disturbances have not been searchedfor, and, in many experiments, the pathologic findings have not been carefully enumerated. Recent studies have questioned the validity of the concept of nonspecific shortening of the life span.1213 There are no data on human beings that support the concept of nonspecific aging acceleration as a late consequence of irradiation. The studies reported here concern certain aspects of aging of skin and hair in a Hiroshima population. These studies fail to show any evidence of a generalized aging acceleration resulting from the 1945 atomic bombing. The validity of the concept of aging acceleration in human beingsas a late consequence of irradiation is of obvious importance in this burgeoning atomic era. At the Atomic Bomb Casualty Commission, manydifferent age-dependent physiologic processes are being studied to gain more information on this largest group of heavily irradiated people. Summary Estimation of age by appearance, skin elasticity and looseness, and hair graying were studied in the irradiated and nonirradiated population of Hiroshima. No differences in these several measurements were detected between the radiation-exposed and nonexposed components of the sample. The study provided no support for the concept of a general, nonspecific aging acceleration—exemplified by aging of skin and hair—as a late radiation sequela. 36 The observations reported in this paper were performed by the nursing service of the Atomic Bomb Casualty Commission. We would like to thank especially Miss Chiyoko Watanaoc, chief nurse; Mrs. Kiyoko Minato; and Miss Chiyo Waki. The Atomic Bomb Casualty Commission is a research agency of the United States National Academy of Sciences-National Research Coun- cil, which is working under a grant from the U. §. Atomic Energy Commission. The commis- sion is administered in cooperation with the Japanese National Institute of Health of the Ministry of Health and Welfare. REFERENCES 1. cHeFFI, M.: Cosmetological aspects of ageing, in A. IL. LANSING (editor): Cowdry’s Problems of Ageing, ed. 3. Baltimore: Williams & Wilkins Co., 1952, p. 909. 2. FURTH, J., A. C. UPTON, K. W. CHRISTENBERRY, W. H. 3. 4. 5. 6. 7. 8. 9. 10. 1). BENEDICT, and J. MOSHMAN: Somelate effects in mice of ionizing radiation from experimental nuclear detonation. Radiology 63:562, 1954. Report of the Committee on Pathologic Effects of Atomic Radiation. Publication No. 452, Section IV. Washington: National Academy of Sciences-National Research Council, 1956. WARREN, s.: Longevity and causes of death from irradiation in physicians. J.A.M.A. 162:464, 1956. SELTSER, R., and P. E, SARTWELL: Ionizing radiation and longevity of physicians. J.A.M.A. 166:585, 1958. ELLINGER, F.: Medical Radiation Biology. Springfield, Il: Charles C Thomas, 1957. CONARD, R. A., et al: Medical surveys of Marshallese people at 5 and 6 years after exposure to fallout radiation. Brookhaven National Laboratory Report 609 (T 179): In press. CONARD, R. a.: An attempt to quantify some clinical criteria of aging. In press. TERADA, H.: Appearance of gray hair as an aging phenomenon in Japanese. Okajima’s Folia Anatomica Japonica 28:435, 1956. FINNEY, D. j.: Probit Analysis, ed. 2. Cambridge: Cambridge University Press, 1952. KIRK, £., and S$. A. KVORNING: Quantitative measurements of elastic properties of skin and subcutaneous tissue in young and old individuals. J. Gerontol. 4:273, 1949. 12. COLE, L. J., P. CG. NOWELL, and J. Ss. ARNOLD: Late effects of x-radiation. The influence of dose fractionation on life span, leukemia, and nephrosclerosis incidence in mice. Radiation Res. 12:173, 1960. 18. ALEXANDER, P., and D. J, CONNELL: Shortening of the life span of mice by irradiation with x-rays and treatment with radiomimetic chemicals. Radiation Res. 12:38, 1960. GERIATRICS, JANUARY 1963