LYON—CONARD—GLASSFORD . . . VOLUME 68, JANUARY 1964 * 51/33
Majuro, where they lived for three and
one-half years. They were examined
yearly by a medical team.
Control Population * Three years after
the thermonuclear detonation, it was
found that the Rongelap population had
doubled on Majuro because of an influx
of relatives and in-laws from otherislands
not exposed to fallout. This nonexposed
population was selected to serve as a control group because they were of the same
genetic stock, comparable size, and similar age and sex distribution. Thus, four
distinct population samples were avail-
able for comparative study: three exposed groups that received 175, 70 and
14R, respectively, and a nonirradiated
control population.
Summary of Past Medical Findings + Re-
ports of previous medical findings con-
cerning
these
irradiated
population
groups have been published ;*-? however,
a brief summary of this background material is pertinent for correlation with
certain intraoral findings obtained during
this current survey.
Rongelap Population » Shortly after con-
tamination of the island by fallout mat-
ter, the more heavily irradiated Rongelap
people (175 R) showed typical symptoms
of acute radiation sickness. Within 48
hours, about two thirds of this group
experienced anorexia and nausea, a few
vomited and others complained of diarrhea. Many developed itching of the
skin and burning sensations in the eyes
with subsequent lacrimation. Two weeks
later, skin lesions from beta radiation
burns and loss of body hair became evi-
dent. Lymphocyte counts showed considerable depression a few days after
exposure. Radiochemical analyses of
urine showed that measurable amounts
of radioactive material had been absorbed internally.
It was apparent that the Rongelap
group had been exposed to three types of
radiation energy: whole-body penetra-
tion, localized skin irradiation, and inter-
nal absorption of radioactive substances.
Theirradiation dose proved to be sublethal since no deaths occurred from
direct exposure to radiation; however,
dosage was judged to be in the high sublethal range because of the degree of
developing hemopoietic depression it
caused.
Penetrating gamma radiations caused
severe effects in peripheral blood elements. Lymphocyte levels fell rapidly and
by the third day were 55 per cent of the
control values. There was only slight recovery after six months, and after four
years, the mean level was about the same
as the control group. Neutrophil levels
also fell to 50 per cent but returned to
normal after one year. Platelet levels fell
to about 30 per cent by the fourth week
but reached 70 per cent of the control
values after six months. After four years,
the platelet level still was below that of
the control population.
During the first few days after initial
exposure to fallout, maximum permissible
body levels of internally absorbed radioactive fission products were approached
or exceeded only in the case of strontium-
89 and the isotopes of iodine. Bodylevels
fell rapidly and three years postexposure,
they were far below the accepted maximum permissible level. At the present
time, it is thought that the original body
burdens appear to be too low to have
produced or to cause any long-term
effects.
Certain clinical observations are difficult to evaluate. Studies on height, weight
and boneagein children seemed to show
some retardation in growth and development; however, no effect in either
eruption time of deciduous and permanent teeth or changes in rate of jaw
growth were noted during this present
examination.
Ailingnae and Uterik Population °
These population groups received 70R
and 14R total-body irradiation, respectively. Although there was evidence of