No gross abnormalities of bone marrow smears were reported at 6 months post exposure. Depressi 7 of peripheral blood elements in the Ailingnue and Rongerik groups was not so prorounced as in the Rongelap group. However, a slight lag i complete recovery in the Ailingnac peripheral blood count has also been noted. The persistent depression of peripheral blood chments in the exposed people makes it appear likely that there is slight residual bone marrow damage. A general anemic tendency has been evident in both exposed and unexposed Marshallese. PriceJones curves, on the average, showed a siignt microcytic tendency. Serum iron levels have generally been normal, and the cause of this anemic tendency has been undetermined. Reticulocyte counts have been about the same in the exposed as in the unexposed people. Except for radiation-induced lesions of the skin, patchy cpilution, and early gastrointestinal symptoms, clinical examinations have revealed no discase processes or symptoms which could be re- lated directly to radiation effects. No prophylactic or specific therapyof radiation effects was ever con- sidered necessary or given. Epidemics of chicken pox and measles that occurred showed no greater incidence or severity in the exposed than in the unexposed Marshallese people. During the first months post exposure about half of the cxposed group exhibited loss of weight of several pounds. This may possibly have been related to their radiation exposure, although it is difficult to rule out effects possibly due to change of environment. At 3 years post exposure the immune response to primary and secondary tetanus antitoxin was tested und found not to be significantly different in the exposed compared to the unexposed populations. Four persons in the exposed population died of discase. (1) 4 46-year-old man with a hypertensive heart disease which had been present at the time of exposure, who died2 years after the accident; (2) a 78-year-old man whodied, 3 years after exposure, of coronary heart discase complicating diabetes; (3) a 35-year-old man who died of acute varicella, 4 years after exposure, who had received only 69 r, having been on Ailingnac at the time of the fallout, and (4) a 60-year-old woman who diced of a cancer of the ovary at 5 years after exposure. There was no apparent relationship between any of these deaths and radiation exposure. Four deaghs have occurred inthe comparison population, The four deaths that _pcrurted:-iin the exposed people since expo esent a mortality rate of 7.1 peed000 population, compared with 8.3 for the Mafshall islands as @ whole. Growth and development studies on the children (height, weight, anthropometric measure- ments, radiagraphie studies for bone age) have revealed that-slight retardation in“growth and develgpmhent has occerred in the-exposed boys who were vier 12 years of age at the ime of exposurc, particulaely those #2 to 18 months of age at expusute, Oily alighi W i inalucty was mated in the exposed female children. It was also noted that children born of exposed parents were slightly retarded and that they hadslightly lower levels of neutrophils, lymphocytes, and platelets, compared with male children of unexposed parents. It was difficult to evaluate the cffects on fertility. However, a review of the birth rate of the exposed group over the past. 7 years scems to indicate no noticeable effect of their exposure on fertility. The 31 births represent a rate of 54 per 1000 population, compared with 37.3 for the Marshall Islands (1957). The 21 births over a 4-year period for the comparison population represent a rate of 72 per 1000 population. A somewhat greater incidence of miscarriages and stillbirths was noted in the ex- posed women during the first several years after exposure, but because of the paucity of vital statistics on the Marshallese and the small number of people involved, the data are not readily amenable to statistical analysis. A cardiovascular survey of the adults (1959)? showed no outstanding differences between the cxposed and unexposed groups. The people appeared to have less hypertension on the whole than is noted in people in the continental United States. An arthritis survey (1959)? showed no great dif- ferences between the exposed and the unexposed people, and about the same incidence as is scen in American populations. Ophthalmological surveys showed no remarkable differences be.ween the exposed and unexposed groups except possibly a slightly greater number of cases of plerygia, pingueculae, and corneal scars in the exposed group. It is not known whether this finding is of any significance in relation to their radiation exposure. Slit-lamp observations showed no opacities of the lens characteristic of radiation exposurc. As a whole, visual and accommodation