oT]
|
©
©
&&
V7
VANDER
MORTENSEN
TROWBRIDGE
RALLISON
|
tT
Oo
T
|
|
|
HH
i
|
|
PRE VALENCE {cases/100 pereons)
ul
+
a
a
1
|
Z\ TUNBRIDGE
ia
20
30
40
50
60
760
80
=90
100
AGE (years}
Fig. 1.
Prevalence of spontaneous thyroid nodules.
The data in Table 4,
From Maxon et al. (164).
taken from a Nuclear Regulatory Commission Report
(234), summarize the estimated occurrence of thyroid neoplasms in the general
U.S. population compared with data on the Marshallese comparison population.
In the Marshallese comparison population, as in other unexposed populations,
the preponderance of thyroid nodules is in the older age group, whereas in the
exposed Rongelap people the reverse is true.
This appears to be the case in
other exposed populations also.* About 1300 children living in Utah were ex-
posed to fallout from the Nevada tests in the 1950s (181), receiving doses
estimated to be considerably higher than those to the Marshallese control
populations, and they had no detectable increase in thyroid abnormalities
compared with the unexposed populations in Arizona.
Table 4.
Age
0-19
20-39
40-59
60-80
grou
Prevalence of thyroid nodules and cancer in unexposed
Marshallese and U.S. populations.
Prevalence of nodularity (%)
Prevalence of cancer (%)
U.S.
Marshallese
U.S.
Marshallese
0.8
2.6
4.3
6.1
2.6
0.08
0.31
0.52
0.73
0.9
7.9
0.7
*The slightly higher prevalence of nodules and carcinoma may be related to the
more rigorous examinations given that group compared with reported surveys
of other world populations.
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