Wolehsk, UU. Leg Kulp, J. Le3 Eckerlmann, W. Rog and
Gaetjen, J. B.
DETERMINATION OF SR-90 AND BRol40 IN
BONE, DARIY PRODUCTS, VEGETATION, AND SOIL.
19
21. Arta2:
°
3
Fission product contamination in many natural materials
requires an efficient chemical procedure for the separa~-
tion, purification, ard absolute measurement of certain
isotopes at very low levels. As part of the study of
the distribution of longerange fallout from nuclear
2btep
tests, a technique for the determination of both strone
tium-90 and barium=140 has been developed.
The sample
materials include bone, cheese, milk, vegetation, and
soil. The first four sample types contain calcium phos-~
phate as a major part of their ash. The separation of
the phosphate from calcium, strontium, and barium is
necessary for these sample types. Soils contain
exchangeable calcium as well as non-exchangeable calcium
in the silicate lattices. Since strontium and barium
will follow calcium under the proper conditions, proe
cedures were designed around the chemistry of calciun,
t
which acts as a carrier for strontium and barium.
In
all cases the preliminary chemical procedure ylelds a
calcium chloride solution carrying the redioactive
strontium and barium.
The radioactivity measurements
are made on the daughters of strontiume90 and bariume
140, that is, yttrium-90 and lanthanumel¥0, respective-~
89.
Wald, Niel
LEUKEMIA IN HIROSHIMA CITY ATOMIC BOMB SURVIVORS.
science 127, 699-700 (1958).
90.
Whitlock, Gaylor P.
RADIATION FROM STRONTIUM=90 NOT FOUND IN MILK IN HARM~-
FUL AMOUNTS.
Dairy 40, 592-3 (1957).
Increased amounts of strontium-90 have been detected in
our milk supply probably as a result of nuclear fallout
which reaches our soil and enters plant life.
Even so,
the radiation level from strontium-90 now reaching human
beings in the United States from all sources is less
than one percent of the amount of radiation which would
be tarmful,
Ie ts possitise ww detect ang measure witn
accuracy the presence of less than one tenetheusandth
of the amount of radioactive strontium which scientists
have declared safe for industrial practice.
a
(Cont'd.)
awit en
ly, which are extracted from the solution.