RNil7
=

ould,

RONGELAP

4
rentTs)

+ Rr LaSigh
4 asians

e
eee

ara tg

Ven
hd

UJAE

°PTT

{>

er)

=>

Pra

Fig 2.—Prevalence of thyroid nodules. Atolls shown in color inset were
previously assumed unexposedto radioiodine from nuclearfaliout.

Table 2.—Proportions of Atoll Populations Screened
for Thyroid Nodularity
ee

Atoll

= 10.

Rongelap

g 9}

Mejit tsland

z

Estimated
Population*

Utrik

Ailuk

= 84
2 73
5 6

Likiep

g 54

Wotje
Maloelap
Lae

& 94
J

Jaluit
Ebon

= 4]
é 34

Ujae
Wotho

7

10

:

r

7

“Distance(mies)

7

500

,

600

Fig 3.—Weighted linear regression. Age-adjusted
prevalence of thyroid nodules weighted by inverse of
population variance is plotted against distance from

BRAVO test on Bikin! Atoll.

ews

tH
100 MILES

Fig 1.—Marshall Islands. BRAVO test site is shown on Bikini Atoll. Peopie on
other atolls were screened for thyroid nodules.

*¥

8.4
aad 0,0 °2.4
rsWe

[oe
tte,

MP eis

4

UTRIK Pte

. "40.6 8

eT ;

100 MILES

=~
RONGELAP

2m)

oo
WOTJE

KWAJALEIN

The Marshall
Islands

o

~38.6

BIKIN,

201

287
278

353

419

Total

22707

4
1

137 (33)

= 4104

187 (70)
34 (46)

8
]
a 05;

217 (61)

te
1723 (16)

5855

1808 (30)

7266 (32)

2
*Projected from 1980 Marshall Islands census data.

tScreening of the entire Kwajalein and Majuro populations was not attempted; only persons from these two

atolls who had lived on the other 13 primary atolls in
1954 were screened.

L

2

759 (59)
517 (65)

6061

1
=o ye

8

184 (64)

1295
792

10791

‘ota

50

122 (61)

364 (78)
443 (83)
149 (72)

269
74

’

263 (95)

486
534
206

teat
Majurot

Kwajaleint

Total No. (%)
Screened

ee

B

:
:
:

4

;
{

4

3 1
£
4
g

1
1

°>

p———

100

200

———+#

300

400

Drstance (miles)

5-2

500

600

:

A

Fig 4.—Logistic regression anatysis. Probability of

thyroid nodule developing in an individual (from
fitted logistic model) is shown for each sex, given
mean age, as function of distance from Bikini Atoll.
Actual prevalence data are also plotted. Females,
top curve, and males, bottom curve.

BIKINI
Re
art.)

Fig 5.— Probability contours. Graph shows fitted probability contours for thyroid
nodules for females, computed from complete logistic model. Distance was
calculated for each contour of fixed probability, given mean ageof females, for
values of 8 from 0° to 80°.

JAMA, Aug 7, 1987—Vol 258, No. 5

Thyroid Neoplasia—Hamilton et al

631

are ee am

|
Totem Ta at)

Select target paragraph3