.. summing. original This gave 8949 rads for the total population including the The total dose received by the original 550, assuming 550. that all live for the 30 years, is 550 (, - e-At P’=~ ) = 11,902 rads For those born after the return, the population would be the difference between the total population in 30 years, the number of deaths and the original Thus, the per capita dose for this group 550 people or 1134. is 8949/1134 11,902/550 = 7.9 rads. = 22 rads. For the original 550, the per capita dose is The ratio of these two to give an estimate of the fraction of the full 30 year dose received by the children is 0.36. The assumption simplicity of no deaths in the original 550 returning was made for and the lack of good death rate data. We also compared the age characteristics IV-3 and the U.S. population in 1970. attached curve. are distorted of the Marshallese This comparison from Table is given in the The slopes are similar above age 35 but the magnitudes by the high birth rate in the Marshall Islands. However, in terms of the relative risk the similar slopes suggest that if the natural cancer rates in the two populations are similar, the relative risk for people above 35 in both populations would be similar because most of the cancer occurs at ages from about 40 and above. magnitude However, the of the relative risk in the U.S. used for the Marshallese will be high by a factor of somewhere around 2-3 because of the distortion caused by the very high proportion of young people who have a relatively low-natural cancer incidence. Using the preceding calculations for a population of 550, calculations were made for other population sizes. For a population of 550 (from preceding): Deaths in 30 years = Births in 30 years = 1277= For a population 164s 160 1300 of 140 (the number that returned to Bikini):