ABSTRACT
The health risk from radiation exposure can be assessed by the use of effective dose (E), or effective dose equivalent (EDE) (HE), recommended by the International Commission on Radiological Protection (ICRP) as the primary dose quantity in radiation protection. The concept of EDE was rst introduced in 1977 and then revised in 1990, when the name was changed to effective dose; however, the U.S. Nuclear Regulatory Agency (U.S. NRC) has only adopted the former de nition in the United States.1,2 The effective dose provides a technical basis to compare the radiation health risk with other kinds of risks. The same magnitude of effective dose can be assumed to produce the same degree of health risks irrespective of the organs or tissues involved in irradiation.
