Comparison of Fallout Exposure Estimated from Incidence Rates of Three Different Acute Diseases

Comparison of Fallout Exposure Estimated from Incidence Rates of Three Different
Acute Diseases
The incidence rates of epilation, purpura and diarrhea among Hiroshima survivors who
were exposed indoors and did not enter the central region examined by O-ho (G. O-ho;
I-Ji Shinpo, No.1746,21-25(1957)) are shown in Fig. 6. As is seen in Fig. 6 incidence
rates of purpura shown by closed circles are of similar behavior to those of epilation
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shown by squares. Then for the relationship between incidence rate of purpura and
exposure dose the same normal distribution for epilation is used. Incidence rates of
diarrhea shown by triangles are very large compared to epilation or purpura in the
distant regions beyond 1.5 km where the fallout exposure produced significant effects.
The incidence rates of diarrhea were rather small in the short distance regions where the
initial radiation exposure dominated. Therefore in the case of diarrhea, a larger
expectation value for the normal distribution than those of epilation and purpura is
required for external exposure from the initial nuclear radiation, and a smaller
expectation value is required for the fallout exposure. The adapted normal distributions
for the relationship between incidence of diarrhea and exposed dose have an expectation
value of 3.026 Gy and standard deviation 0.873 Gy for the initial radiation and an
expectation value of 1.981