-&]n in the
the Rate of Physioal Decay of Radiatio
Biological Samples
f
The Rongelap samples are now unique among our Marshall
pana» collections since they were taken from an area --
gelap Atoll -- in which the radioactivity resulted primar-
7 from a single time source -- the March 1, 1954 Bikini ex{ment; whereas the activity at Eniwetok and Bikini derived
ol several experiments over & number of years.
;
Rongelap decay data were studied with three primary objec-
(1) to evaluate suitability of the decay correction fac-
Aves:
Bor based on soil by a comparison of blological and other mater-
(2) to aid in extrapolating into past or future time beyond
the period of the present survey, and (3) to compare decay rates
yith decline rates.
Eighty-four samples of fish, invertebrates, algae, land
|
plants, plankton, birds, and soil were counted an average of
2.5 (range, 2-73) times for various intervals during the per-
Co from 38 to 500 days after the Bikini test of March 1, 1954.
y=
=When log of count 1s plotted on the ordinate against log
: time after March 1, 1954, on the abscissa (here called a
0B- log plot), a more nearly straight line 1s usually obtained
A when the abscissa is arithmetic (semi-log plot).
A mixture
re fission products is supposed (Coryell and Sugarman)” to give
p straight line by log-log plot with a slope of about -1.25 for
phe period of time involved in this study.
E»
FE
Coryell, C. o D. i. and Su Zarman,
iseio
Products, Book 1,
D.
The decay of a single
N., Radiochemical St
456, MedravHitt
roep The