PRIVACY ACT MATERIAL REMOVED 42 of the reacting antigen was under genetic control. Individuals with a dominant gene designated 4¢* it single or double dose (genotypes 4¢*/Ag*, Ag*/Ag) were reactors [phenotype Ag(a + )| and those homozygousfor the recessive allele Ag nonreactors [Ag(a —)|. The antigen or antigens that react with the antibodies present in the serum of the frequently transfused patient are serum low density £-lipoproteins.'’ A serum from a second patient ( -), the New York antiserum, was also found to react with a low density 8-lipoprotein. Preliminary family studies indicated that reactors were homozygous cr heterozygous for a second gene, while nonreactors were homozygous for the alternate recessive allele. [mmunologic, genetic, and population studies showed that the lipoproteins selected by the two antisera were antigenically distinct and controlled by different genes. '” Sera collected from the inhabitants of Rongelap Atoll in 1962 were tested with both the C.deB. [anti-Ag(a+)| and the New York antisera. The total results compared with those on several! other populations are shown in Table 22. There isa much higher frequency of C.deB. antiserum re- actors and a much lower frequency of New York antiserum reactors in the Rongelap population than in U.S. whites and Negroes. The reasons for these differences are not known, but may depend on differences in past or present selective forces which affect the baiance of the polymorphisms. “Because of the lower frequency of New York antiserum -eactors, the Rongelap population was useful for family studies. From these studies it was tentatively concluded that reactors with the New York antiserum were cither homozygous or heteruzygous for a dormant gene. and nonreactors were homazygous for its alternate allele.” Rediechemical Analyses of the Urine. Determinations of body burdens of gamma emitting isotopes {princtpally Cs'' and Zn*’) by whoiebody gamma spectroscopy were not done during the past two surveys. Data in (961, by that tech- nique, indicated that the body burdens of Cs' ° were not signihcands diferent from those of two years before. and Zn” levels had dropped by a factor of about tO. It was decided, therefore, to defer whole-body counts until the 1965 survey. Results of radiochemical urine analyses for Cs'" and Sr™ on 38 urine samples for 1963 and 27 sampies for |1¥64 are presented in Tables 23 and 24. The data are divided into the following groups: exposed and unexposed of ages <l5 and >15 years, living on Rongelap, Ebeve, and Uurik. Sr" urine levels for 1963 and 1964 have not increased over the 1962 levels. In 1962, the mean Sr*" values from the individual adult 24-hr sam- Group Roscecar Unexposed, age ples were 12.45 pC/'I or 14 pC,g Ca. From these values, on the basis of previous calculations,” ‘ the body burden was estimated as 12.0 myC for aduits and 28.4 myC for children. On the same basis, the estimates for 1963 body burden levels of Srare LE.3 myC (adults) and 21.8 mypC (children); and for 1964, 10.7 mgC (adults) and 23.4 myC (children). As shown in Table 23, the levels of both Cs'** and Sr"" are lower for the people living on the uncontaminated island Ebeye at Kwajalein Acoll. Mean Exposed. age < Thus the return of the Rongelap people to their home island was refiected in annual increases to 1962 in estimated body burdens of Sr" based on urinary excretion values. The annual estimates in mpC for adults were as follows: 2.0 in 1958; 6.0 in 1959; 6.9 in 1961; 12.0 in 1962; 11.3 in 1963. and 10.7 in 1964. The present body burdens are about 5 to 6% (adults) to about 10% (children) of the maximum permissible concentration (MPC) of Ser™ (200 mpC) for non-industrial populations. It appears now that equilibrium with the environ- mental contamination of Sr™ has been reached in the people living on Rongelap Island, and the previously estimated equilibrium value of 23 myeC will not be reached. No bone samples were obtained from autopsy maternal during the past two years for Sr** anal- ysis. Estimates of body burdens from previous analyses of bone samples had shown fairly good correlation with those obtained from unne analyses. Poot In view of the paucity of the previous data on Cs'* urinary levels, it is di.acult to interpret the present levels in terms of body burden. However, the levels are generally less than the mean [958 Cs'" urinary level of about 4 nC,'l. Thisis in accord with the finding by gamma spectrograph determinations that the whole-body burdens of Cs' in 1901 had not increased. Analvses of three coconut crabs for Sr?’ and Cs'* are shown in Table 25. Thoughthe levels of Sr’” (pC/g Ca) are lower than in the crabs ana- Mean Barve Pooled Urieug -Exeosen Age <1 Mean Age15 lyzed in 1962, they are still sufficiently high to ne- cessitate continuation of the ban on their consumption by the people of Rongelap. [tis interesting that the Cs'"’ levels are also quite high in these crahe. Mean SUMMARY Rongelap, all : Rongeiap. al! Ebeve Cunk, all <1 Uunk, alt >1- PRIVACY ACT MATERIAL REMOVED