a yearly average of 0.170 rem per person.

The predicted dose equivalent

dose rate of 0.020 rem per year is nearly a factor of ten below this
recommended limit. The NCRP also recommends a whole body dose equivalent
limit of 0.5 rem in any one year, in addition to natural radiation and
medical and dental exposures, for any individual making up the population. An individual with maximum exposure at Enewetak is not expected
to receive more than three times the average dose equivalent rate

(0.020 rem per year); accordingly, the NCRP limit for an individual is
as unlikely to be exceeded as is the limit for the population as a

whole.

With respect to organs other than the whole body, the NCRP does not
explicitly recommend dose limits for members of the public not occupationally exposed. The International Commission on Radiological Protection (ICRP) has in the past, however, recommended that annual dose rates

to specific organs be limited on one-tenth of the corresponding annual
occupational maximum permissible doses. Similar guides appear in international standards for the design and operation of radiation sources.

The NCRP recommends 15 rem per year as a maximum permissible dose equiva-

lent to bone for occupationally exposed individuals. A derived dose
equivalent limit to bone for an individual not occupationally exposed
then is 1.5 rem per year, exclusive of dose from medical exposures and
natural radiation. The individual with maximm exposure at Enewetak is
not expected to receive more than 0.6 rem per year to bone (three times

the average rate); accordingly, the presumed limit for dose to bone will

not bo exceeded.

The estimated doses to people abiding by the post-Cicanup lifestyle
assume no contribution from exposure to radioactive debris. A major
endeavor of the cleanup was to locate, monitor and remove debris to
assure that no radioactive debris was left to produce unexpected doses.
The debris search included extensive vegetation clearance and extended
to underwater searches by scuba divers.

An indication of the diligence

given to this effort is the fact that some 16,000 rounds of ordnance
residual from World War [I were removed. This ordnance had gone unnoticed
by thousands of persons who utilized the atoll during the nuclear weapons
test period.

Radioactive debris found was made unavailable by sealing

it in concrete on the quarantined island. It is now considered almost
impossible for any residual debris at Enewetak to distort the predicted
low doses.

Expectations are that the restrictions to apply at Enewetak can be

lifted in the future as the major amount of radioactivity currently

present disappears through radiodecay and weathering.

The presence of

transuranic clements in Enewetak soil, especially the very long-lived

alpha radiation emitters of plutonium and americium, was considered as a
possible ceterrent to the eventual lifting of all restrictions since the
inhalation of air containing transuranic elements resuspended from the

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