fon
won bout
Dut al
also
arpetar Ceposiuion
cen
A
iO greater
of£
ot
Twiy growin, sones.
aitional amounts of tie radionuclide.” The
distribution of the radionuclide in the bocy
rOnews the metabolic pains of
calcium.
‘She high varnmover raic of minerais in the
sder 22 years
vears
bunes Of Infants and children uncer
of age is presumed to lead tt o rapid ecuilbraiion or the bone minerals and conseuently to unuorm devosition of strontium90 throughout the skeleton. 3 A yearly
sucement of 39 to 70 per cent or more
© bone minera, ias been estimated during
wee Myst ond second years of Hie.*7** in the
bole
taut,
ae
2.0
to
5.3 per cent of bone caicium
i wedlacce annually" 4 Phe
re
bones of still-
Lorn fetuses and of newborn infants have a
lower stromdum, calcium ratio attributed to
ccacrimination by the placenta which favors
oe
uv a factor of 2 ule passage of calcium over
irontium irom mother to fetus.°? 235 Mfetacic Cdiscrim ination between strontium and
calcium does not become established unth
q
the second year of lite, 149 the “observed
ratios’ of strontium and caicium in bone to
those in the dict being about 0.8 at 2 to 3
months of age, less than O+ ar G to 10
monins, anc 0.25 (adult ratio) ater 2
tration of
bones OF suojects or dLterent a
Yorn City were:
6.81 in infant
9
2
ron
.
S90
jn
or’? in
ware 7
a
.
Deng & Cota emiler,
conirioure signincanuy to the gi
the effec: is localized anatomicauy where it
is respomsibic lor an esiimeaiec SO der cent
bone Ease." The* sorenial dan
stronilum-90 is assumed to be the devclopment of osicogenic sarcoma and possibly leukemia. Aithough the behavior of strontium90 has been examined on ecological and
raciophysics bas “F , iit, 117, Iie sae
veonivedsa rather hehuiveshoia Cose of
weil above 20 racs and wrebauly nearer 1,000
:
raCy has been suyeesiea «cr come sarcomawenesis from
radium deposition. *¥
esium-137 is mot fixec in the
bocy and its distribution is comsicerec io be
:
a
:
uniiorm. The metabolic obchavior of cesium195
Lae
et
>
a
Lo/ Feseze ues that of notassium. it ls rapidly
@ intestinal tract and is dis-
}
cributed uniformly
in the sotr
:
The
biological half-iiie of cesium in chi.aren has
been reported in two siucies to be about
#4 and 38 days anc about itc days
adu
in
|
potassium being .ower in ch
adults, Observe
ed levels of cesiur
were two to four times higher
than
the aver
main larg ely depends
I
on ingestion
ls of food contaminated by Girect
Nluk and mieat are the greatest
ators to human dictary make.
variations in bocy burdens of this
ve not been notec, parucularly
wile related to lean body mass or to poiassium. tee; TS) se, 224 129 Alone with the rela
tively short-lHved zirconium-95, mobium-95,
aiul-Hie,l3 cays’, cesium-137,
8
jhaif-Hie, 8 d
5,760 years}.**
medical signitcance are the hazards o: internally depostied radionuclides Irom iropospheric and stratospheric fallout rather than
those from locallor near-in salout.
Suontium- G3. The principal source of
strontiuin-90 is dictary , through ingestion of
mand
vegetation
Cirectly
contaminated
wough
incorporation
of
strontium-S0
into
t
ne food chain, both plan: and animal.o* 7%
* In children, milk is considered an important source of strontium-90, although contamimaied poisble water may congioute ad-
6
Oo
On
Effects of ionizing radiation
Volume 67 Numoer 4
PATTI rays, contriputes an
fallour,?
i with a hair-hie 7
ard omy dturing the
~
frst few weeks folowing envirommental con-