Effective dose
Effective dose is a measure used in
radiation protection to estimate the risk resulting from an exposure of
ionizing radiation.
Effective dose n is the amount of radiation required to produce a certain effect in n% of a population.
Effective dose equivalent 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 (H) to an individual is found by calculating a weighted average of the
equivalent dose (E) to different body tissues, with the weighting factors (W) designed to reflect the different radiosensitivities of the tissues:
H = ∑
i E
i W
iEffective dose is used as a measure of the likelihood of
stochastic effects of radiation exposure: 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.
The unit for effective dose is the
sievert (Sv).
In
pharmacology,
effective dose is the minimal dose that produces the desired effect of 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%".
