Radiation poisoning

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Radiation poisoning, also called "radiation sickness", is a form of damage to organic tissue due to excessive exposure to ionizing radiation. The term is generally used to refer to acute problems caused by a large dosage of radiation in a short period. Many of the symptoms of radiation poisoning occur as ionizing radiation interferes with cell division. This interference causes particular problems for cells that normally divide rapidly, such as those lining the gastrointestinal tract. Likewise, this is one reason for the effectiveness of radiotherapy in treating cancer — cancer cells are among the fastest-dividing in the body, and will be killed by a radiation dose that adjacent normal cells are likely to survive. Image:Radiation warning symbol.svg

Strictly speaking the correct name for "radiation sickness" is acute radiation syndrome. A chronic radiation syndrome does exist but is very uncommon; this has been observed among workers in early radium source production sites and in the early days of the Soviet nuclear program. While a short exposure can result in acute radiation syndrome, it requires a prolonged high level of exposure to cause the chronic syndrome.

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Measuring radiation dosage

The rad is a unit of absorbed radiation dose defined in terms of the energy actually deposited in the tissue. One rad is an absorbed dose of 0.01 joules of energy per kilogram of tissue. The more recent SI unit is the gray, which is defined as 1 joule of deposited energy per kilogram of tissue. Thus one gray is equal to 100 rad.

To accurately assess the risk of radiation, the absorbed dose energy in rad is multiplied by the relative biological effectiveness (RBE) of the radiation to get the biological dose equivalent in rems. Rem stands for "Röntgen equivalent man." In SI units, the absorbed dose energy in grays is multiplied by the same RBE to get a biological dose equivalent in sieverts (Sv). The sievert is equal to 100 rem.

The RBE is a "quality factor," often denoted by the letter Q, which assesses the damage to tissue caused by a particular type and energy of radiation. For alpha particles Q may be as high as 20, so that one rad of alpha radiation is equivalent to 20 rem. The Q of neutron radiation depends on their energy. However, for beta particles, x-rays, and gamma rays, Q is taken as one, so that the rad and rem are equivalent for those radiation sources, as are the gray and sievert. See the sievert article for a more complete list of Q values.

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Symptoms and effects

Radiation sickness is generally associated with acute exposure and has a characteristic set of symptoms that appear in an orderly fashion. The symptoms of radiation sickness become more serious (and the chance of survival decreases) as the dosage of radiation increases. Prolonged exposure to radiation can induce cancer as cell-cycle genes are corrupted. However, since tumors themselves grow by abnormally rapid cell division, the ability of radiation to disturb cell division is also used to treat cancer (see radiotherapy), and low levels of ionizing radiation have been claimed to lower one's risk of cancer (see hormesis).

Radiation poisoning can result from accidental exposure to natural or industrial radiation sources. People working with radioactive materials often wear film "badges" or other dosimeters to monitor their total exposure to radiation. These devices are more useful than Geiger counters for determining biological effects, as they measure cumulative exposure over time, and are calibrated to change color or otherwise signal the user before exposure reaches unsafe levels.

Radiation caused illness and death after the bombings of Hiroshima and Nagasaki in about 1% of those exposed who survived the initial explosions. The casualty rate due to radiation was higher in Hiroshima, because although Fat Man (the bomb used at Nagasaki) had a higher yield than Little Boy (the bomb used at Hiroshima), Fat Man was a plutonium weapon, which is actually much less radioactive than a uranium weapon of equal yield (except at the moment of critical mass). Both bombs were airbursted, minimizing nuclear fallout (which otherwise would have killed many more).

Radiation poisoning also continues to be a major concern after the Chernobyl reactor accident. Of the 100 million curies (4 exabecquerels) of radioactive material, the radioactive xenon-133 and iodine-131 Chernobyl released were initially the most dangerous. Due to their short half-lives of 5 and 8 days they have now decayed, leaving the more long-lived caesium-137 (with a half-life of 30.07 years) and strontium-90 (with a half-life of 28.78 years) as main dangers. Thirty-one people died as an immediate result of the Chernobyl accident.

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Prevention and treatment

The best prevention for radiation sickness is to minimize human exposure to high levels of ionizing radiation. The use of radionuclides in science and industry is strictly regulated in most countries (in the U.S. by the Nuclear Regulatory Commission). In the event of an accidental or deliberate release of radioactive material, evacuation or sheltering in place are the recommended measures. During the height of the cold war, fallout shelters were identified in many urban areas. Potassium iodide (KI), administered orally immediately after exposure, may be used to protect the thyroid from ingested radioactive iodine in the event of an accident or terrorist attack at a nuclear power plant, or the detonation of a nuclear explosive. KI would not be effective against a dirty bomb unless the bomb happened to contain radioactive iodine, and even then it would only help to prevent thyroid cancer.

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Table of exposure levels and symptoms

Dose-equivalents are presently stated in sieverts:

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0.05–0.2 Sv (5–20 REM)

No symptoms. Potential for cancer and mutation of genetic material, according to the LNT model. This is disputed. (Note: see hormesis). A few researchers even contend that low dose radiation may be beneficial. [1] [2] [3]

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0.2–0.5 Sv (20–50 REM)

No noticeable symptoms. Red blood cell count decreases temporarily.

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0.5–1 Sv (50–100 REM)

Mild radiation sickness with headache and increased risk of infection due to disruption of immunity cells. Temporary male sterility is possible.

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1–2 Sv (100–200 REM)

Light radiation poisoning, 10% fatality after 30 days (LD 10/30). Typical symptoms include mild to moderate nausea (50% probability at 2 Sv), with occasional vomiting, beginning 3 to 6 hours after irradiation and lasting for up to one day. This is followed by a 10 to 14 day latent phase, after which light symptoms like general illness, anorexia and fatigue appear (50% probability at 2 Sv). The immune system is depressed, with convalescence extended and increased risk of infection. Temporary male sterility is common. Spontaneous abortion or stillbirth will occur.

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2–3 Sv (200–300 REM)

Severe radiation poisoning, 35% fatality after 30 days (LD 35/30). Nausea is common (100% at 3 Sv), with 50% risk of vomiting at 2.8 Sv. Symptoms onset at 1 to 6 hours after irradiation and last for 1 to 2 days. After that, there is a 7 to 14 day latent phase, after which the following symptoms appear: loss of hair all over the body (50% probability at 3 Sv), fatigue and general illness. There is a massive loss of leukocytes, greatly increasing the risk of infection. Permanent female sterility is possible. Convalescence takes one to several months.

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3–4 Sv (300–400 REM)

Severe radiation poisoning, 50% fatality after 30 days (LD 50/30). Other symptoms are similar to the 2–3 Sv dose, with uncontrollable bleeding in the mouth, under the skin and in the kidneys (50% probability at 4 Sv) after the latent phase.

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4–6 Sv (400–600 REM)

Acute radiation poisoning, 60% fatality after 30 days (LD 60/30). Fatality increases from 60% at 4.5 Sv to 90% at 6 Sv (unless there is intense medical care). Symptoms start half an hour to two hours after irradiation and last for up to 2 days. After that, there is a 7 to 14 day latent phase, after which generally the same symptoms appear as with 3-4 Sv irradiation, with increased intensity. Female sterility is common at this point. Convalescence takes several months to a year. The primary causes of death (in general 2 to 12 weeks after irradiation) are infections and internal bleeding.

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6–10 Sv (600–1,000 REM)

Acute radiation poisoning, 100% fatality after 14 days (LD 100/14). Survival depends on intense medical care. Bone marrow is nearly or completely destroyed, so a bone marrow transplantation is required. Gastric and intestinal tissue are severely damaged. Symptoms start 15 to 30 minutes after irradiation and last for up to 2 days. Subsequently, there is a 5 to 10 day latent phase, after which the person dies of infection or internal bleeding. Recovery would take several years and probably would never be complete.

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10–50 Sv (1,000–5,000 REM)

Acute radiation poisoning, 100% fatality after 7 days (LD 100/7). An exposure this high leads to spontaneous symptoms after 5 to 30 minutes. After powerful fatigue and immediate nausea caused by direct activation of chemical receptors in the brain by the irradiation, there is a period of several days of comparative well-being, called the latent (or "walking ghost") phase. After that, cell death in the gastric and intestinal tissue, causing massive diarrhea, intestinal bleeding and loss of water, leads to water-electrolyte imbalance. Death sets in with delirium and coma due to breakdown of circulation. Death is inevitable; the only treatment that can be offered is pain therapy.

Louis Slotin was exposed to approximately 21 Sv in a criticality accident on 21 May 1946, and died nine days later on 30 May.

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50–80 Sv (5,000–8,000 REM)

Immediate disorientation and coma in seconds or minutes. Death occurs after a few hours by total collapse of nervous system.

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More than 80 Sv (>8,000 REM)

U.S. military forces expect immediate death. A worker receiving 100 Sv (10,000 REM) in an accident at Wood River, Rhode Island, USA on 24 July 1964 survived for 49 hours after exposure, and an operator receiving 120 Sv (12,000 REM) to his upper body in an accident at Los Alamos, New Mexico, USA on 30 December 1958 survived for 36 hours; details of this accident can be found on page 16 of Los Alamos' 2000 Review of Criticality Accidents [4].

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Radiation poisoning in fiction

Spoiler warning: Plot and/or ending details follow.
  • On the Beach is a post-apocalyptic end-of-the-world novel written by British author Nevil Shute, made into a movie in 1959 and a television movie in 2000. It depicts the lives of various people in Australia awaiting the arrival of a deadly radioactive cloud from a nuclear war in the northern hemisphere. In the end, everybody dies of radiation sickness or suicide. The length of time that such a fallout cloud would survive is greatly exaggerated for effect. The 1959 movie was a sensation and frightened many people.
  • Alas Babylon is a 60's novel by Pat Frank taking a what-if look at possible effects of nuclear war on people in the fictional community of Fort Repose, Florida.
  • The 1983 film Testament follows a suburban family coping with radiation sickness after Soviet nuclear attacks on San Francisco and the continental United States.
  • The 1983 film The Day After portrays the aftereffects of a global nuclear war between the US and the USSR, focusing mainly on the residents of Lawrence, Kansas. Various characters are shown dying of radiation poisoning, in particular showing hair loss and baldness. Because actor Jason Robards played the lead role, it popularly got called "Jason Robards' disease." The movie appeared at about the same time that various members of the Reagan administration were proposing a controversial missile defense system, the Strategic Defense Initiative (SDI), more popularly known as "Star Wars."
  • The 1983 film Silkwood portrayed Karen Silkwood, a metallurgy worker at a plutonium processing plant who was purposefully contaminated, psychologically tortured and possibly murdered to prevent her from exposing blatant worker safety violations at the plant..
  • Mick Jackson's 1984 TV movie Threads follows two Sheffield families and their children through the aftermath of a Soviet nuclear attack. Many characters are shown dying of radiation poisoning, cancers and deformity. Those who survive are shown aging prematurely.
  • Shohei Imamura's 1989 movie Black Rain (黒い雨; kuroi ame) deals with the aftermath of the atomic bombing of Hiroshima. The title refers to the "black rain" of radioactive fallout that fell on Hiroshima after the bombing. It is based on the book of the same name by Ibuse Masuji.
  • 1989's Fat Man and Little Boy is the dramatization of American efforts to construct the first nuclear weapon, during World War II. Scientist Michael Merriman, played by John Cusack, was exposed to a lethal dose of ionizing radiation during a criticality accident. Merriman is shown before his death, in graphic scenes. The character of Merriman was based on Louis Slotin, who died after an identical accident at Los Alamos National Labratory.
  • In the television series 24, second season, a major character inhales a fatal amount of airborne plutonium. The effects on his health are shown on an hour-by-hour basis. He becomes very ill but before dying from the radiation sacrifices his life to divert a nuclear bomb away from Los Angeles, California.
  • In the graphic novel When the Wind Blows by Raymond Briggs, an elderly couple are exposed to fallout after a nuclear war. Much of the second half of the story deals with the effects of radiation poisoning on them and how they interpret what is happening to them. Oblivious to the true danger they are in, they put most of the symptoms they are suffering from down to shock and stress.
  • In the television series Stargate SG-1, the character Daniel Jackson is exposed to a massive dose of radiation (approximately 12sv) while disarming an experimental nuclear weapon on another planet. Allowed to return to his home planet on compassionate grounds, he quickly succumbs to the symptoms of radiation poisoning, eventually only cheating death by ascending to a higher plane of existence.
  • The 1999 time-travel TV series "7 Days" featured an episode in the first season involving a radiation leak from a damaged Russian nuclear submarine. When asked to describe the size of the leak, one scientist explains, "The phrase 'radioactive death cloud' comes to mind." Victims are pictured as pale and sickly.
  • The 2002 film K-19: The Widowmaker shows the events of Soviet submarine K-19, where seven crew members experience acute radiation poisoning (spending 10 to 20 minutes repairing the coolant system of the reactor); the film is based on real events. They immediately experience vomiting and nausea, and become extremely ill. Some of the remaining crew members suffer minor symptoms.
  • The film Detonator (1992) (Pierce Brosnan, Patrick Stewart) featured an elderly scientist and a USSR Red Army General exposed for a few seconds to radiation from a nuclear bomb under construction. The scientist's health slowly deteriorates throughout the film. His symptoms are shown as hair loss, small red spots appearing on his face, bloody vomiting. He has the abilty to speak up until his death.
  • The German short film Tag 26 portrays the life of two survivors after a non-descript nuclear disaster, one of whom's protective radiation suits is pierced. After sealing the hole it is revealed the very small amount of time he was exposed to the contaminated air was enough to cause a blood test taken immediately after his accident to show that he had radiation poisoning. He decides a slow death in his suit is not preferable to a relatively quick on in the open air and removes the suit.
  • In the first season of War of the Worlds, host bodies to the aliens, who need radiation to negate the presence of bacteria, often featured sores to reflect the damage the radiation was doing to the human body (a novelisation of the pilot episode went further with the sickness as their clothes were stained by feces and vomit).
  • In the 2002 film The Sum of All Fears, an Arab man and his son find an atomic bomb in the Sinai desert that was lost when an Israeli bomber was shot down in the early days of the 1973 Arab-Israeli Yom Kippur War. The bomb had been buried there for nearly 30 years. When they uncover it they notice that the side is dented and the interior partially exposed. The man reaches inside and notes that it is warm. Later the man is shown dying from acute radiation poisoning as he is being questioned by a US intelligence agent.
  • The Russian movie "Dead Man's Letters" describes the life and struggle of survivors in a post-apocalyptic world. While the open end leaves room for speculation, most characters gradually die due to the lethal radiation. The movie dates 1986, the year of the Chernobyl accident.
  • The computer game Fallout deals extensivly with radiation effects and treatment. The protagonist travels across post-nuclear California, encountering numerous radiation-induced mutations and highly radioactive zones. Unless special precautions are taken, the player character suffers from increasingly severe syndromes of radiation sickness and eventually dies.
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See also

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Further reading

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External links

de:Strahlenkrankheit es:Envenenamiento por radiación fr:Syndrome d'irradiation aiguë ko:피폭 ja:被曝 pl:Choroba popromienna

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