elevated alkaline phosphatase. A flexible sigmoidoscopy and mammography were negative, blood count was normal, and Papanicolaou smear was class I. She had carcinoma of the endometrium in 1979 which was effectively treated by total abdominal hysterectomy. Septicemia and nonketotic hyperosmolar diabetic coma werelisted on her death certificate as the causes of death. Subject No. 14. This 54-year-old woman died on Ebeye in 1990. When last seen by the Brookhaven team in October 1989 she was taking glyburide for diabetes mellitus and had a fasting glucose of 208 mg/dl and a HbAIclevel of 7.4% (mildly elevated). A blood count was normal. Other problems considered earlier were bilateral cataracts, fibrocystic disease of breasts with negative mammogram in May 1989, negative Papanicolaou smear in 1988, and normalflexible sigmoidoscopy in 1987. The cause of death is unknown. Laboratory Findings: Hematology A teview of “blood counts" (average concentrations of formed blood elements) of the different exposure groups during the four-year reporting period does not reveal any systematic differences among groups. In 1989 and 1990 there was a significant increase in mean platelet count in Utirik exposed women as compared to the unexposed population (Table 1). Figure 2 is a continuation graph in which hematologic data of the two exposed groupscollected since 1956 are portrayedin relation to the expanded Comparison group. Table I gives the mean values (+ /- SD) from which Fig. 2 is derived. The individual counts are given in Appendix B. It is apparent from scanning the four graphs in Fig. 2 that there ism mild butrelatively consistent depression, genedéilly ‘aot statistically significant different, over moat‘efthe 37 post-exposure years, of neutrophil, lymphocyte, and platelet concentrations (the latter in males only) in the Rongelap/Ailingnae group. This depression appears to be of no clinical significance. These consistently slightly lower values for all three formed blood elements over such a long period in the Rongelap group suggests the possibility of radiation related mild impairment of hematopoiesis. However, there is no evidence of impaired leukocytosis in response to infection. Therefore, these differences may reflect a shift in cell compartmentalization (e.g. margination). Hematologic changes in Japanese atomic bomb survivors have been recently reviewed (Finch and Finch, 1988). An early decline in leukocyte counts was detected from 1947 through 1956, but this occurred in both exposed and unexposed groups, and therefore was not an effect of radiation. Indeed, “no clearly established exposure differences have been uncovered except in the case of the leukemias” (Blaisdell and Amamoto, 1966). Therefore, a sustained depression in leukocyte counts, such as seen in the Rongelap group, was not detected among the exposed Japanese. With regard to leukocyte margination, no evidence of a radiation dose-effect in the exposed Japanese was apparent when exercise-induced leukocytosis was quantified (Belsky et al., 1972). In general, radiation has been found to alter leukocyte function in humans only minimally, if at all, and, when dysfunction has been detected, it has been of no clinical importance. The most recent clinical study to confirm this was carried out on Japanese atomic bomb survivors and included phagocytic and bactericidal activities of neutrophils (Sasagawaet al., 1990). It was noted that for ten years after the atomic bombings in Japan the leukocyte counts of persons followed by the Atomic Bomb Casualty Commission gradually decreased by about 35% in both the exposed and unexposed populations (Blaisdell and Amamoto, 1966). This trend was never completely explained, but the decline was chiefly attributable to a decrease in neutrophils. A slight trend in this direction can be detected in total leukocyte counts obtained on the Marshallese over a similar time span. Using data from the unexposed Comparison group, the mean total leukocyte concentration for 1954-1958 was 8,500/ul and for 1969-1974 it was 7,300/ul, a 14% decline. For 1985-1990 it has been A decrease in absolute lymphocyte 7,500/ul. concentration, approximately 1,000/ul, occurred simultaneously. This finding differs from that of the Japanese, in whom it was the neutrophils that were For the Marshallese, predominantly lowered. minimal fluctuation was seen in neutrophil count for the three periods. The reason for the apparent decrease in lymphocyte concentration in both exposed and unexposed Marshallese is unknown.