and for tne people Living at Utirik Atoll, the results are presenced in Table 15. external dose estimates were made, ind These dose estimates were made based upon the following a@sumpctions or 2>servations Li The exposure rate was relatively uniform cnroughout the aroll. 2) The average exposure rate represents the average for all islands within the acoll. 3) Wotje and Ailuk Atolls are representative of the natural background in the Northern Marshall Islands. Te is difficule co estimate an external dose for the inhabitants of Rongelap Atoll apart from typical residents who spend most of their time on Rongelap Island. The reason lies in the nonuniform distribution of radioactive material from island to island within the atoll. While the southern islands of Rongelap were determined to have uniform exposure rates on a per island basis, there were significant diffarences in the exposure rates between islands and substantial heterogeneity in exposure rates on any given island in the northern sector. In UCRL 51879 Rev. 1 (3,4), this problem was approached by estimating the fraction of che time that an individual spends on various activities. mate is reprinted here as Table 16. This esti- Using this as a dDasic assumytion, we have canstructed external exposure rate estimates tor the var‘cus iiving activities based spon our measurements reported in Tables .-i3. The value for the Lagoon exposure rate was assumed to be the same as chat for uncontaminated atolls in the region \~3.7 .R/hr). The value for ‘other islands" was obtained by assuming that che Marshallese would spend an equal amount which we surveyed. >r time on each of the cther is.ands All other estimates are nade sv taking the average of all measurements made within the area of interesx