Capillary Microscopic Observation on the Superficial Minute Vessels of Atomic Bomb Survivors, Hiroshima, 1972-73

Microscopic and photographic studies were conducted in 1972-1973 at the Atomic Bomb Casualty Commission (ABCC) in Hiroshima on the morphology of superficial blood vessels of A-bomb survivors to determine whether the somatic effects of radiation still existed 30 yr after the A-bomb. Control curves representing the relationship between age and score values assigned to morphological changes of the minute blood vessels of the fingernail fold, labial mucosa, and lingual mucosa, which could be regarded as an index of aging, were obtained. These were compared with similar curves obtained from A-bomb survivors with the aim of evaluating the effect of radiation on the aging process of these vessels. 1. The late somatic effects of irradiation which were demonstrated 10 yr after the A-bomb in a previous study (1956-1957) were found to persist in the current study (1972-1973) conducted 30 yr after the A-bomb, though not as pronounced as in the earlier study. A significant effect was observed only in the nail fold of those exposed to 100 rad or more under the age of 10 at the time of bomb (ATB). A statistically significant difference was not observed with labial and lingual mucosae because the number of cases available for score evaluation was small, but a trend was observed for abnormalities of these two sites to be higher in frequency in the group exposed to 100 rad or more under the age of 10 ATB than that of the control group. 2. No significant difference was observed between the control and exposed with regard to radiation effect on the aging process using the relationship of score values to age as an index of aging.