I ©ILERS mee Comment #2, ESTIMATION OF THE HEALTH EFFECTS OF PLUTONIUM AND OTHER ALPHA-ENITTIDG TRANSURATICS The estimate of lung cancer incidence associated with the inhalation of plutonium (or other transuranics) in particulate form is a critical factor, along with source terms and resuspension, in defining the probable impact of the LMFBR's plutonium based fuel-cycle. . 4s subject is discussed in Section 4.6.5 "Particle Lung Dose Effects" of WASH-1535. I quote the first sentence from that section: - "The estimates of lung cancer incidence associated with the inhalation of transuranics used in this report are based upon a calculation of the average radiation dose delivered to the lung and application of tumor incidence estimates for tne uniformly irradiated lung as estimated 4n.the BEIR report."! This cited basis, and hence the derived estimates, are indefensible. "Section 4.6.5 acknowledges "that ‘insoluble’ particles of radioisotopes, when deposited in tissue, provide focal spots of high radiation dose rates close the the particle," so there is no presumption that the exposure by particulates of plutonium is uniform. respiratory tissue of the lung is made up of 108 alveoli. is a complexly organized unit of tissue. The deep Each aveolus If an insoluble alpha-emitting particulate is deposited in this tissue some 10 to 100 alveoli will be exposed. A crude measure of the nonsnitormity of this exposure is that at most about one-miltionth of the lung's alveoli are affected by a single particulate. The significance of the preceding is that in the actual lung exposure by an alpha-enitting particulate, the energy of the’ ionizing radiation is deposited in a very limited volume of tissue, and hence that the actual radiation dose to lung tissue scaled roughly a million times