exposure,

for 89sr,

140pa,

1311,

the rare earth group, and fissile material.

As expected, the Rongelap people had the highest body burdens. By 6 months,
beta activity in the urine samples was barely detectable. Table 2 shows the
main isotopes found at day 1 (extrapolated values) and at day 82. The agreement between the findings at the two laboratories is close considering the
techniques available at that time.
Levels in the Ailingnae group were about
one-half and in the Americans about one-quarter the levels in the Rongelap

group. Only isotopes of iodine, strontium, barium, and a few rare earth elements were detected in any significant degree.
In the Rongelap group, at day

l, 89sr and 1311 were near the maximum permissible levels, and the estimated
total amount of radioactive material in the gastrointestinal tract was about
3 mCi; whether this had any relation to the early gastrointestinal symptoms is
not known.

Table 2.

Estimated body burden (uCi) of Rongelap people.

Activity*
at day 1

897

140R4

Rare earth group

131] (in thyroid gland)
103Ru
45a
Fissile material

Activity**
at day 82

1.6 - 2.2

0.19

0

0.03

0.34- 2.7
~ 1.2

6.4 -11.2
0
- 0.013
0
-~- 0.019
O

- 0.016 (ug)

0.021
0.0

0.0

Max. perm.

total body
burden

40

9

0.7
50
200

0.4

*From U.S. Naval Radiological Defense Laboratory.
**From Los Alamos Scientific Laboratory.

The total whole-body or bone-marrow dose from the absorbed nuclides was

not calculated because of the variety and varied energies of these radiations.

However, the dose is thought to have been quite small compared with the
whole-body gamma dose.
5.

Thyroid Doses*

The fallout produced several possible sources of radiation exposure to
the thyroid gland.
The gamma radiation resulted in thyroid doses of 175 rads

in the Rongelap people, 69 rads in the Ailingnae people, and 14 rads in the
Utirik group. Iodine isotopes are produced in relatively high yields by the
*See second footnote at beginning of this Appendix.

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