was well correlated with age (r=0.89). Lymphocyte cultures in the exposed group showed no significant differences from the unexposed group in response to PHA stimulation (P>0.68). Peripheral blood elements. ~ The changes in various blood elements as a function of age are presented in Tables 1 and 2. In the unexposed population the decreases in lymphocyte levels showed the greatest correlation with age (r =0.91) and appeared to reach a maximum in the 50-60 year age group. Slight depressions in platelet counts, white blood counts, and hematocrit were noted but were less strongly correlated with age. An increase in sedimentation, however, was fairly well correlated with age. In the exposed population the mean levels of neutrophils and platelets were significantly depressed (P<.04) below levels of the. unexposed population particularly in the older age groups, (See Table 2, Fig. 2). The other blood findings were not notably. different. | | Serumprotein patterns. - The results for serum protein studies as determined by electrophoretic analysis are shown in Fig. 3 and Table 2, A slight increase was noted with increasing age in the unexposed Marshallese, but it was not statistically significant, in older people. The gamma globulins increased significantly 7 Alpha and beta globulin levels tended to show some increase though the correlation with age was not significant. to decrease slightly in older people. in the exposed population. Albumen levels tended Pronounced differences were noted The albumen levels were significantly higher and the globulin levels significantly lower than in the unexposed group. : Alpha 1, Alpha 2 and gamma globulins showed the most pronounced depression in the exposed group (Table 2). Serum proteins, particularly gamma globulins