24 T 250r———Tt T —— a T T SKELETAL AGE ASSESSMENTS | SKELETAL AGE (MUNTHS} | T ’ 2801 , T | . 3 GIRLS 1957 -1965 [ 1 T Tr T T T SKELETAL AGE ASSESSMENTS 325; “ BOYS 1987-1965 28| T | wf 200F 200F 4 175 oe 189 4 3 sob = {25- - 2= fod 3 4 _ 125 a Noor MALES EXPOSED s— ——+ MALES UNEXPOSED o———o 7S £ wy 100+ w 0 4 Tae 4 t 5Or 25h ‘ ° eo 1 23 a | + . L 30 j 75 l 100 L 123 | ! 150 _L 178 L 200 L £25 256 ‘/ / i 25 i $0 i 73 _| FEMALES UNFXPOSED o——o_—sis Lo. | 25y- FEMALES EXPOSED 4—-—-—*# / 50K J d a a L 100 i 125 J 130 J 173 1 200 L 225 259 CHRONOLOGICAL AGE (MONTHS) CHRONOLOGICAL AGE (MONTHS) Figure 18. Figure 19. THYROID FINDINGS exposed on Rongelap: 150 rads (from direct measurementof urinary '*'T),’* 100 rads (by indirect measurements on pigs removed from Rongelap plus Marshallese urinary excretion data),”** and 160 rads (based on recent recalculationsof early data*’ - see Appendix 2). Thelast recalculations were based on analysis of pooled urine samples mainly from adult Rongelap people taken 15 days During the past 3 years, the developmentof thyroid abnormalities in a significant number of the people exposed on Rongelap,and in one from the Ailingnae group, hasresulted in extensive thyroid studies and surgical intervention in some cases. The examination and therapyofthefirst 6 cases of nodules of the thyroid gland have been after the detonation; an estimate of the one-day relative proportion of the several radioisotopes of iodine involved. Therelative distribution of radioiodines in fallout depends on the type of explosion but in general ts well known. In addition to '"'], the isotopes '*"I, '**I, and to a less erytent '**I contributed significantly to the thyroid dose, The only direct data available on the Rongelap people are thyroid content of '*'I was 11.2 pCi (5.6 to 22.4 pCi), assuming that 0.1% (0.005 to 0.2%) of the maximum thyroid burden (not corrected for physical decay) was ¢ reted in the urine on the [5th day. The dose of 160 rads to the adult thyroid was calculated from oral intake and inhalation of the various 1odine isotopes, considering their fission yield, the average energy deposited in the thyroid gland per disintegration, and the time of absorption. The dose to the thyroid glands of children <4 years old was then calculated by means of these factors with consideration of pulmonary function and the thyroid size of a child that age.” The main sourceof iodine ingestion was considered to be water, andsince it was being rationed taken 15 days and longerafter the fallout. Three separate estimates have been made of the dose from radioiodines to the thyroid glands of adults children drank the same amountofwateras adults and therefore had the same thyroid burden of radiciodines. The small size of the childhood thy- described.'*-*7-** Since then, the number of cases of nodules and hypothyroidism has increased to 18, and the new cases are described below. The Radiation Dose to the Thyroid Glands The dose to the thyroid gland from radioactive iodine is determined byits uptake by the gland, its half-life in the gland, the size of the gland, and the radiochemical analyses of pooled urine samples at the time of the fallout, it was assumed that the