Effective dose
An effective dose in pharmacology is the amount of drug that produces a therapeutic response in 50% of the people taking it, sometimes also called ED-50. In radiation protection it is an estimate of the stochastic effect that a non-uniform radiation dose has on a human.
Pharmacology
In pharmacology, effective dose is the median dose that produces the desired effect of a drug. The effective dose is often determined based on analysing the dose-response relationship specific to the drug. The dosage that produces a desired effect in half the test population is referred to as the ED-50, for "Effective dose, 50%".
Radiation
In Radiology, effective dose is defined in the same way as it has been in pharmacology above, and a figure that could be used in calculating a certain safety factor, the 'effective dose' would be the absorbed dose (whole body equivalent) required to achieve an adequate (diagnostic) image.
Effective dose is used in radiation protection, to compare the stochastic risk of a non-uniform exposure to ionizing radiation, with the risks caused by a uniform exposure of the whole body. The stochastic risks are carcinogenesis and hereditary effects. It is not intended as a measure for acute or threshold effects of radiation exposure such as erythema, radiation sickness or death.
Effective dose equivalent (Now replaced by Effective Dose) is used to compare radiation doses on different body parts on an equivalent basis because radiation does not affect different parts in the same way. The effective dose (E) to an individual is found by calculating a weighted average of the equivalent dose (H) to different body tissues, with the weighting factors (W) designed to reflect the different radiosensitivities of the tissues:
- <math>E = \Sigma_i H_i W_i</math>
The unit for effective dose is the sievert (Sv). It is measured in joule/kilogram (J/kg).
The International Commission on Radiological Protection provide guidance on the risk caused by radiation. The concept of effective dose was introduced in 1977[1]. It was then included as “effective dose equivalent” into Publication 26 by ICRP.
References
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See also
es:Dosis efectiva (Radiobiología)fr:Dose efficace it:Dose efficace nl:Effectieve dosis (farmacologie) no:Effektiv stråledose pl:Dawka skuteczna pt:Dose efetiva ru:Эффективная доза
fi:Efektiivinen annos- ↑ Jacobi W (1975). "The concept of effective dose - A proposal for the combination of organ doses". Radiat. Environ. Biophys (12): 101–109.
