BLOOD BROMINE LEVELS el 7 ] 93 | I Le — RED CELLS 6 — r oe 5 ° » K 4 Cl Rb 2 Cc 3 Sab 9 zn Br iW = 3i- Rb K 4 Fe Ca Cr 2h Cu Zn Fe SERUM Cr Br “ Cu Zn 1 ee ~ 1 5 ____ lo ENERGY(keV) 1 15 Fic. 1. Typicai EDXRF spectrum of red cells and serum from a New York subject. nonanticoagulated and EDTA-anticoagulated tube, respectively (11)). It was further determined that the serum separator of Vacutainer tube Model B-D 6512 contains no Br. Water samples which were transported in polyethylene containers similar to those used for serum andred cell frozen storage had no detectable Br. Additional evidence that contamination did not account for the elevated Br levels in the blood samples come from data on three New York subjects whose serum and red cell specimens were prepared in the Republic of the Marshall Islands concurrently with the Marshallese specimens. All three serum Br values of the New York subjects were lower than the lowest Marshallese serum level: moreover, the mean value of the three red cell Br concentrations was lower than that of the mean Marshallese value. It was concluded, therefore, that Br contamination was not a factor in the analysis. Typical EDXRF spectra from red cells and serum samples, taken from a New York subject, are shown in Fig. !. The peak intensities (peak area) are proportional to the corresponding elemental concentration in the sample. The results of the analyses for each element normalized to the mean value of the New York group are shown in Fig. 2. The relative group means for each elementtested are Summarized in Table 1. The striking elevation of serum and red cell Br in the Marshallese was unique among the different elements evaluated by EDXRF. . i a7 fg"5 F t t