81
tissues" were not.
Since the "t" test is weakened by non-
normality of sample distributions and differences between the
sample variances,
non-parametric methods were employed to
determine whether these factors could control the decisions
based on the "t" tests.
A test suggested by White
(1952), based
on rank, was employed to test the significance of differences
"between areas" where the sample sizes were unequal.
"between tissues-within areas" test,
pairs,
signed ranks test was used.
For the
the Wilcoxen (1945) matched:
The results of both paramet-
ric and non-parametric tests are summarized in Table ll.
The
correspondence of both methods strongly suggests that the specif
activity of zinc-65 differed significantly in both eyes and live:
between the Kabelle and Rongelap samples,
but not between the ey:
and livers of fish from the same location.
The graphical plot of the descriptive statistics in Fig.
and the tests of significance in Table 11 indicate that the
ratios of zinc-65
to stable zinc
in goatfish
tissues in 1959
were significantly higher at Kabelle than at Rongelap.
provides further
evidence that
effective mixing of
This
fallout
radiozine in the waters of the lagoon had not occurred between
the time of the initial contamination of the atoll and the time
the samples were collected.
Inspection of the levels of total zinc in the eyes of the
Rongelap sample of 20 goatfish
(Table 4)
suggested a negative
6