A total of 289,868 locus tests, based on 28 different protein phenotypes and using one-dimensional electrophoresis to detect variant proteins, has yielded one probable mutation in the offspring of "proximally exposed" parents, who received an estimated average gonadal exposure of 31 to 39 rem in the atomic bombings of Hiroshima and Nagak. There were no mutations in 208,196 locus tests involving children of "distally exposed" parents, who had essentially no radiation exposure. Studies of the genetic effects of atomic bombs have been in progress in Hiroshima and Nagasaki since 1946 (1-5). The first generation of studies was essentially morphological in nature. More recently, profiting from technological developments, studies have been undertaken at the cytogenetic (6, 7) and biochemical (8) levels. We present here a progress report on the results of the biochemical approach at approximately the midpoint of the study. No statistically significant difference between the children of exposed and control parents can be demonstrated at this time (nor was it expected at this juncture in the study). In addition to the timeliness of a progress report, however, the present publication is dictated by three other considerations. (i) The current intense interest in the genetic effects of low-level ionizing radiation has prompted a complete re-evaluation of 30 years of genetic studies on the effects of the atomic bombs; the present data can be integrated into that treatment. (fi) The control aspects of the data of this study can be combined with similar data from other studies to yield a direct estimate of the rate at which spontaneous mutation results in electrophoretic variants of proteins; this should be useful in planning the feasibility and magnitude of any other genetic studies of this type. (Wi) A wealth of data on biochemical variants in Japanese has accumulated during the past 7 years; this description should clear the way for the presentation of this information.

No abstract

A 2-year ophthalmologic study of age and radiation-related ophthalmologic lesions among the atomic bomb survivors in Hiroshima and Nagasaki was conducted in 1978-80. The study sample in both cities was composed of all persons exposed to 100+ rad, their controls, and all other persons with a previous record of axial opacities or posterior subcapsular changes. Most of the losses were due to persons who refused to participate or for whom it was not possible to arrange for an ophthalmologic examination at the time of the regularly scheduled medical examination. It should be emphasized, however, that the loss of persons in both the control and the 100+ rad groups did not change systematically with increasing age by city. Increased lenticular opacities, other lens changes, and loss of visual acuity and accommodation occurred with increasing age in both exposed and control subjects as manifestations of the normal aging process. A highly significant excess risk for all age categories in the 300+ rad group in comparison to those in the control group was observed for both axial opacities and posterior subcapsular changes in Hiroshima, but not in Nagasaki. A stronger radiosensitive aging effect for persons who were under 15 years old at the time of the bombing (ATB) was observed for both axial opacities and posterior subcapsular changes in Hiroshima.

No abstract

No abstract