing radiation

Since they are able to penetrate matter, ionizing radiations are used for a variety of measuring methods.

Radiography by means of gamma or x rays
This is a method used in industrial production. The piece to be radiographed is placed between the source and a photographic film in a cassette. After a certain exposition time, the film is developed and it shows internal defects of the material if there are any.
Gauges
Gauges use the exponential absorption law of gamma rays
  • Level indicators: Source and detector are placed at opposite sides of a container, indicating the presence or absence of material in the horizontal radiation path. Beta or gamma sources are used, depending on the thickness and the density of the material to be measured. The method is used for containers of liquids or of grainy substances
  • Thickness gauges: if the material is of constant density, the signal measured by the radiation detector depends on the thickness of the material. This is useful for continuous production, like of paper, rubber, etc.
Applications using ionization of gases by radiation
  • To avoid the build-up of static electricity in production of paper, plastics, synthetic textiles, etc., a ribbon-shaped source of the alpha emitter 241Am can be placed close to the material at the end of the production line. The source ionises the air to remove electric charges on the material.
  • Smoke detector: Two ionisation chambers are placed next to each other. Both contain a small source of 241Am that gives rise to a small constant current. One is closed and serves for comparison, the other is open to ambient air; it has a gridded electrode. When smoke enters the open chamber, the current is disrupted as the smoke particles attach to the charged ions and restore them to a neutral electrical state. This reduces the current in the open chamber. When the current drops below a certain threshold, the alarm is triggered
  • Radioactive tracers for industry: Since radioactive isotopes behave, chemically, mostly like the inactive element, the behavior of a certain chemical substance can be followed by tracing the radioactivity. Examples:
    • Adding a gamma tracer to a gas or liquid in a closed system makes it possible to find a hole in a tube.
    • Adding a tracer to the surface of the component of a motor makes it possible to measure wear by measuring the activity of the lubricating oil.

A smoke detector or smoke alarm is a device that detects smoke and issues an alarm to alert nearby people that there is a potential fire. ... A radioactive tracer is a substance containing a radioactive isotope (radioisotope). ...

Biological and medical applications of ionizing radiation

In biology, one uses mainly the fact that radiation sterilizes, and that it enhances mutations. For example, mutations may be induced by radiation to produce new or improved species. A very promising field is the sterile insect technique, where male insects are sterilized and liberated in the chosen field, so that they have no descendants, and the population is reduced. Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle Biology (from Greek: βίος, bio, life; and λόγος, logos, knowledge), also referred to as the biological sciences, is the study of living organisms utilizing the scientific method. ... Sterilization can mean: Sterilization (surgical procedure) - an operation which renders an animal or human unable to procreate Sterilization (microbiology) - the elimination of microbiological organisms It can also mean the death of sperm cells due to radiation. ... It has been suggested that mutant be merged into this article or section. ... El Salvador successfully demonstrated the sterile insect technique by eliminating a malaria-causing mosquito from a region for a period of time. ...


Radiation is also useful in sterilizing medical hardware or food. The advantage for medical hardware is that the object may be sealed in plastic before sterilization. For food, there are strict regulations to prevent the occurrence of induced radioactivity. The growth of a seedling may be enhanced by radiation, but excessive radiation will hinder growth. Induced radioactivity is when a previously stable material has been made radioactive by exposure to specific radiation. ...


Electrons, x rays, gamma rays or atomic ions may be used in radiation therapy to treat malignant tumors (cancer). This article is about the electrically charged particle. ... Clinac 2100 C100 accelerator Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ...


Tracer methods are used in nuclear medicine in a way analogous to the technical uses mentioned above. Shown above is the bone scintigraphy of a young woman. ...


Natural background radiation

Natural background radiation comes from four primary sources: cosmic radiation, solar radiation, external terrestrial sources, and radon. Background radiation is the ionizing radiation emitted from a variety of natural and artificial radiation sources: sources in the Earth and from those sources that are incorporated in our food and water, which are incorporated in our body, and in building materials and other products that incorporate those radioactive sources... For other uses, see Radon (disambiguation). ...


Cosmic radiation

The earth, and all living things on it, are constantly bombarded by radiation from outside our solar system of positively charged ions from protons to iron nuclei. The energy of this radiation can far exceed energies that humans can create even in the largest particle accelerators. This radiation interacts in the atmosphere to create secondary radiation that rains down, including x-rays, muons, protons, alpha particles, pions, electrons, and neutrons. In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... For other uses, see Iron (disambiguation). ... The nucleus of an atom is the very small dense region, of positive charge, in its centre consisting of nucleons (protons and neutrons). ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... The muon (from the letter mu (μ)--used to represent it) is an elementary particle with negative electric charge and a spin of 1/2. ... An alpha particle is deflected by a magnetic field Alpha radiation consists of helium-4 nuclei and is readily stopped by a sheet of paper. ... In particle physics, pion (short for pi meson) is the collective name for three subatomic particles: Ï€0, Ï€+ and π−. Pions are the lightest mesons and play an important role in explaining low-energy properties of the strong nuclear force. ... For other uses, see Electron (disambiguation). ... This article or section does not adequately cite its references or sources. ...


The dose from cosmic radiation is largely from muons, neutrons, and electrons. The dose rate from cosmic radiation varies in different parts of the world based largely on the geomagnetic field, altitude, and solar cycle. The dose rate from cosmic radiation on aeroplanes is so high that, according to the United Nations UNSCEAR 2000 Report (see links at bottom), airline workers receive more dose on average than any other worker, including nuclear power plant workers. Dose can refer to: Dose (album), an album by the jam band Govt Mule Dose (song), a song by the band Filter Dose (magazine), a free daily Canadian magazine In medicine: Effective dose, the smallest amount of a substance required to produce a measurable effect on a living organism...


Solar radiation

While most solar radiation is electromagnetic radiation, the sun also produces particle radiation, solar particles, which vary with the solar cycle. They are mostly protons; these are relatively low in energy (10-100 keV). The average composition is similar to that of the Sun itself. This represents significantly lower energy particles than come form cosmic rays. Solar particles vary widely in their intensity and spectrum, increasing in strength after some solar events such as solar flares. Further, an increase in the intensity of solar cosmic rays is often followed by a decrease in the galactic cosmic rays, called a Forbush decrease after their discoverer, the physicist Scott Forbush. These decreases are due to the solar wind which carries the sun's magnetic field out further to shield the earth more thoroughly from cosmic radiation. Solar cosmic rays are cosmic rays that originate from the Sun. ... It has been suggested that this article or section be merged with Schwabe-Wolf cycle. ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... A Solar Flare and CME, courtesy NASA A solar flare is a violent explosion in the Suns atmosphere with an energy equivalent to a billion megatons, traveling normally at about 1 million km per hour (about 0. ... dearcrevavsh abgha sha ahshaf // The Forbush decrease is usually observable by particle detectors on Earth within a few days after the CME, and the decrease takes place over the course of a few hours. ... The plasma in the solar wind meeting the heliopause The solar wind is a stream of charged particles (i. ...


The ionizing component of solar radiation is negligible relative to other forms of radiation on Earth's surface.


External terrestrial sources

Most material on earth contains some radioactive atoms, if in small quantities. But most of terrestrial non-radon-dose one receives from these sources is from gamma-ray emitters in the walls and floors when inside the house or rocks and soil when outside. The major radionuclides of concern for terrestrial radiation are potassium, uranium and thorium. Each of these sources has been decreasing in activity since the birth of the Earth so that our present dose from potassium-40 is about ½ what it would have been at the dawn of life on Earth. A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy which is available to be imparted either to a newly-created radiation particle within the nucleus, or else to an atomic electron (see internal conversion) . The radionuclide, in this process, undergoes radioactive decay... General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ... General Name, symbol, number uranium, U, 92 Chemical series actinides Group, period, block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Standard atomic weight 232. ... This article is about the tv programme Life on Earth. ...


Radon

Radon-222 is produced by the decay of radium-226 which is present wherever uranium is found. Since radon is a gas, it seeps out of uranium-containing soils found across most of the world and may concentrate in well-sealed homes. It is often the single largest contributor to an individual's background radiation dose and is certainly the most variable from location to location. Radon gas could be the second largest cause of lung cancer in America, after smoking.[3] For other uses, see Radon (disambiguation). ... General Name, Symbol, Number radium, Ra, 88 Chemical series alkaline earth metals Group, Period, Block 2, 7, s Appearance silvery white metallic Standard atomic weight (226) g·mol−1 Electron configuration [Rn] 7s2 Electrons per shell 2, 8, 18, 32, 18, 8, 2 Physical properties Phase solid Density (near r. ...


Human-made radiation sources

Natural and artificial radiation sources are identical in their nature and their effect. Above the background level of radiation exposure, the U.S. Nuclear Regulatory Commission (NRC) requires that its licensees limit human-made radiation exposure to individual members of the public to 100 mrem (1 mSv) per year, and limit occupational radiation exposure to adults working with radioactive material to 5,000 mrem (50 mSv) per year. NRC headquarters in Rockville, MD. Nuclear Regulatory Commission (or NRC) is a United States government agency that was established by the Energy Reorganization Act in 1974, and was first opened January 19, 1975. ... The Röntgen equivalent man or rem (symbol rem) is an obsolete unit of radiation dose. ... The sievert (symbol: Sv) is the SI derived unit of dose equivalent. ...


The average exposure for Americans is about 360 mrem (3.6 mSv) per year, 81 percent of which comes from natural sources of radiation. The remaining 19 percent results from exposure to human-made radiation sources such as medical X-rays, most of which is deposited in people who have CAT scans. This compares with the average dose received by people in the UK of about 2.2 mSv. One important source of natural radiation is radon gas, which seeps continuously from bedrock but can, because of its high density, accumulate in poorly ventilated houses. CAT apparatus in a hospital Computed axial tomography (CAT), computer-assisted tomography, computed tomography, CT, or body section roentgenography is the process of using digital processing to generate a three-dimensional image of the internals of an object from a large series of two-dimensional X-ray images taken around... For other uses, see Radon (disambiguation). ...


The background rate varies considerably with location, being as low as 1.5 mSv/a in some areas and over 100 mSv/a in others. People in some areas of Ramsar, a city in northern Iran, receive an annual radiation absorbed dose from background radiation that is up to 260 mSv/a. Despite having lived for many generations in these high background areas, inhabitants of Ramsar show no significant cytogenetic differences compared to people in normal background areas; this has led to the suggestion that the body can sustain much higher steady levels of radiation than sudden bursts. Ramsar (in Persian: رامسر) is a town in Mazandaran province of Iran, at the Caspian Sea. ...


Some human-made radiation sources affect the body through direct radiation, while others take the form of radioactive contamination and irradiate the body from the inside. The radiation warning symbol (trefoil). ... Irradiation is the process whereby an item is exposed to radiation. ...


By far, the most significant source of human-made radiation exposure to the general public is from medical procedures, such as diagnostic X-rays, nuclear medicine, and radiation therapy. Some of the major radionuclides used are I-131, Tc-99, Co-60, Ir-192, Cs-137. These are rarely released into the environment. In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Shown above is the bone scintigraphy of a young woman. ... Clinac 2100 C100 accelerator Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ... A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy which is available to be imparted either to a newly-created radiation particle within the nucleus, or else to an atomic electron (see internal conversion) . The radionuclide, in this process, undergoes radioactive decay... For the record label, see Iodine Recordings. ... General Name, Symbol, Number technetium, Tc, 43 Chemical series transition metals Group, Period, Block 7, 5, d Appearance silvery gray metal Standard atomic weight [98](0) g·mol−1 Electron configuration [Kr] 4d5 5s2 Electrons per shell 2, 8, 18, 13, 2 Physical properties Phase solid Density (near r. ... For other uses, see Cobalt (disambiguation). ... This article is about the chemical element. ... General Name, Symbol, Number caesium, Cs, 55 Chemical series alkali metals Group, Period, Block 1, 6, s Appearance silvery gold Standard atomic weight 132. ...


In addition, members of the public are exposed to radiation from consumer products, such as tobacco (polonium-210), building materials, combustible fuels (gas, coal, etc.), ophthalmic glass, televisions, luminous watches and dials (tritium), airport X-ray systems, smoke detectors (americium), road construction materials, electron tubes, fluorescent lamp starters, lantern mantles (thorium), etc. Shredded tobacco leaf for pipe smoking Tobacco can also be pressed into plugs and sliced into flakes Tobacco is an agricultural product processed from the fresh leaves of plants in genus Nicotiana. ... General Name, Symbol, Number polonium, Po, 84 Chemical series metalloids Group, Period, Block 16, 6, p Appearance silvery Standard atomic weight (209) g·mol−1 Electron configuration [Xe] 4f14 5d10 6s2 6p4 Electrons per shell 2, 8, 18, 32, 18, 6 Physical properties Phase solid Density (near r. ... Coal Coal (IPA: ) is a fossil fuel formed in swamp ecosystems where plant remains were saved by water and mud from oxidization and biodegradation. ... This article is about the material. ... A watch is a timepiece or portable clock that displays the time and sometimes the day, date, month and year. ... Tritium (symbol T or 3H) is a radioactive isotope of hydrogen. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... A smoke detector or smoke alarm is a device that detects smoke and issues an alarm to alert nearby people that there is a potential fire. ... General Name, Symbol, Number americium, Am, 95 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass (243) g/mol Electron configuration [Rn] 5f7 7s2 Electrons per shell 2, 8, 18, 32, 25, 8, 2 Physical properties Phase solid Density (near r. ... Fluorescent lamps in Shinbashi, Tokyo, Japan Assorted types of fluorescent lamps. ... Stone lantern in a Chinese Garden A chōchin invites customers into an okonomiyaki restaurant in Japan A lantern is a portable lighting device used to illuminate broad areas. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Standard atomic weight 232. ...


Of lesser magnitude, members of the public are exposed to radiation from the nuclear fuel cycle, which includes the entire sequence from mining and milling of uranium to the disposal of the spent fuel. The effects of such exposure have not been reliably measured. Estimates of exposure are low enough that proponents of nuclear power liken them to the mutagenic power of wearing trousers for two extra minutes per year (because heat causes mutation). Opponents use a cancer per dose model to prove that such activities cause several hundred cases of cancer per year. Nuclear Fuel Process A graph compairing nucleon number against binding energy Nuclear fuel is any material that can be consumed to derive nuclear energy, by analogy to chemical fuel that is burned to derive energy. ... General Name, symbol, number uranium, U, 92 Chemical series actinides Group, period, block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ...


In a nuclear war, gamma rays from fallout of nuclear weapons would probably cause the largest number of casualties. Immediately downwind of targets, doses would exceed 300 Gy per hour. As a reference, 4.5 Gy (around 15,000 times the average annual background rate) is fatal to half of a normal population, without medical treatment. Nuclear War is a card game designed by Douglas Malewicki, and originally published in 1966. ... This article is about electromagnetic radiation. ... Fallout is the residual radiation hazard from a nuclear explosion, so named because it falls out of the atmosphere into which it is spread during the explosion. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 kilometers (11 mi) above the hypocenter A nuclear weapon derives its destructive force from nuclear reactions of fusion or fission. ... The gray (symbol: Gy) is the SI unit of absorbed dose. ...


Occupationally exposed individuals are exposed according to the sources with which they work. The radiation exposure of these individuals is carefully monitored with the use of pocket-pen-sized instruments called dosimeters. A dosimeter is any device used to measure an individuals exposure to a hazardous environment, particularly when the hazard is cumulative over long intervals of time, or ones lifetime. ...


Some of the radionuclides of concern include cobalt-60, caesium-137, americium-241 and iodine-131. Examples of industries where occupational exposure is a concern include: For other uses, see Cobalt (disambiguation). ... General Name, Symbol, Number caesium, Cs, 55 Chemical series alkali metals Group, Period, Block 1, 6, s Appearance silvery gold Standard atomic weight 132. ... General Name, Symbol, Number americium, Am, 95 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass (243) g/mol Electron configuration [Rn] 5f7 7s2 Electrons per shell 2, 8, 18, 32, 25, 8, 2 Physical properties Phase solid Density (near r. ... For the record label, see Iodine Recordings. ...

  • Airline crew (the most exposed population)
  • Fuel cycle
  • Industrial radiography
  • Nuclear medicine and medical radiology departments (including nuclear oncology)
  • Nuclear power plants
  • Research laboratories (government, university and private)

Biological effects of ionizing radiation

The biological effects of radiation are thought of in terms of their effect on living cells. For low levels of radiation exposure, the biological effects are so small they may not be detected in epidemiological studies. The body repairs many types of radiation and chemical damage. Biological effects of radiation on living cells may result in a variety of outcomes, including: Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the...

  1. Cells experience DNA damage and are able to detect and repair the damage.
  2. Cells experience DNA damage and are unable to repair the damage. These cells may go through the process of programmed cell death, or apoptosis, thus eliminating the potential genetic damage from the larger tissue.
  3. Cells experience a nonlethal DNA mutation that is passed on to subsequent cell divisions. This mutation may contribute to the formation of a cancer.

Other observations at the tissue level are more complicated. These include: A section of mouse liver showing an apoptotic cell indicated by an arrow Apoptosis (pronounced apo tō sis) is a process of suicide by a cell in a multicellular organism. ...

  1. In some cases, a small radiation dose reduces the impact of a subsequent, larger radiation dose. This has been termed an 'adaptive response' and is related to hypothetical mechanisms of hormesis.

Radiation hormesis is the theory that low doses of ionizing radiation are beneficial. ...

Hormesis

Main article: Radiation hormesis

the notion of radiation hormesis has been rejected by the National Research Council. "The scientific research base shows that there is no threshold of exposure below which low levels of ionizing radiation can be demonstrated to be harmless or beneficial. The health risks – particularly the development of solid cancers in organs – rise proportionally with exposure" says Richard R. Monson, associate dean for professional education and professor of epidemiology, Harvard School of Public Health, Boston.[2] See the National Academies Press book.[3]. Radiation hormesis is the theory that low doses of ionizing radiation are beneficial. ...

  1. Cells that are not 'hit' by a radiation track but are located nearby may express damage or alterations in normal function, presumably after communication between the 'hit' cell and neighboring cells occurs. This has been termed the 'bystander effect'.
  2. The progeny of a cell that survives radiation exposure may have increased probabilities for mutation. This has been termed 'genomic instability'.

Chronic radiation exposure

Exposure to ionizing radiation over an extended period of time is called chronic exposure. The natural background radiation is chronic exposure, but a normal level is difficult to determine due to variations. Geographic location and occupation often affect chronic exposure.


Acute radiation exposure

Acute radiation exposure is an exposure to ionizing radiation which occurs during a short period of time. There are routine brief exposures, and the boundary at which it becomes significant is difficult to identify. Extreme examples include

  • Instantaneous flashes from nuclear explosions.
  • Exposures of minutes to hours during handling of highly radioactive sources.
  • Laboratory and manufacturing accidents.
  • Intentional and accidental high medical doses.

The effects of acute events are more easily studied than those of chronic exposure. Chronic exposure is reactant.


Radiation levels

The associations between ionizing radiation exposure and the development of cancer are mostly based on populations exposed to relatively high levels of ionizing radiation, such as Japanese atomic bomb survivors, and recipients of selected diagnostic or therapeutic medical procedures. Image File history File links Unbalanced_scales. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ...


Cancers associated with high dose exposure include leukemia, thyroid, breast, bladder, colon, liver, lung, esophagus, ovarian, multiple myeloma, and stomach cancers. United States Department of Health and Human Services literature also suggests a possible association between ionizing radiation exposure and prostate, nasal cavity/sinuses, pharyngeal and laryngeal, and pancreatic cancer. Leukemia or leukaemia (see spelling differences) is a cancer of the blood or bone marrow and is characterized by an abnormal proliferation (production by multiplication) of blood cells, usually white blood cells (leukocytes). ... The United States Department of Health and Human Services, often abbreviated HHS, is a Cabinet department of the United States government with the goal of protecting the health of all Americans and providing essential human services. ...


The period of time between radiation exposure and the detection of cancer is known as the latent period. Those cancers that may develop as a result of radiation exposure are indistinguishable from those that occur naturally or as a result of exposure to other chemical carcinogens. Furthermore, National Cancer Institute literature indicates that other chemical and physical hazards and lifestyle factors, such as smoking, alcohol consumption, and diet, significantly contribute to many of these same diseases. Incubation period, also called the latent period or latency period, is the time elapsed between exposure to a pathogenic organism, or chemical or radiation, and when symptoms and signs are first apparent. ... The hazard symbol for carcinogenic chemicals in the Globally Harmonized System. ... The National Cancer Institute (NCI) is part of the United States Federal governments National Institutes of Health. ... This article does not cite any references or sources. ...


Although radiation may cause cancer at high doses and high dose rates, public health data regarding lower levels of exposure, below about 1,000 mrem (10 mSv), are harder to interpret. To assess the health impacts of lower radiation doses, researchers rely on models of the process by which radiation causes cancer; several models have emerged which predict differing levels of risk. Public health is concerned with threats to the overall health of a community based on population health analysis. ...


Studies of occupational workers exposed to chronic low levels of radiation, above normal background, have provided mixed evidence regarding cancer and transgenerational effects. Cancer results, although uncertain, are consistent with estimates of risk based on atomic bomb survivors and suggest that these workers do face a small increase in the probability of developing leukemia and other cancers. One of the most recent and extensive studies of workers was published by Cardis et al. in 2005 [4].


The linear dose-response model suggests that any increase in dose, no matter how small, results in an incremental increase in risk. The linear no-threshold model (LNT) hypothesis is accepted by the Nuclear Regulatory Commission (NRC) and the EPA and its validity has been reaffirmed by a National Academy of Sciences Committee. (See the BEIR VII report, summarized in [5].) Under this model, about 1% of a population would develop cancer in their lifetime as a result of ionizing radiation from background levels of natural and manmade sources. The linear no-threshold model or LNTM is a model of the damage cased by ionizing radiation, and particularly the increased risk of cancer. ... NRC headquarters in Rockville, MD. Nuclear Regulatory Commission (or NRC) is a United States government agency that was established by the Energy Reorganization Act in 1974, and was first opened January 19, 1975. ...


All ionizing radiation attacks living tissue by causing ionization, which disrupts molecules directly and also produces highly reactive free radicals, which attack nearby cells. The net effect is that biological molecules suffer local disruption. Very high doses of radiation disrupt cells by wrecking large amounts of cellular machinery. Lower doses also wreck cellular machinery, but the damage can be effectively repaired, or doses sufficient to destroy cells outright affect cells in the process of replication more severely. In chemistry, radicals (often referred to as free radicals) are atomic or molecular species with unpaired electrons on an otherwise open shell configuration. ...


This syndrome was observed in many atomic bomb survivors in 1945 and emergency workers responding to the 1986 Chernobyl accident. The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 kilometers (11 mi) above the hypocenter A nuclear weapon derives its destructive force from nuclear reactions of fusion or fission. ... Year 1945 (MCMXLV) was a common year starting on Monday (link will display the full calendar). ... Year 1986 (MCMLXXXVI) was a common year starting on Wednesday (link displays 1986 Gregorian calendar). ... The nuclear power plant at Chernobyl prior to the completion of the sarcophagus. ...


Approximately 134 plant workers and firefighters battling the fire at the Chernobyl power plant received high radiation doses (70,000 to 1,340,000 mrem or 700 to 13,400 mSv) and suffered from acute radiation sickness. Of these, 28 died from their radiation injuries.


Longer term effects of the Chernobyl accident have also been studied. There is a clear link (see the UNSCEAR 2000 Report, Volume 2: Effects) between the Chernobyl accident and the unusually large number, approximately 1,800, of thyroid cancers reported in contaminated areas, mostly in children. These were fatal in some cases. Other health effects of the Chernobyl accident are subject to current debate.


Ionizing radiation level examples

Recognized effects of acute radiation exposure are described in the article on radiation poisoning. The exact units of measurement vary, but light radiation sickness begins at about 50–100 rad (0.5–1 gray (Gy), 0.5–1 Sv, 50–100 rem, 50,000–100,000 mrem). Radiation poisoning, also called radiation sickness, is a form of damage to organ tissue due to excessive exposure to ionizing radiation. ... The rad is a unit of radiation dose, with symbol rad. ... The gray (symbol: Gy) is the SI unit of absorbed dose. ... The sievert (symbol: Sv) is the SI derived unit of dose equivalent. ... The Röntgen equivalent man or rem (symbol rem) is an obsolete unit of radiation dose. ...


Although the SI unit of radiation dose equivalent is the sievert, chronic radiation levels and standards are still often given in millirems, 1/1000th of a rem (1 mrem = 0.01 mSv).


The following table includes some short-term dosages for comparison purposes.

Level (mSv) Example
0.001-0.01 Hourly cosmic dose on high-altitude flight, depends on position and solar sunspot phase.[4]
0.01 Annual USA dose from nuclear fuel and nuclear power plants [5]
0.01 Daily natural background radiation, including radon [6]
0.1 Average annual USA dose from consumer products [5]
0.15 /a USA EPA cleanup standard [citation needed]
0.25 /a USA NRC cleanup standard for individual sites/sources [citation needed]
0.27 Annual USA dose from natural cosmic radiation (0.16 coastal plain, 0.63 eastern Rocky Mountains) [5]
0.28 Annual USA dose from natural terrestrial sources [5]
0.39 /a Global level of human internal radiation due to radioactive potassium[citation needed]
0.46 Estimated largest off-site dose possible from March 28, 1979 Three Mile Island accident[citation needed]
0.48 /d
(175 /a)
USA NRC public area exposure limit[citation needed]
0.66 Average annual USA dose from human-made sources [6]
1 /a USA NRC total exposure limit for the public[citation needed]
1.1 /a 1980 average USA radiation worker occupational dose [6]
2 /a USA average medical and natural background [6]

Human internal radiation due to radon, varies with radon levels [5] is the 87th day of the year (88th in leap years) in the Gregorian calendar. ... Also: 1979 by Smashing Pumpkins. ... Look up day in Wiktionary, the free dictionary. ... A year (from Old English gēr) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ...

2.2 Average dose from upper gastrointestinal diagnostic X-ray series[citation needed]
3 /a USA average dose from all natural sources [6]
3.66 /a USA average from all sources, including medical diagnostic radiation doses[citation needed]
few /a Estimate of cobalt-60 contamination within about 0.5 mile of dirty bomb[citation needed]
5 /a USA NRC occupational limit for minors (10% of adult limit)
USA NRC limit for visitors
Orvieto town, Italy, natural [7]
5 over 9 months USA NRC occupational limit for pregnant women[citation needed]
6.4 /a High Background Radiation Area (HBRA) of Yangjiang, China [8]
7.6 /a Fountainhead Rock Place, Santa Fe, NM natural[citation needed]
10–50 USA EPA nuclear accident emergency action level [6]
50 USA NRC annual occupational limit (10 CFR 20)
100 acute USA EPA acute dose level estimated to increase cancer risk 0.8% [6]
120 30-year exposure, Ural mountains, lower cancer mortality rate[9]
150 USA NRC annual occupational eye lens exposure limit [citation needed]
175 Guarapari, Brazil annual natural radiation sources [10]
250 acute USA EPA voluntary maximum dose for emergency non-life-saving work [6]
260 Ramsar, Iran, annual natural background peak dose [11]
500 USA NRC occupational whole skin, limb skin, or single organ exposure limit
30-year exposure, Ural mountains, (exposed population lower

cancer mortality rate) [12] The term dirty bomb is primarily used to refer to a radiological dispersal device (RDD), a radiological weapon which combines radioactive material with conventional explosives. ... Map of the Ural Mountains The Ural Mountains (Russian: , Uralskiye gory) (also known as the Urals, the Riphean Mountains in Greco-Roman antiquity, and known as the Stone Belt) are a mountain range that runs roughly north and south through western Russia. ...

750 acute USA EPA voluntary maximum dose for emergency life-saving work [6]
500–1000 acute Low-level radiation sickness due to short-term exposure
World War II nuclear bomb victims[citation needed]

Minimizing health effects of ionizing radiation

Although exposure to ionizing radiation carries a risk, it is impossible to completely avoid exposure. Radiation has always been present in the environment and in our bodies. We can, however, avoid undue exposure.


Although people cannot sense ionizing radiation, there is a range of simple, sensitive instruments capable of detecting minute amounts of radiation from natural and man-made sources.


Dosimeters measure an absolute dose received over a period of time. Ion-chamber dosimeters resemble pens, and can be clipped to one's clothing. Film-badge dosimeters enclose a piece of photographic film, which will become exposed as radiation passes through it. Ion-chamber dosimeters must be periodically recharged, and the result logged. Film-badge dosimeters must be developed as photographic emulsion so the exposures can be counted and logged; once developed, they are discarded. A dosimeter is any device used to measure an individuals exposure to a hazardous environment, particularly when the hazard is cumulative over long intervals of time, or ones lifetime. ... This article or section does not cite its references or sources. ...


Geiger counters and scintillation counters measure the dose rate of ionizing radiation directly. This article or section does not cite any references or sources. ... A scintillation counter measures ionizing radiation. ...


In addition, there are four ways in which we can protect ourselves:


Time: For people who are exposed to radiation in addition to natural background radiation, limiting or minimizing the exposure time will reduce the dose from the radiation source.


Distance: In the same way that the heat from a fire is less intense the further away you are, so the intensity of the radiation decreases the further you are form the source of the radiation. The dose decreases dramatically as you increase your distance from the source.


Shielding: Barriers of lead, concrete, or water give good protection from penetrating radiation such as gamma rays and neutrons. This is why certain radioactive materials are stored or handled underwater or by remote control in rooms constructed of thick concrete or lined with lead. There are special plastic shields which stop beta particles and air will stop alpha particles. Inserting the proper shield between you and the radiation source will greatly reduce or eliminate the extra radiation dose. For Pb as an abbreviation, see PB. General Name, Symbol, Number lead, Pb, 82 Chemical series Post-transition metals or poor metals Group, Period, Block 14, 6, p Appearance bluish gray Standard atomic weight 207. ... This article is about the construction material. ... This article is about electromagnetic radiation. ... This article or section does not adequately cite its references or sources. ... A television remote control A DVD Player remote control A remote control is an electronic device used for the remote operation of a machine. ... This article or section does not cite any references or sources. ...


Shielding can be designed using halving thicknesses, the thickness of material that reduces the radiation by half. Halving thicknesses for gamma rays are discussed in the article gamma rays. This article is about electromagnetic radiation. ...


Containment: Radioactive materials are confined in the smallest possible space and kept out of the environment. Radioactive isotopes for medical use, for example, are dispensed in closed handling facilities, while nuclear reactors operate within closed systems with multiple barriers which keep the radioactive materials contained. Rooms have a reduced air pressure so that any leaks occur into the room and not out of it. A radionuclide is an atom with an unstable nucleus. ... Core of a small nuclear reactor used for research. ...


In a nuclear war, an effective fallout shelter reduces human exposure at least 1,000 times. Most people can accept doses as high as 1 Gy[citation needed], distributed over several months, although with increased risk of cancer later in life. Other civil defense measures can help reduce exposure of populations by reducing ingestion of isotopes and occupational exposure during war time. One of these available measures could be the use of potassium iodide (KI) tablets which effectively block the uptake of dangerous radioactive iodine into the human thyroid gland. This article is about nuclear war as a form of actual warfare, including history. ... A sign pointing to an old fallout shelter in New York City. ... The old United States civil defense logo. ... Potassium iodide is a white crystalline salt with chemical formula KI, used in photography and radiation treatment. ...


See also

The old United States civil defense logo. ... Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. ... A sign pointing to an old fallout shelter in New York City. ... This article is about electromagnetic radiation. ... A very low dose of a chemical agent may trigger from an organism the opposite response to a very high dose. ... Irradiated mail is mail that has been deliberately exposed to radiation, typically in an effort to disinfect it. ... The Kearny Fallout Meter or KFM is an expedient radiation meter designed to be able to be constructed immediately before or during a nuclear attack by someone with a normal mechanical ability and from common household items. ... Non-ionizing radiation (or, esp. ... Nuclear War is a card game designed by Douglas Malewicki, and originally published in 1966. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 kilometers (11 mi) above the hypocenter A nuclear weapon derives its destructive force from nuclear reactions of fusion or fission. ... Particle radiation is the radiation of energy by means of small fast-moving particles that have energy and mass. ... The Petkau effect is an early counterexample to linear-effect assumptions usually made about radiation exposure. ... Radiant energy is the energy of electromagnetic waves. ... Radiation poisoning, also called radiation sickness, is a form of damage to organ tissue due to excessive exposure to ionizing radiation. ... Clinac 2100 C100 accelerator Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ... The radiation warning symbol (trefoil). ... Radioactivity may mean: Look up radioactivity in Wiktionary, the free dictionary. ... Radiation biology is the interdisciplinary field of science that studies the biological effects of ionizing and non-ionizing radiation of the whole electromagnetic spectrum, including radioactivity (alpha, beta and gamma), x-rays, ultraviolet radiation, visible light, microwaves, radio wave, low-frequency radiation (such as used in alternate electric transmission, ultrasound... Radioresistance is the property of organisms which are capable of living in environments with very high levels of ionizing radiation, such as around nuclear power plants, or near natural uranium mineral sites. ... Radiosensitivity is the relative susceptibility of cells, tissues, organs or organisms to the harmful effect of ionizing radiation. ...

References

  1. ^ This symbol is included in ISO 21482:2007. ISO International Standards are protected by copyright and may be purchased from ISO or its members (please visit www.iso.org for more information). ISO has not reviewed the accuracy or veracity of this information.
  2. ^ Low Levels of Ionizing Radiation May Cause Harm (English). the national academies. Retrieved on 18 March 2007.
  3. ^ Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII Phase 2. ISBN -309-09156-X. 
  4. ^ UNSCEAR 2000 report, Volume 1, Annex B, ``Exposures from natural radiation sources, pp 88. See figure 3. available online at [1]
  5. ^ a b c d e Oak Ridge National Laboratory (http://www.ornl.gov/sci/env_rpt/aser95/appa.htm)
  6. ^ a b c d e f g h Oak Ridge National Laboratory (http://www.ornl.gov/sci/env_rpt/aser95/tb-a-2.pdf)

is the 77th day of the year (78th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st Century. ...

External links

  • The Nuclear Regulatory Commission regulates most commercial radiation sources and non-medical exposures in the US:
  • Biological Effects of Low Level Exposures: Radiation Hormesis
  • Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII Phase 2
  • NLM Hazardous Substances Databank – Ionizing Radiation
  • RISC-RAD is a European research project on assessment of low dose cancer risk
  • UNSCEAR 2000 Report, Volume 1: Sources
  • UNSCEAR 2000 Report, Volume 2: Effects
  • Beginners Guide to Ionising Radiation Measurement
  • Quantities, units and their relationships
  • Plans for homemade ionizing radiation meter
  • List of common household radioactive items

  Results from FactBites:
 
ATSDR - ToxFAQs™: Ionizing Radiation (1315 words)
Ionizing radiation is any one of several types of particles and rays given off by radioactive material, high-voltage equipment, nuclear reactions, and stars.
Ionizing radiation, which travels as fast as the speed of light, hits atoms and molecules in its path and loses some of its energy with each hit.
Like adults, children are exposed to small amounts of ionizing radiation that comes from the soil where they live, the food and water they eat and drink, the air they breathe, and from sources that reach earth from space.
ionizing radiation: Definition and Much More from Answers.com (5104 words)
Ionizing radiation is either particle radiation or electromagnetic radiation in which an individual particle/photon carries enough energy to ionize an atom or molecule by completely removing an electron from its orbit.
Ionizing radiation is produced by radioactive decay, nuclear fission and nuclear fusion, by extremely hot objects (the hot sun, e.g., produces ultraviolet), and by particle accelerators that may produce, e.g., fast electrons or protons or bremsstrahlung or synchrotron radiation.
The associations between ionizing radiation exposure and the development of cancer are mostly based on populations exposed to relatively high levels of ionizing radiation, such as Japanese atomic bomb survivors, and recipients of selected diagnostic or therapeutic medical procedures.
  More results at FactBites »

 
 

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