SLIDE 43 Environmental levels of external exposure. Exposure rates were observed to decline following each test. At Rongelap and Utirik the residual levels from BRAVO fallout overshadowed the residual radiation from other tests. Occational elevations due to fresh fallout were evident, however, the exposure rate would return to the BRAVO baseline within several weeks. The levels at Bikini Island during the early 70's were about 5 times the levels at Rongelap. The levels og the sputhern islandsof Enewetak are very close to natural background; 10 C kg “h (3.7MRh~). This low-level was due to Pe 1S} re a | Fp) eet > .@) [oa b= 0a a uJ [vu attsTV ale) ac UTIRIK ATOLL Oaase UST) mactek ILC) Ps va = o tt <a vy eK = af uJ ax | 2 4 F) 10! Roya 10> TIME PAST REHABITATION, days 46 EXPOSURE RATE AT ONE METER ABOVE SURFACE the extensive clean-up at Enewetak prior to rehabitation.