- 29 € initially or later on, based on different amounts of alpha emitter burden given to an organ initially, then the interpretation of his remark depends upon whether he is comparing high dose - high dose rate levels which are relatively inefficient for cancer production (by dhe gute aareet virtue of overkill of cells) (see sy comments on hits pages 4, 5 and 13) with lower dose and dose rate levels, or comparing different dose and dose rate levels in the region of ascending dose-incidence relationship. - It should be pointed out again that the author apparently regards chromosomal structural changes or mutations as constituting the mechanism of carcinogenesis and has indicated that the chromosomal effects of alpha radiation are directly proportional to the number of alpha Interactions,”independent of alpha interaction rates, and vary linearly with alpha dose rate, The linear relationship between effect and dose or dose rate indicates lack of dependence of effect per unit dose on dose size or dose rate, Therefore, it does not follow that tumor incidence per unit dose, on the basis of a mechanism that has a linear dose-effect relationship, will change with change in dose size or dose rate, Page 13, lines 23-26 - “For this reason a given cancer risk is equated with smaller cumulative alpha doses and with much smaller internal alpha emitter burdens as the period of exposure decreases, Comments: This is an enigmatic statement, but taken literally appears to be unfounded for the same reasons given and referred to in mf comments on the previous sentenceson this page and on the author's pages 4 and 5.