CESIUM-137 PASSAGE FROM PRECIPITATION TO MILK
GERALD M. WARD, JAMES E. JOHNSON, and HAROLD F. STEWART*
Colorado State University, Fort Collins, Colorado
ABSTRACT
One of the principal objectives of this ‘Cs study at Colorado State
University was to establish useful ratios for the passage of Blas
through the steps of the food chain to man. This paper presents coef-
ficients that have been calculated for the transfer of '’Cs from
precipitation to forage plants and from forage plants and other feeds
to milk.
METHODS
Three fiber-glass funnels, each witha catcharea of 47.2 sq ft, were
located 5 ft aboveground and were used as precipitation collectors ina
pasture area. An 80-cm? ion-exchange column of Dowex 50-W-X12 was
connected to each funnel. At the top of the column a glass-wool filter
was placed to collect the sediment invariably contained in each sample.
The columns were selectively eluted for '’Cs in the laboratory with
1 liter of 0.5.4 NH,NO;.
Forage samples were collected by cutting known areas of randomly
selected sites in the pasture. Hay samples were taken with a core
sampler from bales of hay. The forage and hay samples were dried
and ground to a constant density before counting. Grain was counted
in a pelleted form.
Milk was collected from cows on pasture and composited. For
Studies involving feed comparisons, milk from each cow and a sample
*U. S. Public Health Service Officer.
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