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Cobalt therapy is the medical use of gamma rays from the radioisotope cobalt-60 to treat conditions such as cancer. Beginning in the 1950s, cobalt-60 was widely used in external beam radiotherapy (teletherapy) machines, which produced a beam of gamma rays which was directed into the patient's body to kill tumor tissue.
Cobalt-60 (60 Co) is a synthetic radioactive isotope of cobalt with a half-life of 5.2714 years. [ 3 ] [ 4 ] : 39 It is produced artificially in nuclear reactors . Deliberate industrial production depends on neutron activation of bulk samples of the monoisotopic and mononuclidic cobalt isotope 59
It is estimated that almost 80 percent of people received a dose less than 500 mrem (equivalent to 5 mSv); 18 percent, between 0.5 and 25 rems (5–25 mSv); and only two percent (about 80 people) received doses greater than 25 rems (250 mSv). Of these, five people received a dose between 300 and 700 rems (3–7 Sv) over a period of two months. [3]
A radiation accident occurred in Samut Prakan Province, Thailand in January–February 2000. The accident happened when an insecurely stored unlicensed cobalt-60 radiation source was recovered by scrap metal collectors who, together with a scrapyard worker, subsequently dismantled the container, unknowingly exposing themselves and others nearby ...
For example, for calcium the U.S. Food and Drug Administration set the recommended intake for adults over 70 years at 1,200 mg/day and the UL at 2,000 mg/day. [16] The European Union also sets recommended amounts and upper limits, which are not always in accord with the U.S. [ 17 ] Likewise, Japan, which sets the UL for iodine at 3000 μg ...
This reaction has a half-life of about 5.27 years, and due to the availability of cobalt-59 (100% of its natural abundance), this neutron bombarded isotope of cobalt is a valuable source of nuclear radiation (namely gamma radiation) for radiotherapy. [1] 59 27 Co + 1 0 n → 60 27 Co
Naturally occurring cobalt, Co, consists of a single stable isotope, 59 Co (thus, cobalt is a mononuclidic element). Twenty-eight radioisotopes have been characterized; the most stable are 60 Co with a half-life of 5.2714 years, 57 Co (271.811 days), 56 Co (77.236 days), and 58 Co (70.844 days). All other isotopes have half-lives of less than ...
Relative biological effectiveness. In radiobiology, the relative biological effectiveness (often abbreviated as RBE) is the ratio of biological effectiveness of one type of ionizing radiation relative to another, given the same amount of absorbed energy. The RBE is an empirical value that varies depending on the type of ionizing radiation, the ...