WORKING HYPOTHESIS: The acutely-exposed study population received both external and internal radiation, as previously reported. The dosimetry is discussed in detail in previous reports (1,2,3-14). The external gamma calculations seem fairly reliable and uniform for the population. The initial, individual internal body burdens of nuclides, especially a number of short-lived iodine isotopes, show much greater variation and uncertainty, even though radiochemical urin- alyses were performed within 15 days on the pooled urines of the exposed popu- lation. On the 7th, 23rd, 24th, and 47th days post detonation, 24-hour urine collections from each individual from Rongelap and Ailinginae were sent to the The quantification of the New York Operations Office (AEC) for analysis. shorter-lived isotopes of iodine, particularly 133-134- and 1357, would be Two of the younger (1 yr old at the time of exposure) impossible to measure. Rongelap children (Studies No. 3 and 5) were noted to be clinically myxedematous at age 9. Subsequent evaluations have revealed almost total ablation of their This would suggest a thyroidal dose of thyroids (Case 3 greater than Case 5). Therefore, the dose to the thyroid in this at least 2000 rem, possibly more. small study group probably has a much wider standard error than was previously appreciated. The potential magnitude of this standard error imposes severe constraints on the statistical analysis of those data dependent on organspecific dosimetry. The enclosed tables present a synopsis of the significant data obtained during calendar year 1979. surgery. During this period 14 patients underwent thyroid The spectrum of the surgical pathologic opinions is presented in Table LII. This is a greater divergence in the determination of carcinoma vs. benign tumors than presented in previous years. Because of this divergence, we are in the process of impaneling a formal Thyroid Pathology Review Group, representing a cross section of opinions from some of the country's best surgical pathologists. For each case a majority and a minority report (as indicated) will be developed and suitable statistics will be developed for each position. Since the subgroups of the study population are so small, the assignment of a single case to the cancer or benign category will have a profound impact on the incidence, and/or period prevalence, risk/rad ratio, etc.