26 Table i4 Serum Iodine Serum Protein-Bound Icdine Date Group Average, ug% Range, ug% No. samples Percent over 8 pe% 1959 1962 1963 1964 1964 1965 1965 Rongelap Rongelap Rongelap Medical team Rangelap Rongelap exposed Rongelap unexposed 6.2 8.6 8.1 49 7.1 7.6 7.0 4.1- 92.2 4.6 - 12.0 1.9 - 12.0 25- 69 2.0 - 10.2 43-119 3.9 - 10.7 12 14 29 10 11 31 19 16 64 66 36 42 28 1966 Utirik exposed 11.8 6.9 —- 28.7 25 92 1966 Rongelap exposed 6.1 3.1- 11.8 19 16 Serum Butanol-Extractable Iodine 1959 Rongelap 4.9 2.7 - 8.7 12 Serum Iodine Chromatography Group Total iodine, Av 4g% 1434-1964 1965-1966 Rongelap Rongelap 6.98 7.40 2.22 2.80 4.53 4.21 19 18 1964-1966 Americans 5.09 0.80 3.76 25 1966 Utirik 18.10% lodoprotein, Av ue % 9,20 T,+T73, Av pg% No. samples 4.00 5 *One Untirik sample was quite high in total iodine (32.0 ag%) suggesting contamination of this sample. The remaining 4 samples showedtotal iodine levels very nearly equal to the combined iodoprotein and thyroxine values. tion in PBI is a general phenomenonwhichaffects the entire population. — The difference between PBI and BEIin 12 cases was 1.5 ug%, which is somewhatgreater than an average value of 0.6 ug% in the United States.**-*? This was suggestive evidence for the presence of iodoprotein in serum, and theresults obtained by large consumption of seafood. Analysis of 24-hr urine samples from 28 people at the Boston Medical Laboratory in 1965 gave an averagevalueof 105 yg iodine per day (range: 19.5 to 279), which average iodoprotein level of 2.22 ug% was found. Thyroid Uptake of Radioiodine. Uptake of radioiodine by the thyroid wastested in 1965 on column chromatography substantiate this, as an The average value for the amount of thyroxine iodine plus triiodothyronineiodinein these sera was 4.53 ne%. Five plasma samples from Utirik people assayed in 1966 showed an unusually high average of 9.2 ug% of iodoprotein. (See Table 14.) These data may be compared with results obtained on 25 normal North American controls residing temporarily in Washington, D.C., who showed an average serum iodoprotein level of 0.8 pe% and an average 7,+ 7; iodine level of 3.76 ug%. Dietary lodine and Urinary Excretion of Iodine. The supply of iodine in the Marshallese diet has generally been considered adequate in view of the is within the range of values found in an unselected population living in the Eastern United States.** A complete table of urinary iodine ex- cretion data is presented in Appendix4. 21 Marshallese (12 exposed and 9 comparison adults) with no knownthyroid abnormalities. Studies with '**I were performed witha collimated 1-in. Nal crystal 25 cm from the patient’s neck. The '*7] was milked daily from tellurium- 132 bound to a resin by elution with 0.1 M NH,OH, and it was calibrated against a *°*’Cs standard. The ‘*7I (5 to 10 wCi) was administered by mouth before breakfast, and counts were obtained over the neck at =, 1, 2,3,and4hr;a single 3-hr urine was assayed for ‘*7I. A predose count of the neck was performed, since a small amount of what was presumed to be **’Csin-