Health Physics Pergamon Press 1972. Vol. 22 (March), pp. 245-250. Printed in Northern Ireland
IRON-55 IN RONGELAP PEOPLE, FISH AND SOILS
T. M.
BEASLEY,* E. E. HELD
Laboratory of Radiation Ecology, College of Fisheries, University of Washington,
Seattle, Washington
407871
and
R.
M.
CONARD
Medical Department, Brookhaven National Laboratory, Upton, L.I., New York
(Received 5 February 1971; in revisedform 12 April 1971)
ve
Abstract—The **Fe body burdens for 60 residents of Rongelap Atoll are reported. The
measured burdens are approximately 3 times higher than those ofa similar numberofresidents
from ‘Vokai-mura, Japan. Since previous measurements in 1966 revealed substantial *°Fe body
burdens in Japanese residents, the current Rongclapese **Fe body burdens pose interesting
questions.
INTRODUCTION
SINCE 1965, the distribution of *5Fe in the biosphere has been studied both in the United
States and in the Scandinavian countries,
Initially, ®*le concentrations: were determined
in Alaskan Eskimos, residents of Richland,
Washington, and in representative foodstuffs of
both.@ Subsequently, ®*ie concentrations in
environmental samples and in residents of
Finland™ and Swedenwere reported which
generally confirmed the findings of the earlier
study. Additional research shows that (i)
marine organisms and people whose diet is
largely scafood contain the highest concen-
trations in 1966 and continue to decrease.'%7)
JAAKKOLA'! has recently presented an excellent
summary of the measurements of 55Fe in
includes
a
We determined the **Fe body burdens of
* Present address: Environmental Sciences Branch,
Division of Biology and Medicine, U.S. Atomic
Energy Commission, Washington D.C. 20545.
the dicts of males or females. Thus, the deter-
mination of °5Fe in this population is of interest
for comparison with other maritime cultures.
Second, Rongelap Atoll received high-level
fallout following the detonation of a thermonuclear device at Bikini Atoll in 1954.00 We
considered it probable that retention of ®5Fe
ai the atoll from that event, coupled with input
from world wide fallout from large-scale
METHODS AND ‘TECHNIQUES
valuable
natives at Rongelap Atoll in the Marshall
Islands. Onur interest in this particular population derives from two important considerations.
First, the Rongelapese are a maritime culture,
and they derive a large portion of their dict
from the sea.Prominent in this diet are the
‘There are no apparent qualitative differences in
to elevated concentrations of 5*Fe in marine
species in the Rongelapese diet and therefore
unusual body burdens of this radionuclide in
Rongelap residents.
the **Fe levels in people reached peak concen-
which
Estimates of fish consumption vary, but daily
intakes between 75-150 g appear reasonable.
nuclear device testing in 1961-1962 might lead
trations of **Fe;“) (ii) residents of the northern
hemisphere have higher *5Fe body burdens than
those of the southern hemisphere;") and (iii)
Finnish Lapps
bibliography.
reef fishes; goatfish (Mudloidicthys, sp.), mullet
( Neomyxus, sp.) and surgeon-fish (Acanthurus, sp.).
‘The method of separation of 95Fe wasidentical
to that previously described.“ The counting
technique was changed slightly; a gas filled
(Xe) proportional counter operating in anticoincidence with an umbrella of nine Geiger—
Miller tubes was used to detect the 5.9-keV
A-ray emitted in the clectron capture decay of
*°Ie. Pulses from the proportional counter
were recorded in a 512-channel multichannel
analyzer. The detection system was surrounded
by 4in. of lead shielding and the resultant background counting rate under the
**I'e
photopeak
was
1.7.
counts/min7,
24 5
ye
ge