pean populationsthusfar tested and consistent with that of populationsliving near the equator. Thedistribution of haptoglobin types showed the populationto be relatively homogeneous.'? Transferrins in all sera were type CC, the common European type.'? B-Amino-iso-butyric acid urinary levels showed the Marshallese to be the highest excreters of this acid of any population thus far reported.'*""‘ Levels in the exposed group were about the same as in the unexposed group, and nocorrelation was found with body burden level of radionuclides; this indicates that there is probably no correlation with radiation exposure. Hemoglobin types were considered normal (all had type AA,). Sickling tests showed nosickling tendency in any of the people. Glucose-6-phosphate dehydrogenase of the red cells appeared to be normalin the Marshallese. Studies of Gm phenotypes showed the Marshallese to have 100% Gm"? and nearly 100% Gm'*"’. There was a complete absence of Gm* and a high frequency of Gm-like (Gm‘).'* Serurn studies for the Ag system reveal that the Rongelapese compared with other world populations have a high frequencyof C.deB. antiserum reactors and a low frequency of New York antiserum reactors.'* Considerable cauuon must be exercised in evaluating the results of these studies on genetically inherited characteristics because of the small number of samples tested. The data do seem to indicate relative homogeneity of the population andcloset 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. Numerous blood cultures for chromosomeanalysis have been taken on past surveys. The results of these studies will be presented in this report. Other Laboratory Studies: Serum protein levels were generally on the high side of normal; electrophoretic patterns showed the increase in proteins was largely due to an increase in the gammaglobulin fraction. The reasonfor this is not apparent. Numerous chronic infections may be an explanation. Sodium 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 mightbe related to the fact that the formernative diet was probably lowerin salt content than the present more Westernized diet.'* It will be interesting to see whethertheincidence of hypertension will later increase. Serum cholesterol levels (1957, 1959) were somewhatlowerin the exposed population than in the comparison or Utirik populations but were in the low normal range. No abnormally high or low readings were noted. Serum creatinine levels (1957) were in the normal range with no abnormallevels noted. Serum vitamin B,, concentrations (1958, 1959) were generally significantly higher than American levels. The possibility of contamination of the samples with bacteria producing vitamin B,, must be considered, since myeloproliferative and liver diseases were not seen. Folic actd levels were found to be somewhatlow in the Rongelap population and probably reflected low dietary folic acid. Serum protein-boundiodine levels have repeatedly been shownto be generally slightly elevated. Evidencefor thyroid dysfunction has only recently been noted in the people along with the recent developmentof thyroid nodules. Thyroid studies will be reviewed in detail in a later section. Glucosuria and elevated blood sugar were found in a number of Rongelappeople. A relatively high incidence of diabetes is prevalent in the Marshallese people. A survey for intestinal parasites (1958) showed 75% of the people to be infected with various types.'* For the three major pathogensfound, the over-all infection rates were, for Entamoeba histotytica, 18.2%; for hookworm, 5.5%, and for Trichures trichiura, 34.3%. Eosinophilia (>>5%) has consistently been noted in about half the people. The fact that half the cases with eosinophilia showed no helminthic infectionsat all suggests that other factors besides parasitic infections must be responsible. The eosinophilia may be related to chronic fungus and other infections, particularly of the skin. Complementfixation studies for parainfluenza1, 2, and 3, respiratory syncitial, psittacosis, and Q fever showed antibodies to all groups of viruses except that for Asian influenza, which probably had not yet seriously involved the people of the Marshall Islands. The antibody titers appeared to be somewhat lowerin the exposed people. Immunoelectrophoretic analysis showed neither a paraproteinemia nora typical picture of antibodydeficiency-syndrome, but a high frequency of increases of some of the immunoglobulins was noted.