26 Table 14 Serum Iodine Serum Protein-Bound Iodine Group Average, ue% Range. ng% No. samples Percent over 8 ug% Rongelap Rongelap Rongelap Medical team Rangelap Rongelap exposed Rongelap unexposed Rongelap exposed Uurik exposed 6.2 8.6 8.1 4.4 7.1 7.6 7.0 6.1 11.8 4.1- 9.2 4.6 - 12.0 1.9 - 12.0 2.5- 6.9 2.0 - 10.2 4.1 -11.9 3.9 - 10.7 3.1 - 11.8 6.9 - 28.7 12 14 29 10 11 31 19 19 25 16 64 66 36 42 28 16 92 Date 1959 1962 1963 1964 | 1964 1965 1965 1966 1966 Serum Butanol-Extractable Iodine 1959 Rongelap 49 2.7- 8.7 12 Serum lodine Chromatography Group Total iodine, Av pg% 195% 1Y¥o4 1965-1966 Rongelap Rongelap 6.98 7.40 1964-1966 Americans 5.09 1966 Uurik 18.10° 7, + Ti, Av ug® No. samples 2.22 2.80 4.53 4.21 19 18 0.80 3.76 25 lodoprotein, Av ug% 9.20 5 4.00 *One Uutirik sample was quite high in total iodine (32.0 4@%) suggesting contamination of this sample. The remain- ing 4 samples showedtotal iodine levels very nearly equal to the combined iodoprotein and thyroxine values. tion in PBI is a general phenomenon whichaffects the entire population. Thedifference 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 the results obtained by column chromatography substantiate this, as an average iodoprotein level of 2.22 ug% was found. The average value for the amount of thyroxine iodine plus triiodothyronine iodine in these sera was 4.53 ug%. 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 controlsresiding temporarily in Washington, D.C., who showed an average serum iodoprotein level of 0.8 ug% and an average 7, +7, iodine level of 3.76 ug. Dietary lodine and Urinary Excretion of lodine. The supply of iodine in the Marshallese diet has generally been considered adequate in view of the large consumption ofseafood. Analysis of 24-hr urine samples from 28 people at the Boston Medica] Laboratory in 1965 gave an average value of 105 zg iodine per day (range: 19.5 to 279), which is within the range of values found in an unselected population living in the Eastern United States." A complete table of urinary iodine excretion data is presented in Appendix 4. Thyroid Uptake of Radioiodine. Uptake of radioiodine by the thyroid wastested in 1965 on 21 Marshallese (12 exposed and 9 comparison adults) with no known thyroid abnormalities. Studies with '"*[ were performed with a collhimated 1-in. Nal crystal 25 cm from the patient’s neck. The '**I was milked daily from tellurium132 bound to a resin by elution with 0.1 Af NH,OH, and it was calibrated against a ''Cs standard. The '**I (5 to 10 4Ci) was administered by mouth before breakfast, and counts were obtained over the neck at 4, 1, 2,3, and 4hr:a single 3-hr urine was assayed for '**I. A predose count of the neck was performed, since a smal amount of what was presumed to be ‘Csin-