45 number . Most of ‘ ited Pig. ; ind were ¥ asations, Am i 2d. Some ¥ imation,¥ ame sec. #2 ‘ith anti. : radually 4% m the fallout was the radioiodineabsorption fro of the carlycxe not fully appreciated at the tim 1931, isotopes the , aminations. [n addition to ***I ly to the thy133] and '35I contributedsignificant ical urine hem ioc rad roid dose. On the basis of esti- re It was analyses several weeks after exposu ed about 160 eiv d rec roi mated that the adult thy s gamma. The rad s 175 rads from radioiodinesplu smaller glands of the young children, however,re- rads ceived an estimated 700 to 1400 rads plus 175 gamma.}! (Table 7). Genetic effects have not been specifically studied because of the small number of people involved. However, no apparentradiationinduced genetic changes have been found on routine physical examinationsin the first-generation children of exposed parents, with the possible exception of suggestive evidence of increased miscarriages andstillbirths among the exposed women. Malignancies ort lived, ths after mal hair ition has Except for growth retardation in some children and some thyroid abnormalities reviewed below, the general health of the exposed people has been good and aboutthe sameas that of the unexposed population. The incidence of the diseases usually encountered in these people was about the same in both groups. Six cases of cancer have developed in the exposed group,all in females, 3 of the genital tract that resulted in death and 3 of the thyroid gland. Because the thyroid gland received a larger dose, the malignancies of that gland cannot be compareddirectly with the others. Therefore the genital cancers in the females. are less positively related to radiation exposure. Leukemia surveys, including physical findings, studies of leukocyte counts. and morphology, alkaline phosphatase staining, and basophil counts of 4000 white cells, showed no evidence of leukemia or leukemic tendency in any of the exposed people over the 15-year period. ring the Mortality Degenerative Diseases During the 15 years there have been 16 deaths in the exposed group (Rongelap + Ailingnae). This represents 13.0 deaths per 1000 per annum compared with 8.3 for the Marshall Islands as a whole (1960). None of these deaths could beattributed directly to radiation exposure. The higher mortality in the exposed group mustbe interpreted with caution since the numbers of people involved are too small for a sensitive statistical test and there were more older people in the exposed group. Cardiovascular and arthritis surveys, as well as the general results of physical examination, have not shown any apparentincreased incidence of degenerative disease in the exposed people. The Marshallese people appear to have less hypertension on the whole than is noted in the continental United States. An increased incidence of diabetes of the old-age type has been noted in the Marshallese, but no moreso in the exposed than in the unexposed population. Fertility Growth and Development Studies ._Ppeared , ut 15% ) y on the | LATE EFFECTS ck of re. scarring ive been - een con. |: develophe semiin about ap. By 6 ‘ed, have of this us urine ed inter- srobably id drinkfirst few highest, were ape case of At that o be too evels fell ‘Xposure ‘um per- y in the cts were al expocance of me pe ot Ip et tn ya lesser General Health It has been difficult to evaluatetheeffects of exposure on fertility. During the early period after exposure there may have been somerelative infertility. However, the birth rate of the exposed groups over the past 15 years indicates no noticeable effects onfertility (see Table 7) since it has been aboutthe sameas that of the comparison population. Noradiation-induced sex ratio alteration has been seen, Miscarriages,Stillbirths, Genetic Effects The incidence of miscarriages andstillbirths in the exposed women was about twice that in the unexposed women duringthefirst 4 years after exposure. No difference has been noted since then I00b302 Anthropometric measurements and radiographic studies for bone age on the children have revealed slight retardation in growth and development in boys exposed on Rongelap at age <(12 years, particularly in those exposed at age 12 to 18 months. Only slight immaturity was noted in similarly exposed girls. Male children born to exposed parents have shownslight growth retardation andslightly lower levels of peripheral blood elements compared with male children of unexposed parents, but the latter finding has not been evident since 1963. The slight growth difference did not appear to justify the conclusion that it is associated with exposure of the parent. In 1965 marked hypothyroidism with atrophyof the thyroid gland be-