PRIVACY ACT MATERIAL REMOVED 9 D. HORMONE TREATMENT In 1965, the seriousness of the developmentof thyroid lesions in the Rongelap people was recognized, and a panel of experts was called together to review the findings and make recommendations regarding the possibility of initiating preventive therapy.!9-23 The concensus was that the more heavily exposed Rongelap group should be placed on replacementthyroxineforlife in order to block TSH secretion by the pituitary gland. It was hoped that nullifying the stimulating activity of this hormoneon the thyroid would inhibit development of benign and malignant nodules, and that growth and development in the hormonedeficient children would be improved. The possibility of developmentof pituitary tumors, which has been noted in hypothyroid animals® and human beings,86 might be prevented. Ethical considerations ruled out randomizedclinicaltrials of therapy. Synthetic L-thyroxine (Synthroid, Flint Drug Co.), which might be more stable than dessicated thyroid under tropical conditions, was recommended at a dose of 0.3 mg/day for people <50 years of age and 0.2 mg/dayfor those >50. Treatment was supervised by the health aide, but difficulties in maintaininga strictly regular treatment Figure 37. Same comparisonas in Figure 36, for subject No. 3 and his younger brother (No.83). regimen soon became apparent. In an effort to overcomethis problem it was found that giving the entire weekly dose at one time waseffective and safe, and resulted in maintenance of normal levels of thyroxine.87 Even on this simplified treatment schedule a few of the people, including some who had undergone thyroidectomy, showed low thyroxine levels indicating that they were not consistently taking the medication. (This was one of the reasons for establishing the post of resident physician in the Islands in 1972 to monitor the treatment program as well as offer health care.) For 4 people on this regimen who developed abovenormal T, levels, associated with complaints of nervousness and palpitation, the dose was reduced. In view of the recent appearanceof thyroid nodules among the Ailingnae group andin a subject exposed in uéero, all persons exposed on theatoll are now included in the treatment program. The hormonetherapy has unquestionably enhanced growth and development in the growthretarded Rongelap children (Figures 21, 36, and 37 show the improvementin the two most stunted boys). However, the benefit of such treatmentre- Figure 36. Left: Subject No. 5 (shorter) and his younger brother (No. 85) in 1963. Right: Same two boys in 1973 after No. 5 had been given thyroid hormonefor 8 years. garding developmentof nodularities in the thyroid is uncertain. Of the children exposed at age < 10 years in the more highly exposed Rongelap group, only two have not developed lesions. Theless exposed Ailingnae group,in which developmentof