city of vital statistics in the Marshallese and the
small numbersof people involved.
No diseases, infectious or noninfectious, have
developed which could be related directly to radiation effects. The incidence of diseases in the exposed people noted during the +-vear survey, as in
previous surveys, remained about the same as
found in the unexposed comparison population.
A limited survey of immune responses of the exposed groupat 3 years post-exposure’ showedthat
the antibody response to tetanus antigenic stimu-
lus was not significantlydifferent from the response
in the unexposed group.
Three deaths have occurred in the exposed
people. Thefirst was in a 46-yr-old man whodied
of hypertensive heart disease | vear post-exposure.
examined by comparing differences between the
mean peripheral blood elementlevels of this group
and the corresponding group of unexposed women
with differences between levels in exposed and unexposed men of the same age group.Nosignificant
differences were seen.
It might be questioned whether or not the
present low body burden of radionuclides might
contribute to delayed recovery of hemopoietic
function. Admittedlylittle is known of possible
effects of such lowlevel exposure on the marrow,
particularlyif, as in the case of the Marshallese,
a significant dose of penetrating radiation has been
previously received. However, it is not believed
that the small amount of additional radiation im-
posed on the marrowfrom this source would be
He had hadthe disease at the timeofirradiation.
sufficient to retard hemopoietic recovery.
post-exposure. He was a diabetic of long standing
and died apparentlyof coronaryheart disease. A
third occurred in April 1958, after the present
survey, in a 35-yr-old man from the group that
received 69 r, due to pneumonia complicating a
exposure revealed a drop in the mean leukocyte
The second occurred in a 78-yr-old man at 2 years
Hematological examination at 3 years post-
counts compared with 2-vear levels in both the ex-
posed and unexposed people. The possibility was
considered that a population trend downward in
leukocyte counts was occurring such as has been
severe case of chickenpox. In none of these cases
was there anydirect evidence that death was due
seen in Japan.'* However, this does not seem to be
the case, since leukocyte levels this year are not
further depressed compared with previouslevels.
elements of the exposed people over the 4-year
skin subsided rapidlv, and only 12 casesstill show
much more rapid recovery seen in animalstudies,
but generally conforms to the recovery pattern
possible that the acute stage of the beta burns may
have caused some of the fluctuation observed in
’ showed earliest recovery (by'1 year post-exposure),
epilation, complete regrowth of hair occurred by
6 months post-exposure.
No acute effects of the internal absorption of
to radiation exposure.
Lag in recovery of some of the peripheral blood
period since exposure is in sharp contrast to the
seen in the Japanese exposed at Hiroshima and
Nagasaki. In the Marshallese the myelocyticseries
with lymphocytes and platelets exhibiting much
slower recovery. The present hematological examinations reveal that the mean leukocyte level has
The acuteeffects of the beta irradiation ofthe
residual scarring and pigment abberation. It is
the white blood cell count. In those showing
radionuclides were observed.
virtually recovered to the control level, but more
LATE EFFECTS
posed group. Thrombocyte production still does
seen, but certain of the more fundamentalof these
individuals had lower counts than in the unex-
not appear to have recovered completely asevidenced by the lower mean levels in the exposed
people both individually and as a group. As has
been pointed out, however, the slightly lower
peripheral blood level of these elements has not
impaired in anyobservable waytheir resistance to
disease.
There has been considerable speculation as to
whether there is a lowered reserve hemopoietic
capacity in the marrowof the exposed people. The
effect of the natural stresses of childbearing and
menstruation in women 15 to +5 vears of age was
5904253
Late effects of radiation exposure have not been
effects that have been observed in animals and to
a lesser extent in man will be mentioned in relation to the Marshallese.
Shortening of life span'*-*? has not been evident.
The 3 deaths that have occurred in the exposed
population do not appear to indicate a higher
mortality rate than seen in the comparison popu-
lations. From these observations it would appear
that some of the higher estimates oflife shortening
per roentgen maybe too high.
Premature aging'~-’”is difficult to assess. From
observations over the past 4 years the impression is