372. The problem of longevity in irradiated human populations with special He reference to A-bomb survivors up to 1972 was reviewed by Anderson [A9]. concluded that evidence for a tumour-independent shortening of life was equivocal and, in his opinion, this experience would be at variance with other reported experience in man. For this reason, judgement on the interpretation of the Japanese data should be reserved pending further evidence. However, from their review of thirty years experience with the A-bomb survivors [02!, Finch and Beebe [F1] could find no convincing evidence for a generalized increase in mortality from natural causes other than cancer, in contrast with the requirements of the hypothesis of accelerated aging. 373. A re-examination of the mortality experience of A-bomb survivors up to September 1974 was performed by Beebe, Land and Kato [B6]. The number of deaths from non-neoplastic diseases, whose increment could in principle be suggestive of a non-specific life-shortening, was at the time about 14.000 among 82.000 survivors. In the irradiated sample, cerebrovascular diseases, other circulatory diseases and diseases of the digestive system showed no evidence of an increase. Deaths from diseases of blood or blood-forming organs were apparently increases, but difficulties with the diagnosis made this finding uncertain. All other non-neoplastic conditions were apparently unaffected. 37h. When all diseases except tumours and diseases of the haemopoietic system were pooled together, their combination produced no further evidence of a relationship to radiation dose. Although the sample group in the Life Span Study could indeed be regarded as a highly selected group, there was no evidence that selection due to survival from early effects, as suggested by others might have favourably influenced the subsequent mortality. [S41, R10], It was concluded therefore that the views that ionizing radiation may cause premature aging in man or that the carcinogenic effect is only a part of a more general acceleration of aging find no support in the Japanese experience: radiation effects on long-term mortality do not appear diffuse but rather specific and focal and principally cancerogenic. 375. The latest available analysis of the mortality experience of Hiroshima and Nagasaki survivors should also be reported for completeness [B23, B24], although the information contained in them is essentially that discussed in Beebe, Land and Kato 'B6). These contributions showed that age-specific