Urinary excretion of radionuclides @ P. S. Harris ET AL.
The most important urine samples from the pointof-view of dose reconstruction were those assayed at the
LASLat the end of March 1954 for '*'I (see Table 1). No
other samples were obtained soon enoughafter exposure
to successfully measure '*'I. The value of the samples to
dose reconstruction requires careful consideration in
regard to their completeness and representativeness,
primarily because seemingly small volumes of urine
were obtained. The Marshallese health assistant, who
directed the collection, assured the on-site LASL inves-
tigator (P.S.H.) that complete 24-h urine samples could
221
gamma-ray emissions made on raw samples and on the
volatile fraction.******5> Only the earliest samples collected by LASL and measured for ''T within 30 d of
exposure have offered quantitative measurement data
useful for reconstructing doses to the thyroid gland from
radioiodines.
Gamma
activity
measurements
used
a
photomultiplier-based scintillation detector (Fig. 1) developed at LASL coupled to a 100-channel spectral
analyzer. The detector system was referred to as the
“scintillation arm counter” (SAC), because the operator’s
be collected, and afterwards, were collected. The original
interpretation of the urine data by one of us (P.S.H.**)
arm could be inserted into the chamber that held up to
two 500-mL bottles. While no records have been found
collections. Herein, as well as in Simonetal. (2010b), we
ness, we believe the scintillation fluid to have been
diphenyl oxazol (PPO) plustripheny! dioxazol (POPOP)
in toluene as used in the construction of a whole-body
was that urine samples collected were complete 24-h
support the interpretation that, on average, those are
legitimate conclusions.
of the dimensions, wall material, and scintillator thick-
counter at Los Alamos (Anderson et al. 1956) with a
Radioactivity measurements
Several types of measurements and assays for different radionuclides were performed in 1954 though
some of the radiometric analyses were rudimentary by
today’s standards and, in some cases, the measurement
techniques were non-specific or had insufficient detection sensitivity (Table 2 and Appendix). Table Al
summarizes the various assays conducted on urine samples collected in 1954. Here again, this summary was
developed from the collection of literature available to
us. Because of the importance of the LASL '°'T measure-
similar but larger design.
The detector system was used for measurements of
'S'T in liquid form. Measurements of both the raw urine
sample and the volatile fraction were made.*****55* Tt
was found near the end of March 1954 that 77% of the
gamma emissions were in the volatile component and it
was identified to be '*'I through determination of the
half-life.******55 However, the measurements of activity
of '*'T in urine used for all subsequent intake calcula-
tions** (Lessard et al. 1985; Simon et al. 2010b) were
ments to dose reconstruction, we emphasize those measurements, though in Table Al, we also briefly review
the methods and findings of the other various radionuclides measurements based on descriptions that can be
found today in archival documents.
REAR END VIEW OF SAC
Array of *
PM tubes
LASL samples and measurements. Iodine-131 in
adult urine samples following the deposition of Bravo
fallout was measured at LASL.*#7>**#*588 There were
primarily two types of measurements: measurements of
Table 2. Bioassay measurements reported by investigation group
(Y indicates that assay was conducted).
Radionuclide
81Cs
Sr
LASL
(ee Tangham
1954)
USNRDL
(Cronkite
et al. 1956)
Walter Reed
(Woodward
et al. 1959)
Y
Y
—
Y
Y
—
Sr
—
Y
—
—
13 ly
Y
—
—
“Ba
Y
Y
—
239,240Dy,
Y
Y
__
Y
Y
Y
—
BRy
Ca
Gross beta-activity
Pu
Y
—
Detector shell containing liquid scintillator
FRONT VIEW OF SAC
etCae
bottle
Y
—
—
—
Fig. 1. Drawing of front and rear views of “scintillation arm
counter’ (SCA) developed at LASL for gammaactivity measurements and used to assess ''I activity of pooled urine sample in
1954.