RMI Nuclear Justice Documents

FINAL REPORT
This has been a broad and long term study of the morphological and physiological
effects of radiation from radioiodine (i3t I} on the thyroid of both man and rats.
Numerous lines of investigation have been in progress since the fi St of a series of
these contracts which began in 1951.

Earlier

more time was devot

served in man treated with } 31 I for hyperthyroidism.

With the worl

to changes obprimarily centered

in the department of surgery and being in charge of radioiodine thfrapy, there was a

unique opportunity not only to study in great detail the precise behavior of a treatment dose of 131 I, but to obtain tissues under controlled conditio

Operation was otherwise indicated) and thus relate the findings t

tions that had been made with respect to radiation long before.

(when a thyroid
extensive observa-

M pre than 500 patien:

with hyperthyroidism have been studied in great detail (to be desq ribed) and followed
for many years with the hope that with the initial information std red on each of thes
cases the ultimate long term results over many years might be mors meaningful.

These

human studies were embarked upon because of the bizarre nuclear cfanges we discovered
in the late 1940's and the then unpredictable outcome of the radi; ition effect that
resulted in hypothyroidism.
Simultaneously,

experiments on the effects of 131 I radiatio

in rat thyroids we

designed and carried out on many groups of several hundred rats e ch, trying to find
the amount of radiation which would lead to the bizarre nuclear c hanges which might

also lead to the formation of neoplasms.

Although years were spé nt dealing with

varying doses which for a long time were far too large;

in later years it gradually

became evident that thyroid neoplasms were more readily produced vyhen the dose was

sO small that no obvious histologic changes were produced.

Furtlermore, it was nece

sary to use very young animals and observe the animals for at ledst one half of thei
normal life span.

Each animal experiment required approximately|three years for pos