Maximum Permissible Internal Dose of Radionuclides: Recent Changes in Values

The development of dose rate standards and dosage units is briefly described. The recommendations of the April, 1956 meeting of the International Commission on Radiological Protection are summarized and the effects of these recommendations on operations of large atomic energy installations are discussed. It is concluded that, because of the conservative practice of health physics in the past, the new ICRP proposed changes in exposure standards will not require any major alteration of current practices.