the “normal” range for individual counts by the eighth or ninth week, nedher of (hese values
for either the high or low exposure groups had returned to the mean levels of any of the cantrol
populations fisted in Table 4.tf at this Gime, nor by the end of the study at 15 weeks.* ¢)
Lymphocyte counts remained depressed at least through the 12th week and probably through
the 15th week.
*
The present findings in the Marshallese are in accord with these characteristics, namely,
a) total white cell and neutrophile counts showed no definite minimum at four weeks as evidenced in Japanese groups A to D, but rather {fluctuated during the first feggweeks with minimum mean counts occurring in the sixth week or later. b) Neutrophile -. were unstable
over the first five weeks, and recovery to control levels was not complete by the 10th week.
c) Lymphocyte counts remained depressed throughout the period of observation, |
Platelet data in the Japanese are not sufficient to allow more than rough qualitative comparisons. This is unfortunate since changes in platelet counts in the present studies appeared
to show a more consistent pattern than did the leukocyte counts. Platelet counts on one individual considered as atypical response in a non fatal Japanese” indicated an apparent low at approximately day 30. This time trend agrees with that seen in the Marshallese and Americans
exposed to fallout radiation.
a
it is worthy of note that the period of peak incidence of purpura in the Japanese victims occurred between the 25th and 30th day, which corresponds to the time of maximumplatelet depression in the exposed Marshallese.
4.13.4
Comparison with Data from Laboratory Accidents
Although in the Los Alamos and Argonne accidents“ "° the type of radiation and the conditions of exposure were markedly different from either the Japanese or the Rongelap situations,
a large component of penetrating gamma radiation was received and thus attempts at comparison may be of value. Some findings in the hematological responses are pointed out: a) a
uniform early rise in white and neutrophile counts over the first few days, similar to that seen _
early in the Rongerik American group was observed uniformly.{ b) Of three high-exposure but
non-lethal cases, the total white and leukocyte counts continued to show some degree of de~
pression into the seventh week or beyond. c) The lymphocyte counts in individuals exposed to
as little as 50 rem showedaninitial marked depression. In most cases the lymphocyte counts
remained at low levels throughout the period of observation. d) Platelet counts were done by
a different method, and absolute counts are therefore not comparable. However, of the three
high-dose survivors, times of maximum depression were not inconsistent with the value of 30
days obtained in the present studies.
The Argonne Laboratory accident™ involved four Individuals who were estimated to have
received 136, 127, 60, and 9 rep, respectively. The findings in the two highest exposed individuals in general were consistent with those in the present study. An initial neutrophilic leukocytosis was followed by fluctuations in total count, with low values continuing into the seventh
week, Recovery was not complete by the 20th week. The lymphocyte count depression was
rapid and marked, and recovery was
‘evident by the 20th week. Minimumvalues for the
platelet count were obtained between the 25th and 31st day.
4.13.5
Comparison with Animal Data
The time trends and severity of peripheral blood count change following total body radiation in animals has been critically examined recently,®! and the following general conclusions
are presented.
*Counts 2 years later were not significantly different from control Japanese values.”
ftCounts on the Rongelap people 6 months after exposure showed noelevation of the mean
total white count, neutrophile or lymphocyte counts over values obtained during the 10th week.
{No counts were taken on the Rongelap and Ailinginae groups during this early period.
85
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