458 FALLOUT EFFECTS—CONARD & HICKING Internal absorption of radionuclides, largely from eating and drinking contaminated food and water, and to a lesser extent from inhalation of fallout, resulted in detectable radioactivity in urine samples. However, during the first few days when the body burdens were highest the maximum permissible concentrations were exceeded only for Sr and the radioisotopes of iodine. The dose to the thyroid glands of the adults from the radioiodines absorbed was estimated to be about 150 to 160 rads. Follow-Up Health Status.—Medical evaluation of the health status of the exposed people over the years since the accident has revealed about the same incidence of illness and disease as noted in the unexposed population with certain exceptions noted below. General health and nutrition have continued to be satisfactory and comparable to the unexposed comparison population. Annual hematologic follow-up studies revealed that the levels of white blood cells and platelets of the peripheral blood in the exposed group never quite reached thelevels of the unexposed comparison population (Fig 1). Mortality and Aging.—There were ten deaths in the exposed population over the ten-year period; this represents a mortality rate near that observed for the other Marshallese people. A recent study in which certain criteria of aging were put on a numerical basis did not reveal any differences in 2. Gross picture of sectional thyroid gland showing nodules in 14-year-old Marshallese girl. group, it was not statistically significant. The exposed girls showed nosignificant differences compared with unexposed girls. The slight retardation of growth noted in the boys suggests that radiation may be a causal factor, although possible mechanisms are not clear. The dose to the bones from internally absorbed isotopes is believed to have been too small to have affected bone growth. Thesefindings aré being published in detail by Sutowetal.‘ Development of Thyroid Nodules.—Thyroid nodules were detected in three girls nine and ten years after exposure; two girls were 13 and one was 14. years of age at the time of detection. These girls were in the higher dose group in which there were 29 children (<18 years of age); 17 of the 29 were girls, with 6 girls in the 10 to 15 year range. Of 75 unexposed comparison children, 37 were girls and 21 of the girls were in the age range of 10 to groups.” 15 years. No thyroid nodules were noted in this latter group. No lymph node involvement was grossly evident. The individuals were hospitalized and two had complete thyroidectomies and the Effects.—Effects on fertility. were not apparent as judged by comparison of the birth rates for the had a cobblestone appearance with multiple hard nodules and were at first thought to be malignant. lated to radiation exposure was the fact that during the first four years after exposure an increase in miscarriages and stillbirths was noted in the exposed women, 41% of the births (13 in 32 births) in this group terminated in nonviable offspring compared with 21% (8 in 38 births) in the unexposed women. Nospecific genetic studies have of pathologists, all of whom agreed that the nodules were not malignant and resembled in many respects adenomatoid goiter seen with iodine deficiency, with its characteristic regenerative rather than neoplastic proliferation. It should be noted that goiters are rare in the Marshall islands since no iodine deficiency exists (Fig 2 and 3). age scores between the exposed and unexposed Fertility, Miscarriages, Stillbirths, and Genetic exposed and unexposed populations. Possibly re- been carried out, but no difference in incidence of abnormalities in children of exposed compared with those of unexposed women has been observed. Growth and Development Studies.—-Anthropometric examinations of the 42 exposed and 75 unex‘posed children have been conducted over the past five years. Using nonparametric statistical meth- ods, comparisons of weight, stature, and bone age (the latter determined from roentgenograms of the wrist and knee) were made between exposed and unexposed children of the same age groups. Boys exposed at 1 to 5 years of age showed retardation of statural growth as well as bone age. This was most marked in those boys exposed at 12 to 18 months of age. The average skeletal maturation in the exposed boyswas about seven months behind their unexposed peers. Though weight gain also appeared slightly retarded in this 114 third a partial thyroidectomy. Grossly, the glands Sections of the tissues were reviewed by a number 3. Section of thyroid gland shows characteristic multi- ple, discrete nodules with wide variation in size and growth pattern. Some consist of microfollicular tissue, some of colloid cysts, while others show hyperplasia with papillary infolding of epithelium.