SUMMARY AND CONCLUSIONS

Extensive modification of the MIATHEW-ADPIC code suite has produced
contours of Castle Bravo accumulated and time-integrated deposition for gross
fission products. Through the use of dose conversion factors, these contours have
been converted to dose rates and total doses up to the time of evacuation from the
atolls

affeeted

by

the

debris

cloud.’ In

addition,

both

time-integrated surface concentrations have been calculated.

instantaneous

and

For the nesrest

atolls, the calculations agree well with the measurements and total dose estimates

based on these measurements. At the more cistant atolls the agreement is not as
good, indicating the need for more "tuning" of the code input parameters.
The internal dose to the inhabitants of the affected atolls have not heen made
in

this

report.

Interviews with natives of Rongelap Village and

Ailinginael 8!

indicate that manv people ate fresh seafood and drank water from cisterns following
eontamination of their islands.

Although there is no direct evidence that those at

Utirik ate and crank contaminated food and water, it seems likely that they did
since the dry deposition from Bravo was considerably less than at atolls to the west.
However, the previous section indicated that rain probably necurred during the time
of fallout. This would result in wet deposition, producing local doses 10 to 30 times
greater than in those areas where rain did not occur.

This effect could have

resulted in develooment of thyroid nodules in those Utirik residents who consumed

contaminated food and water.

REFERENCES

1.

Hawthorne, Howard A., Ed., “Compilation of Local Fallout Data from Test

Detonattons 1945-1962 Extracted from DASA 1251," Vol. If - Oceanie U. S.
Tests, DNA 1251-2-EX, DASIAC, Santa Barnara. CA 95102, May 1279,

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