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 oR the sputhern islands_o9f Enewetak are very close to natural background; 10 C kg h (3.7MRh *). This low-level was due to ve 1S} & a pa n ud 4 Oo [oa <a OPERATION Maasc UTIRIK ATOLL. OPERATION REDWING oa v9 ram rs oe > ul v8 (o)] = ha a4 it ee ea =) f Pa re EXPOSURE RATE AT ONE METER ABOVE SURFACE the extensive clean-up at Enewetak prior to rehabitation. Tey toa Tees TIME PAST REHABITATION, days