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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 to ionizing radiation.
For example, assume the shelter is in an area of heavy fallout and the dose rate outside is 400 roentgen (R) per hour, enough to give a potentially fatal dose in about an hour to a person exposed in the open. If a person needs to be exposed for only 10 seconds to dump a bucket, in this 1/360 of an hour he will receive a dose of only about 1 R.
Early on it was found that X-rays, gamma rays, and beta radiation were essentially equivalent for all cell types. Therefore, the standard radiation type X is generally an X-ray beam with 250 keV photons or cobalt-60 gamma rays. As a result, the relative biological effectiveness of beta and photon radiation is essentially 1.
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]
The dose equivalent is calculated by the following equation: [4] Dose equivalent = Absorbed dosage x Tissue weighting factor Tissue weighting factor reflects the relative sensitivity of each organ to radiation. [4] The effective dose refers to the radiation risk averaged over the entire body. [4] It is the sum of the equivalent dosage of all ...
Cobalt-60 beam machine from 1951 Cobalt units use radiation from cobalt-60, which emits two gamma rays at energies of 1.17 and 1.33 MeV, a dichromatic beam with an average energy of 1.25 MeV. The role of the cobalt unit has largely been replaced by the linear accelerator, which can generate higher energy radiation.
Dose area product (DAP) is a quantity used in assessing the radiation risk from diagnostic X-ray radiography examinations and interventional procedures, like angiography.It is defined as the absorbed dose multiplied by the area irradiated, expressed in gray-centimetres squared (Gy·cm 2 [1] – sometimes the prefixed units dGy·cm 2, mGy·cm 2 or cGy·cm 2 are also used). [2]