The accumulation of data from these surveys 1s
becoming increasingly voluminous. Since conditions have not been favorable for performance of
. extensive statistical analyses or use of electronic
computing procedures to store and manipulate the
data, the annual survey reports published by this
Laboratory are made as complete as possible. This
report, therefore, includes a considerable amount
of raw data, much of it in appendices, so that
others may have an opportunity to make further
calculationsif desired.
This report also contains a brief addendum on
the vegetation of Rongelap Island.
’
DOE ARCHIVES
Summaryof Past Findings
Reports have been published on the findings of
surveys made at the following times after expo-
sure: tnitial examination,’ 6 months,’ 1 year,’ 2
years,‘ 3 years,®> and 4 years.* The following isa
brief summary of the findings previously reported.
During the first 24 to 48 hr after exposure,
about % of the Rongelap people experienced
anorexia and nausea. A few vomited and had
diarrhea. Many also experienced itching and
burning of the skin, and a few complained oflachrymation and burningof the eyes. Followingthis,
the people remained asymptomatic until about 2
weeks after the accident, when cutaneouslesions
and loss of hair developed, due largelyto beta ir-
radiation of the skin. It was apparent when the
people were first examined, a few days after exposure, that the lymphocytes were considerably depressed and thatsignificant doses of radiation had
probably been received. In addition to the wholebody dose of radiauon and the beta irradiation of
the skin, radiochemical analyses of the urine
showed that measurable amountsof radioactive
material had also been absorbed internally. The
effects of the radiation can best be summarized
under three headings according to the modeof exposure: penetraung irradiation, skin irradiation,
and internal irradiation.
PENETRATING IRRADIATION
The changes in the peripheral blood of the more
heavily exposed Rongelap people who received
175 r will be reviewed in the section on hemato-
logical examinations (see Figures 33, 35, and 38,
and Appendices 1 and 2). The changes in the
Ailingnae and Uturik groups were similar but bess
marked. Certain unexplained fluctuations have
occurred from year to year in the peripheral blood
levels of the comparison populations as well as of
the exposed groups. Depression of the peripheral
blood elements as represented by mean populauion levels occurred as follows.
Lymphocytes fell promptly and bythe third day
were about 55%of the control values in adults,
and slightly lower in children, There was only
slight recoveryafter six months. At 2 years, although further recovery was evident, the mean
values of these cells werestill found to be below
the comparison population levels (75 to 80%). At
3 years the mean lymphocyte counts wereslightly
below those of the comparison population. At 4
years the mean level appeared to be aboutthe
same as that of the comparison population, but
many counts remained lower.
Neutrophil levels fluctuated considerablyduring the first few weeks but fell gradually to a low
of about 50% of comparison population levels by
the 6th week after exposure. Slow recovery en-
sued, but at 6 monthsthey werestill slightly below
the unexposed levels. However, by | year post ex-
posure they had returned to the level of the com-
parison 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 | year the mean
platelet count was still belowthat of the control
population but higher than at the 6-monthsurvey.
Althoughfurther increases were apparent at the
2-, 3-, and 4-year examinations,the levels were
still belowthose of the comparison population.
Changes in hematocrit were not remarkable in
anyof the groups.
Clinical examinations revealed no disease proc-
esses or symptoms which could be attributed to
radiation effects, aside from skin lesions, Joss of
hair, and early symptoms. Epidemics of chicken
pox and measies occurred. The diseases encountered were no more severe or frequentin the irradi-
ated group than in the unexposed group, even
during the period of greatest depression of periphera] blood elements. Three persons in the exposed
population died of disease: (1) a 46-year-old man
with a hypertensive heart disease which had been