to that of the phaneasa, which was counted for 30
RESULTS AND DISCUSSION
In future whole-body counting of these people,
it will be possible, by counting for longer periods
All three of the above methods were used for
estimating the body burdens of gamma- and betaemitting radionuctides itt the Marshallese people.
Individual values for all the people examined in
1959 may be found in Appendix 7 for gamma
spectrographic analvses and in Appendix 8 for
absolute measurement of trace amountsof other
radionuclides that maybe present.
Sincé a total of 227 Marshallese persons were
surveyed with the whole-bodycounter, in addition
to numerous controls, the spectral analyses were
radiochemical analvses.
performed with the aid of a 704 IBM computer.
Environmental Estimate
Radiochemical Procedures
the environmental estimate of body burden. The
Twenty-four-hour urine specimens were collected in plastic bottles and sent to BNL for radio-
chemical analysis.A modification of the method
of Farabee*® was used for the analysis of Sr®®. Sr
was precipitated as the alkaline phosphate, ashed
One method used (the least quantitative) was
environmental estimate of internally-deposited
Sr°? was made in two ways. In the first method,
animals subsisting on diets similar to human diets
were sacrificed and their tissues were analyzed
radiochemically. A number of rats were collected
with HNO, and H,O., and dissolved in dilute
HNO,,. After the solution was brought up toa
volume of 800 cc, the alkaline earths were com-
on Rongelap Island at 2, 4, and 5 years after the
exchange column (Dowex-50 in the Na form),
and the column was rinsed with 300 cc of a solu-
radiation contamination. The Sr?°/Ca ratios of
various tissues of these rats were measured directly and comparedto the ratios of the food and soil
plexed with EDTA, and the pH wasadjusted to
5.5. The solution was then passed through an ion
tion of 1% citric acid and 0.75% EDTA at a pH of
5.0, The combined effluents contained >95% of
the total Ca. The column was then rinsed with 6
WV HNO, to remove the Sr°°. Carrier Sr was added
to the Sr®° fraction and precipitated with 70%
fuming HNO,, Yttrium-90 was milked and counted
by the method of the AEC Health and Safety
Laboratory.*!
The supernatant from the alkaline phosphate
precipitation was measured and divided into two
portions. One portion was scavanged for cesium
with added carrier by meansof a double precipi-
tation of the aluminum suifate and the chloroplatinate.'' The second portion was analyzed for
K by flame spectrophotometry.
Food samples were weighed and dry-ashed ina
muffle furnace at 800°C. The ash was weighed,
and a small portion was counted for gross beta
activity. The ash was dissolved in dilute HNO,
and processed by the method described above for *
urine analysis.
All counting was done in a low-level beta anti-
coincidence type of counter, designed and built at
BNL. Samples were mounted on glass fiber filter
discs with nylon rings and discs and Mylar flm.
Samples were counted against NBS standards
processed and counted underidentical geometry.*'
1189999
1954 accident. If the diet of these rats, primarily
land plants, was sufficiently similar to the diet of
human beings inhabiting this area, the rat analyses might serve as indicators of the humaninterngl
on Rongelap collected at the same time; thatis, the
environmental contamination was compared with
the directly measured contamination in animal
tissue. Extrapolation of the environmental! data
gives the equilibrium value which can be expected, whereas the direct measurement gives the
value at the time of measurement (and thus the
percent of the equilibrium value for the individual
radionuclides).
The Sr?°/Ca ratios for different plant foods on
Rongelap varied greatly, and the diet of the rats
was too uncertain for an “average’”’ diet to be as-
sumed. Therefore, for a body burden estimateit
was necessary to use the Sr°°/Ca values ofthesoil
itself.
The “‘strontium-calcium observed ratio” (OR)
of Comar**? was used to denote the preferential
utilization of calcium in the following manner:
OR
sample-precarsor—~
Sr/Ca of sample
Sr/Ca of precursor
= SE
The Sr® discrimination ratio in the chain from
soil (s) to bone (4) via plants ( p) can be expressed
as follows:
OR,.,=(OR,.,)(OR,_,)=(0.7)(0.25) =0.18.
Te
and using an 8-in.Nal crystal, to improve the
muy
a
oe Ca,
min (Figure 52).