854 BENINSON, RAMOS, AND TOUZET Table 3— MEAN STABLE STRONTIUM IN FOODS Food Numberof samples Calcium, % in ash Strontium, ppm in ash Mg of Sr/ g of Ca Milk Baberlac compuesto 24 10 15.0 11.8 140 123 0.95 + 0.08 0.85 + 0.09 Milk Nido 10 11.3 140 1.26 + 0.21 15.6 116 0.92 + 0.06 90 0.59 + 0.09 Eledé6n con fécula y glicidos Baberlac simple Biberol Yogalmina Levulosa 10 10 9 11.3 14.2 10 17.4 200 10 25.2 551 2.28 + 0.38 10 6.4 170 2.65 + 0.40 310 200 9.91 + 1.10 0.80 + 0.06 10 Osteolact 10 Nestégeno 10 Eled6n con fécula 10 Secalbum Nesttin Quaker Farex 7 10 15.2 15.3 13.7 14.6 3.13 25.0 171 70 110 140 100 1.50 + 0.20 0.48 + 0.08 1.15 + 0.05 0.72 + 0.06 1.02 + 0.15 0.69 + 0.05 Composite Diets Age group, months 6 to 9 9 to 12 12 to 24 24 to 36 Adults 10 9 10 10 10 1.21 1.24 1.31 1.35 1.75 + + + + + 0.20 0.17 0.26 0,21 0,22 information and the mean levels given in Tables 1 to 3; the results are summarized in Table 4. Strontium-90 intakes are meansof the pe- riod 1961-1963; annual values show an increase of about 40% in these three years. Table 4 shows that for young children the strontium/ calcium and the *Sr/calcium ratios in total dietare very close to those in milk, In particular, the Sr/calcium ratio in total diet averaged over the first year of life can be taken to be the same as that of milk. Typical intakes are on the order of a few picocuries of Sr and about 1 mg of natural strontium per day. 90Sr AND NATURAL STRONTIUM IN BONES OF CHILDREN 90s; Samples of bone were limited at most to a few bones per child. Skeletal-burden estimations must, therefore, rely on some knowledge of the distribution of values within the body. There is some evidence of a very high turnover in the skeleton in the first two years of life,’ and therefore it will be assumed that bones are uniformly labeled.

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