EFVECTS OF JONIZING RABLATION
were suffrient in number to allow all samples
te be taken in rapid succenmon, and time int-Tvals were rigidly cont rolled.
4.2
Metheds of 7 cating Dara,
Comtrol Groups
Pee. Be xeoe ee Resem counts were not available
en the eapneed Marshallese of Americans:
hener the inieidaale cantd now he wend ne their
een control, In order to estimate the wvrerty
of the hematalagne response it wan necemery to
eatablish control groupe ax comparable as poe
sible with respect to age, race, sex, background
and habits. A control group of 115 Marshallese from Majuro atoll (Control Group A),
comparable with respect to nge and sex to exposture Group Twas obtained during the initial
observation period.® For comparison with the
exposed) Americans, blood counts were done on
approximately SS) American men on duty at
Kwajalein. All who had not been on duty in
the tropics for more than 2 months were excluded, since the exposed Ameneans had been
in the area for that period of time before exposure. Tn addition, several who were recently
associated with radioactive materials were excluded. The resulting smaller group of 67 was
used as the Rway- American control group,
Data from the control group A> were examined to determine the age and <x dependency
of the several hematological determinations.
To obtun valid comprrisons within and among
the various exposure groups, the age and sex
dependencies noted for the control groups were
tuken into account.
Although each individual
in all groups was studied hematologically, those
Marshallese with serious long-standing diseases
were omitted from the analysis. A total of two
"A second contral group oof <2 Marshallese from
Majuro atoll fcontral Group Bi were obtained during
the § month medical resurvey. While data from these
individuals are given in this report, they are not used
for comparisons because of a measles epidemic during
the resurvey.
from Group A and two from contral Greep B
were omitted on thin baa
In the following descnptions and compari-
sons of the data. hnding» in the es paned grown
are frequently expresmed in termes of percent of
the appropriate agp and sex control greap. ft
should be noted, however, that in shbaervational
@idies of this kind, wadnern fecters could
pewaldy accent fur portal the differences noted
hetireen the comtred and rrpaewre greups cron
eA ROM le morgrerr
erm Pobnn 0 tr
Let com perchle control groupe
Tw addition, it
was not powible to obtain more than a single
lewd sample on each control individual. For
these reasons, statistical texts of <ignificance
vere applied mainly to time changes within an
exposure group, and not to differences bet ween
control and exposure groupe. For the purpose
of detecting significant changes in the hematological pattern, nonparametric tests (1. e., statisticnl tests for which it is not necesaary to specify
the functional distribution of the variate under
study) were used (2-7).
The advantages of
nonparametric methods have been summarized
by Moses (M}.
4.3,
Hematological Findings, General
In Tasce 4.1 are shown for control group A, by
aye and <ex, the mean values for the total white,
neufroplile, inphoevte aid platelet counts, as
well as for the hematocrit.
The age and sex
breakdown used for comparisons among exposure ; oups is shown in Table 4.2. In this
breakdown the age and se~ dependencies noted
for the Marshallese control groups were taken
into account insofar as was practicable. It
should be noted that the Grroup B control values
(Table 4.1) ayreed closely with the Group A
ontrol data.
To allow additional comparison
hetween effects on children and adults, the neu-
trophile counts were arbitrarily separated into
the age groups used for the lymphocyte counts.
Monocytes and eosinophiles were broken down
al4o into the same aye groups. The age and
tote ee -
“2