Jn
The accumulation of data from these surveysis
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.
Summary of Past Findings
Reports have been published on the findings of
surveys made at the following times after exposure: initial examination,’ 6 months,’ | year.' 2
years.' 3 years,” and 4 years.* The following is a
brief summaryof the findings previously reported.
Durin she:fem 24 to 48, hr a
=pesure,
anorex#®
ong Jap pile ¢
aad* nee
tenced
few vomited and had
diarrhea. Btany also ‘experienced edad and
burningofthe skin, and a few oq
rymatt
nd burning of the «
:
the people remained asympsomthic eatDe
weeks after the accident, when cutancouslesic
and toss of fair deidiieped, due largely to beta i
: r
radiation of the skift It was apparent when the
people werefirst ewamined, a few days after exposure, thatghe lympljicytes were considerably depressed and that-aig@@ficant doses of raditicn had
probably been received. In addition to the wholebody dose of radiation and the beta trradiation 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 exposure: penetrating irradiation, skin irradiation,
and internal irradiation,
PENETRATING IRRADIATION
The changes in the peripheral blood of the more
heavily exposed Rongelap people who recetved
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 Utirik groups were similar but less
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 population levels occurred as follows.
Lymphocytes fell promptly and by the third day
were about 55% of the control values in adults.
and slightly lower in children, There was only
slight recovery after six months. At 2 years, although further recovery was evident, the mean
values of these cells were still found to be beiow
the comparison population levels (75 to 80%). At
3 years the mean lympho
ts wereslightly
below those of the comparison population. At4
years the mean level appeared to be about the
same as that of the comparison population, bu:
many counts remained lower.
Neutrophil levels fuctuated considerably dur
ing the first few weeks but feil gradually to a low
of about 50% of comparison population levels by
the 6th week after,Xposure. Slow recovery en
sedout at 6m
-were still slightly belov
™
at ls. ‘He@rver, by 1 year post ex
. poraryhadreturned'tg{he level of the com
. parisonpepulation ang
telve.remained so, wit
eee sibleexception of thogaf children <UL
Fold, which4 nerally havébeen lower thar
oseof the unexposed children of comparablh
age.
ae
Platelet
del to about 30%
of the unexpose:
yrttle¢rh week. By 6 months they ha
0% ashe COM@ipals; at | vear the mea
phatifer count waa still belo
t of the contre
population but higher than at the 6-month surve:
Although further increases were apparent at th
2-, 3-. and 4-year examinations, the levels wer
still below those of the comparison population,
Changes in hematocrit were not remarkablej
any of the groups.
Clinical examinations revealed no disease proc
esses or symptoms which could be attributed!
radiation effects, aside from skin lesions, loss:
hair, and early symptoms. Epidemics of chicke
pox and measles occurred. The diseases encour
tered were no more severe or frequent in the irrad
ated group than in the unexposed group, eve
during the pertod of greatest depression of peripl
eral blood elements. Three persons in the expose
population died of disease: (1) a 46-year-old ma
with a hypertensive heart disease which had bee