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Radiation weighting factors that go from physical energy to biological effect must not be confused with tissue weighting factors. The tissue weighting factors are used to convert an equivalent dose to a given tissue in the body, to an effective dose, a number that provides an estimation of total danger to the whole organism, as a result of the ...
Effective dose is a dose quantity in the International Commission on Radiological Protection (ICRP) system of radiological protection. [1]It is the tissue-weighted sum of the equivalent doses in all specified tissues and organs of the human body and represents the stochastic health risk to the whole body, which is the probability of cancer induction and genetic effects, of low levels of ...
This is taken into account by the equivalent dose (H), which is defined as the mean dose to organ T by radiation type R (D T,R), multiplied by a weighting factor W R. This designed to take into account the biological effectiveness (RBE) of the radiation type, [ 8 ] For instance, for the same absorbed dose in Gy, alpha particles are 20 times as ...
Dose equivalent calculates the effect of radiation on human tissue. [4] This is done using tissue weighting factor, which takes into account how each tissue in the body has different sensitivity to radiation. [4] The effective dose is the risk of radiation averaged over the entire body. [4] Ionizing radiation is known to cause cancer in humans. [4]
The second weighting factor is the tissue factor W T, but it is used only if there has been non-uniform irradiation of a body. If the body has been subject to uniform irradiation, the effective dose equals the whole body equivalent dose, and only the radiation weighting factor W R is used. But if there is partial or non-uniform body irradiation ...
Earlier definitions going back to 1945 were derived from the roentgen unit, which was named after Wilhelm Röntgen, a German scientist who discovered X-rays. The unit name is misleading, since 1 roentgen actually deposits about 0.96 rem in soft biological tissue, when all weighting factors equal unity.
The NRC's definition of dose equivalent is "the product of the absorbed dose in tissue, quality factor, and all other necessary modifying factors at the location of interest." However, it is apparent from their definition of effective dose equivalent that "all other necessary modifying factors" excludes the tissue weighting factor. [17]
The body is divided into a set of sensitive tissues, and each tissue, T, is assigned a weight, w T, according to its estimated contribution to cancer risk. [20] The absorbed dose, D γ, that is delivered to each tissue is determined from measured dosimetry. For the purpose of estimating radiation risk to an organ, the quantity characterizing ...