(5)
The worst years scem to be 13953 an? i957.
“t)
Many Grah chis.i or have received thyrcid Joses of several reds.
(ad)
The St.
(e)
These ccse estivates need to be improved.
Gearge exposures were sizable.
data shouid be releascd; air beta concentrations
Tor 1951,
i952,
In particular,
field gamma
shculd be nace available
1353 and 1955; and if not contrary to the interests of
national security, xiieten yields for the July 1962 tests are needed.
Perhaps a future “im ident’ will provide the needed calibration check!
PREDICTED TH.CID CANCERS
I realize that any attempt to predict an increase in cancer due to low
doses of radiation is subject to great inaccuracy and criticism.
This is
especially true when the dose estimates are so very approximate.
There
fore, it sheuld be understood that the following estimates were made pri-
marily to indicate whether or not an effort to search for increased
thyroid cancers would be justified.
Archer anc 5 impson 1) have tabulated 10 thyroid cancers in 2253
children x-irradiated as infants for “an enlarged thymus" with an average
dose of 225 rads, and an average follow-up time of 14.5 years.
we have no
.
i
at later
:
At present
tion en how many additional thyroid cancers will develop
na
m
|
38.5 years.
They have calculated that 0.05
dencere should have been expected normally in this
iyperiod. Assuming a linear relation between
dose and incidence’, there should be l case per 50,000 read-children.
el
me
* To my satisfaction this relation has neither been proved or disproved
adaquately for thyroid cancer.