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Radioactivity
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Radioactivity Radioactivity is the disintegration of atomic nuclei that releases energy by the emission of subatomic particles and electromagnetic rays. These subatomic particles are called alpha and beta particles. Productions of electromagnetic rays include X-rays and gamma rays. Most of the atoms making up matter are generally stable. It is the isotopes of these atoms that are not stable and constantly producing radiation. They are totally dangerous to life compounds. Radioactive Iodine? Iodine is a nonmetallic solid element. The French chemist Barnard Courtois discovered iodine in 1811. The human body requires traces of Iodine. It is part of thyroxin, a hormone produced by the thyroid gland that controls the rate of physical and mental development. A lack of Iodine can also cause goiter. Iodine is added to salt to prevent such diseases. Iodine-131 is the most important radioactive isotope in the environment. Radioactive iodine-131 was discovered by Glenn T. Seaborg and John Livingood at the University of California - Berkeley in the late 1930's. Formation of Iodine-131 Iodine-131 is an artificially produced by-product resulting from uranium atoms during operation of nuclear reactors and by plutonium in the detonation of nuclear weapons. Radiation type Iodine-131 produces beta minus particle and gamma rays. Iodine-131 Xenon-131 53 protons 54 protons 78 neutrons 77 neutrons In the above reaction during beta-minus decay Xenon is formed. One neutron of Iodine-131 turns into a proton and electron. The wording equation is as following: 131^I e- + gamma + 131^Xe Properties of Iodine-131 Radioactive Iodine has the same physical properties as stable Iodine. However, radioactive Iodine decays with time. Iodine-131 found in nuclear facilities and waste treatment plants quickly form compounds with the mixture of chemicals present. However, Iodine released to the environment from nuclear power plants is usually a gas. Iodine-131 has a physical half-life of about 8 days. Its biological half-life in thyroid is about 80 days. Iodine-131 releases beta energy of 806 keV with 89.3% of intensity. The amount of gamma rays released is 365 keV 81.3 % of intensity. Iodine usage Iodine is among the most widely used radionuclide in the medical field. Due to its short half-life and useful beta emission, Iodine-131 is used extensively in nuclear medicine. Its tendency to collect in the thyroid gland makes Iodine especially useful for diagnosing and treating thyroid problems. Radioactive Iodine can cause thyroid problems and help diagnose and treat thyroid problems. Doctors also use lower doses of Iodine-131 to treat overactive thyroids. Low doses can reduce activity of the thyroid gland, lowering hormone production in the gland. Doctors must maintain the fine balance between the risks and benefits of using radioactive iodine. On one hand, this small, additional exposure may tip the balance in favor of cancer formation. On the other, this small additional exposure can restore health by slowing an overactive thyroid and improve health conditions. Iodine–131 is also used to diagnose abnormal liver function, renal blood flow and urinary tract obstruction. But it is used widely in treatment of hyperthyroidism. The treatment, in cats, consists of injecting a single dose of radioactive iodine into the cat. When absorbed in the body, Iodine is concentrated in the thyroid gland and those cells that are most active (thyroid tumor cells) will absorb most of the radioiodine. Therefore, the radioactive Iodine preferentially enters the tumor cells in the thyroid gland and the radioactivity kills these cells while doing very little damage to the normal thyroid cells. Through normal bodily processes, the radioactive Iodine is removed from the body and is lost in the urine and feces. There is no anesthesia and the success rate is approximately 95%. Blood work needs to be performed prior to treatment to rule out any other medical problems. The main drawback is that the cat will have to stay at the hospital until the levels of radioactivity have dropped to below the levels set by the State and the Federal Government. This may take as little as four days or as much as a week. Exposure Iodine-131 is a gaseous fission product that forms within fuel rods as they fission. Unless reactor chemistry is carefully controlled, they can build up too fast, increasing pressure and causing corrosion in the rods. As the rods age, cracks or wholes may breach the rods. Cracked rods can release radioactive iodine into the water that surrounds and cools the fuel rods. There, it circulates with the cooling water throughout the system, ending up in the airborne, liquid, and solid wastes from the reactor. From time to time, reactor gas capture systems release gases, including iodine, to the environment under applicable regulations. Anywhere spent nuclear fuel is handled, there is a chance that iodine-131 will escape into the environment. Nuclear fuel reprocessing plants dissolve the spent fuel rods in strong acids to recover plutonium and other valuable materials. In the process, they also release iodine-131 into the airborne, liquid, and solid waste processing systems. The detonation of nuclear weapons also releases iodine-131 into the environment. Atmospheric testing in the 1950's and 60's released radioactive iodine to the atmosphere, which has disseminated around the world, and is now found at very low levels in the environment. Radioactive iodine can be inhaled as a gas or ingested in food or water. It dissolves in water so it moves easily from the atmosphere into humans and other living organisms. People are exposed to I-131 from nuclear power plant emissions. Some industrial facilities also emit radioactive iodine to the environment, as well as medical institutions. Radioactive iodine is usually emitted as a gas, but may contaminate liquids or solid materials as well. If a family member has been treated with I-131, you may have increased exposure to it through their body fluids. Radioactive iodine can enter the body by ingestion or inhalation. It dissolves in water so it moves easily from the atmosphere into humans and other living organisms. Protection The thyroid cannot tell the difference between radioactive and non-radioactive iodine. It will take up radioactive iodine in whatever proportion it is available in the environment. If large amounts of radioactive iodine are released during an nuclear accident, large doses of stable iodine may be distributed by government agencies to keep your thyroid gland from absorbing too much radioactive iodine: Raising the concentration of stable iodine in the blood, increases the likelihood that the thyroid will absorb it instead of radioactive iodine. EPA has issued a variety of regulations that limit the release of radionuclides, including I-129 and I-131, to the environment. These regulations address airborne and liquid releases from nuclear reactors, airborne emissions from a variety of industrial and governmental facilities, and allowable radioactive releases from radioactive waste disposal systems. EPA has established Maximum Contaminant Levels that limit the concentration of radioactive iodine and other radionuclides in drinking water from public water suppliers. Detection Living near a nuclear power plant may slightly increase your annual exposure to I-131. Detecting radioactive iodine in the environment requires specialized equipment. Most major medical centers can test for isotopes of iodine in your body. When I-131 is ingested, some of it concentrates in the thyroid gland. The rest passes from the body in urine. Airborne I-131 can be inhaled. In the lung, radioactive iodine is absorbed, passes into the blood stream and collects in the thyroid. Any remaining iodine passes from the body with urine. Testing of nuclear weapons during the 1950s resulted in widespread exposure of the U.S. population at that time (~160 million people) to a potentially hazardous radioactive substance: Iodine-131 (I-131). Since then, exposure to I-131 has been linked with the occurrence of thyroid disorders and thyroid cancer. Residents of some geographical areas experienced higher cumulative average doses of I-131 than others, and areas downwind from nuclear test sites especially were affected. Ingestion of the milk from cows and goats who grazed in nearby contaminated pastures was a primary route of human exposure to I-131. Safety There are certain safety regulation to make sure one does not come in contact with Iodine-131. It should be carried to the patient’s room in either a shielded cart or the manufacturer’s shipping container under constant surveillance and control of radiation safety workers. The transportation container must be securely locked. All staff attending to Nuclear Medicine therapy patients must wear whole body radiation dosimeters. Urine collection should be avoided. Conclusion Radioactivity occurs naturally over a long period of time. All radioisotopes are dangerous to human health. However they can be used for diagnosing or treating certain diseases. That’s why we are trying to produce them artificially. But we need to make sure certain regulations are carried out. Bibliography: Radioactivity Radioactivity is the disintegration of atomic nuclei that releases energy by the emission of subatomic particles and electromagnetic rays. These subatomic particles are called alpha and beta particles. Productions of electromagnetic rays include X-rays and gamma rays. Most of the atoms making up matter are generally stable. It is the isotopes of these atoms that are not stable and constantly producing radiation. They are totally dangerous to life compounds. Radioactive Iodine? Iodine is a nonmetallic solid element. The French chemist Barnard Courtois discovered iodine in 1811. The human body requires traces of Iodine. It is part of thyroxin, a hormone produced by the thyroid gland that controls the rate of physical and mental development. A lack of Iodine can also cause goiter. Iodine is added to salt to prevent such diseases. Iodine-131 is the most important radioactive isotope in the environment. Radioactive iodine-131 was discovered by Glenn T. Seaborg and John Livingood at the University of California - Berkeley in the late 1930's. Formation of Iodine-131 Iodine-131 is an artificially produced by-product resulting from uranium atoms during operation of nuclear reactors and by plutonium in the detonation of nuclear weapons. Radiation type Iodine-131 produces beta minus particle and gamma rays. Iodine-131 Xenon-131 53 protons 54 protons 78 neutrons 77 neutrons In the above reaction during beta-minus decay Xenon is formed. One neutron of Iodine-131 turns into a proton and electron. The wording equation is as following: 131^I e- + gamma + 131^Xe Properties of Iodine-131 Radioactive Iodine has the same physical properties as stable Iodine. However, radioactive Iodine decays with time. Iodine-131 found in nuclear facilities and waste treatment plants quickly form compounds with the mixture of chemicals present. However, Iodine released to the environment from nuclear power plants is usually a gas. Iodine-131 has a physical half-life of about 8 days. Its biological half-life in thyroid is about 80 days. Iodine-131 releases beta energy of 806 keV with 89.3% of intensity. The amount of gamma rays released is 365 keV 81.3 % of intensity.
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