TABLE 4: Distribution of thyroid nodule type by gender. Male (%) Female (%) Total Adenomatous nodules 8 (25) 24 (75) 32 Adenomas 2 (29) 5 (71) 7 Occult papillary carcinomas 2 (29) 5 (71) 7 Carcinomas 1 (10) 9 (90) 10 Total 13 (23) 43 (77) 56* * The total number of nodules exceeds the number of surgeries because four patients had two dregories of nodules. 3) Whatwas therelation of radiation dose to time of nodule detection? The strong correlation between higher dose and earlier nodule developmentis shown in Fig. 5. While this graph gives an overview of the epidemic in relation to dose, it offers little understanding of the role of the variables that shapedit. The predominant nodule type was the children one to six years of age. Three pf these children were on Utirik (ages: 1, 5, and § years). The correlation between dose and fime to adenomatous nodule, the ratio of these to all other types being 4:3. Adenomatousnodules are not neoplastic. Therefore, Fig. 5 predominantly describes the relation of radiation dose to nonneoplastic nodular disease. Secondly, the prominent association of higher radiation dose with early nodule development is influenced by age-related variability in susceptibility to thyroid cancer (NRC BEIR V, 1990) and benign tumors (Ron etal., 1989; Shore et al., 1985). The mean age of the Rongelap people at the time of exposure was 27.6 years, but the range of ages was 0 (there were 4 persons in utero) to >80 years, and susceptibility would have varied accordingly. Inferences concerning dose and time to development of adenomatous nodules can be extracted from data on persons exposed at equivalent ages, thereby controlling for susceptibility. In Figure 6 the time to developmentof nodulesis graphed against dose in until ten years after exposure and after [he first nodules had been detected. Therefore, the Effect of thyroid suppression on development off thyroid nodules was not of consideration for theffirst 10 years after exposure. In addition almost all adenomatous nodules in this group had been identified within five years of initiation of thyroxine suppression. A similar age-controlled analysis for the other three nodule types is not useful because there are too few observations per group. 4) What was the relation between nodule development and age at exposure? The relation of nodule type to dose anf age at exposure is shown in Fig. 7a-d. The graphsfindicate a similarity in the age- and dosq@related developmentof all four nodule types in the Utirik 20