Executive Summary

Abstract

Current radiation protection legislation and regulation worldwide is based on the three fundamental principles: justification, limitation, and optimization of human exposure to ionizing radiation, introduced by International Commission on Radiological Protection (ICRP) in its Publication 26 (1977). The practical implementation of the limitation and optimization principles requires a quantitative measure of radiation exposure. In 1978, ICRP defined for this purpose the protection quantity effective dose equivalent, HE. In ICRP Publication 60 (1991), HE was replaced by the related quantity, effective dose, E. Like HE, E is a measure for whole-body exposure, and it is used internationally for setting exposure limits and for guiding quantitatively the practical implementation of the optimization principle for the control of radiation induced stochastic effects. The effective dose to the whole body is defined as