-
3-
predictions nor discussed them in public, primarily because I felt that most
of my estimates of dose might be somewhat unreliable.
Working in isolation
at the time, I was aware of 3) milk measurements for only 1 of the 7
years of Nevada testing:
doses for the other 6 years I estimated from
measurements of beta-activity in the air or from fission yield during the
growing season
(3)
New information now permits improved estimates for 5 of
the 7 test years, and for the remaining 2 I have set lower and higher Limits.
For 1962, our analysis of milk from Pendleton's 39 stations scattered
throughout Utah indicated that for the daily consumption of 1 liter (1.06
quarts) of milk, the average I}3) intake for the year was 45,000 picocuries”
assuming a 3 day delay from milking to consumption (23) ,
This agreed closely
with the 37,000 pCi intake reported by the U. S. Public Health Service for
the Salt Lake milk pool.
The corresponding infant thyroid doses*” were 0.77
or 0.63 rads*** respectively.
For 1958 and 1957, USPHS analysis of the Salt Lake milk pool indicated
average yearly intakes of 11,242 and 73,040 pCi I'?? with associated infant
thyroid doses of 0.2 and 1.3 rads, respectively
For 1953 and 1952, the beta activity in fallout-collection trays at
Salt Lake City was 15,000,000 disintegrations per minute/ft® at 12 hours after
the detonation of shot "Nancy" on 24 March, 1953, and 23,000,000 dpm/ft® at
le hours after the detonation of shot "Easy" on 7 May, 1952.
Infant thyroid
doses have been calculated by the St. Louis Group as 2-12 rads for this 1953
shot and 3-13 rads for this 1952 shot (see pp. 529-530, ref. 3).
of Limitations exist in using these values.
shot during each year:
tion.
<A number
First, they are for only one
additional shots may have caused additional contamina-
Second, the measurements were made in Salt Lake City, not in the
pasture lands:
pasture contamination could have been higher or lower.
I have
used these values for yearly exposures only because I am unaware of better
data (although it may exist and could be uncovered).
My presumably less
%
A picocurie is 2.22 disintegrations per minute.
RK
Assuming 30% uptake ina 2 gram thyroid with a subsequent effective retention half-time of 7.6 days.
*¥*, vad is the absorption of 100 ergs of energy per gram of tissue.