49 The 9°Sr content of coconut crabs has not become sufficiently lower over the years to allow lifting of the ban on eating them. Since we have been assigned the responsibility of monitoring the body burdensof radioactive materials in the Bikini people when they return to their home island from Kili, radiochemical urine analyses were done on 14 Bikini people in 1969.59 As expected, the levels of 187Cs and 9°Sr were quite low. In view of the radiological decontamination being done on Bikini in anticipation of their return, no significant increase in body burdens of the peopleis likely to occur. SPECIAL STUDIES Genetically Inherited Characteristics; Blood Grouping Studies A large body of data has been collected from genetic studies on the Marshallese people. The results not only are of great anthropological interest but also may show in time some possible genetic effects of radiation exposurein future generations. Blood grouping studies show that the Marshallese have a relatively high B gene frequency, a high N gene frequency, an extremely high R! genefre- quency, and total absence of Kell and Diego factors.°° These characteristics differ from those of Polynesians and suggest a relationship of the Marshallese people with Southeast Asians and Indonesians. Haptoglobin studies showeda frequency of the Hp! gene higher than in European populations thus far tested and consistent with that of populations living near the equator. The distribution of haptoglobin types showed the population to be relatively homogeneous.®! Transfernnns in all sera were type CC, the common European tvpe.61 B-Aminoisobutyric acid urinary levels showed the Marshallese to be the highest excreters of this acid of any population thusfar reported.®?.63 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 is probably no correlation with radiation exposure. Hemoglobin types were considered normal (all had type AAg). Stckling tests showednosickling tendency in any of the people. Glucose-6-phosphate dehydrogenase of the red cells appeared to be normal in the Marshallese. Studies of Gm phenotypes showed the Marshallese to have 100% Gm'4+)and nearly 100% Gm®+). There was a complete absence of Gm* and a high frequency of Gm-like (Gm¢).64 Serum studies for the Ag system reveal that the Rongelapese compared with other world populations have a high frequency of C.deB. antiserum reactors and a low frequencyof New York antiserum reactors.65 Considerable caution mustbe exercised in evaluating the results of these studies on genetically inherited character- istics because of the small number of samples tested. The data do seem to indicate relative homogeneity of the population andclosest kinship with people of Southeast Asia. These data also maybe useful as a base line, should genetic changes appear in later generations, possibly related to radiation exposure. Other Laboratory Studies Serum protein levels were generally on the high side of normal; electrophoretic patterns showed the increase in proteins to be due largely to an increase in the gammaglobulin fraction (see Aging Studies). The reason for 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 Amer- icans. The generally lower incidence of hypertension in the Marshallese might be related to the fact that the former native diet was probably lower in salt content than the present more Westernized diet.6§ It will be interesting to see whetherthe incidence of hypertension will later increase. Serum cholesterol levels (1957, 1959) were somewhat lowerin 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 By. concentrations (1958, 1959) weregenerally significantly higher than American levels. The possibility of contamination of the samples with bacteria producing vitamin B,2 must be considered, since myeloproliferative and liver diseases were not seen. Folic acid levels were found to be somewhatlow in the Rongelap population and probablyreflected low dietary folic acid. Glucosuria and elevated blood sugar were found in a number of Rongelap people. A relatively high incidence of diabetes is prevalent in the Marshallese people. A survey forintestinal parasites (1958) showed 75% of the people to be infected with various