procedures) under ‘field conditions.’ Dietary iodine -has apparently been adequate. In 28 cases the mean twenty-four-hour urinary iodine excretion was 105 microgm. (range, 19.5 to 279 microgm.). In 1963, nine vears after the accident, a twelve- vear-old yirl in the exposed group was found to have a nodule of the thyroid gland. In 1964, 2 additional cases with thyroid nodules were found in exposed yirls thirteen and fourteen years old. In March, 1965, 3 additional cases in exposed people were noted in boys thirteen and eighteen years of age and in the first adult, a .forty-one-year-old woman. In September, 1965, a further examination was carried out, and 5 additional exposed people with nodules varying in size from 2 to 8 mm. were found. One of these was a forty-five-year-old woman in the group that received only an estimated 69 rads. In addition, there were 5 people in whom the thyroid gland appeared to be roughened or minimal nodularity was considered likely. These cases are not included in Table 1 because of the minimal nature of the physical findings. Table 1 lists the cases with thyroid abnormalities. Table 2 shows the incidence of thyroid disease in the more heavily exposed group of 55 living Rongelap people as a function of age. The 1 case in the less exposed group of 16 is not included. Not including the 5 recent cases with minimal changes, the incidence of thyroid abnormalities (nodules in addition to hypothyroidism) was highest in the children exposed at less than ten years of age (55 per cent of this group). The greater incidence in females (8 of 16) than in males (5 of 13) exposed is in line with the greater incidence of thyroid abnormalities usually noted in the female. was similar to that outlined above, and only specific differences are noted here. CASE REPORTS Case |. a |4-year-old Marshallese girl, was 3 years old when exposed to radioactive Fallout. Her response to this radiation was typical of the group. Clinically, she has re- mained euthyroid throughout the period of observation (in 1957 the cholesterol was 135 mg., and in 1964 the protein- bound iodine was 6.8 microgm. per 100 ml.). [In March, 1963, she was found to have a 2-cm. nontender, firm nodule of the left lobe of the thyroid gland. In August, 1964, a total thyroidectomy was performed, with dissection of the anterior compartment of the neck. (It was at first thought from thefrozen section that the nodules were malignant.) Grossly, the glands showed multiple nodules with cystic and hemorrhagic areas (Fig. 1). The gland weighed 12 gm. The pathological diagnosis was adenomatoid goiter. The microscopical appearance was reported as follows: Among the nodular formations ... there are adeno- matoid nodules, with and without regeneration and hemorrhage, and adenomas, some consisting of very pale, almost clear celis. Numerous papillary formations present are somewhat alarming. However, no evidence of talignant change is found. In some places the intranodular thyroid tissue is arranged in lozenge-shaped masses associated with somewhat atypical cells. The recovery from the operation was uneventful except for a transitory episode of hypoparathyroid tetany, and the patient is being treated with levothyroxine, 0.3 mg. per day. GASE 2. , a 14-year-old Marshallese yirl, was exposed to fallout at 3 years of age and showed a typical course. She was apparenuy euthyroid during repeated examinauons (the protefn-bound iodine being 7.4 microgm. in 1958 and 8,1 microgm: per 100 ml. in 1964, and the cholesterol being 128 mg. per 100 ml. in 1959). In March, 1964, a firm, nontender nodule, 1.5 cm. in diameter, was discovered in the left lobe of the thyroid yland. In August, 1964, a total thyroidectomy was per- Tase 1. TAyrotd Abnormalities in Exposed Marshallese.* Patient PRESENT AGE aT AGE Ex posure vr oe 14 3 14 Sex F F 15 18 4 7 F M 41 30 F 17 14 6 3 F F 29 34 M F 19 40 45 12 12 1 8 1 1 Diacnosia TREATMENT Noteo 3 12 Date ABNORMALITY M 3/63 Adenomatoid thyroid nodules Complete thyroidectomy (1964) 3/64 3/65 Adenomatoid thyroid nodules Adenomatoid thyroid nocules roidectomy (1964) Partial thyroidectomy (1964) Partial thyroidectomy (1965) 3/65 Papillary & follicular thyroid carcinoma Thyroidectomy—surgical & with radioiodine (1965) Levothyroxine, 0.3 my./day 3/64 3/65 9/65 9/65 Adcnomatoid thyroid nodules Adenomatoid thyroid nodules 3-mm. nodule of left lobe 2-mm. nodule of right lower lobe F 9/65 6-8-mm., smooth nodule of left lower pole M 3/65 Hypothyroidism protein-bound iodine < 2 microgm./100 mi. (Mar. 1965); M 9/65 9/65 3/65 2-mm. nodule of right lower pale 5-mm. nodule at midline marked retardation of growth, Hvporhvroidism protein-bound iodine < 2 microgm./100 ml. (Mar, 1965); Complete thyroidectomy & parathy- Partial thyroidectomy (1965) Levothyroxine, 0.3 my./day Levothyroxine, 0.3 mg/day Levothyroxine, 0.3 mg/day Levothyroxine, 0.3 mys./day Levothyroxine, 0.3 my./day ‘ Levothyroxine, 0.3 mg/day marked retardation of growth. *Does not include 5 patients believed 10 have minimal thyroid irregularities (2 were 12-yr. old girls, 1 a 26-yr.-old woman, & 2 men 31 & 37 yr. of age); no thyroid nodules detected in 200 unexposed Rongelap people. tExposed to only 69 r of whole-body radiation (see text). 9012951 PRIVACY ACT MATERIAL REMOVED- St eq ee. The first 6 patients have been hospitalized and have undergone surgery. These cases are briefly summarized below. Their response to the radiation Srp NT rs PRA OS ST UR TYBee aces the exposed as compared with the unexposed population. Determinations of basal metabolic rate were not done owing to difficulties of carrying out the