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. BIOLOGY AND MEDICINE
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_ UNCLASSIFIED |.
for the first year of reoccupation and will gradually decline thereafter. The Rongelapese who
go on fishing expeditions to other islands could be exposed to levels of radioactivity higher
than those of Rongelap; however, much of their time is spent on fishing boats over waters with
gamma activity near background values. Thus the external gamma radiation received by the
‘ people may be of some significance in- evaluating the Rongelap data. For occupationalcon-
"ditions, the National Committee on Radiation Protection and Measurement ‘recommends that “
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There is no radiation standard which appliés directlyto ‘the Rongelap situation. However,’
standards established for normal atomic energy activities: involving much larger ‘numbersof
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Rongelapese as3 a whole can be expected to be initially 0.5 roentgen or less per year.
adult workers not be exposed to more than 0.3.rem (roentgen equivalent for man) of whole body ,
‘radiation per week, or a 13-week dose of 3 rems when the weekly limit is exceeded. This
' standard is further restricted by an age qualification, which provides that the maximum permissible accumulated dose in rems, atany age, is equal to five times the numberof years”
beyond age 18, provided no. annual increment exceeds 15 rems. Thus, for persons over 18
_-years of age the accumulated maximum permissible dosage is 5(N-48) rems, whereN-1s the
age. This standard appliesto all critical organs except the skin, for which the value is. double. .
For a large population, in contrast with the small group of Rongelapese, the maximum per- .
missible exposure is an average‘of 14 million remsper million persons ‘during the period —- ..
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from conception up
uj to the ageof 30, and one-third of that “amount in each decade thereafter.
“Food Supply and Body Content otstrontium 80 o o
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Strontium 90 is the radioactive:isotope of principal¢
concernin thie food chain of. the .
Marshallese.. Analysis.of the results from all the Pacific Islands surveyed shows a decline of |
“’-strontium 90 with the passage of time, except in the land crabs. Additional collections of land -
crabs will be made on Rongelap to establish the reason for the increase in strontium 90 ACH
tivity.
Maximum permissible exposure to strontium90 for the general population, in terms.of
per gram of calcium). Exposure of the Rongelapese can be reduced by eliminating land crabs
from the diet and by reducing the consumption of such native plants as pandanus. Because
only a-part of the strontium 90 will go from food to bone, these measures may limit the ultimate body burden for the Rongelapeseto substantially less than 100 Sunshine Units.
Swine,‘chickens, ducks, and rats have continued to live ¢on Rongelap during the period of
highest strontium 90 contamination in the soil--plant-animal cycle. Examinations of rats collected and sacrificed two years after. the initial fallout show no gross or pathological changes
’ that could definitely be
b ascribed to xadiation. Medical Surveillance
When the Rongelap people are returned to their home. island, they will be given regular |
monthly medical examinations by. local health personnel and an annual examination by a
physician from the United States. A dispensary will be maintained for regular health services.
Any unusual body accumulation of ‘strontium 90 will be detected before harmful effects result.
Biological Surveys
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A suinmary report of the: Several biological surveys made of the Marshall Islands is‘being
prepared by the AEC staff. The basic studies were made by the University of Washington, the
Naval Radiological Defense Laboratory, and the New York Health’ and
a Batety Laboratory.
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UNCLASSIFIED
td
‘maintainedlevel in the body, is 100.Sunshine Units (100 micromicrocuries of strontium 90.