Experience from
The dose from
The total estimated dose is then
Fr COPY |
XERO
The LASL estimate of 11.2 pCi was
The value of 11.2 pCi will be used as a basis for
“orn
XERO:
The number of
individuals in these age groups and the volume of urine from each age group
ie approximately as follows: 4
The pooled samples represent all age groups.
therefore, take 5.6 to 22.4 wCi as the range of adult psi thyroid burden.
day.
Variation in the biological half-life and other factors indicate that a
range of 0.05 to 0.2% should be placed on this number” (see appendix). We,
all following considerations. This estimate was based on the assumption of
0.1% of the maximum thyroid burden being excreted in the urine on the 15th
than the NRDL estimate.
obtained by direct counting of Tae in the urine and should be more reliable
content as 6.4 pCi pal at 1 day.” 4
collected samples from each memberof the exposed group 43 and 46 days
post-detonation and, by an indirect method, estimated the average thyroid
tion and estimated® the 1-day thyroid content as 11.2 uCi of !3)_ usNRDL
Scientific Laboratory collected pooled 24-hour samples 15 days post-detona-
The Los Alamos
Urine samples were taken from
which the average thyroid burden of ? a has been estimated.
iodine content of individuals from Rongelap.
Unfortunately, no direct measurement was possible on the radioactive
Internal Deposition of Iodine Isotopes
We will, therefore, take the average whole-body gamma dose as 175 + 25 R.
effect of time indoors, does not differ significantly from the value of 175 Rr. .
tions, this estimate, which does not contain any correction for the small
47 +47 +114 = 208 R.
Within the error of the measurements and the accuracy of the asaump-
the dose from fallout during cloud passage.
Sedan indicates that the dose from the cloud itself is approximately equal to
the fallout from H + 18 to evacuation at H + 51 i8 114 R.
the eatimated dose from fallow during cloud pasaage is 47 R.
decay during thie interval, and use the reading of 375 mR/hour at 7 days,
If we asaume a Mnear buildup of fallout from H + 6 to H + 18, qo '-2
-2-
a1
11
7
Individuals
Number of
18,011
4,629
1,155
Volume of
Urine (ml)
75.0
20.1
4.3
Volume
% of Total
On the other hand, if water (and food) were the principal
These are:
(1) radioactive decay before inhalation or oral
These factors
For oral ingestion it was assumed
In the case of inhalation, uniform
1.85
—1.38
2.00
0.68
0.57
1.23
1.50
0.31
12357,131
1ee
1.38
2.00
0.487
0.27
1.23
1.50
0.148
y'35/,131
Oral Ingestion
23377131
Delay inreaching the thyroid after inhalation or tngestion would
However, the ps2 daughter of the 78-hour
ingestion.
year-old girls assuming (1) inhalation as the mode of intake and (2) oral
oe and ph before reaching the thyroid.
We can now prgceed to estimate the doseto the thyroids of 3- to 4-
te! 3? has been neglected and would approximately compensate for decay of
lower these factors somewhat.
ingestion.
dose due to yp3} alone for inhalation and 2.6 times the ie dose for oral
The dose to the thyroid in rads from all three isotopes {s thus 3.4 times the
Net Facior
Fission yiela®
Energy
Decay
Inhalation
Ratio of doses for the two modes of inteke.
1335/7131
Table I.
thirds at H + 30.
that, on the average, one-third of the intake occurred at H + 10 and two-
distribution in the cloud was assumed.
are presented in Table I for yis3 and eo
average energy deposited in the thyroid per disintegration.
ingestion, (2) differences in the fission yields of the chaina,® and (3) the
iodine isotopes.
Three items contribute to the differences in dose from the various
source, the time of ingestion would be extended from H + 6 to H + $1.
H+6toH +18.
and ee
Associated with this te are the shorter -lived isotopes ee ee
If the iodine entered by wayof inhalation, the time of intake was
are presumably also those of adults.
The urine samples are typical of adults and the calculated thyroid burdens
>16
§$- 16
< §&
Age Group
-3-
madhtinet.