The accumuPatton of data from these surveysis
Auingnae and Utrik groups were similar but less
marked. Certain unexplained fluctuations have
becoming increasingly voluminous. Since conditions have not been favorable for performance of
occurred trom vear to vear in the peripheral blood
computing procedures to store and manipulate the
data, the annual surveyreports published bythis
Labpratory are made as complete as possible. This
biood elements as represented by mean population levels occurred as follows.
extensive statistical analvses or use of electronic
report, therefore, includes a considerable amount
levels of the comparison populations as well as of
the exposed groups. Depression af the peripheral
Lymphocytes fell promptiv and bvthe third dav
of raw data, much of it tn appendices. so that
were about 55%c of the control values in adults.
calculationsif desired.
slight recoveryafter six months. At 2 vears, at-
others mav have an opportunity to make further
This report also contains a brief addendum on
the vegetation of Rongelap Island.
Summary of Past Findings
Reports have been published on the findings of
surveys made at the following.times after expo-
sure: initial examination,' 6 months.: | vear,* 2
years,’ 3 years,> and @ years.* The following isa |
brief summaryof the findings previously reported.
During the first 24 to +8 hr after exposure,
about % of the Rongelap people experienced
anorexia @nd nausea. A few vomited andhad
diarrhea. Many also experienced itching and
burning of the skin, and a few complained oflachrymation and burning of the eyes. Followingthis,
the people remained asymptomatic until about 2
weeks after the accident, when cutaneous lesions
and loss of hair developed, due largely to beta ir-
radiation of the skin. It was apparent when the
people werefirst examined, a few days after expo-
sure, that the lymphocytes were considerably depressed and that significant doses of radiation had
probably been received, In addition to the whole-
body dose of radiation and the beta irradiation of
the skin, radiochemical analyses of the urine
showed that measurable amounts of radioactive
material had also been absorbed internally. The
effects of the radiation can best be summarized
under three headings according to the mode of ex-
and slightly lower in children. There was only
though further recovery was evident, the mean
values of these cells.were still found to be below
the comparison gopulatioggdevels (75 to 80%). At
3 years the mean lymphocydcounts wereslightly
below those of the comparig@n population. At
years the mean level appeared to be about the
same as that of the com#ariseg population, but
many gounts remained lower.
Neutrophil levels fluctuated considerably dur-
ing the first few weeks but fell gradually to a low
of about 30% ef comparison population levels by
the 6th wetafter exposure. Slow recover¥en-
sued, but-at 6 monthsthey werestill slightly below
the unexposed levels. However,dby | year post ex-
posure they had returned to the level of the comparison population and have remained so, with
the possible exception of those of children < 12
years old, which generally have been lower than
those of the unexposed children of comparable
age.
Platelets fell to about 30% of the unexposed
values by the 4th week. By 6 months they had
reached 70% of the controls: at 1 year the mean
platelet count was still below that of the control
population but higher than at the 6-month survey.
Although further increases were apparent at the
2-, 3-, and +-vear examinations, the levels were
still below those of the comparison population.
Changes in hematocrit were not remarkable in
anv of the groups.
Clinical examinations revealed no disease proc-
The changes in the peripheral blood of the more
heavily exposed Rongelap people who received
esses or symptoms which could be attributed to
radiation effects, aside from skin lesions, loss of
hair, and early symptoms. Epidemics of chicken
pox and measles occurred. The diseases encountered were no moresevere or frequent in the irradiated group than in the unexposed group, even
during the period of greatest depression of periph-
logical examinations(see Figures 33, 35, and 38,
and Appendices | and 2}. The changes in the
population died of disease: (1) a 46-vear-old man
with a hypertensive heart disease which had been
posure: penetrating irradiation, skin trradiation.
and internal irradiation.
.
e
PENETRATING IRRADIATION
175 r will be reviewed in the section on hemato-
1185552
eral blood elements. Three persons in the exposed