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 tad Q nd ra 5 oe) eu) > re) a < ac ve UTIRIK ATOLL OeyOMLOL Bie OPERATION REDWING ff li = rm Fa S 7 hos = Pr uJ a = ° 5 Gl TIME. PAST REHABITATION, days EXPOSURE RATE AT ONE METER ABOVE SURFACE 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 islandsof Enewetak are very close to h natural background; 10°’ C kg (3.7 MR h « This low-level was due to the extensive clean-up at Enewetak prior to rehabitation.