Table 3: Major thyroid nodules types*, total (internal and external) mean thyroid-absorbed

dose, and time from exposure (1954) to time of surgery, grouped by age.**
Column

A

B

Cc

D

E

Type of

Benign

Total

of (n)

Thyroid

Years to

Cancer

Percent

Dose +/-SD

+/-SD

Benign (16)***

16:1

62

3289+ /-1323

Benign (5) |

1,25:1

9

7
7

1415+ /-150
970 + /-689

20+ /-9
19+ /-5

Utirik <10 yr
(n=57)

Benign (7)
Cancer (2)
Adenomatous (3)
nodules

3.5:1

12
4
5

509 + /-137
526
478 + /-178

28+ /-3
26
28+ /-3

Utirik >10 yr
(n= 102)

Benign (12)
Cancer (3)
Adenomatous (7)

4.0:1

11
3
7

198 + /-41
168 + /-6
171+ /-0

24+ /-4
22+ /-8
23+ /-8

Nodule (n)

Rong <10 yr
(n=26)

Rong >10 yr
(n= 54)

Cancer (1)
Adenomatous(16)
nodules
Cancer (4)
Adenomatous (4)
nodules

Ratio

4
62

nodules

2490
3289+ /-1323

856+ /-649

Surgery

14+/-4

15
14+/-4

19+ /-5

nodules over? Inspection of Fig. 4a shows that
the answerto (1) is in the affirmative, at least for
the Rongelap people. No adenomatous nodule
has been found at surgery for 12 years. The
detection of adenomatous nodules spanned 15
years beginning 9 years after exposure. For the
Utirik group, detection spanned 12 years,
beginning 19 years after exposure.
For question (2), the answer is less clear.
Although only 1 neoplastic nodule (a carcinoma)
has been diagnosed in the past 10 years in the

Rongelap population, several have been found in
the Utirik group during the same period (Fig. 4b).
A striking observation is the virtually identical
percentof neoplastic lesions that have occurred over
thirty-six years of observation in the two exposed
groups, being 8 individuals for the 86 Rongelap
persons (9.3%) and 15 individuals for the 167 Utirik
persons (9.0%).
Given the great differences
between the two groups in total-body and thyroidabsorbed radiation doses, it is clear that (1) other

factors, such as the possibility of thyroid cell killing

18

OLINem

* If two thyroid nodules occurred in the same individual only the “higher grade” nodule was counted.
** Ten years of age is used as cut-off for the younger group because Rongelap children below this age received
a mean thyroid-absorbed dose of >2000 cGy and thereby sustained extensive thyroid injury, a factor that
influenced nodule type. All others received lower doses. Two in Utero Rongelap children who received
<2000 cGy are not included in the table.
*** "Benign" nodules include adenomatous nodules, adenomas, and occult papillary carcinomas.

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