Table 9. The integral 30-, 50-, and 70-y dose equivalents for bone marrow and bonesurfaces for intake of 90Sr beginning atvarious ages. Age intake begins Birth 4 months 9 months 1Sy 4y 12 y 18 || | ! | Bone marrow 30 y 50 y 70 y 414 41.7 43.1 438 43.2 493 485 620 625 63.7 643 640 704 698 Integral dose equivalent, mrem Bonesurface 30 y 50 y 70 y 30 y 750 756 766 771 770 835 82.9 122 123 127 129 126 137 116 182 184 187 189 187 199 175 223 224 227 229 228 241 217 Effective 50 y 70 y 8.6 8.7 90 9.1 90 10.0 9.3 12.9 15.7 130 158 °13.3 + 16.0 13.4 16.1 133 161 144 173 13.6 165 Table 10. The integral 30-, 50-, and 70-y effective dose equivalent for continuous intake of 137Cs and 90Sr beginning at various ages. Integral effective dose equivalent, mrem? Age intake begins | 50 y 70 y 702 0.02 0.02 0.02 9 months 367 560 683 0.03 0.02 0.02 663 786 L5y 4y ' 30 y 580 : | | 70 y 386 4 months - | ~ Oy Birth } | 30 y Fraction due to 70Sr 12y 398 370 391 469 18 y 513 592 714 564 585 687 708 705 829 0.02 0.02 0.03 0.02: 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 4 The effective dose equivalent is a unit defined by the ICRP (1984) which allows for the different mortality risks associated with irradiation of different organs, together with a proportion of the hereditary effects. Discussion reason is the consistently higher intake of local The result of our analysis is that the integral 30-, 50-, and foods, and thus !3’Cs , for adults found in the 70-y effective dose diet surveys from the Marshall Islands. Also, equivalent estimated for intake beginning as adults at a contaminated atoll is greater than that for intake beginning at any other age. Consequently, the estimated integral dose equivalent for adults is a conservative estimate for infants and children. There are two basic reasons for this result. The first, and major, S000 TS the higher intake of food in general by adultsis supported by diet surveys of other societies; the intake for adults is greater than for infants and children. The second reason is that even for continuous 137Cs intake that declines at a rate equal to the 21