STRONTIUM IN DIET AND BONE
853
Table 2— FALLOUT AND Sr IN MILK
~
Period
Cumulative
deposition,
mec/km?
Average
fallout rate.
mc/km? per year
,
Average
level in milk.
pe/g of Ca
First semester 1960
6.8
0.60
First semester 1961
7.7
0.96
L.4U
3.22
8.8
9.4
10.6
0.70
2.68
1.15
3,05
3.04
3.01
Second semester 1960
Second semester 1961
First semester 1962
Second semester 1962
First semester 1963
Second semester 1963
Multiple
7.1
8.0
11.5
1.02
2.21
1.63
2.14
1.85
4.17
regression with the use of data from Table 2 gives a = 0.27
and b = 0.42.
With the use of the expression, milk levels can be predicted with a
standard deviation of the estimate of i0.37 pe per gram of calcium.
Prediction of levels in other baby foods based on milkis difficult since
some of the brands are fortified with animal or mineral calcium and
inclide variable amounts of cereals.
Stable Strontium
Natural strontium determinations in food items are less compre-
hensive and are based on a sampling period of 1'4 years (Table 3).
Results show that milk-based baby food and milk have about 1 mg of
strontium per gram of calcium. Only scanty results are available for
other individual foods not covered by Table 3. This table, however, in-
cludes values for several samples of composite diets which have been
analyzed. The composition of these samples was based on dietary information discussed later in this paper.
Mean Daily Intakes
Estimation of daily intakes for children of different age groups requires qualitative information on diet composition which is not available for most regions in Argentina. This information could be obiained
with a reasonable degree of reliability only for Buenos Aires Prov-
ince.°-’ Breast feeding introduced some uncertainty, particularly in the
age group of 0 to 6 months. Best available estimates for contribution to
daily calcium intake from breast feeding in Buenos Aires Province are
47 and 17% for age groups of 0 to 3 and 3 to 6 months, respectively.
A compilation on diet composition and contribution of different
foods to calcium intake has been published elsewhere.'’® Daily-intake
estimates of natural strontium and *’Sr have been computed from that