rs
ll
ret.
wpe.
eh
eo
Es
A
.
me
mee
Table 4. Estimates of the daily intake of 9°Sr
from local foods by age at Rongelap Atoll.
Age
0 to 3 months
4 to 8 months
9 months tol4y
15yto3y
4ytolly
12 ytol7y
218y
90Sr intake, pCi/d
0.056
0.57
3.4
9.2
8.2
11
14
Infant (4 to 8 months). For infants between 4
and 8 months, we assumethat diluted coconut
milk is given occasionally to supplement or
replace breast milk. On the average, breast
milk accounts for 95% of the 1.3 L/d intake and a
mixture of equal parts water and coconut milk
make up the other 5%. The daily intake of
137Cs is thus:
326 pCi/L (0.95) 13 L/d
(0.05)
5 4.7 pCi/mL
+ 1300 mL/d
= 403 pCi/d + 153 pCi/d
Cesium-137
Newborr/Fetus. The concentration of !37Cs
in the fetus in the early months of pregnancy
appears to be less than that of the mother
(linumaet al., 1969) and about equal to that of
= 556 pCi/d,
where the !37Cs concentration in coconut milk is
Spiers, 1967). Thus, the average concentration of
4.7 pCi/mLand in breast milk is 325 pCi/L.
Infant/Child (9 months to 1.4 y). Breast
milk or formulais still the main food source for
appear to be somewhat less thanthat of the
amounts of local foods are given to the infants to
the mother in the latter months of pregnancy
and at birth (linuma et al., 1969; Wilson and
137Cs during the entire gestation period would
mother.
Infant (0 to 3 months). The entire diet for
this age range is essentially breast milk or
formula. Measurements of 137Cs in breast milk
and in the diet of a 24-y-old woman show that
about 30% of the ingested 157Cs is secreted per L
infants/children in this age group, but small
supplement the milk. We assume the !37Cs
intake to be no more than 20% of the adult
intake. Consequently, the 137Cs intake from
breast and coconut milk is 556 pCi/d, as for
infants 4 to 8 months (see above), plus 217 pCi/d
(0.20 x 1085 pCi/d) from local foods, for a total
infant diet being breast milk, the intake of 137Cs
daily intake of 773 pCi.
Child (1.5 y to 3 y).
their mothers show that the concentration of
137Cs_ in infants on breast milk never exceeded
from our diet model when imported foods are
available is 517 pCi/d (Appendix A,
Table A-2).
of milk (Aarkrog, 1963). Consequently, with the
by an infant would not exceed the adult intake.
In fact, measurements of 137Cs in the infants and
the 137Cs concentration in their mothers (Rundo,
1970); the infant's 137Cs concentration, on the
average, was 75% of the mother.
Using the
value of 30% for the 137Cs ingested that is
secreted per L of milk and the average adult
intake of 1085 pCi/d, the !37Cs concentration in
breast milk would be 326 pCi/ L. If the average
milk intake by the infant is 1.3 L/d, the average
J
a)
daily intake of !3’Cs for an infant is 424 pCi/d.
G25 S
The average daily
intake of 137Cs for children aged 1.5 y to 3 y
Child (4 y to 11 y).
The average daily
-intake of 137Cs from our diet model for children
aged 4 y to 11 y, when imported foods are
available,
is
594
pCi/d
(Appendix
A,
Table A-3).
.
Teenage (12 y to 17 y}. The average daily
intake of 137Cs for teenagers from our diet model
when imported foodsare available is 761 pCi/d
(Appendix A, Table A-4).