roid then resulted in a substantially larger dose. The total estimated dose razathe variousfodine».- isotopesto the child’sgland was-about?000 rads, with a range of 700 to . Theglands received an additional 175 radsfom external gammaradiation. Details of these calculations have-been given by James and Ngandare presented. in- 2. Although the skin overlying the thyr@ ix, gland’ lw wasfrequently thesite of “beta burns” as shown in Figure 20, the deposit of radioactive materials in this area probably did not addsignificantly to the thyroid dose, since mastof the beta irradiations - were too weak to have penetrated to thedepthof the gland. Previous Thyroid Studies Until 1963 no thyroid abnormality was detected in either the exposed or the comparison population, except for one case of asymptomatic diffuse thyroid enlargement seen in an unexposed woman. Figure 20. “Beta burns”’ of neck (subject No. 39, March 1954). The area over the thyroid was a frequent site of burns. It has not been possible to perform basal metabo- lism rate determinations, but careful physical examination ofthe thyroid and a varietyof tests of thyroid function have been performed during the previous surveys. care has been taken to ensure that glassware and syringes were not contaminated with iodine. This of Foss et al.” at Brookhaven National Laboratory, the Boston Medical Laboratories, and Bio-Science Laboratories, Van Nuys, California. In addition, medical team, whose blood was obtained at the same time and underthe sameconditionsas that of the natives. The elevation in PBI could be due Protein-Bound lodine.*®> The serum proteinboundiodine has been determined by the methods estimation of the butanol-extractable iodine of serum was doneat Bio-Science Laboratories, and also column chromatography of the serum iodine by a modification of the method of Galton and Pitt-Rivers.** In several instances the capacity of thvroxine-binding alpha globulin (TBG) was mea- sured at NIH by a-method described previously.*’ The results of analyses for iodine in serum are shownin Table 14. (See Appendix 3 for complete protein-bound iodine data.) It is apparent that on several occasionsand with severaldifferent methods the average serum protein-boundiodinein the inhabitants of both Rongelap and Utirik is higher than normal, and that from 16 to 64% of the natives on Rongelap and 90% on, Utirik show values that are above the normal range by American standards. No significant differences in the PBI levels have been noted between the group that had been exposed to radiation and the unex- posed group. Thefirst results showing an elevated PBI were obtained in 1958, and since that time can be seen by the factthat the total iodine is not markedly greater than the PBI andby the normal values for PBI obtained in 1964.9n members of the to a general increase in serum PBI in all the Rongelap population,or it could be due to theoc- currence of somegenetic differentte, spithat a sub- stantialfraction of the populatian-gasws abnor- mally high PBls.aggahesemainder of the poputa- tion is normal. Ln the‘first ease, a plotof the level of PBI versus.feequency of occurrence agphat jevel would shoy.aijrmatdistribution,except that the whole curveiwoulitbe‘displacedaboatg ag% upwardscla, ééond‘case, the distribution curve would bebimedal, bnda family show | familial, fing, dé.precise typedepending on the manner ofaiiheritance. Figure.2!, a distribution curve PBI level¥ersus incidence-at that level, shows no-evidencefor a bimodal distribu- tion. The low number of PBI vaiies begween 7.75 and 8.0 ug% segms to be due to sfatistcal fluctu- ation because of the small numbers of cases. Furthermore, the elevated values (defined as those above 8.0 ng%) did not show a familial pattern of distribution. It appears, therefore, that the eleva- PRIVACY ACT MATERIAL REMOVED