I. Introduction This report is written in support of a petition by the Natural Resources Defense Council to the Environmental Protection Agency (EPA) and the Atomic Energy Commission (AEC) requesting (1) a reduction of the existing radiation protection standards applicable to the internal exposure of man to insoluble alcha-emitting hot particles and (2) the establishment, with respect to such materials, of standards governing the maxinum permissible concentrations in air and maximum permissible surface contamination levels in unrestricted areas. Before proposing modifications to existing radiation protection standards related to plutonium exposure! , we review in the following section the gravity of the public health concern as slutonium becomes a princival article of commerce in the nuclear power industry. of this report focuses narrowly on plutoniun-239, "while mu cn the discussion is, nevertheless, germaine to all radionuclides in insoluble particles with a hign specific activity. (The definition of ssecific activity and other technical tarms in this resort are given in the Glossary). The justification for focusing on plutonium has been aptly stated by the International Corzrmission on Radiological Protection (ICRP): "“en2 amphasis on plutonium is clearly a reflection of the gener~ al consensus that, in terms of amount available, projected 12, extant of anticipated accidental human exposure, and Usa, railsroxicizy, olutonium is the most formidable radionuclide l/ in the pericdic table." Qf Compounds 1372, p.1.] of [ICRP Publication 19, "The Metabolism Plutonium and Other Actnides," Pergamon Press, \ As the me ” age soe + ee