57 counts and types, alkaline phosphatase staining, and basophil counts of 4000 white cells showed no evidence of leukemia or leukemic tendency. One child in the irradiated group had 3% basophils but no other positive findings. The cardiovascular and arthritis surveys, as well as the generalresults of the physical examinations, have not shown any apparent increased incidence of degenerative diseases in the exposed people. No radiation-induced cataracts have been observed in any of the exposed people. Genetic effects have not been specifically studied because of the small numberof people involved. No apparentradiation-induced genetic changes have been detected on routine physical examination in the first-generation children of exposed parents. Hematological surveys again showed considerable quency of the Hp’ gene to be higher than in European populations thus far tested and consistent with populationsliving near the equator. Thedistribution of haptoglobin types showed the population to be relatively homogeneous. 7ransferrins in all sera were type CC, the common European type. B-Amino-iso- butyric acid urinarylevels showed the Marshallese to be the highest excre- tors of this acid of any population thusfarreported. Levels in the exposed group were about the same as in the unexposed group, and no correlation was found with body burden level of radionuclides; this indicates that there ts probably no correlation with radiation exposure. Glucose-6phosphate dehydrogenase of the red cells appeared to be deficient in the Marshallese. Considerable cau- tion must be exercised in evaluating the results of reasonsfor these fluctuations are not apparent. At 5 years post exposure, exposed people still had these studies on genetically inherited characteristics because of the small number of samples tested. The data do seem to indicate relative homogeity of the population and closest kinship with people of Southeast Asia. These data also may be useful as a base line should genetic changes appearin later generations, possibly related to radiation exposure. peared for the first time to equal those of the un- Results of other laboratory studies carried out during the 5-year survey included the following: Serum protein levels. as has been noted before. were fluctuation in the year-to-vear meanlevel of leuko- cytes in both the exposed and unexposed groups. The mean deukocyte level of the exposed group showed a marked decrease at the time of the 1960 survey (no unexposed people were examined). The mean platelet levels 10 to 15% belowthose of the unexposed group, However. /ymphocyte levels ap- exposed group. Mean erythrocyte levels were also slightivy lower in the exposed people. These blood elements in the Ailingnae group also showed some slight depression below the unexposed levels but not quite so markedas seen in the Rongelap ex- posed group. A general anemic tendency was noted in all the Marshallese, both exposed and unexposed. Price-Jones curves, on the average, showed a slight microcytic tendency. Serum tron levels were generally normal. The fact that some of the blood elements in the exposed group have not yet returned to the levels in the unexposed group raises the possibility that a residual radiation effect on the bone marrowpersists, but other, not immediately apparent, factors may be in- volved. Studies ofgenetically inherited characteristics. Blood grouping studies in the Marshallese showed relatively high B gene frequency, a high N genefrequency, an extremely high R' gene frequency, and total absence of Kell and Diego factors. These characteristics differ from those of Polynesians and suggest relationship with Southeast Asians and Indonesians. Haptoglobin studtes showed the fre- generally on the hizh side of normal; the reason for this is not apparent. Complement fixation studies for parainfluenza |, 2. and 3, respiratory syncitial., psittacosis, and Q fever showed antibodies to all groups of viruses except that for Asian influenza. which probablyhad not vet seriously involved the people of the Marshall Islands. The antibody titers appeared to be somewhat lowerin the exposed people. Sod:um levels in the urine and food indicated about the same consumption of NaCl as in Americans. The generally lower incidence of hypertension in the Marshallese might be related to the fact that the formernative diet was probably lower in salt content than the present, more westernized diet. It will be interesting to see whethertheincidence of hypertension will later increase. Repeat studies ofprotein-bound iodine, total iodine, and butanol- extractable todine of the sera showed levels lower than previously reported, and the previous higher readings are thoughtto be in error because of contaminated glassware, although somereadings were still somewhathigh. Fourcases of g/ucosurta associated with elevated blood sugar were found in the unexposed population, which indicated a rather