oe ve
a
~h6-
the degree of variance or scatter about the line, but alee by
the nature of the deviation from lineerity among the smooth, curvilinear plots.
Those curves which were concave upward vere
fish tissues, none of which had been counted nore than seven
times.
The average slope of 83 decays on log-log plots was
-1.43.
Table VIII shows a breakdown into groups by types of
organisms and by tissues, and all samples grouped by collecting
dates are recorded itn Appendix Table XII.
Differences in decay rates of tissues of the animals
are not great, although the liver rate of decay is steepest to
& degree that is of borderline significance.
Comparison of rate
of decline of food items, -1.75, with rate of decay of all
samples, -1.43, shows that food items, with the exception of
such plants as the coconut, decline more rapidly in their radioactive content than can be accounted for solely on the basis
of their physical decay.
However, the steep trend of decline
may result from the inadequacies of sampling.
The January 1955
collection may reflect variability in the effects of currents
or season.
Future sampling will show whether the indicated
decline is truly unusually steep, or a vagary of sampling.
From a study of the decay curves it is seen that most
blological samples follow the soil trend sufficiently well to
justify use of the soil decay rate in correcting sample counts
back to the time of collection over short periods.
some samples diverge widely.
nut,
However,
Of greatest concern is the coco-
in the milk of which the radicactivity may decay very