OF: ‘ “oe she Fx gross disturbances in physicleyy are wilikeiswithout Yargerdoses (2). "Of the manyt pes ofchanges. which radiation can ispaererere -s cre : cause in cells cr isis. ne ie Conta Unigue for regiacion, fany, ii na : : be - 4 can presumably result from a varie This summary view aon carcinogenesis is conpativle with the ideas leading to the. conclusion reached earlier, that fictitious dose averaging to larger tissue masses need not be conservative. The possibility of various modes of carcinogenesis is acknowlecged, and in particular, mention is made of a pathway mediated by tissue disruption. Disease proriies are highly species specific. exception. also. . Cancer 3s na Gross characteristics are obviously highly species specific A rat and a mouse are distinct and yet incredibly similar. The gross tissue cifferen ces are articulated out through subtly different cr informational resonances amongst cell populations, - the collective pehaviar being phased ultimately, though perhaps reisotely, by the «genetic controls of the cells. Not to belabor this point unnecessarily, - cancer profiles are species specific; gross characteristics and, of course, genetic material _ are also species specific. Collective detuning of tissus, by tissue disruption seer, as acceptable an origin Tor the tissue instabilities of cancer as does an isolated single cell event. Return now to the problem of risk estimates associated with radioactive particulates in human jungs. Host of what has been said earlier in this comnent has been general, and has been aimed at showing that there was no inherent conservetism in the method of estimating cancer risks set forth in the first sentence oF 4.6.5, and that riorcever the method could be far from conservatiy The conclusion could as weil ba applied to Vyitphatic tissue ar te bronchial tissue.