exposure rates by a factor of two. expect to receive first-year and 30-year integral doses of 0.2 and On the basis of these data, we calculated the integral first- 4.3 rem respectively. year and 30-year whole body external actions (cases 3a and 3b) reduce the gamma~ray doses for each age group 30-year values by a few tenths of for each living pattern presented in arem. Table 1. somewhat if the Phase II houses The results were then combined by "folding in" the present population distribution. Remedial These values would increase (the next group to be built) were The effect constructed within area 2 of Fig. 7 of radioactive decay was included in (cases 4a and 4b) because of the the calculation; however, higher gamma exposure rates the additional reduction in exposure rates measured in this area. due to possible weathering, other hand, leaching, If, on the the Phase II houses were or agricultural crop production built within the interior of processes was not included. Bikini Island instead of along the . The results of these calculations .Shores (cases 5 and 6) we would and a comparison with appropriate expect the external dose levels to recommended guide values are given increase to about 0.28 rem during the in Table 4 for each case under first year and 5.9 rem over 30 years. consideration. Of course, Table 5 lists the dose variations these cases are only approximations of between the various age groups for the expected living patterns, and each case. the results should be regarded expected to spend a- considerable accordingly. The minimum external Because the adults are ‘fraction of their time within the doses, as we might expect, may be interior of Bikini Island as well realized by living on Eneu Island. as on other islands, Estimated values, levels are slightly higher than including natural their dose background, are 0.12 rem during the those of the children. first year and 2.9 rem over 30 differences, however, are expected years. to be somewhat overestimated A significant fraction of The relative these values is due to exposure because aging is not considered in received while visiting other the calculations. islands having higher contamination levels. These doses may be compared with Future inhabitants of the the appropriate guide values, given existing houses along the lagoon in the title of Table 4, which are road on Bikini Island (case 2) may those set forth by the International -19-