i ! 29 \adult) statures and weights, measured at age 21 or older, of subjects exposed to radiation at age < 17 indicated that those exposed in Hiroshima attained a mean height markedly lower than normal and that the degree of retardation diminished with increasing age at exposure, being greatest in TS TS WYRE RET eth IR IRE EE SBR mea see AE RE mE re tennfee those exposed at age <5. The effect was more prominent in boys. The preliminary tabulations of growth data in the Marshallese children16-45 showed similar trends. Subsequently, the extent of the thyroid injury documented in the Marshallese children provided the basis for the present assumption that growth retardation reflected primarily the results of impaired thyroid function. It is anticipated that when adult (final) anthropometric measurements become available, further evalua- tion of the growth pattern of the Marshallese children (including further assessmentof the effect of thyroid hormone administration) will be possible. dividuals >40 years old have revealed the cardiac changes expected with aging: arteriosclerosis heart disease with occasional catdiac decompensation. Auricular fibrillation has been noted in a-few people; rheumatic heart disease in anly two. Peripheral vascular diseases (thrombophlebitis, peripheral venous disease, hemorrhoids) appear © be less common than in Americans. Oscillometrie studies showed peripheral pulses to be excep» tionally good, even in older people and in diabetics (see below). No luetic, metabolic, or nutritional form of heart disease has been seen. 2. Arthritis 7 ve ManyMarshallese>40 years of age complain of joint symptomsin the arms and legs and to a lesser extent in the-tower back. Many,particularly the older ones, have complamed algg of vague musclepais in the arms aad legs. Someolder women develop marked: kyphosis im.thaylower G. DEGENERATIVE DISEASES The aging process is accompanied by an increased incidence of degenerative diseases, andirradiated animals have shown increases both in general aging phenomena and in such diseases; therefore, in these studies careful consideration has been given to signs of aging andto the incidence of cardiovascular diseases, arthritis, and other de- thoracic-lumbar region whichhay be related partly to the squatting or stooping position necessary for cooking over openfires. X rays show many of the above complaints to be associated with osteoarthritic changes; but many people with complaints do not have definite bone changes. Arthritis seems no more commonin the exposed thanin the unexposed population, andits general incidence does not differ greatly from that among Ameri- generative diseases. cans. Rheumatoid_arthritis has sTaxelysagen seen. 1. Cardiovascular Diseases gave positive results in only a feweases (Sof 184 Cardiovascular diseases appear to be no more prevalent among the Marshallese than in Americans or other populations, and nodifference was found between their incidences in the exposed and unexposed groups. Hypertension appears to be somewhatless prevalent among the Marshallese than among Americans. Blood pressures > 140/90 have been recorded in only about 9% ofthe people, andthe increasing percentage of older people in the study groups does not seem to have raised the incidence of hypertension. Manyof the younger people, particularly females, have notably lower blood pressures (90-100/55-65). The generally lower blood pressures in the Marshallese have been thought to be related to lower dietary salt intake,?-46 but the gradually increasing use of imported foods of greater salt content has caused no apparentincrease in hypertension. Serum sodium and potassium levels have usually been in the normal range. Routine chest x rays and ECG’s on in- Examination of the saiaabar =‘Theaumigetio” tested in 1959).8 3. Nephrosclerosis a wep vet aOF *? Primary kidneydisease has not-peerdaoted|fie- quently, but nephrosclerosis has occasiong seen complicating cardiovascular disease. 4. Aging Sg. Radiation in sublethal doses may reduce longevity in animals and man. Induction of malignant transformationis well documented and accounts for most of the early deaths. However, development of premature senescence with associated degenerative diseases and immunodeficiency, as a late effect of exposure,is also believed to accountfor some degree oflife shortening in animals.*7-#9 For humans, definite proof of such effects is lacking, the only documentedlife-shortening effect being related to malignancies.%.51 In the Japanese bomb survivors, the correlation oflife-shortening with