In 1954 the people of Rongelap in the Marshall Islands were accidentally’ exposed to radioactive fallout during the atomic bomb resting program. Fortunately the exposure proved to be sublethal. Numerous reports have - documented both the early effects of radiation, on blood cells and skin (Cronkite, Bond, Conard, Shulman, Farr, Cohn, Cohn, Dunham, & Browning, 1955), : and the late effects, particularly in regard to growth retardation of children and the development of thyroid nodules and malignancies (Conard, Sutow, colcok, -. Dobyns, & Paglia, 1969). Among the many studies on this population, the investigation of the possibility that radiation causes premature aging had. been of continuing interest, particularly because such findings have been ‘reported in irradiated animals (Furth, Upton, Christenberry, Benedict, & Moshman, 1954). Some 200 unexposed Marshallese people served as an excellent comparisam population for these studies since they are closely related and live in the same environment. For aging studies measurements © were made during physical examinations on characteristics considered to be criteria of aging (Conard, 1960; Conard, Lowrey, Eicher, Thompson, & Scott, 1966). Among these were skin elasticity and looseness and hair grayness; accomodation,. ” visual acuity, and arcus senilis of the eyes; hearing loss; nerve and | neuromuscular function, vibratory sense, and hand strength; response to light extinction test and rapid movement test, systolic blood pressure; and levels of blood cholesterol and body potassium (40x), Most of these criteria showed varying degrees of correlation with age and afforded a means of arriving at a “biological age" score for each individual. * However, none of the tests showed any significant indication of premature aging in the exposed group that might be associated with radiation exposure. i i ' t | i