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2
1
CRER~1068
strontium~-87 (390 keV, ta = 2.8 h) and barium-139 (165 kev,
ty = 1.4 h) when irradiated in a flux of slow neutrons.
Following such an irradiation,
and appropriate chemical purifica-
tion, the induced activity in each sample was compared with
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standards on a Y scintillation spectrometer.
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Calcium hag been determined in order to establish
strontium-90/ealciumratios in components of the Canadian diet.
The method used was the classical oxalate precipitation (1) with
CC eee Pe ae mee
minor modifications.
SAMPLING PROCEDURES
Samples of flour, wheat and milk were available through
national networks originally proposed for the monitoring of
'fallout!'
in the Canadian diet.
Other produce was sampled less
representatively through purchases from the retail market in
the major cities of Alberta, British Columbia, Manitoba, Ontario
and Quebec.
Wheat
Arrangements were made with the Grain Research Laboratory,
Winnipeg, to supply and composite samples of the 1959 and 1960
wheat crop from their 306 sampling districts.
Nine composite
Samples were prepared representing roughly similar geographical
areas within each of the three Prairie Provinces.
A single
combining aliquots from the three provinces in proportion to their
annual production.
:
Soe chendemtte
composite sample was made up for the years 1959 and 1960 by