Effective dose is a dose quantity in the International Commission on Radiological Protection (ICRP) system of radiological protection.It is the tissue-weighted sum of the equivalent doses in all specified tissues and organs of the human body. It represents the stochastic health risk to the whole body, which is the probability of cancer induction and genetic effects, of low levels of ionizing radiation. It takes into account the type of radiation and the nature of each organ or tissue being irradiated, and enables summation of organ doses due to varying levels and types of radiation, both internal and external, to produce an overall calculated effective dose.
The SI unit for effective dose is the sievert (Sv) which corresponds to a 5.5% chance of developing cancer. The effective dose is not intended as a measure of deterministic health effects, which is the severity of acute tissue damage that is certain to happen, that is measured by the quantity absorbed dose.
