burden curve for 905, reconstructed from raw data and Eq. 1, was considered a more accurate history. A detailed presentation of the greater variation in radiochemical analysis of urine versus direct body burden measurements can be found in Mi8l, Figure 9 illustrates the variation exhibited in the body burden of 5 randomly chosen subjects over the 25 year monitoring period. variations may have had a dramatic impact on the mean data. These individual In Figure 2, which illustrates the adult male, adult female, and adult population mean 137¢6 body burden for the 25 year exposure period, a decrease followed by an increase was seen during the years 1958 through 1963. Although the Castle BRAVO test ini-~ tially contaminated Rongelap in March 1954, it had been proposed that the Hardtack Phase I series added to this an amount of contamination equal to that responsible for the Figure 2 body burden pattern (Co63). Figure 9 suggests that most individuals counted in those years had body burdens which remained the same or declined; however, one individual's burden (#881 M) rose and fell quite differently from the others. Several factors could have contributed to this variation from the mean such as departure and return to the atoll, sickness, the dietary contribution of imported foods, etc. Since the mean values are based on small numbers of persons who were chosen at random, it is conceivable that individuals like 881 M influenced the mean body burdens to a greater degree than * recontamination of the inhabited atolls. The impact of the individual body burden pattern on the true mean value is moot since body burdens of all individuals were not monitored consistently throughout their residence intervals except in the few cases exhibited in Figure 9.