SMR CPST TAT ve tbe ee at awe ut approximately 4,200 rad (600 rad x 7) in I equivalents from shortlived iodine isotopes. Such a “correction” could well make the high prevalence of hypothyroidism in the exposed Marshallese more in keeping with the expectations from the experience with therapeutic '"I. Several other factors may be contributing to the fact that the prevalence of hypothyroidism in this population is greater than is observed after '"I exposure. The estimates of thyroid exposure, particularly that due to the short-lived isotopes of iodine, is only approximate for the reasons already discussed and could have been underestimated. A reevalu- ation of these calculations is currently under way at Brookhaven National aa othe Me the patients at highest risk, it is Laboratory. Second, the hypothyroid- considerable. From the results in Table 3, one must even consider the ism on which the risk estimates are based has largely been overt, whereas the present study has employed sensi- possibility that an elevation in the "TSH level could have contributed to the development of the early thyroid tive biochemical -techniques not generally used in previous studies. A third consideration is that the early and severe thyroid dysfunction accurred in persons exposed as very youngchildren, whereastherisk estimates are based almost exclusively on data obtained in adults with hyperthyroidism. The radiosensitivity of nodularity. Such a possibility justifies the prophylactic administration of levothyroxine sodium in the exposed Rongelap and Ailingnae population. The high frequency of delayed thyroid disease after a nuclear explosion over 100 miles distant is striking. Continued careful medical observation of the exposed Marshallese will be required for the possible development of hypothyroidism, as well as thyroid nodularity. the young thyroid, at least for neo- plastic changes, is greater than that in older persons.’ Whatever the reason(s), it is apparent that, while the true prevalence of hypothyroidism is not definable in this population ‘because of thyroid surgery in many of References 1. Robbins J, Rall JE, Conard RA: Late effects of radioactive iodine in fallout, Combined Clinical Staff Conference at the National Institutes of Health. Ann Intern Med 1967;66:1214-1240. 2. Conard RA, Knudsen KD, Dobyns BM, et ak roid disease: A controlled study. JAMA 1980; 244:1802-1805. Marshallese Population Accidentally Exposed to Redioactive Fcllout, report BNL 50424. Upton, NY, Brookhaven National Laboratory, 1975. 3. Conard RA, Larsen PR, Robbins J, et ak Thyroid Hypofunction Appearing as a Delayed Manifestation of Accidental Exposure to Radioactive Fallout in a Marshallese Population, report SM 224/607. Vienna, International A 20-year Review of Medical Findings in a Review of Medical Findings in a Marshallese Population 26 years After Accidental Exposure to Radioactive Follout, report BNL 51261. Upton, NY, Brookhaven National Laboratory, January 1981. . 4. Duffy BJ Jr, Fitzgerald PJ: Cancer of the thyroid in children: A report of 283 cases. J Clin Endocrinol 1950;10;:1296-1308. 5. Favus MU, Schneider AB, Stachura ME, et 2): Thyroid cancer occurring 2s a late conse- quence of head and neck irradiation: Evaluation of 1,056 patients. N Engl J Med 1976;294:10191025. thyroid neoplasms after childhood irradiation for tinea capitis. JNCI 19380;65:7-11. 9. Larsen PR, Conard RA, Knudsen K, et ak: Atomic Energy Agency, 1978, pp 102-114. 10. Larsen PR: Radioimmunoassay of thyroxine, triiodothyronine, and thyrotropin in human serum, in Rose NR, Friedman H (eds): Manual of Clinical Immunology. Washington, DC, Ameriean Society of Microbiology, 1976, pp 222-230. - 11. Garnick MB, Larsen PR: Acute deficiency of thyroxine-binding globulin during L-asparaginase therapy. N Engl J Med 1979-301:251-253. 12. James RA: Estimate of radiation dose ta thyroids of the Rongelap children following the Bravo event. Univ Calif Rediat Lob publication 12273, December 1964.: 13. Mochizuki Y, Mowafy R, Pasternack B: Weights of human thyroids in ‘New York City. Health Phys 1963,9:219-221. 14. Rall JE, Conard RA: Elevation of the serum protein-bound iodine level in Inhabitants . 7. Maxon HR, Saenger EL, Thomas SR, et ak Clinically important radiation-associated thy- REPOSITORY BNL of the Marshall Islands. Am J Med 1966;40-883- 16. Rallison ML, Dobyns BM, Keating JR, et -al: Thyroid diseases in children: A survey of . subjects potentially exposed to fallout radiation. Am J Med 1974;56:457-463, 17. Becker DV, McConahey WM, Dobyns BM, et ak The results of the thyrotoxicosis therapy follow-up study, in Fellinger K, Hofer R (eds): Further Advances in Thyroid Research. Vienna, Gistel G et Cie, 1971, vol 1, pp 603-607. 18. Thein-Wai W, Larsen PR: Effects of week- ly thyroxine administration on serum thyroxine, . and 3,5,3’-triiodothyronine, thyrotrosin, and the thyrotropin response to thyrotropia-releasing hormone. J Clin Endocrinol Metab 1980;50:560- 564. : 19. Book SA, McNeill DA, Parks NJ, et ai: Comparative effects of iodine-132 and iodine-131 in rat thyroid glands. Radiat Res 1950;81:216- 253. 20. Walinder G, Jonsson C-J, Sjoden A-M: Dose rate dependentin the goitrogen stimulated mouse thyroid: A comparative investigation of the effects of roentgen, "I and '“I irradiation. Acta Radiol Ther Phys Biol 1972;2:24-36. +2009 ~ 205 JAMA, March 19, 1982—Vol 247, No. 11 The Medical Resear ch Center ISLANDS. BOXNo, S7EDICAL DEPT 2012564 gland. Am J Med 1977;63:967-978. RECORDS. COLLecTION 7ARSHALL FOLDER 15. Maxon HR, Thomas SR, Saenger EL, et al: Tonizing irradiation and the induction of clinically significant disease in the human thyroid 8 Ron E, Modan B: Benign and malignant 6. Carroll RG: The relationship of head and neck irradiation to the subsequent development of thyroid neoplasms, Semin Nucl Med 1976; 6411-420. 836. PUBLICATIONS Brookhaven National Laboratory Upton, L, L, New York Hypothyroidism and Fallout Exposure—tLarsen et al 1575