Bone-marrow dose equivalent rate, mrem/y 2.0 1.8 fF 1.6 F —B——O— —e— —oO— Newborn #£«'-4-month old 93-month old 1.5-y old —iy— 12-yold —A— 1.4 + —e—— 4-yold 18-y old 1.2 1.0 0.8 0.6 0.4 0.2 § 0 20 . 40 60 Bone-marrow dose equivalent rate, mrem/y 2.0 1.87 1.27 1.0 0.67 oar i i 0.2 (b) 0 —~™— Newborn —k— —ia— 4yold 12-9 old —Oo— —8— —o— 4month old 9-month old ~=—s«*1.y old —a———«18-y old 10 Years after ingestion 20 30 Figure 4. The annual bone-marrow dose whenintake of 9°Sr beginsat different ages; (a) showslifetime dose equivalent rates and (b) shows an expanded viewof(a) for the first 30 y of exposure. 9008256 20