s ce eeee tt. a oy telat,Niemann eS ~ a a Ba + 4 iated directly to radiation effects during thefirst few years post exposure. No prophylactic or specific therapy for radiation effects was ever con- sidered necessary or given. Epidemics of chicken pox and measles that occurred during thefirst year showedno greater incidenceor severity in the exposed than in the unexposed Marshalles people. During thefirst months post exposure about % of the exposed people exhibited Joss ofweight of several pounds. This may possibly have been related to their radiation exposure, although it was difficult to rule out possible effects due to changeof environment. At 3 years post exposure the immune response to primary and secondary tetanus antitoxin was tested and foundnotto besignificantly different in the exposed compared with the unexposed populations. There were 10 deaths in the exposed populations over the 10-year period (see Table 6). Of these, 2 deaths were recorded as due to malignancies, The 10 deaths that have occurred in the exposed population represent a mortality rate of 12.2 per 1000 population per annum, compared with 8.3 for the Marshall Islands as a whole (1960). The somewhat higher death rate in the exposed group is partly offset by the higher proportion of older people; those >65 years of age wereoriginally 20% in the exposed group and only 7% in the unexposed group. Growth and development studies on the children (height, weight, anthropometric measurements, and radiographicstudies for bone age) have revealed slight retardation in growth and development in the boys exposed on Rongelap who were <12 years of age at the time of exposure, particu- larly those 12 to 18 months of age at exposure. Onlyslight immaturity was noted in the female children ofthis group. In studies of children born showeda slight growth retardation and slightly lower levels of peripheral blood elements compared with male children of unexposed parents; however, this latter finding has not been evident since 1963. The slight growth difference does not appearto justify a conclusion that there is an association with exposure of the parent. It was difficult to evaluate the effects on fertility. However, a review of the birth rate of the exposed groupsoverthe past 10 years seemsto indicate no noticeable effects of their exposure on fertility. The theme ¢ - yee Ae eAEI Bt RR eat aa . 1 Cer of exposed parent(s), it was noted that males 5008288 50 births represent a rate of 61 per 1000 population per annum comparedwith 37.3 for the Marshall Islands (1957). She incidence of miscarriages andstillbirths in theseexposed women wasabout twice that in the unexposed women during the first 4 years after exposure, but no difference has been noted since then (see Table 8). A cardiovascular survey of the adults (1959)° showed no outstanding differences between the exposed- and unexposed groups. The Marshallese people appeared to have less hypertension on the whole than is noted in people in the continental United States. Anarthritis survey (1959) showed no greatdifferences between the exposed and the unexposed people, and about the sameincidenceas is seen in American populations. Ophthalmological surveys showed no remarkable differences between the exposed and unexposed groups exceptpossibly a slightly greater numberof cases of pterygia, pingueculae, and cornealscars in the exposed groups. It is not known whether these findings are of any significancein relation to their radiation exposure. Slit-lamp observations showed no opacities of the lens characteristic of radiation exposure. As a whole, visual and accommodation levels in the Marshallese appeared to be abovethe average in the U.S. population. Dental surveys’ showed nosignificant differences in caries rate between exposed and unexposed groups. However, the incidence and severity of peridontal disease was slightly greater in the exposed group. It is not known whetheror not this finding is related to radiation effects. The poor oral hygiene generally observed in the Marshallese had its usual results, namely, high caries rate in teen-age children, severe peridontal lesions in adults (heavy calculus andloss of alveolar bone), and edentulous mouthsin the aged. Radiation exposure did not appearto have affected developing dentition in the exposed children. Aging studies were done in which various param- eters usually associated with aging were measured or estimated on a 0 to 4+ scale (skin looseness, elasticity, and senile changes; graying of the hair and balding; accommodation, visual acuity, and arcus senilis; hearing; cardiovascular changesincluding blood pressure and degrees of peripheral and retinal arteriosclerosis; neuromuscular func- tion; and hand strength). Comparison of these measurements in exposed and unexposed individ-