58 the blood volumes and the red cell volumesofthe Caucasianslivingin the Islands and the Caucasians of the Siri and Moore groups; furthermore, duration of residency in the Islands has nosignificant effect. Earlier data had suggested that Caucasians living in the Marshall Islands might have reduced blood volumes andred blood cell volumes. Though this may be true for certain individuals, it does not seem to hold true for the group as a whole. Test for Australia Antigen The Australia antigen, a serum protein first detected in the serum ofthe Australian aborigines, was searched for in the Rongelap population.* Details of these studies are presented in Appendix 16. Samples of sera from 250 Rongelap people were examined between 1958 and 1965. Ofthese, 237 were consistently negative, | 1 were consistently positive (4.4%), and 2 were inconsistent. Family studies indicated that positive subjects were homozygous for the genes. This antigen has been found to be relatively commonin someformsof leukemia. * These studies were carried out by Dr. B.S. Blumberg, Institute for Cancer Research, Philadelphia, Pa. q | it REGRESSION LINES SIRI { ! BY 10.91 +0,090 (TBwW) RCV #0.08 +0.0474 (TBW) n BV *0647+0.45 (Tew) MOORE { RCV 90.158 + 0.05296 (TBW) BV 0.5337 +0.0767 (TBwW) MARSHALLESE { RCV « -01749+0.0441 (TBW) CAUCASIANS { BV «1.2101 +0.0792 (TBW!] IN PACIFIC RCV #019947+00419(TBW) + b ' VOLUME, LITERS [" 3b ~ 2 ] IK W. SIRI o 10 “f wee MARSHALLESE “] ee —-— CAUCASIANS “7° MOORE IN PACIFIC l l 20 l 30 ! 40 TOTAL BODY WATER, LITERS Figure 67. i 56 60 Since the Rongelap people will be medically examinedfor manyyears,it will be interesting to see whetherthe presence of this antigen is related substantially to disease, particularly leukemia. ESTIMATION OF INTERNAL BODY BURDENS. OF RADIONUCLIDES In the 1965 survey, the body burdensof radio- nuclides were determined by use of a portable shadow-shield type of whole-body counter and by radiochemical analysis of 24-hr urine specimens. Whole-Body Counting The use of the shadow-shield type of whole- body counter represents a departure from previous surveys, in which a 21-ton steel room had been transported to Rongelap andused for this purpose. Correlations between the two techniques werees- tablished by standardizations using the permanent steel room and a duplicate of the shadowshield at Brookhaven National Laboratory. The body ‘°K values of the Rongelapese provide another means of correlation. The shadow-shield counter (Figure 68) is very similar to the one described by Palmer and Roesch" and to the Hanford whole-body counter.'* It was installed on Rongelap in one of the newly acquired air-conditioned trailers. The de’ tector, an 11%-in.-diameter Nal (TI) crystal 4 in. thick (Harshaw), is housed in a lead shielding supported bya steel plate about 14 in. above the bed. The subject to be counted lies on a foam rubber cushion in the trough between the two walls of lead bricks, and is moved to a position under the detector by a motor-driven worm-screw drive. The system was Calibrated with a plastic phantom man, both in a stationary position beneath the counter and with movement equivalent to the length of the body during the count. Thesignal from the detector was picked up by 7 photomultiplier tubes mounted on the crystal, and the gamma-ray spectrum was analyzed with a 400-channel pulse-height analyzer (RIDL). The gamma-rayspectral data were read out on rolls of adding-machine paperfor immediate evaluation, and on punchedpapertapefor subsequent data processing which involved transfer of the data from the punched papertape to magnetic tape and subsequentanalysis in termsof radioisotopes by a spectral stripping program en an IBM-7094