EMSL-LV-0539-22 EMSL-LV-0539-22
METABOLISM OF AMERICIUM-241 IN DAIRY ANIMALS
U.S. ENVIRONMENTAL PROTECTION AGENCY
Environmental Monitoring and Support Laboratory
Las Vegas, Nevada 89114
October 1978
Prepared under
Memorandum of Understanding
No. EY-76-A-08-0539
for the
U.S. DEPARTMENT OF ENERGY
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EMSL-LV-0539-22 EMSL-LV-0539-22
METABOLISM OF AMERICIUM-241 IN DAIRY ANIMALS
by
W. W. Sutton, R. G. Patzer, A. A. Mullen,
P. B. Hahn, and G. D. Potter
Environmental Monitoring and Support Laboratory
U.S. Environmental Protection Agency
Las Vegas, Nevada 89114
October 1978
This work was performed under
Memorandum of Understanding
No. EY-76-A-08-0539
for the
U.S. DEPARTMENT OF ENERGY
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ABSTRACT
Groups of lactating cows and goats were used to examine americium-241
metabolism in dairy animals. Following either single oral or intravenous
nuclide doses, samples of milk, urine, blood and feces were taken over a 168-
hour collection period and the americium concentrations were determined by
gamma counting. Gastrointestinal uptake of americium by both cows and goats
was estimated to be 0.014 percent of the respective oral doses. The cumulative
percentage of oral dose transported to milk and urine was 4.4 x 10 and
1.1 x 10~3 respectively for cows and 4.4 x 10~3 and 1.2 x 10~3 respectively
for goats. The relatively high americium concentrations noted in caprine milk
following the oral doses are discussed. Plasma concentrations of americium
decreased rapidly following all intravenous injections. The average percentage
of injected americium transferred to milk, urine and feces was 3, 6 and 2
percent respectively for cows and 2, 4 and 2 percent respectively for goats.
In both intravenously dosed groups, approximately 30 percent of all americium
released from the body was found in the urine during the first 24 hours after
injection. All animals were sacrificed 8 to 9 days after dosing. Bovine bone
retained the greatest fraction of the administered dose followed by the liver. \
However, liver retained the greatest amount of americium in the goats following
both oral and intravenous doses. Comparisons are presented between americium-
241 and plutonium-238 transport in dairy cows.
ii
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INTRODUCTION
Bovine and, to a somewhat lesser extent, caprine metabolism of ingested
americium is of considerable importance for an analysis of exposure pathways
to human populations. Milk and milk products form a direct link in man's
food supply and a significant percentage of beef comes from cows and bulls
discarded from dairy herds. Results on nuclide transport in dairy animals
have been reported at previous Nevada Applied Ecology Group meetings (Stanley
et al., 1974, 1975; Button et al., 1977a, 1977b, 1977c; Patzer et al., 1977a,
1977b; and Mullen et al., 1977). The primary purpose of these metabolism
studies has been to determine gastrointestinal uptake of the various nuclides,
to determine the amount of activity that was trasnferred to the milk and to
establish what fraction of the dose was retained by the tissues. In addition
to administering oral nuclide doses to the dairy animals, several of the
projects have also included intravenous dosing of one or two animals so as
to establish plasma clearance characteristics and to provide an estimate of
nuclide loss into the gastrointestinal tract (e.g., bile secretion).
The transport of ingested plutonium-238 to milk has been reported by
Stanley et al. (1974, 1975). Following an acute oral plutonium nitrate dose,
2.0 x 10-Lf percent of the ingested plutonium was recovered in milk. Multiple
oral doses of plutonium dioxide resulted in 2.0 x 10"5 percent of the dose
being transferred to milk. Information on gastrointestinal uptake of americium
and the subsequent nuclide transport to milk is not currently available for
dairy animals. Low gastrointestinal absorption values, e.g., <0.05 percent of
dose (Hamilton, 1947), <0.01 percent of dose (Scott et al., 1948) and 0.012
percent of dose (Sullivan and Crosby, 1975), have been reported following the
administration of americium-241 to laboratory rats. Following intravenous
nuclide doses to lactating Suffolk sheep, McClellan et al. (1962) noted that
plutonium-239 and americium-241 both reached peak concentrations in the milk
7 hours after injection. However, americium was cleared more rapidly from
the plasma and its subsequent transfer to milk was greater than was observed
for plutonium.
Objectives of the current investigation were (1) to establish the gastro-
intestinal uptake of americium, (2) to determine the amount of activity
transported to milk, (3) to examine the plasma clearance rate of americium,
(4) to quantify the excretion characteristics of americium in urine and feces,
and (5) to establish the tissue deposition pattern of americium in dairy
animals. In pursuing the objectives, samples of blood, milk, urine and feces
were taken from groups of cows and goats after the animals had received either
oral or intravenous doses. Tissue collections were made at time of sacrifice.
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METHODS AND MATERIALS
The study was conducted in two phases at the Nevada Test Site farm. Four
lactating dairy cows, confined to individual metabolism stalls, were used in
the initial phase. Two of the cows, average weight 575 kg, were each given
single 41.7-mCi oral doses of americium-241 chloride. The oral doses were
placed in gelatin capsules (doubly encapsulated) containing cellulose fiber
and were administered using a balling gun. The other two cows, average weight
598 kg, were each given single intravenous doses (0.96 mCi) of citrate-buffered
americium-241 chloride. Intravenous doses were approximately 5 ml in volume
and were administered by jugular venipuncture. No intravenous or oral dose
adjustments were made for individual variations in animal weight.
Daily milk, urine, fecal and blood samples were taken beginning 1 day
prior to dosing and continuing until approximately 168 hours after dosing. The
cows were each catheterized with an in-dwelling, inflatable urinary catheter
and the urine drained through polyethylene tubing into 20-liter plastic bottles
placed at the rear of each stall. A grid-covered pan, lined with polyethylene
sheeting, was used to collect the feces. Milk was collected with individual
bucket milkers twice daily and single blood samples were taken by jugular
venipuncture. All urine, milk and fecal collections were weighed and then
combined (a.m. + p.m.) into respective 24-hour composites for each animal. A
Hobart mixer was used to mix the large fecal collections while respective
composites of milk and urine were shaken thoroughly in plastic containers. \
Weighed subsamples were then taken from the respective composites and placed
in individual 200-ml aluminum cans with formaldehyde added as preservative.
On the second and fifth post-dosing day, three subsamples were taken of each
composite to confirm the degree of sampling variability. Blood was collected
at 8-hour intervals through the first day and then on a 24-hour basis. Samples
were centrifuged and the plasma and cells separated using disposable pipettes.
The packed cells were washed two times with physiological saline. Samples of
plasma and cells were then individually diluted with distilled water and formal-
dehyde was added as a preservative. A limited number of whole blood samples
was also taken.
The second phase of this study used five dairy goats and basically followed
the same procedures as the bovine experiment. Two goats, average weight 35 kg,
were each given a single oral dose (1.91 mCi) of americium-241 nitrate. A
second pair of goats, average weight 36 kg, each received a single 41.7-yCi
intravenous dose of citrate-buffered americium-241 nitrate. One goat served
as a control animal and did not receive americium. As before, oral doses were
placed in gelatin capsules and were administered using a balling gun. Intra-
venous doses were administered by jugular venipuncture.
The goats were maintained under conditions similar to those used during
the bovine experiment, but in smaller and more elevated metabolism stalls which
allowed easy access for the twice daily hand milkings. Urine was collected
by catheter and the fecal pellets were collected in a modified tray. Twenty-
four hour composite sampling was again conducted for milk, urine and feces.
Due to the pellet nature of goat feces, an electric meat grinder (General
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Slicing Company) was used to mix the daily collections. The grinder was
dismantled and cleaned between each mixing. Commercially purchased soda
crackers were also run through the grinder as part of the cleaning process.
In a few cases, some of the ground crackers were subsequently analyzed for
americium to check for cross-contamination. Blood was collected from the
goats at 8-hour intervals for the first day followed by daily collections
through the seventh day post-dosing.
Cows and goats were sacrificed 8 to 9 days after dosing (Tables I and II)
using intravenously administered euthanasia solution. Extensive precautions
were taken in the sacrifice area (Nevada Test Site farm) to reduce any
possibility of cross-contamination during tissue collection. Results of
tissue analyses on the control goat suggested that cross-contamination or
respiratory exposure was indeed minimal. All animals were weighed at time
of sacrifice and partially exsanguinated before tissue samples were taken.
Organs and tissues were removed from the animals within approximately 60
minutes of sacrifice. Extraneous tissue (adipose tissue or muscle associated
with bone samples) was discarded and the required sample, plus formaldehyde,
was sealed in 200-ml aluminum cans. Total weights were taken on most organs
so that the percentage of administered dose retained by a specific tissue or
organ could be calculated. When this was not practical (for muscle, bone,
blood, etc.), total americium content was based on extrapolated organ weights
using the respective percentage of body weight reported by Davis et al. (1975),
Smith and Baldwin (1974) and Matthews et aZ.(1975). Americium concentrations
from the femur (diaphysis and epiphysis), sternum, vertebra and rib were
averaged to estimate the osseous retention values. Differences did exist,
however, in the total number of individual samples that went into the
average bone value. For bovine bone, the femur value was derived from two
diaphysis and two epiphysis samples, and two samples each of vertebra and
rib were collected. The same bones were sampled from the goats but only one
diaphysis and one epiphysis sample per animal was collected as well as only
one sample each of vertebra and rib. One sternum sample was taken from each
cow and from each goat.
Americium-241 decays through the emission of alpha particles and 36
percent of its disintegrations are accompanied by a 60-keV gamma ray. Gamma
counting was considered the most feasible analytical technique for use in
conjunction with these experiments. Most samples were counted in 200-ml
aluminum cans using a phoswich detector which consisted of a thin Nal
scintillator backed by a thick Csl scintillator. Checks were made for gain
shifts and changes in efficiency with an aliquot of the dosing solution.
Backgrounds were taken before, during and after a series of counts to confirm
that contamination of the counting chamber had not occurred. Various spiked
standards (feces, milk, urine, plasma, blood cells, distilled water and agar)
were also prepared. The amount of americium added (spike) was based on (1)
the supplier's value for the stock solution and on (2) the calculated con-
centration range (percentage of dose per gram) likely to occur in milk, urine,
etc., throughout the project. Different spiking levels within each group,
e.g., milk, were separated by at least one order of magnitude and three
replicates were prepared at each concentration. The americium-241 used in
these experiments was obtained in the nitrate form from Amersham/Searle
Corporation.
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While the phoswich system was the primary detection method, other coun
ing techniques were also employed during the study. Certain fecal samples
from the orally dosed animals contained high concentrations of americium. ror
these assays the sample size was reduced to 25 grams (plus formaldehyde and
a 2-percent agar solution) and they were analyzed using a FIDLER counting
system, i.e., Nal(Tl) crystal and a single-channel analyzer. Furthermore,
many samples of plasma, packed cells and whole boood were assayed in dispos-
able 50-ml polypropylene centrifuge tubes using a Nal(Tl) well crystal.
Selected samples were counted using both the phoswich system and the Nal(Tl)
detector. Appropriate standards, blanks, duplicate assays and efficiency
calculations were used to assess the results from all counting systems.
TABLE I
BACKGROUND INFORMATION ON THE FOUR DAIRY COWS DOSED WITH AMERICIUM
Animal
Number
Americium
Dose
Animal
Weight*
Sacrifice Time
Post-treatment
(days)
Average Daily Output
During Experiment (kg)
Milk Urine Feces
269
281
184
280
single oral dose
(41.7 mCi) of
americium- 241
chloride
single oral dose
(41.7 mCi) of
americium-241
chloride
single intravenous
dose (0.96 mCi) of
citrate-buffered
americium-241
chloride
single intravenous
dose (0.96 mCi) of
citrate-buffered
americium-241
chloride
568
582
677
518
8
8
9
9
9.4
15.1
20.3
9.8
11.2
11.7
20.3
10.1
20. 6X
14.5
30.3
14.0
*Weight taken at time of sacrifice.
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TABLE II
BACKGROUND INFORMATION ON THE DAIRY GOATS DOSED WITH AMERICIUM
Animal
Number
Americium
Dose
Sacrifice Time
Animal Post-treatment
Weight* (kg) (day_sl_
Average Daily Output
During Experiment (kg)
Milk Urine Feces
goat 1
goat 2
goat 3
goat 4
goat 5
single oral dose
(1.91 mCi) of
americium-241 nitrate
single oral dose
(1.91 mCi) of
americium-241 nitrate
control animal
no dose administered
single intravenous
dose (41.7 yCi) of
citrate-buffered
americium-241 nitrate
single intravenous
dose (41.7 pCi) of
citrate-buffered
americium-241 nitrate
29.5
40.5
31.5
30.9
40.5
8
8
8
8
8
1.5
1.6
1.8
2.6
1.9
1.4
1.9
2.0
3.4
1.5
0.6
0.9
0.9
1.4
0.8
^Weight taken at time of sacrifice.
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After assaying the samples by direct counting methods, radiochemical
analyses (Eberline Instrument Corporation, Albuquerque, New Mexico) were
performed on (1) a portion of the quality assurance samples, (2) on sets of
samples that demonstrated considerable between-animal or within-animal vari-
ability and (3) on samples that contained less than 1 pCi of americium per
gram of material. These radiochemical assays were conducted using alpha
spectrometry. The total sample was ashed in a muffle furnace and then
dissolved in acid with americium-243 added as a tracer. Following liquid
extraction, the sample solution was passed through a cation exchange column
and the americium was electroplated for analysis.
RESULTS AND DISCUSSION
Approximately 0.014 percent of the oral americium dose was absorbed from
the gastrointestinal tract of dairy cows. Of this relatively small amount,
essentially 3 percent was subsequently transported to milk, 8 percent was
transported to urine and about 3 percent was probably returned to the digestive
tract over the first 168 hours after dosing. At time of sacrifice (192 hours)
86 percent of the absorbed americium was recovered in the bovine carcass. A
somewhat similar distribution resulted when the nuclide was introduced intra-
venously. Based on results from a single animal (goat 1), americium transport
in the goat followed this general pattern after oral exposure. The estimated
americium gastrointestinal uptake for this orally dosed goat was 0.016 percent
of the administered nuclide. The above mentioned findings for the orally
dosed animals are summarized in Table III. Carcass retention values used in
this table were derived by summing the americium recovered in bone, liver,
kidney, lung, spleen, heart, gonads, thyroid, muscle and plasma for the
individual animals.
Values for goat 2 are also included in Table III. Relative to the carcass
retention value (3.1 x 10~3 percent of dose), the total amount of americium
transported to goat 2 milk (8.3 x 10"3 percent of dose) appears much too high.
Milk and carcass values were confirmed by both direct counting techniques and
by radiochemical assays. Possibilities of sample contamination were considered
but americium concentrations in goat 2 milk followed the expected pattern (peak
concentration at 48 hours with subsequent gradual decline) and americium concen-
trations in the sample replicates did not indicate irregularities. Tissue
values also followed the expected deposition pattern but contained less americium
than was noted for goat 1. Americium concentrations for urine, feces and blood
plasma were similar between goats 1 and 2. The calculated gut absorption of
americium (1.6 x 10~2 and 1.2 x 10~2 percent of the oral dose for goats 1 and
2 respectively) was also similar but the curious metabolic pattern suggests that
for goat 2 the gut uptake may have actually been less than this calculated
estimate.
The mean percentage of dose contained in plasma, milk, urine and feces for
the two orally dosed cows is shown in Table IV. Values are given for each
collection interval and for the total transport to milk, urine and feces during
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TABLE III
GROSS ESTIMATE OF AMERICIUM TRANSPORT IN DAIRY ANIMALS
FOLLOWING A SINGLE ORAL AMERICIUM-241 DOSE
Milk
(168 h)
Urine
(168 h)
Feces
(168 h)
Carcass
(192 h)
Estimated**
G.I. Uptake
Cow 281
% of Oral
Dose
4.4 x ICT4
9.0 x 10-4
93.1
1.4 x 10~2
1.6 x 10~2
% of Absorbed
Dose
2.8
5.8
2.9*
87.7
-
Cow 269
% of Oral
Dose
4.5 x 10-^
1.3 x ID"3
81.5
1.1 x 10~2
1.3 x 10~ 2
% of Absorbed
Dose
3.3
9.6
2.9*
83.6
-
Goat 1
% of Oral
Dose
5.6 x 10-4
1.6 x 10~3
85.8
1.3 x ID-2
1.6 x 10~2
% of Absorbed
Dose
3.6
10.5
1.9*
84.0
-
Goat 2
% of Oral
Dose
8.3 x 10~3
6.6 x 10~4
85.5
3.1 x 10~3
1.2 x 10-2
% of Absorbed
Dose
67.5
5.4
2.0*
25.0
-
*Based on observed nuclide transport to feces for intravenously dosed animals.
**Preliminary summation composed of 1) the total transport (168 h) to milk and
urine, 2) recovered activity estimate for each carcass (192 h) and 3) the
extrapolated amount of absorbed americium returned to the gastrointestinal tract.
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TABLE IV
MEAN PERCENTAGE OF ORAL AMERICIUM DOSE NOTED IN BLOOD PLASMA,
MILK, URINE AND FECES FOR TWO DAIRY COWS
DURING THE 168-HOUR SAMPLING PERIOD
Time
After Dosing
8 h
12 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
Total
Plasma*
3.22 x 10~5
1.59 x 10^
2.33 x 10-^
2.69 x lO"4
1.32 x 10-^
1.13 x 10-1*
1.99 x 1CT4
2.09 x 10~5
2.34 x 10~5
-
Milk
-
-
9.11 x 10~5
9.37 x 10~5
9.41 x 10~5
7.44 x 10~5
3.96 x 10~5
2.88 x 10~5
1.56 x 10~5
4.37 x IQ-1*
Urine
1.03 x 10~5
-
8.61 x ID"5
2.75 x ID"4
2.68 x lO-1*
1.80 x 10~4
1.24 x 10-^
8.03 x 10~5
6.12 x 10~5
1.09 x 10-3
Faces
3.10 x 1C-2
-
5.60
9.59
31.0
20.5
12.1
6.57
1.93
87.3
*Extrapolated values
TABLE V
MEAN PERCENTAGE OF ORAL AMERICIUM DOSE NOTED IN BLOOD PLASMA,
MILK, URINE AND FECES FOR TWO DAIRY GOATS DURING
THE 168-HOUR SAMPLING PERIOD
Time
After Dosing
8 h
15 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
Total
Plasma*
8.12 x 10-5
1.62 x lO'1*
1.44 x 10~4
6.01 x 10~5
3.56 x 10~5
2.00 x 10~5
1.86 x 10~5
1.30 x 10~5
1.07 x ID"5
-
Milk
2.18 x 10-6
-
1.81 x 10-1*
3.80 x ID"3
1.86 x 10-^
6.87 x 10~5
2.95 x 10~5
2.75 x 10~5
1.31 x 10-^
4.43 x ID"3
Urine
1.85 x 10~5
-
2.59 x 10-4
3.93 x 10-1*
1.91 x 10~4
1.10 x ID"1*
4.39 x lO-5
8.12 x lO-5
5.49 x lO-5
1.15 x 10~3
Feces
5.86 x 10-5
-
20.39
48.05
14.25
2.39
3.83 x 10-1
1.10 x 10-1
4.25 x 10~2
85.62
*Extrapolated values
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the 168-hour collection period. Three days after dosing the largest daily
amount of americium was excreted in the feces but the fecal nuclide content
was relatively high from post-dosing day 2 through day 5. It will be noted
that plasma levels rose to a peak plateau between 24 and 48 hours after
dosing. Milk and urine concentrations, as expected, reflected this plasma
increase with the greatest amount of americium being released (in milk and
urine) during the 48- and 72-hour collection periods. Total nuclide transport
to bovine milk and urine was 0.0004 and 0.001 percent of the administered
oral dose, respectively. Table V presents the mean percentage of dose
contained in plasma, milk, urine and feces for the two orally dosed goats.
While results from both animals were used to compute the milk values, it
should be remembered that for one goat the americium transport to milk was
unexplainably high.
Americium concentrations decreased rapidly in the plasma of all intra-
venously dosed animals (Tables VI and VII). The initial plasma nuclide
reductions were slightly more pronounced in the goats. However, in both
groups of dairy animals the plasma retention of americium had dropped to
below 1 percent of the original dose by the second day. A portion of the
circulating americium had obviously been excreted in the urine during this
initial time period and a much larger fraction had most likely been retained
in the liver. At time of sacrifice the percentage of dose remaining in the
plasma was quite close in both groups of animals (cows - 0.06 and goats -
0.03). Rapid plasma clearance rates have also been reported for rats (Taylor,
1962), sheep (McClellan et al., 1962), dogs (Bruenger et al., 1969) and
baboons (Rosen et al., 1972) following americium injections.
Bovine plasma extrapolations (to percentage of dose per total plasma
weight) were based on the assumption that whole blood would be 8 percent of
the body weight and subsequently that plasma represented 60 percent of the
whole blood. Caprine plasma was calculated at 55.9 ml per kg of body weight
(Klement et al., 1955). However, some animal weight loss occurred during
the study. This was especially evident in the dairy cows, thus introducing
another extrapolation step to estimate total blood plasma. Multiple samples
of bovine whole blood, plasma and cells collected at time of sacrifice and
analyzed by both the direct counting and radiochemistry techniques, indicated
that approximately 89 percent of the whole blood americium was found in the
plasma. While this was the most thorough check on the distribution of americium
in whole blood, it was evident from other bovine and caprine collections that,
in spite of some fluctuation in the percentage distribution, the major fraction
of whole blood americium was appearing in the plasma.
Tables VIII through XIII present a comparison of the mean americium
transport to milk, urine and feces for all treatment groups. Values are
expressed as both the percentage of the dose recovered per total collection
and as the percentage of dose per gram of milk, urine or feces. Where the
respective tables show a blank at an early post-dosing time (8 hours through
24 hours) it indicates a slight alteration in the sampling schedule. However,
the blank shown at the 168-hour interval for bovine urine resulted from
catheter displacement during a portion of this collection interval.
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TABLE VI
PERCENTAGE OF AMERICIUM DOSE REMAINING IN BOVINE PLASMA
FOLLOWING AN ACUTE 0.96 mCi INTRAVENOUS INJECTION
OF CITRATE-BUFFERED AMERICIUM-241 CHLORIDE
Time
post injection
8 h
12 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
Sacrifice
(approximately
216 h)
Cow 184
% of Dose per
Total Plasma*
2.82
2.74
9.90 x 10-1
4.69 x 10-1
2.92 x ID" J
2.08 x ID"1
1.35 x ID"1
1.15 x 10-1
8.49 x 10-2
4.47 x 10~2
% of Dose per
Gram of Plasma
8.07 x 10~5
7.82 x 10~5
2.83 x 10-5
1.35 x 10~5
8.46 x 10~6
5.96 x 10~6
4.10 x 10~6
3.37 x 10~6
2.57 x 10~6
1.40 x 10~6
Cow 280
% of Dose per
Total Plasma*
4.30
1.07
1.43
5.47 x 10-1
3.49 x 10-1
1.92 x 10"1
2.84 x ID'1
2.71 x ID"1
2.02 x 1Q-1
6.62 x 10~2
% of Dose per
Gram of Plasma
1.59 x IQ-1*
3.97 x 10~5
5.30 x 10~5
2.10 x 10~5
1.34 x 10~5
7.35 x 10~6
1.09 x 10~5
1.08 x 10~5
8.06 x 10~6
2.65 x 10~6
^Extrapolated values
10
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TABLE VII
PERCENTAGE OF AMERICIUM DOSE RETAINED IN CAPRINE BLOOD PLASMA
FOLLOWING A SINGLE INTRAVENOUS DOSE (41.7 pCi) OF
CITRATE-BUFFERED AMERICIUM-241 NITRATE
Time After
Injection
8 h
15 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
192 h
Percentage of Dose
per Total Body Plasma*
Goat 4
6.86 x 1CT1
3.89 x 10-1
2.85 x 10-1
1.63 x ID'1
1.15 x 10"1
5.28 x 10~2
4.08 x 10~2
5.52 x 10-2
3.84 x 10~2
2.64 x 10~2
Goat 5
6.14 x 10-1
3.77 x 1CT1
2.66 x 10-1
1.68 x 10-1
1.13 x ID'1
7.91 x 10-2
5.04 x 10~2
5.52 x 10~2
3.36 x 10-2
3.60 x 10~2
Percentage of Dose per
Gram of Plasma
Goat 4
2.81 x 10-^
1.62 x 10-4
1.21 x 10-4
7.19 x 10~5
5.32 x 10-5
2.57 x 10-5
2.08 x 10~5
2.85 x 10~5
2.16 x 10~5
1.54 x 10~5
Goat 5
2.42 x I0~k
1.50 x I0~k
1.06 x 10-4
6.84 x 10~5
4.65 x 10~5
3.29 x 10~5
2.08 x 10~5
2.31 x 10~5
1.43 x 10~5
1.58 x 10~5
*Extrapolated values
11
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TABLE VIII
MEAN PERCENTAGE OF AMERICIUM DOSE TRANSFERRED TO
MILK DURING THE 168-HOUR COLLECTION PERIOD
Time
After Dosing
8 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
Total
Oral Dose
Cows
9.11 x 1CT5
9.37 x 10~5
9.41 x 10-5
7.44 x 10~5
3.96 x ID"5
2.88 x ID"5
1.56 x ID'S
4.37 x ID"4
Goats
2.18 x 10~6
1.81 x 10-4
3.80 x 10~3
1.86 x 10-4
6.87 x 10~5
2.95 x ID'5
2.75 x ID"5
1.31 x 1Q-4
4.43 x ID'3
Intravenous Dose
Cows
1.41
4.70 x 10-1
2.81 x 10-1
2.29 x 10-1
1.67 x 10-1
1.08 x ID"1
9.39 x 10"2
2.76
Goats
1.13
3.18 x 10-1
1.95 x 10-1
1.09 x 10-1
7.20 x 10~2
6.72 x ID"2
5.76 x 10~2
4.44 x 10~2
1.99
TABLE IX
MEAN PERCENTAGE OF AMERICIUM DOSE
TRANSFERRED PER GRAM OF MILK
Time
After Dosing
8 h
12 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
Oral Dose
Cows
1.09 x 10~8
1.88 x 10-9
8.87 x 10~9
7.98 x 10~9
6.10 x 10~9
3.33 x 10~9
2.06 x 10"9
1.48 x 10"9
Goats
3.32 x 10~9
-
1.52 x 10~7
1.74 x 10-6
1.08 x ID"7
4.47 x ID'8
3.24 x 10-8
1.90 x 10~8
1.02 x lO"7
Intravenous Dose
Cows
1.53 x 10-4
1.25 x 10-"*
3.95 x 10-5
2.48 x 10-5
1.71 x 10-5
1.30 x 10"5
9.28 x 10~6
8.77 x 10~6
Goats
1.12 x 10"3
-
1.85 x 10-4
7.15 x 10-5
4.35'X 10-5
3.43 x 10"5
3.75 x 10-5
2.92 x 10-5
2.96 x 10~5
12
-------
TABLE X
MEAN PERCENTAGE OF AMERICIUM DOSE TRANSFERRED TO
URINE DURING THE 168-HOUR COLLECTION PERIOD
Time
After Dosing
8 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
Total
Oral Dose
Cows
1.03 x 10~5
8.61 x 10~5
2.75 x IQ-1*
2.68 x ID'4
1.80 x 10~4
1.24 x lO-4
8.03 x ID'5
6.12 x 10~5
1.09 x 10~3
Goats
1.85 x 10-5
2.59 x 10-^
3.93 x 10~4
1.91 x 10~k
1.10 x 10-^
4.39 x 10- 5
8.12 x ID"5
5.49 x 10-5
1.15 x 10~3
Intravenous Dose
Cows
1.93
1.31
8.87 x ID"1
5.40 x ID'1
3.28 x ID"1
2.91 x ID"1
2.01 x ID"1
-
5.49
Goats
2.07
6.07 x ID"1
6.55 x ID'1
2.95 x 10-1
2.14 x 1Q-1
2.00 x 10-1
1.32 x ID"1
1.09 x 10-1
4.28
TABLE XI
MEAN PERCENTAGE OF AMERICIUM DOSE
TRANSFERRED PER GRAM OF URINE
Time
After Dosing
8 h
12 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
Oral Dose
Cows
2.13 x 10~9
1.20 x 10~8
2.01 x 10~8
4.33 x ID"8
2.37 x 10~8
1.42 x 10~8
9.25 x 10~9
5.23 x 10-9
4.24 x 10~9
Goats
3.65 x 10~8
-
4.01 x 10~7
1.77 x 10~7
1.05 x 10~7
8.49 x 10~8
5.34 x 10~8
4.59 x 10~8
3.25 x 10-8
Intravenous Dose
Cows
5.37 x ID"4
1.60 x 10~4
9.49 x 10~5
5.77 x 10~5
4.01 x 10~5
2.35 x ID'5
1.86 x 10~5
1.60 x 10~5
-
Goats
3.33 x 10~3
-
5.47 x 10-^
1.87 x 10-tt
1.08 x ID"4
1.15 x 10~^
1.05 x lO"1*
6.10 x 10~5
6.47 x 10~5
13
-------
TABLE XII
MEAN PERCENTAGE OF AMERICIUM DOSE TRANSFERRED TO
FECES DURING THE 168-HOUR COLLECTION PERIOD
Time
After Dosing
8 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
Total
Oral Dose
Cows
3.10 x lO-2
5.60
9.59
31.00
20.50
12.08
6.57
1.93
87.30
Goats
5.86 x 10~5
20.39
48.05
14.25
2.39
3.83 x 10-1
1.10 x ID'1
4.25 x 10-2
85.62
Intravenous Dose
Cows
5.88 x ID"1
4.99 x 10-1
4.54 x 10'1
2.96 x 10-1
2.01 x 10-1
1.52 x ID"1
1.50 x ID"1
8.10 x ID'2
2.42
Goats
3.11 x lO-2
3.19 x 10-1
5.80 x ID"1
3.35 x ID"1
2.86 x 10-1
1.64 x 10-1
1.98 x ID"1
1.77 x 10-1
2.09
TABLE XIII
MEAN PERCENTAGE OF AMERICIUM DOSE
TRANSFERRED PER GRAM OF FECES
Time
After Dosing
8 h
12 h
24 h
48 h
72 h
96 h
120 h
144 h
168 h
Oral Dose
Cows
4.76 x ID'6
5.85 x 10-^
1.18 x ID"3
1.97 x 10-3
2.28 x ID"3
1 1.00 x ID-3
6.28 x 10-4
2.41 x 10-^
7.20 x 10~5
Goats
2.62 x 10~7
-
2.86 x lO-2
5.48 x lO-2
1.61 x lO-2
3.05 x ID"3
6.41 x 10-1*
1.88 x 10-^
7.05 x 10~5
Intravenous Dose
Cows
9.47 x 10-5
3.63 x lO-5
3.08 x 10~5
2.45 x lO-5
1.46 x 10~5
1.11 x 10~5
8.21 x 10-6
7.16 x lO-6
6.36 x 10-6
Goats
5.70 x lO-5
-
3.53 x ID"4
3.74 x 10~4
2.60 x 10-1*
2.38 x ID'4
2.80 x 10-^
2.57 x W~^
2.68 x W~k
14
-------
Nuclide transport to milk, urine and feces was basically similar between
orally dosed cows and goats. Peak americium concentration in bovine milk
(Table IX) was considered to have occurred 48 hours after nuclide ingestion
and the high 12-hour concentration resulting from an unexpectedly high value
for one animal, does not appear to be an accurate reflection of the americium
transport. For caprine milk, peak nuclide concentration also occurred 48
hours after dosing with somewhat of a peak plateau between post-treatment
hours 24 and 72. Total americium transfer to milk for the individual goats
was 5.67 x 10~u and 8.28 x 10~3 percent of the oral dose. Peak americium
concentrations in the urine (Table XI) following nuclide ingestion occurred
at the 48-hour period for cows and at the 24-hour period for the goats. Amer-
icium concentrations in the feces (Table XIII) were highest at the 72-hour
and at the 48-hour post-ingestion periods for cows and goats, respectively.
Americium transport to milk, urine and feces was also basically similar
(between cows and goats) after intravenous dosing. The average percentage
of injected americium transferred to milk, urine and feces was 3, 6 and 2
percent respectively for cows and 2, 4 and 2 percent respectively for goats.
In both groups a large portion (approximately 30 percent) of all americium
released from the body (milk, urine and feces) was found in the urine during
the first 24 hours after injection. Taylor et al. (1961) noted that, during
the early post-dosing stages, americium was excreted at a greater rate than
was plutonium. Further studies have clearly shown that a large fraction of
the total americium excretion from dogs is released via the urine 1 day after
nuclide injection (Lloyd et al., 1970).
At time of sacrifice nuclide retention differences were noted between
cows and goats. Bovine bone retained the greatest fraction of the administered
dose (Table XIV) followed by the liver. However, liver retained the greatest
amount of americium in the goats following both oral and intravenous doses.
Differences in nuclide deposition are quite evident in the intravenously dosed
animals. Caprine bone contained only 13 percent of the injected americium,
an observation that contrasted with the intravenously dosed cows where nearly
51 percent of the dose was retained in the skeleton. In the orally dosed cows,
approximately 48 percent of all americium retained in the carcass was found
in the skeleton. For the orally dosed goats, 24 percent of the carcass amer-
icium was recovered in bone. However, it should be remembered that total
carcass retention following oral dosing has been based on the americium recovered
in only liver, bone, kidney, lung, spleen, thyroid, gonads, muscle, heart and
plasma. Small amounts of americium were undoubtedly present in other tissues
and organs which, if included in the total carcass value, would reduce these
relative percentages of skeletal retention.
The mean percentage of americium dose retained per gram of tissue is
shown for all treatment groups in Table XV. In each case the femur shaft
contained less americium per gram than did the epiphysis, and the sternum
contained more americium per gram of tissue than did the vertebra. The
relatively high concentration in goat rib following intravenous injections
is somewhat surprising at this early sacrifice time. In general, the skeletal
deposition pattern in goats is more difficult to interpret than that for the
15
-------
TABLE XIV
Bone
Liver
Kidney
Lung
Spleen
Thyroid
Muscle
MEAN PERCENTAGE OF AMERICIUM DOSE RETAINED
IN DAIRY ANIMALS AT TIME OF SACRIFICE
Oral Dose
Cows
5.66 x ID"3
4.08 x 10~3
3.75 x 10-^
2.82 x 10-4
7.84 x 10"5
5.67 x 10-7
9.55 x 10-4
Goats
1.67 x 10-3
5.43 x ID"3
1.51 x 10"4
9.96 x 10~5
8.04 x 10-6
3.55 x 10~7
6.69 x 10-4
Intravenc
Cows
50.5
40.8
2.4
1.7
0.7
0.2
5.4
us Dose
Goats
12.7
47.4
0.9
0.5
0.4
0.02
4.4
TABLE XV
MEAN PERCENTAGE OF AMERICIUM DOSE
RETAINED PER GRAM OF TISSUE
Diaphysis
Epiphysis
Sternum
Vertebra
Rib
Liver
Kidney
Lung
Spleen
Thyroid
Muscle
Mammary Gland
Heart
Oral Dose
Cows
3.47 x 10-8
5.77 x 10-8
8.69 x ID"8
7.32 x 10-8
4.48 x 10~8
4.30 x lO"7
1.54 x ID"7
5.15 x 10~8
3.34 x 10-8
1.22 x 10-8
3.60 x 10-9
4.26 x 10-8
7.29 x 10~8
Goats
8.54 x 10-7
1.01 x 10-6
1.01 x 10~6
5.50 x 10-7
8.53 x 10-7
7.96 x 10-6
1.23 x 10-6
1.20 x 10" 7
6.44 x 10-8
8.11 x 10~8
4.36 x 10-8
4.37 x 10-7
1.21 x 10-7
Intravenous Dose
Cows
3.05 x 10-4
6.07 x 10"4
6.79 x 10-4
6.58 x 10-4
4.38 x 10""+
3.82 x 10-3
1.15 x 10-3
2.64 x 10-4
2.71 x 10-4
7.08 x 10-5
1.93 x 10-5
4.81 x 10"4
2.88 x 10-4
Goats
3.58 x 10-3
6.33 x 10"3
5.43 x 10"3
4.67 x 10-3
6.83 x 10-3
5.66 x 10-2
6.97 x 10-3
1.09 x 10-3
2.93 x 10-3
3.78 x 10-3
2.85 x 10-4
2.49 x 10-3
1.05 x 10~3
16
-------
cows which revealed a similar pattern after both the oral and intravenous
doses. Short term americium metabolism in rats (Taylor, 1962) also demon-
strated the increased americium deposition in the epiphysis relative to the
diaphysis. Vertebra and sternum had greater americium concentrations per
gram than did either the femur or rib in an intravenously dosed baboon
sacrificed 1 month after nuclide injection (Rosen et al., 1972). However,
the sternum retained less americium per gram than either the rib, femur or
vertebra in dogs (Lloyd et al., 1972) sacrificed at various time intervals.
Variations in total skeletal retention have also been related to the particu-
late characteristics of the americium dose (Lindenbaum et al., 1970).
In both intravenously and orally dosed dairy animals, the liver retained the
greatest amount of americium on a per gram of tissue basis. Following the
liver, americium concentrations were second highest in the kidney. The extent
of americium retention in the liver has been shown to be affected by animal
age and sex (Durakovic et al., 1973). Furthermore, since americium retention
may be influenced by the absolute size of various organs, it should be noted
that livers of lactating cows have been projected to be approximately 20
percent heavier than livers from non-lactating cows (Smith and Baldwin, 1974).
Rollins and Durakovic (1972) reported americium retention differences in the
livers of lactating and non-lactating rats following intravenous doses on or
before the day of parturition. While there were no liver differences in
americium concentration between lactating and control rats, liver weights were
greater in the lactating animals. During the current americium experiment
using cows and goats, actual liver weights were taken for all animals and the
americium retention has been reported on a per organ basis and on a per gram
of tissue basis.
Thyroid glands, composed of spherical follicles and an interfollicular
area of highly vascular connective tissue, have been found to retain relatively
high concentrations of americium in beagle dogs. Taylor et al. (1969), using
autoradiographic techniques, showed that the americium was being retained
extracellularly in the interfollicular regions. High thyroid concentrations
were not noted in the dairy animals used for the current experiment.
Tables XVI, XVII, and XVIII present some comparisons between the transport
of americium-241 and plutonium-238 in Holstein dairy cows. Twenty-four-hour
collections of urine and milk (Table XV) contained noticeably higher nuclide
concentrations when the animals were injected with americium, as opposed to
Plutonium. Nuclide retention in the liver (Table XVII) was also greater for
animals that had been dosed with americium. There was a marked similarity
in the nuclide deposition pattern following ingestion of either americium-241
chloride or citrate-buffered plutonium-238 nitrate (Table XVIII).
17
-------
TABLE XVI
COMPARISON OF AMERICIUM-241 AND PLUTONIUM-238 TRANSPORT TO MILK,
URINE AND FECES IN HOLSTEIN DAIRY COWS (Values Expressed
as a Percentage of the Respective Intravenous Doses)
Time
post-inj ection
24 h
48 h
72 h
96 h
120 h
Total
Americium-241*
Milk Urine Feces
1.41
0.470
0.281
0.229
0.167
2.56
3.25
0.887
0.540
0.328
0.291
5.30
1.09
0.454
0.296
0.201
0.152
2.19
Plutonium-238**
Milk Urine Feces
0.450
0.434
0.273
0.186
0.142
1.49
0.991
0.476
0.393
0.278
0.243
2.38
0.272
0.605 x
0.514
0.423
0.391
2.21
^Average values from two cows each given an intravenous dose (0.96 mCi)
of citrate-buffered americium-241 chloride.
**Average values from four cows each given an intravenous dose (16.0 mCi)
of citrate-buffered plutonium-238 nitrate (Sutton et al., 1977b) .
18
-------
TABLE XVII
COMPARISON OF AMERICIUM-241 AND PLUTONIUM-238 RETENTION IN HOLSTEIN DAIRY COWS
APPROXIMATELY ONE WEEK AFTER RECEIVING SINGLE INTRAVENOUS DOSES
(Values Expressed as a Percentage of Dose per kg of Tissue)
Tissue
Diaphysis
Epiphysis
Sternum
Liver
Kidney
Muscle
Lung
Thyroid
Spleen
Heart
Americium-241*
3.05 x 10"1
6.07 x ID"1
6.79 x ID"1
3.82
1.15
1.93 x 10~2
2.64 x ID"1
7.08 x 10~2
2.71 x 10'1
2.88 x ID"1
Plutonium-238**
2.56 x 10~2
8.26 x 10~2
8.25 x 10"1
2.48
2.97 x 10-1
2.63 x 10~2
4.36 x 10~x
3.36 x 10'1
1.95 x 10-1
9.59 x 10-2
^Average values from two cows sacrificed nine days after receiving an intravenous
dose (0.96 mCi) of citrate-buffered americium-241 chloride.
**Average values from two cows sacrificed six days after receiving an intravenous
dose (16.0 mCi) of citrate-buffered plutonium-238 nitrate (Patzer et al., 1977b)
19
-------
TABLE XVIII
TRANSPORT OF ORALLY ADMINISTERED PLUTONIUM-238 AND AMERICIUM-241 TO EDIBLE BOVINE PRODUCTS
% of
% of Dose/Liter
Dose of Milk % of % of
Secreted at Peak % of % of Dose Dose/g
Nuclide No. of in Milk Concen- Time of Dose Dose/g in Muscle of
Dose Animals (Cumulative) tration Sacrifice in Liver of Liver (Skeletal) Muscle
Citrate- Buffered
Plutonium 3 mCi/
animal acute dose
(Stanley et al. ,
1974)
Plutonium Dioxide
1 mCi/animal/day
for 19 consecu-
tive days (Stanley
et al., 1975)
Americium Chloride
41.7 mCi/animal
acute dose
4
4
2
2.0 x ICT4
2.0 x 10~5
4.4 x 1Q-4
4.9 x 10~6
2.7 x 10~ 7
8.6 x 10~6
2 animals
sacrificed
93 days
post-
treatment
2 animals
sacrificed
42 days
post-
treatment
2 animals
sacrificed
73 days
post-
treatment
2 animals
sacrificed
8 days post-
treatment
3.5 x 10~3
5.3 x lO'1*
6.2 x 10-4
4.1 x 10~3
3.7 x 10~7
5.3 x 10~8
5.8 x 10~8
4.3 x 10~7
2.0 x 10~3
8.7 x 10~5
1.3 x 10-1*
9.6 x W~k
6.7 x 10~9
3.3 x lO"10
3.4 x 10-10
3.6 x 10~9
-------
FUTURE PLANS
In addition to preparing a final report on the curium-243 metabolism studies,
summary comparisons will be presented on the biological transport of plutonium,
americium, curium and neptunium in dairy animals. One comparative report has
already been presented (Patzer et at., 1977b). Results will also be compiled and
presented from a recently conducted study (Patzer et al., in preparation) on the
relative transport of plutonium-238 and plutonium-239 in dairy cows.
21
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REFERENCES
Bruenger, F. W., W. Stevens and B. J. Stover. 1969. "Americium-241 in the
Blood: In Vivo and -In Vitro Observations." Rad. Res. 27:349-360.
Davis, C. N., L. E. Davis and T. E. Powers. 1975. "Comparative Body Compo-
sitions of the Dog and Goat." Am. J. Vet. Res. 35:309-311.
Durakovic, A. B., J. G. Hollins and M. C. Storr. 1973. "Influence of Age
and Sex on the Metabolism of Americium by Rats." Health Phys. 24:541-546.
Hamilton, J. G. 1947. "Metabolism of the Fission Products and the Heaviest
Elements." Radial. 45:325-343.
Hollins, J. G., and A. B. Durakovic. 1972. "Metabolism of Americium in
Lactating Rats." Health Phys. 22:627-631.
Klement, A. W., Jr., D. E. Ayer and E. B. Rogers. 1955. "Simultaneous use
of Cr51 and T-1824 Dye in Blood Volume Studies in the Goat." Am. J. Physiol.
181:15-18.
Lindenbaum, A., M. W. Rosenthal, J. J. Russell, E. S. Moretti and D. Chladek.
1970. "Metabolic and Therapeutic Studies of Plutonium and Americium."
pp. 149-152. In Argonne National Laboratory Annual Report. ANL-7770.
Lloyd, R. D., C. W. Mays, G. N. Taylor and D. R. Atherton. 1970. "Americium-
241 Studies in Beagles." Health Phys. 25:149-156.
Lloyd, R. D., W. S. S. Jee, D. R. Atherton, G. N. Taylor and C. W. Mays. 1972.
"Americium-241 in Beagles: Biological Effects and Skeletal Distribution."
pp. 141-148. In Radiobiology of Plutonium. B. J. Stover and W. S. S. Jee,
Eds. J. W. Press. Salt Lake City, Utah. 552 pp.
Matthews, C. A., W. W. Sv/ett and R. E. McDowell. 1975. "External Form and
Internal Anatomy of Holsteins and Jerseys." J. Dairy Soi. 55:1453-1475.
McClellan, R. 0., H. W. Casey and L. K. Bustad. 1962. "Transfer of Some
Transuranic Elements to Milk." Health Phys. 5:689-694.
Mullen, A. A., S. R. Lloyd, R. E. Mosley, G. D. Potter and R. G. Patzer. 1977.
"Absorption, Distribution and Milk Secretion of Neptunium in the Dairy Goat."
In Transuranics in Desert Ecosystems. M. G. White, P. B. Dunaway, and
D. L. Wireman, Eds. USDOE-NVO-181. pp. 267-279.
Patzer, R. G., W. W. Sutton, and G. D. Potter. 1977a. "Passage of Sand
Particles through the Gastrointestinal Tract of Dairy Cows." pp. 151-165.
In Environmental Plutonium on the Neavada Test Site and Environs. M. G. White,
P. B. Dunaway and W. A. Howard, Eds. USERDA-NVO-171.
22
-------
Patzer, R. G., W. W. Sutton, P. B. Hahn, and G. D. Potter. 1977b. "Com-
parisons of Curium-243 and Plutonium-238 Biological Transport in Dairy
Animals Following Intravenous Injection." In Transuranics in Desert
Ecosystems. M. G. White, P. B. Dunaway, and D. L. Wireman, Eds. pp. 243-265.
Rosen, J. C., N. Cohen and M. E. Wrenn. 1972. "Short Term Metabolism of
ZH1Am in the Adult Baboon." Health Phys. 22:621-626.
Scott, K. G., D. H. Copp, D. J. Axelrod and J. G. Hamilton. 1948. "Metabolism
of Americium in the Rat." J. Biol. Chem. 175:691-703.
Smith, N. E., and R. L. Baldwin. 1974. "Effects of Breed, Pregnancy, and
Lactation on Weight of Organs and Tissues in Dairy Cattle." J. Dairy Sci.
57:1055-1060.
Stanley, R. E. , E. W. Bretthauer and W. W. Sutton. 1974. "Absorption,
Distribution and Excretion of Plutonium by Dairy Cattle." pp. 163-185. In
The Dynamics of Plutonium in Desert Environments. P. B. Dunaway and M. G.
White, Eds. USAEC-NVO-142.
Stanley, R. E., E. W. Bretthauer and W. W. Sutton. 1975. "Absorption,
Distribution and Excretion of Plutonium by Dairy Cattle." pp. 97-124. In
The Radioecology of Plutonium and Other Transuranics in Desert Environments.
M. G. White and P. B. Dunaway, Eds. USERDA-NVO-153.
Sullivan, M. F., and A. L. Crosby. 1975. "Absorption of Uranium-233,
Neptunium-237, Plutonium-238, Americium-241, Curium-244, and Einsteinium-253
from the Gastrointestinal Tract of Newborn and Adult Rats." pp. 105-108.
In Pacific Northwest Laboratory Annual Report. BNWL-1950 (PT. 1).
Sutton, W. W. , R. G. Patzer, P- B. Hahn and G. D. Potter. 1977a. "Biological
Transport of Curium-243 in Lactating Dairy Goats." pp. 167-178. In Environ-
mental Plutonium on the Nevada Test Site and Environs. M. G. White,
P. B. Dunaway and W. A. Howard, Eds. USERDA-NVO-171.
Sutton, W. W., R. G. Patzer, P. B. Hahn and G. D. Potter. 1977b. "Bovine
Transport and Retention of Plutonium-238 with Special Emphasis on the Gastro-
intestinal Uptake of In Vivo Labeled Milk." pp. 179-192. In Environmental
Plutonium on the Nevada Test Site and Environs. M. G. White, P. B. Dunaway,
and W. A. Howard, Eds. USERDA-NVO-171.
Sutton, W. W. , R. G. Patzer, P. B. Hahn, and G. D. Potter. 1977c. "Plutonium
Retention in Dairy Calves Following Ingestion of Either In Vivo Labeled or
In Vitro Labeled Milk." In Transuranics in Desert Ecosystems. M. G. White,
P. B. Dunaway, and D. L. Wireman, Eds. USDOE-NVO-181. pp. 229-241.
Taylor, D. M. 1962. "Some Aspects of the Comparative Metabolism of Plutonium
and Americium in Rats." Health Phys. 5:673-677.
23
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Taylor, D. M., F. D. Sowby, and N. F. Kember. 1961. "Metabolism of Americium
and Plutonium in the Rat." Phys. Med. Biol. 6:73-86.
Taylor, G. N., W. S. S. Jee, N. Dockum, and E. Hromyk. 1969. "Microscopic
Distribution of Americium-241 in the Beagle Thyroid Gland." Health Phys.
17:723-725.
24
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DISTRIBUTION
1-40 Environmental Monitoring and Support Laboratory-Las Vegas
41 Mahlon E. Gates, Manager, DOE/NV, Las Vegas, NV
42 Troy E. Wade, DOE/NV, Las Vegas, NV
43 David G. Jackson, DOE/NV, Las Vegas, NV
44 Paul J. Mudra, DOE/NV, Las Vegas, NV
45 Elwood M. Douthett, DOE/NV, Las Vegas, NV
46 - 47 Ernest D. Campbell, DOE/NV, Las Vegas, NV
48 - 49 Paul B. Dunaway, DOE/NV, Las Vegas, NV
50 Roger Ray, DOE/NV, Las Vegas, NV
51 Robert W. Taft, DOE/NV, Las Vegas, NV
52 Leon Silverstrom, DOE/NV, Las Vegas, NV
53 Robert W. Newman, DOE/NV, Las Vegas, NV
54 Bruce W. Church, DOE/NV. Las Vegas, NV
55 - 56 Technical Library, DOE/NV. Las Vegas, NV
57 Chief, NOB/DNA, DOE/NV, Las Vegas, NV
58 Hal Hollister, DOEC, DOE/HQ, Washington, DC
59 Tommy F. McCraw, DOEC, DOE/HQ, Washington, DC
60 L. Joe Deal, DOEC, DOE/HQ, Washington, DC
61 - 65 Major General Joseph K. Bratton, Director, MA, DOE/HQ,
Washington, DC
66 Gordon C. Facer, MA, DOE/HQ, Washington, DC
67 Robert L. Watters, BER, DOE/HQ, Washington, DC
68 Jeff Swinebroad, BER, DOE/HQ, Washington, DC
69 Robert W. Wood, BER, DOE/HQ, Washington, DC
70 William S. Osburn, Jr., BER, DOE/HQ, Washington, DC
71 Ray Brechbill, DOE/SAN, Oakland, CA
72 Marcy Williamson, HSL/INEL, DOE/ID, Idaho Falls, ID
73 Steven V. Kaye, Oak Ridge National Lab., Oak Ridge, TN
-74 Helen Pfuderer, ESIC, Oak Ridge National Lab., Oak Ridge, TN
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75 H. E. Wahlgren, CARL, Oak Ridge National Lab., Oak Ridge, TN
76 H. E. Walburg, CARL, Oak Ridge National Lab., Oak Ridge, TN
77 Asst. Admin, for Research and Development, EPA, Washington, DC
78 Deputy Asst. Admin, for Radiation Programs, EPA, Washington, DC
79 Director, Div. of Criteria and Standards, ORP, EPA, Washington, DC
80 Director, Div. of Field Operations, ORP, EPA, Washington, DC
81 Director, Div. of Technology Assessment, ORP, EPA, Washington, DC
82 Director, Office of Technical Analysis, EPA, Washington, DC
83 Library, EPA, Washington, DC
84 Regional Administrator, Region IX, EPA, San Francisco, CA
85 Regional Radiation Representative, Region IX, EPA, San Francisco, CA
86 Director, Radiochemistry and Nuclear Engineering Branch, EPA,
Cincinnati, OH
87 Director, Eastern Environmental Radiation Facility, EPA, Montgomery, AL
88 Harold F. Mueller, ARL, NOAA, Las Vegas, NV
89 Gilbert J. Ferber, ARL, NOAA, Silver Spring, MD
90 K. M. Oswald, Mgr., Health and Safety, LLL, Mercury, NV
91 Richard L. Wagner, LLL, Livermore, CA
92 Howard W. Tewes, LLL, Livermore, CA
93 Paul L. Phelps, LLL, Livermore, CA
94 Mortimer L. Mendelsohn, LLL, Livermore, CA
95 J. C. Hopkins, LASL, Los Alamos, NM
96 Harry S. Jordan, LASL, Los Alamos, NM
97 Lamar J. Johnson, LASL, Los Alamos, NM
98 George E. Tucker, Sandia Lab., Albuquerque, NM
99 Carter D. Broyles, Sandia Lab., Albuquerque, NM
100 Melvin L. Merritt, Sandia Lab., Albuquerque, NM
101 R. Glen Fuller, Oracle, AZ
102 Richard S. Davidson, Battelle Memorial Institute, Columbus, OH
103 Arden E. Bicker, REECo, Mercury, NV
104 Savino W. Cavender, REECo, Mercury, NV
105 Auda F. Morrow, CETO, Mercury, NV
106 Billy Moore, NTSSO, DOE/NV, Mercury, NV
107 Leo Bustad, Director, Veterinary Medicine, Washington State University,
Pullman, WA
108 Vincent Schultz, Washington State University, Pullman, WA
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109 Arthur Wallace, University of California, Los Angeles, CA
110 Wesley E. Niles, University of Nevada, Las Vegas, NV
111 Library, University of Nevada, Las Vegas, NV
112 Verle R. Bohman, University of Nevada, Reno, NV
113 Lloyd P. Smith, President, Desert Research Institute, University
of Nevada, Reno, NV
114 Paul R. Fenske, Desert Research Institute, University of Nevada,
Reno, NV
115 William S. Twenhofel, U.S. Geological Survey, Denver, CO
116 Manager, Desert National Wildlife Range, U.S. Fish and Wildlife
Service, Las Vegas, NV
117 Supervisor, Region III, Nevada Fish and Game Department,
Las Vegas, NV
118 Paul Lyons, Nevada Wildlife Research, Division of Archives,
Capitol Building Annex, Carson City, NV
119 Deward W. Efurd, McClellan Central Lab., McClellan Air Force
Base, CA
120 L. L. Skolil, San Diego State University, San Diego, CA
121 - 148 Technical Information Center, DOE, Oak Ridge, TN
(for public availability)
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