This is followed in Section III by-a review of the specific radiation protection regulations that are in force in the United States today and which are at issue. This section focuses on the existing guidelines for Pu-239, bat it is to be understood that, in this and subsequent sections,. it should be applied to all alpha-emitting radionuclides that meet the hot particle criteria developed in this report. Before reading Section III, those unfamiliar with the national and international organizations which have primery responsibility for recommending or establishing radiation protection standards, may find it useful to read Appendix A, where these orcanizations and their authority are reviewed. Section IV presents assumptions inherent in the existing radiation protection standards and identifies those assump- tions that are inappropriate when applied to insoluble alpHa-emitting particulates. ’ The biological data which demonstrate that these assumptions are inappropriate when applied to hot particles are discussed in Section V. Utilizing the data presented in Section V, the criteria that define a hot particle are developed in Section VI. Recommendations for exposure standards for hot particles are then developed in Section VII and summarized in Section VIII. aria . peee et Pot . a mot Samet se wate Tb a Pe na Myofei Ns oS Peet Bie ep Me ee . . . ale 7 - . . . ' . ' 7