........ ..:+3 ... B. The International Commission on Radiological Protection (ICRP) The ICRP originated in the Second International Congress of It has been looked to as the appropriate Radiology in 1928. body to give general guidance on widespread use of radiation sources caused by rapid developments in the field of nuclear ICRP recommendations deal with the basic principles energy. To the various national protection of radiation protection. bodies is left the responsibility for introducing the detailed technical regulations, recornrnendations, or codes of practice Recommendations are intended best suited to their countries. to guide the experts responsible for radiation protection practice. ...... .... ~.........-. — ICRP states that the objectives of radiation protection are to nrevent acute radiation effects and to limit the risks of late effects It holds that it is unknown whether a ~o an acceptable level. threshold exists, and it is assumed that even the smallest doses NTOpractical alternative in~”ol~’e a proportionately small risk. was found to assuming a linear relationship between dose and This implies that there is no wholly “safe” dose of effect. radiation. Exposure to natural background radiation carries a probability However, the of causing some soxnatic or hereditary injury. Commission believes that the risk resulting from exposures received from natural background should not affect the justification Accordingly, of an additional risk from rnan-m.ade exposures. any dose limitations recommended by t’ne Commission refer only to exposure resulting from technical practices that add to natural background radiation. These dose limitations exclude exposures (These same received in the course of medical procedures. . qualifications with regard to natural background and medical procedures are applied to h- CRP and FRC recommendations.) ICRP (\ wishes de-.’eloped the concept of “acceptable risk. “ Unless man to dispense with activities involting exposures to ionizing radiation, he must recognize that there is a degree of risk and must limit the radiation dose to a level at which the assumed risk is deemed to be acceptable to the individual and to society \ ~in ~iew of the benefits derived from such acti%ties. For planned or controlled exposures of individuals and populations, the ICRP has recommended the term “dose limit. “ Recommended dose limits are thought to be associated with a very low degree of For unplanned exposures from uncontrolled sources risk. . ..... ....... ... ... .. .. . .... ..... ........... ......../ III-3 !