Health Physics

lying at more southern latitudes, e.g., Kwajalein, Majuro
and others (Breslin and Cassidy 1955; Becket al. 2010).
Prior to the Bravo test, there was little experience

with assessing internal contamination from exposure to
fallout or predicting the related health consequences. One
central reason that investigators from the Los Alamos
Scientific Laboratory (LASL) conducted the urine sam-

pling was to correlate data collected during Operation
Greenhouse (Enewetak 1951) and in the UK on deter-

mining the relative hazards of external and internal
exposure to radioactive debris from atomic weapons.*
The data obtained from bioassay were also believed to be
potentially useful for radiation safety purposes in the
future, particularly since the weapons testing program
was envisioned to continue for years to come.
Soon after the exposures took place from the deposition of Bravo fallout, investigators at LASL realized
that urinary excretion of radionuclides by the Marshallese could be used as an index of internal contamination,°

and plans were madeto obtain 24-h urine samples from
the islanders and the military weather observers stationed
on Rongerik.* On the 15th dayafter fallout, the first urine
collection was conducted by LASL.Otherinstitutions, in
particular, the Naval Radiological Defense Laboratory
(NRDL), and later Brookhaven National Laboratory
(BNL), also collected urine samples in 1954; however,

their purposes were primarily to documentthe effects

and responses to, at that time, levels of environmental

exposure without precedent (Bond et al. 1955; Conard
et al. 1956).

The earliest report on radioactivity assays in urine
samples collected from Marshallese was from one of us
in the form of a laboratory memo referred to here as
Harris (1954)**. In that document, summary results of

assays (countrates and activity concentrations) of '*'I in

urine from the exposed adult population on Rongelap
Island and on nearby Sifo Island on Ailinginae were

reported and simple estimates of thyroid doses from '*'1

estimated. As will be discussed, the LASL urine samples,
while obtained from individual adults, were mixed to

form “pooled” samples from which aliquots were

assayed for '*'I activity and other radionuclides. At a

later date, a modest change in detector efficiency for

* Telex communication (memorandum). Los Alamos Scientific
Laboratory to USAEC, Washington, DC. 10 March 1954. Availableat:

** Harris PS. A summary of the results of urine analysis on
Rongelap natives Americans and Japanese fishermen to date. Memo to
AEC. Los Alamos, NM: Los Alamos Scientific Laboratory; 1954.

August 2010, Volume 99, Number 2

'S!T measurements was determined.’’ Neither the mod-

ifications, nor the original data, however, were ever

In addition to collections by LASL, urine samples
were also collected by the Atomic Energy Commission

(AEC) New York Operations Office’s (NYOO) Health

and Safety Laboratory (HASL) (Bouville and Beck
2000) and the NRDL (Cronkite et al. 1956; Woodward et

al. 1959). There does not appear, however, to be any
single source of information on all urine samples obtained by the different laboratories. From the sparse
historical record, it appears that some of the sampling
efforts were partially coordinated. For example, urine
samples collected by Navy personnel on 24 and 25
March 1954, under the NRDLauspices, were distributed

to HASL, LASL, and NRDL.** In 1958, the Walter Reed
Army Institute of Research (Department of Nuclear
Medicine), in conjunction with the Department of Pathology of BNL reported on the determination of internally
deposited radioisotopes from urine samples collected in
1954. Those data appear to be counting data from which the
radionuclide excretions (in terms of activity per day) were
reported in 1959 by Walter Reed Army Institute of Research.
Possibly because of the poor documentation available on the various urine samplings conducted by different laboratories, James (1964), for an estimation of doses

to Rongelap children, mistakenly assumed and reported
that the pooled urine samples collected by LASL were
20.1% urine (by volume) from ages 5-16 y and 4.8%
from ages <5 y. Those volumes described the Walter
Reed samples reported by Woodwardet al. (1959). The
LASL samples, in fact, only included urine from adults.
In later years, dose assessments for the Marshallese

on Rongelap, Ailinginae and Utrik (Lessard et al. 1985)
and the American military on Rongerik (Goetz et al.

1987) were conducted, though none were published in
peer-reviewed journals. Lessard et al. (1985) estimated

external and internal thyroid doses to the Marshallese on
Ailinginae, Rongelap, and Utrik from the Bravo test
using data of Harris** and other kinds of information.

Other authors later cited Lessard et al. (1985) as that

analysis was easily the most thorough and best docu-

mented analysis at that time. However, all of the above

reports incorrectly reported that the pooled urine sample
collected by LASL included urine from children.
It is unusual, given the significance of the primary
bioassay data, that after 55 years, it is so poorly documented in the open literature. However, one of us
** Harris PS. Bravo fallout. Written circa 1980, unpublished


** Memorandum from E.P. Cronkite (NRDL) to Merril Eisenbud
(NYOO), 4 April 1954.

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