C.W. Mays - Page 10
Table 4
BSTIMATED THYROID CANCERS
FOR THE 565 INFANTS NLAR ST. GEORGE IN 1953
ASSUMPTION
NUMBER OF CANCERS
(A) Iodine 131 effect equals
X-ray effect
(B) Effect equals 1/10 of
X-ray effect
2
-
9
0.2
-
O49
(C) High Threshold
wm
0
eee
"NATURAL" INCIDENCE BY 15
YEARS OF AGE
0.0L
If the additional doses received before birth
and in later childhood had been included, the estimated
number of radiation~induced cancers would have been
even higher than shown in Tables 3 and 4.
DISCUSSION
1)
The St. George study has the advantage that the
"natural" occurrence of childhood thyroid cancers is
extremely unlikely among the 565 infants exposed in 1953.
The probability of one natural case is one in one hundred
whereas the chance for two natural cases is only one
in ten thousand.
Is it possible that genetic or environmental factors
might increase the "natural" incidence in this region
one hundred
thousand
by a factor of
/ to
ten / times greater than for the
rest of the USA?
I do not know.
test this hypothesis.
But I do know how to
Individual estimates should be
Iade of the most probable dose to each St.
based on source of milk and thyroid size.
George child
These
children should then be classified into graded dose
categories.
The high-dose children will probably be
those who drank local milk as infants fror 19 May -
19 June 195% (and to a lesser extent, from 17 March -
17 April 1953, and from 31 August - 30 September 1957).
* The approximate size of a child's thyroid at iodine 131
intake can be calculated from his age at intake.
DOEARCHIVES
4b