“ubsly elas meinor witn the Rongelap data, t*? average ~“Fe body * burdens agreed within 15 per cent of those calculated using body “ weights. oe | | | Table 1 gives the average body burdens of SF re in a selected ‘ group of Rongelapese sampled in March, 1970, and Figure 1 shows | a frequency distribution of the body burdens of males and females. Iron-55 levels in the blood samples weresufficiently high to permit count rate measurements to + 5 per cent at the 95 per cent (20) confidence level. Not all donors were weighed in 1970, therefore body weights from previous years were used to compute total blood volumes. However, weights from previous years applied mostly to younger donors. Since weight generally in- ereases with age, some individual estimates of 56 body burdens, and therefore the averages shown in Table 1, are likely to be conservative. The maximum body burden in the males was 0.85 uci, while three females had body burdens greater than this value. maxdmum observed female body burden was i. O pci, ; The approximately 1/100th of the maximum permissible body burden which has been established for non-occupationally exposed individuals considering the total body as the critical organ (18). Previous measurements of Sore body burdens during a period of increasing 55 re fallout generally showed that 55e body burdens of females were higher than those of males (4,5). Presumably this is due to higher tir" eYt™