We believe our most significant findings are:
l.

The dependence of radicstrontium uptake on soil calciun,

2.

The remarkable uniformity in the radiostrontium activity 18 biological

3,

Our inability to account for the bulk of the debris from MIKE.

4,

The absence of grossa fractionation of either $r89 or Sr9O In samples

naterials when the concentration is expressed as d/min/gm Ca.

analysed,

The data provide a tentative measure of the significance of
muclear detonations to date. What would we find a few years
there were no intervening detonations? Milk being the princ

of human Ca, we have estimated the rate at which Sr90 would
from soil, assuming the availability remains as it is. © Ap

depleted
F discusses

half life from soil can vary widely in pastures that feed mi

Conet 1.5 to

this question for two extreme situations and concludes that

U.5 years for fields from which cowpees are cropped continuoy

bdological

to cows that feed elsewhere, and 170 years for pastures in w

feed. The bulk of the Sr7O in Case I is transferred to fi
cows fed by cowpeas grown elsewhere.

Here is an example of oe provles

obt ained,

6 a/

Ca is @ representative figore for $r99-9% of which aout 1.5 d/s

is Sr, This compares with 870 d/m/gm Ca at tolerance (1 pcolin a 7 Kg
skeleton containing
Ca). The ratio of the observed activity to the

tolerance activity
thus approximate
- Potential deposition of
material now stored in the atmosphere TER eas
Thus, we can tentatively conclude that if the Sr’
in soil isinot depleted

by biological and/or physical processes in a decade or two,

formed biological calcium in Eastern United States is now at
with the soil (as seems to be the case), a skeleton which beggns to develop

at this tine would be expected to contain .1 of the tolerancp

burden will diminish slowly with radiosct

AW'decay

reduced by a shift in the equilibrius between soil

but can

burden. This

ami biological calcium,

00131986.043

1091012

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