Committed dose equivalent

Committed dose equivalent and Committed effective dose equivalent are dose quantities used in the United States system of Radiological Protection for irradiation due to an internal source. Committed dose equivalent and Committed effective dose equivalent are dose quantities used in the United States system of Radiological Protection for irradiation due to an internal source. CDE is defined by the United States Nuclear regulatory Commission in Title 10, Section 20.1003, of the Code of Federal Regulations (10 CFR 20.1003), such that 'The Committed dose equivalent, CDE (HT,50) is the dose to some specific organ or tissue of reference (T) that will be received from an intake of radioactive material by an individual during the 50-year period following the intake'. 'The calculation of the committed effective dose equivalent (CEDE) begins with the determination of the equivalent dose, HT, to a tissue or organ, T. Where DT,R is the absorbed dose in rads (one gray, an SI unit, equals 100 rads) averaged over the tissue or organ, T, due to radiation type, R, and WR is the radiation weighting factor. The unit of equivalent dose is the rem (sievert, in SI units).' This is defined in Title 10, Section 20.1003, of the Code of Federal Regulations of the USA the CEDE dose (HE,50) as the sum of the products of the committed dose equivalents for each of the body organs or tissues that are irradiated multiplied by the weighting factors (WT) applicable to each of those organs or tissues. 'The probability of occurrence of a stochastic effect in a tissue or organ is assumed to be proportional to the equivalent dose in the tissue or organ. The constant of proportionality differs for the various tissues of the body, but in assessing health detriment the total risk is required. This is taken into account using the tissue weighting factors, WT, which represent the proportion of the stochastic risk resulting from irradiation of the tissue or organ to the total risk when the whole body is irradiated uniformly and HT is the equivalent dose in the tissue or organ, T, in the equation:' Committed Effective Dose Equivalent (CEDE) refers to the dose resulting from internal radiation exposures. The CEDE is combined with the Deep-Dose Equivalent (DDE), the dose from external whole body exposures, to produce the Total Effective Dose Equivalent (TEDE), the dose resulting from internal and external radiation exposures. Both quantities can be expressed in rem or sieverts (Sv). The intake of radioactive material can occur through four pathways:1. inhalation of airborne contaminants such as radon 2. ingestion of contaminated food or liquids3. absorption of vapors such as tritium oxide through the skin4. injection of medical radioisotopes such as technetium-99m Some artificial radioisotopes such as iodine-131 are chemically identical to natural isotopes needed by the body, and may be more readily absorbed if the individual has a deficit of that element. For instance, 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 attack at a nuclear power plant, or the detonation of a nuclear explosive which would release radioactive iodine.Other radioisotopes have an affinity for particular tissues, such as plutonium into bone, and may be retained there for years in spite of their foreign nature. Not all radiation is harmful. The radiation can be absorbed through multiple pathways, varying due to the circumstances of the situation. If the radioactive material is necessary, it can be ingested orally via stable isotopes of specific elements. This is only suggested to those that have a lack of these elements however, because radioactive material can go from healthy to harmful with very small amounts. The most harmful way to absorb radiation is that of ingestion absorption because it is almost impossible to control how much will enter the body.