Reliable assessments of actual doses must be determined through personnel monitoring.
External radiation
dosimeters do not appear to be a practical means of personnel monitoring for individual external dose
measurements, although certain individuals within given populations may be relied upon to wear them.
A "lifestyle model" which includes estimates of occupancy factors for various locations in a given atoll
has been coupled with environmencal monitoring data to estimate average external radiation doses to
{ndividuals,
This model will be revised as needed so that it closely approximates che actual lifestyle
of the people.
The more important internal pathway can be monitored direcrly by conventional techniques of bioassay
and whole
body counting of individuals.
A portable shadow shield whole body counter has been constructed
and mounted in a shipboard trailer for use in the Marshall Islands,
It is‘capable of quantitative
detection of very small quantities of certain radionuclides in the body such as
Cs and 60co, the
primary environmental gamma emitters at Bikini, Enewetak and Rongelap Atolls,
The system clearly identifies individuals in the Rongelap population who are not following the recommended dieta
restriccions
on eating coconut crabs from certain locations, (42,43)
Body burdens of 90sr/90y, 239,240py and 24lam
are estimated by the radiochemical analysis of urine samples.
Urine sample collections and whole body
counting will be performed every one to cwo years at Bikini and Enewetak Atolls when the people return,
and every two to three years at Rongelap Atoll until the results warrant less frequent measurement
intervals.
Summary
Marshall Islands Radiological Followup has consisted of intensive environmental studies at Bikini,
Enewetak, and Rongelap Atolls to gather radiological data on the excernal radiation environment and on
radioactivity in food chains,
Radiation and radioactivity levels in these atolls are being reduced with
time.
These changes are monitored in annual or biannual environmental surveys.
used to make conservative estimates of population doses and dose coumitments.
Updated information is
When people have returned,
actual internal doses to individuals are determined for whole body counting and bioassay data.
These
results are combined with environmental data on the external radiation environment to complete the total
dose assessment picture.
References
1.
Dunning, G. M., "Radioactive Contamination of Certain Areas in the Pacific Ocean from Nuclear
Tests, A Summary of the Data from the Radiological Surveys and Medical Examinations", USAEC Report,
August, 1957.
2. Held, E. £E., "Gamma Dose Rates at Rongelap Atoll, 1954-1963", USAEC Report, UWFL-91, May 1965.
3.
Donaldson, L. R., et al.
"“Bikini-Eniwerok Studies, 1964, Part I and LI", University of Washington,
Laboratory of Radiation Biology, UWFL-93, September 15, 1966.
4.
Beck, H. L., Bennett, B. G. and McCraw, T. F., "External Radiation Levels on Bikini Atoll; May
1967, USAEC Report, HASL-190, December 1967.
5.
Bennect, B. G. and Beck, AH. L., "External Radiation on Bikini Atoll", Nature 223: 925-928 , 1969.
6,
Held, E. £., “Radiological Resurvey of Animals, Soils and Ground Water at Bikini Atoll, 1969-1970",
University of Washington, College of Fisheries, NVO-269-8 (Rev. 1), February 1971.
7.
Smith, A. E. and Moore, W, E., ‘Report of Radiological Clean up of Bikini Atoll, Office of Dose
Assessment and Systems Analysis", Western Environmental Research Laboratory, Environmental Protection
Agency, SWRHL-lllr, January 1972.
8. McCraw, T. F. and Lynch, 0. D. T. Jr., "Exposure Rate Reduction on Bikini Island Due to Concrete
Dwellings, USAEC Report, WASH-1273, June 1973.
9.
1974,
:
McCraw, T. F,, "Levels of Environmental Radioactivity in Bikini Atoll", USAEC Report, WASH-1289,
10.
Enewetak Radiological Survey, Volumes I, II and III, USAEC Nevada Operations Office, Report NVO-140,
October 1973,
11,
Lynch, 0. D. T. Jr., McCraw, T. F., Nelson, V. A., and Moore, W. E., "Radiological Resurvey of
Food, Soil, Air and Ground Water at Bikini Atoll, 1972", USERDA Report, ERDA-34, February 1975.
12,
Gudiksen, P. H., and Robison, W. L., "Preliminary External Dose Estimates for Future Bikini Acoll
Inhabitants, Lawrence Livermre Laboratory Report, Preliminary UCRL-51879, August 1975.
13.
Palumbo, R. F. and Lowman, F. G., "The Occurrence of Antimony-125, Europium-155, Iron-55 and
Other Radionuclides in Rongelap Atoll Soil", USAEC Report UWFL-56, April 7, 1958,
14,
Lowman, F. G., "Marine Biological Investigations at the Eniwetok Test Site", from Disposal of
Radioactive Wastes, International Atomic Energy Agency, Vienna, 1960,
15. Walker, R. B., Held, E. E. and Gessel, S. P., "Radiocesium in Plants Grown on Rongelap Atoll
Soils, Rec. Advan. Bot. 2: 1363-1367, 1961.
16.
Cole, D. W., Gessel, S. P. and Held, E. E., "Tension Lysimeter Studies of Ion and Moisture Move-
ment in Glacial Till and Coral Atoll Soils! Sofl Sci. Soc. Am. Proc. 25:
321-325,
1961,
17.
Lowman, F. G. and Palumbo, R. F., “Occurrence of Bismuth-207 at Eniwetok Atoll, Nature 193:
18.
Chakravarti, D. and Held, E. E., “Chemical and Radiochemical Composition of the Rongelapese
796-797, 1962,
Diet", J. Food Sci. 28: 221-228, 1963.
19, Kenady, R. M., "The Soils of Rongelap Atoll, Marshall Islands", University of Washington Press,
Corvallis, 1962.
20.
Held, E. E., "Qualitative Distribution of Radionuclides at Rongelap Atoll", Amer. Inst. Biol,
Sei,, Reinhold Publ. Co., New York, 1963, pp. 167-169.