29
graph. The data are handled somewhatdifferently
this year: because ofcertain differences noted in
age and sex groups between the exposed andthe
unexposed, in addition to the comparisons of mean
levels for entire groups, comparisons are also made
for the age and sex groupsof age 7 to 15, 16 to 40,
and >40years.
~
Thedata are summarized in Tables 12 and 13
andin Figures 34 to 50. In Appendices | and 2 are
presented summaries of the mean blood counts of
the exposed population and the various comparison populations since exposure in March 1954. In
Appendix 3 arelisted the individual blood counts
for 1961. It should be noted that in 1960 only the
exposed group were examined; therefore, the last
complete data on both exposed and unexposed
groups are for 1959. In Appendix 4 the individual
alkaline phosphatase and basophil counts are
presented.
Leukocytes
The meanleukocyte levels in 1961 were somewhatbelow the 1959 levels in the population at
large, while both exposed groups (the only groups
examined in 1960) showed slight increase over
the 1960 level. Changing neutrophil and lympho-
classified according to age and sex,andin thescattergram (Figure 36) showing the larger number of
individual counts below rather than abovethe
mean line of the unexposed. A cumulative percentage distribution curve of counts combining the
younger and older males (Figure 38) shows the
curve for exposed males definitely displaced to the
left of the curve for unexposed males of the same
age groups. Amongthefemales, only in the older
group were the neutrophils slightly depressed (see
Figures 35 and 37). In groups aged 15 to 40 years,
both sexes showedslightly higher neutrophillevels
than unexposed people of the same age.
Lymphocytes
As with neutrophils, the exposed population at
large showeda slight (6.3%) deficit of lymphocytes
compared with the unexposed population (see
Table 12 and Figure 39). Amongthe males, only
the younger age group showedslightly lowerlev-
els, while the three female groups all showed lower
levels. This may be seen in the histogram (Figure
35), the scattergrams(Figures 40 and 41), and the
cumulative percentage distribution curve(Figure
42),
cyte mean levels were generally parallel. As will
Eosinophils, Monocytes, and Basophils
heavily exposed Rongelap people largely accounted for the lower leukocyte levels. The Ailingnae
group (69 r) showed about the samelevels of the
the unexposed group. As has been noted previous-
be broughtout, a slight deficit in both neutrophils
and lymphocytes in certain age groups of the more
various leukocytes as the unexposed group. The
meanlevel of leukocytes in the exposed Rongelap
people (175 r) was about 6% belowthat in the un-
exposed group. The percentagedistribution of the
various white cell levels in all groups was not very
different from that previously reported. Table 12
and Figure 34 show leukocytelevels.
Neutrophils
The mean neutrophil count for the exposed
population wasslightly (7.3%) below the mean
count of the unexposed comparison population.
(See Table 12 and Figure 34.) However, examination of the mean counts by age and sex groups
made it apparent that the deficit was largely accountedfor in the young(age 7 to 15) and older
males (age >40 years). This is demonstrated in
the histogram (Figure 35) showing the percentage
differences in the exposed and unexposed groups
These all showed slightly lower levels than in
1959. The levels of monocytes and eosinophils in
the exposed group were somewhat lower than in
ly, eosinophil counts >5% of the total white count
were commonin both groups.
Platelets
The mean levels of platelets in the various age
groups in both exposed and unexposed popula-
tions were about the sameas two years previously
(see Table 12 and Figure 43). However,thelevel
in the exposed group as a whole, asin the past,
remained below the unexposed level by about
12%. Age distribution scattergramsfor the individual platelet counts in both males and females of
the exposed population showed more counts below
than above the unexposed meancurves(see Figures 44 and 45). This was also borne out by com-
parison of the cumulative distribution curves of
the exposed and unexposed populations,theformer showing a continued displacementto theleft
(Figure 46). The platelet levels showed most depression in the exposed male groups of ages 7 to 15