37 counts and types, alkaline phosphatase staining, and basophil counts-e£4000 white cells showed no evidence of leukemia or leukemic tendency. One childin the irradiated group had 3% basophils but no other positive findings. The cardiovascular and arthritis surveys, as well as the general results of the physicalexaminations, have not shown any apparent increased incidence of degenerative diseases in the eXposed people. No radiation-induced cataracts have been observed in anyof the exposed people. Genetic effects have not been specifically studied because of the small number of people involved. No apparentradiation-induced genetic changes have been detected on routine physical examina- tion in the first-generation children of exposed parents. Hematological surveys again showed considerable fluctuation in the year-to-year meanlevel of leukocytes in both the exposed and unexposed groups. The mean leukocyte level of the exposed group showed a marked decrease at the ume of the 1960 survey (no unexposed people were examined). The reasons for these fluctuations are not apparent. At 5 years post exposure, exposed people still had mean platelet levels 10 to 15% below those of the unexposed group. However, lymphocyte levels ap- peared for the first time to equal those of the unexposed group. Mean erythrocyte levels were also slightly 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 marked as 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 marrow persists, but other, not immediately apparent, factors may be involved. . Studies ofgenetically inherited characteristics. Blood grouping studies in the Marshallese showeda rela- tively high B gene frequency, a high N genefre- quency, 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 studies showed the fre- quency of the Hp‘ gene to be higher than in European populations thus far tested and consistent with populations living near the equator. The distribution of haptoglobin types showed the population to be relatively homogeneous. Trans- jerrins in all sera were type CC, the common Euro- pean type. B-dA mino-iso-butyrie acid urinary levels showed the Marshallese to be the highest excre- tors of this acid of anv population thus far re- ported. Levels in the exposed group were about the same as in the unexposed group, and no cor- relation was found with body burden level of radionuclides; this indicates that there is probably no correlation with radiation exposure. Glucose-6- phosphate dehydrogenase of the red cells appeared to be deficient in the Marshallese. Considerable caution must be exercised in evaluatingthe results of these studies on genetically inherited character- istics 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” appear in later generations, possibly related to. radiation exposure. : Results of other laboratory studies carried out during the 5-year survey included the following: Serum protein levels, as has been noted before, were generally on the high side of normal; the reason for this is not apparent. Complementfixation studies for parainfluenza 1, 2, and 3, respiratory syncitial, psittacosis, and Q fever showed antibodiesto all groups of viruses except that for Asian influenza, which probably had notyet seriously involved the people of the Marshall Islands. The antibodytiters appeared to be somewhat lower in the exposed people. Sodium levels in the urine andfood indicated about the same consumption of NaCl as in Americans. The generally lower incidence of hypertension in the Marshallese mightbe related to the fact that the former native diet was probably lower in salt content than the present, more westernized diet. It will be interesting to see whether the incidence of hypertension will later increase. Repeat studies of protein-bound todine, total iodine, and butanolextractable 1edine of the sera showedlevels lower than previously reported, and the previous higher readings are thoughtto be in error because of contaminated glassware, although some readings were still somewhathigh. Four cases of glucosuria associated with elevated blood sugar were found in the unexposed population, which indicated a rather