that applying to the surveys on occupationally-exposed people and much less than that carried by the studies on A-bomb survivors. 387. Tnduction of leukaemia and of a variety of tumours has been throughout the years the experience of the Japanese survivors of the A-bombs. These pa- thological conditions have produced some shortening of life, whose magnitude can be accounted for entirely on their basis. The absence of non-specific life-shortening among A-bomb victims is undisputable not only because this conclusion has been confirmed during more than thirty years, but because the sample size (and therefore the accuracy of the finding) leaves little margin for other conclusions. 388. The negativity of this survey is remarkable for a number of reasons. Firstly, the quality of the radiaton received: at least in the case of Hiro- shima, this had a substantial neutron component and therefore, in accordance with the evidence discussed under paragraphs 192-213, it could have been expected to be considerably more effective. Secondly, the modality of the ir- radiation (acute, high dose-rate) would be expected to produce a maximum of life-shortening by comparison, for ‘example, with the low-dose-rate occupational exposures. Thirdly, the absolute amount of radiation absorbed over the whole body (or the order of 100 rad or more) which should also have produced a substantial life-shortening effect. But since there is no evidence to sup- port the hypothesis that a selection of the early survivors might have favourably influenced the subsequent long-term mortality experience [R10], the con- clusion must be accepted that up to the present time there is in this large sample of persons no evidence of a diffuse non-specific effect of life-shor- tening. Any long-term effects are, on the contrary, very specific, focal and essentially cancerogenic. 389. In conclusion, the evidence concerning a non-specific radiation-—induced life-shortening effect in man has been shortly reviewed in the preceding paragraphs. This review has produced essentially negative answers, except for the old American radiologists. The data from this group of people are, however, in contrast with a massive bodyof data in experimental animals where such a non-specific effect, particularly at low-medium doses of radiation, cannot be substantiated. What is more, the data on the American radiologists are also in sharp contrast with the much larger and more reliable experience on the A-bomb