high as 16.2 were used, whereas for the
decay factor of only 1.02 was used.
last collection a
The counts for the 1956-
1957 samples, which were not corrected for decay, are presented in the appendix tables.
The levels of radioactivity
for plant tissues other than scorched leaves are based on wet
tissue weights; to convert the latter values to a wet weight
basis it is necessary to divide them by 6, the approximate
dry to wet ratio for this tissue.
based on dry weights.
The values for soils are
All values in the text tables are ex-
pressed in tc/kg; values in the appendix tables are expressed
in thousands of d/m/g/.
The rate of decline was plotted on a log-log scale be-
cause of its similarity to the decay curve of mixed fission
products.
The isotopes present in the samples were indicated by
the decay curves but in one soil and four plant samples they
were specifically identified by radiochemical analysis*.
*Work done by D.
J.
South