24 axis deviation was normalorto the right in most individuals. Left axis deviation, and only of mod- erate degree, was presentin six individuals, two in the younger unexposed group,three in the older unexposed group, and onein the older exposed group. The electrical position of the heart ina great majority of both the unexposed and exposed subjects was vertical. In 22 subjects it was intermediate and in 9 (all unexposed) it was moderately horizontal. Rotation of the heartelectrically in the combined groups was clockwise in 25 subjects and counterclockwise in 36, with about equal distribution between the exposed and unexposed groups. 4. RSTandT Waves. Abnormalvariations were carefully noted for indications of coronary or myocardial insufficiency and/or myocardial disease or damage. Deviations of the RST segmentfrom the tsoelectric line were found to be minimal; they occurred in only five of the 84 unexposed subjects and in only oneof the 38 exposed subjects. T wave abnormalities were of appreciable degree in only a few instances in the older group. The abnormalities were chiefly in lower T waves and wererelated to hypertensive disease. T wave changes were most marked in a 51-year-old male ( = 80) of the exposed groups who hadarteriosclerotic heart dis- ease and auricular fibrillation. Marked RST and T wave changes were noted in an 81-year-old male (+46) of the exposed group, who had marked hypertensive and arteriosclerotic cardiovascular disease, and had prolonged auriculo- years of age in the exposed group, and then toa degree compatible with age. Since there were no individuals examined in the unexposed group > 70 years of age for comparison, any assumption that the arteriosclerosis was increased in these four individuals by their exposureto fallout radiationis unwarranted. Otherwise the presence and the amountofarteriosclerosis was fairly well distributed between both populations, as can be seen in Table 14. It was not observed in a degreepremature or advanced for the given age. 2. Arterial Blood Pressures. Biood pressures greater than 140 systolic and 90 diastolic were considered abnormal. Onthis basis in the exposed group noneofthe 24 subjects <(50 ofage and seven of the 16 subjects >50 had hypertension, but mostly of mild degree. There were 17 cases of hy- pertension tn the unexposed group,2 in those <50 . years of age and 15 in those >50. The diastolic blood pressure showed only infrequent increase abovethe level of 90 mm; as would be expected, this occurred chiefly in the older group. The overall incidence of hypertension for the total population examined was 9.2%. 3. Oscillometry Readings. Table 16 ventricular conduction time as noted above. Amongthe unexposed population there wasevidence of myocardial insufficiency accordingto RST and T wave changes in a 51-year-old male (#947), a 64-year-old female (#861), a 55-year- old male (#993), a 64-year-old female ( 858), and a 64-year-old male (#884); the last had changes sufficient to indicate.a healed anterior septal cardiac infarct. Other Cardiovascular Observations 1. Peripheral Vascular Findings. Clinicalestimation was madeofthe degreeofarterial changes in the peripheralvessels (radial, brachial, and dorsalis pedis). The degree of abnormality was graded by 0 to 4+ sclerosis (see section on aging studies). Arteriosclerosis was seen chiefly in subjects >50 year of age in both exposed and unexposed groups. It was not marked exceptin four individuals >70 Observations were taken on the legs at the mid-calf. In almostall subjects the pulsation was sufficient to indicate normal blood How. Although the readings were lower in the Marshallese than might be expected in Caucasians. it appeared that peripheral vascu- Ophthalmological Findings (% Incidence) Pterygium Pinguecula Corneal pigment Corneal scars ’ Arcus senilis Phthisis bulbi Nystagmus Strabismus Argyll-Robertson pupil Cataracts Aphakia Vitreous opacities Exposed Unexposed 23.0 24.0 12.0 9.0 38.0 1.3 1.3 8.3 1.3 21.0 22.0 2.6 3.4 26.0 0.0 0.7 0.7 0.0 19.0 1.3 4.1 10.3 1.3 0.0 Retinal arteriosclerosis Chorioretinal scars 11.0 1.3 12.3 0.7 Driisen Congenital anomalies 2.6 3.9 0.0 0.0 Macular degeneration 0.0. 0.0