(MPC)sub(a) values for isotopes of plutonium

The plutonium MPC values presently in use for occupational exposure control were computed some 20 years ago. Since then the ICRP have produced revised lung and gastro-intestinal tract models and a systematic distribution model for Pu. Nuclear decay data, and specifications for reference man have also been revised, and dosimetric techniques have been improved. The newer data are used to compute inhalation [i.e. (MPC)sub(a)] values for several Pu isotopes used in reactors and power sources. Variability if the values dependent upon the deposition of the aerosol as a function of particle size is discussed and the updated estimates are compared with those now in force or projected. (author)