et fe vofed (ee vlted Comments on Appendix II; "Basic Considerations in the Assessment of the Cancer Risks and Standards for Internal Emitters" by Edward A. Martell* Page 2, lines 9-13 -"Bair et al. (10) £311 to take into account the full implications of some of the recent published results: in particular, the observed higher tumor risks for 38pu09 than for Pud9 (11) the apparently limited biological response of mammal lung cells from 38pu and Pu incorporated into ceramic microspheres Comments: 12, vee! It is highly unlikely that Dr. Bair would fail to take into account the implications of data emanating from his own Laboratory (11)**; similarly, it is not realistic to assume that Dr. Richmond would fail to appreciate data from his own experimental work. Page 2, lines 13-17 - "...and the tobacco smoke radioactivity results (14) , The latter results imply that as little as a few picocuries of insoluble alpha emitting particles in the lung may give rise to a significant risk of lung cancer and other serious health effects in the chronic exposure case." Comments: The Public Health statistics correlating tobacco smoking and incidence of lung cancer and other diseases do not distinguish selectively between the alpha emitters and the rest of the tobacco smoke as causative agents, Extensive epidemiological observations suggest that the etiology of lung cancer in smokers is different from that in irradiated populations. The excess risk of lung cancer produced by radiation persists for at least three decades after single or briefly fractionated exposures; it does not show any appreciable return toward normal levels for twenty years following - + an initial 8-12 year latency. On the other hand, when smoking is continued for a prolonged period and then terminated, excess risk remains constant for only 1-3 years after which a steady decline to normal occurs in 10-14 years. The striking difference in the temporal pattern of excess mortality * The author referred to herein is Dr. Martell. **Numbers throughout are to Dr. Martell's references.