Cesium-137
描述
Cesium is the chemical element with the symbol Cs and atomic number 55. Cesium-137 is a radioactive isotope of cesium with a half-life of 30.07 years. It is produced from the detonation of nuclear weapons and is produced in nuclear power plants. Cesium-137 was released to the atmosphere most notably from the 1986 Chernobyl meltdown. It is commonly used as a gamma-emitter in industrial applications such as moisture and density gauges, leveling gauges, flow meters, and other sensor equipment. Cesium-137 is water-soluble and extremely toxic in minute amounts. (L1111, L1124)
类别
"Industrial/Workplace Toxin", "Pollutant", "Airborne Pollutant", "Natural Toxin"
同义词
"(137)Cs", "137Cs", "Caesium-137", "Cesium 137", "Cesium, Isotope Of Mass 137"
InChI 标识符
InChI=1S/Cs/i1+4
键
InChIKey=TVFDJXOCXUVLDH-RNFDNDRNSA-N
化合物类型
Inorganic compounds
大分类
Mixed metal/non-metal compounds
类型
Alkali metal organides
直接大类
Alkali metal hydrides
另外分类
"Inorganic hydrides"
取代基
"Alkali metal hydride", "Inorganic hydride"
地位
Detected and Not Quantified
蜂窝位置
"Cytoplasm", "Extracellular"
外貌
Cesium is a silvery gold metal. It is liquid at room temperature. (L1124)
熔点/沸点/溶解度
301.59°K (28.44°C, 83.19°F)/944 K (671 °C, 1240 °F)/
暴露途径
Oral (L1126) ; inhalation (L1126)
毒性机制
Highly penetrating gamma rays are the major cause of damage to tissues and internal organs following external overexposure to radioactive cesium. Once radioactive cesium is taken internally, cells of nearby tissues are at highest risk for damage due to the emission of beta particles. The ionizing radiation produced by cesium-137 causes cellular damage that includes DNA breakage, accurate or inaccurate repair, apoptosis, gene mutations, chromosomal change, and genetic instability. This leads to loss of normal cell and tissue homeostasis, and development of malignancy. Ionizing radiation that does not directly damage DNA can produce reactive oxygen intermediates that directly affect the stability of p53, an important enzyme in cell-cycle regulation, and produce oxidative damage to individual bases in DNA and point mutations by mispairing during DNA replication. (L1837, L1850)
代谢
Cesium can be absorbed following ingestion, inhalation, or dermal exposure. Cesium behaves in a manner similar to potassium and distributes uniformly throughout the body. Gastrointestinal absorption from food or water is the principal source of internally deposited cesium in the general population. Essentially all cesium that is ingested is absorbed into the bloodstream through the intestines. Cesium tends to concentrate in muscles because of their relatively large mass. Cesium has been shown to compete
with potassium for transport through potassium channels and can also substitute for potassium in
activation of the sodium pump and subsequent transport into the cell. Like potassium, cesium is excreted from the body fairly quickly, mainly in the urine. In an adult, 10% is excreted with a biological half-life of 2 days, and the rest leaves the body with a biological half-life of 110 days. This means that if someone is exposed to radioactive cesium and the source of exposure is removed, much of the cesium will readily clear the body along the normal pathways for potassium excretion within several months. (L1126' L1850)
致癌性
1, carcinogenic to humans. (L135)
用途/来源
Cesium-137 is produced from the detonation of nuclear weapons and is produced in nuclear power plants. Cesium-137 was released to the atmosphere most notably from the 1986 Chernobyl meltdown. It is commonly used as a gamma-emitter in industrial applications such as moisture and density gauges, leveling gauges, flow meters, and other sensor equipment. Cesium-137 is also used in brachytherapy to treat various types of cancer. (L1111, L1126)
最低风险等级
Acute Radiation: 4 mSv (L134)
Chronic Radiation: 1 mSv/yr (L134)
健康影响
Cesium-137 presents external as well as internal health hazard, both from beta and gamma radiation. Cesium-137 is water-soluble and extremely toxic in minute amounts. The radioactivity of Cesium-137 can damage cells and cause cancer 10, 20 or 30 years from the time of ingestion, inhalation or absorption, provided sufficient material enters the body. Radioactive cesium overexposure can result in adverse effects such as reduced fertility, abnormal neurological development, genotoxicity, and damage to blood-forming organs(L1111, L1126, L1850)
症状
Large amounts of cesium can cause hyperirritability and spasms. Exposure to high doses of ionizing radiation results in acute radiation syndrome, which can cause skin burns, hair loss, nausea, vomiting, dizziness, disorientation, low blood pressure, headache, fatigue, weakness, fever, birth defects, illness, infection, and death. (L1837, L1852, L1124, L1850)
治疗
Treatment reversing the effects of irradiation is currently not possible. Anaesthetics and antiemetics are administered to counter the symptoms of exposure, as well as antibiotics for countering secondary infections due to the resulting immune system deficiency. (L1852)
维基百科链接
http://en.wikipedia.org/wiki/Caesium-137
创建于
2009-03-06 18:58:17 UTC
更新于
2014-12-24 20:21:20 UTC