NERC-LV-539-18
RADIATION SURVEILLANCE OE RUMINANTS ON AND ABOUT THE NEVADA TEST SITE
by
Donald !.). Smith
Radiological Research Program
National Environmental Research Center
U. S. ENVIRONMENTAL PROTEC, iN AGENCY
I -, " V ,-,.-, -: r- '.!,— , ,.J',
ihed
This study performed under a Momoraridum of
Understanding No. AT(26-l}-539
for the
U. S. ATOMIC ENERGY COMMISSION
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This report was prepared as an account of work sponsored by the United
States Government. Neither the United States nor the United States
Atomic Energy Commission, nor any of their employees, nor any of their
contractors, subcontractors, or their employees, makes any warranty,
express or implied, or assumes any legal liability or responsibility
for the accuracy, completeness or usefulness of any information, apparatus,
product or process disclosed, or represents that its use would not infringe
privately-owned rights.
Available from the National Technical Information Service,
U. S. Department of Commerce,
Springfield, VA. 22151
Price: paper copy $3.00; microfiche $.95.
(JU1
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NERC-LV-539-18
RADIATION SURVEILLANCE OF RUMINANTS ON AND ABOUT THE NEVADA TEST SITE
by
Donald D. Smith
Radiological Research Program
National Environmental Research Center
U. S. ENVIRONMENTAL PROTECTION AGENCY
Las Vegas, Nevada
Published November 1972
This study performed under a Memorandum of
Understanding No. AT(26-1)-539
for the
U. S. ATOMIC ENERGY COMMISSION
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ABSTRACT
The National Environmental Research Center-Las Vegas is engaged in various
radiation research and surveillance activities. A portion of this work is
concerned with the metabolism and tissue burdens of radionuclides in domes-
tic and wild ruminants.
The 90Sr levels in bones from three species of ruminants grazing on or near
the Nevada Test Site have shown a steady decline since the cessation of
atmospheric testing in 1962. Levels of 90Sr observed in desert bighorn
sheep (0\)jj> cana.de.W4A ne&on-t] ranged from 3.9-13.4 pCi/g of ash in 1964
(average of 9.7 pCi/g of ash) and from 1.0-12.0 pCi/g of ash in 1971
(average of 5.8 pCi/g of ash).
Levels of gamma emitting radionuclides found in the Nevada Test Site beef
herd remain low, with the liver as the edible organ containing the highest
levels of radioactivity.
In addition, the operation of an experimental dairy farm, the maintenance
of an experimental beef herd, and the use of the dairy herd in controlled
metabolism studies are discussed.
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INTRODUCTION
The National Environmental Research Center-Las Vegas (NERC-LV), is engaged
in various research and surveillance activities. Much of this work is con-
cerned with the metabolism and tissue burdens of radionuclides in domestic
and wild ruminants. This research requires three types of support activities
on the Nevada Test Site (NTS). These are: (1) the maintenance of an experi-
mental beef herd, (2) the conduction of wildlife surveillance, and (3) the
operation of an experimental dairy farm.
During 1957 an Animal Investigation Program was established by the Atomic
Energy Commission (AEC). In 1964 this program was assigned to the NERC-LV.
The objectives of the Animal Investigation Program are:
1. To determine tissue concentrations of fresh and/or aged fission
and activation products in biological samples obtained from bovine on
the NTS and from off-site ranches, if required.
2. To develop and conduct wildlife studies on and near the NTS in
cooperation with State and Federal wildlife agencies in order to.
assess radionuclide content of various edible wildlife species.
3. To maintain veterinary relations with the off-site population.
4. To investigate alleged damage to domestic animals from the AEC's
activities.
The research reported was performed as part of the Animal Investigation Pro-
gram and was supported by the U. S. Atomic Energy Commission under a Memo-
randum of Understanding.
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Experimental Beef Herd
Since 1957 a beef herd has grazed on the NTS * '. The original herd was
purchased from area ranches. The descendants of this herd now number
80 grade or nonpurebred Herefords. They routinely graze the natural vege-
tation growing in the fallout zones of three atmospheric tests which were
detonated in the early sixties. This herd is maintained in the same manner
as herds neighboring the NTS.
Twice a year the herd is rounded up and six beef animals are sacrificed.
The animals are necropsied and samples collected for radioanalysis and
histopathology. No gross or microscopic lesions have been noted that can
be directly attributed to radiation ^2> 3'. In 1970 the calving was 96%
and the average weight gain was 1.5 pounds per day between May and
October.
Table 1 presents a summary of the analytical data from the tissues collected
from beef animals grazing on the NTS that were sacrificed on October 29, 1970.
As shown in the table, certain radionuclides (95Zr, 106Ru) detected in the
ingesta in the ruminants are not readily absorbed through the gut but are
passed out of the animals in the feces. The 131I levels found in the
thyroids are believed to have resulted from an atmospheric nuclear deto-
nation that was conducted by a foreign nation on October 14, 1970. The
International Commission on Radiological Protection (ICRP) recommended
biological parameters and radiation protection guides in ICRP Reports 2
and 10. Cesium is biologically similar to potassium, and is, therefore,
incorporated into the soft tissues of the body. Thus, the radiation dose
from 137Cs is evaluated based on the total body dose. The highest concen-
tration of 137Cs (80 pCi/kg) in an edible tissue was found in the liver of
one of the cattle. Assuming an adult was to consume one pound of this liver
per week, for a year, his dose commitment could be calculated as shown
on page 4.
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Table 1. Summary of Analytical Results of Tissues from Beef Animals,
October 29, 1970 (reported on wet weight basis)
Bone Bone
Rumen Femur Femur
Isotope Content Liver Lung Muscle Thyroid Wet Weight Ash
K 0.8(7) 1.6(7) 1.3(7) 1.9(7)
g/kg 0.5-1.9 1.0-2.5 1.0-1.9 1.1-3.7 <0.3 NA < NA
NA NA NA " NA NA 1.0(7) 4.3(7)
pCi/g 0.4-1.9 1.5-8.3
45(5) <25 <25 <25 <25 NA NA
pCi/kg 45-50
106Ru 250(2) <250 <250 <250 <250 NA NA
pCi/kg 200-300
1311 <0.025 <0.025 <0.025 <0.025 6.2(6) NA NA
pCi/g 4.3-9.7
137Cs <25 80(1) 230(1) 45(3) <25 NA NA
pCi/kg 30-50
144Ce 500(7) 300(3) <250 <250 <250 NA . NA
pCi/kg 300-800 250-400
First number is average, number in parenthesis is number of samples with
detectable activity, third set of numbers is the range.
NA = Not analyzed.
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Dose Calculation
80 pd/kg x - x 1 ,bM x
yr
_g _ ~
x ]. pCi = 122 x TO"6 ~ = o.i mrem/yr of consumption.
This level of approximately 0.1 mrem would be about 'three orders of magni-
tude below the radiation protection guides recommended by the Federal Radia-
tion Council and the ICRP.
Wildlife Surveillance
In addition to the beef surveillance, the Animal Investigation Program is
charged with conducting surveillance of wildlife which may enter the food
chain of man. Samples are collected from at least one mule deer every
three months. These samples are usually collected from road killed animals
but are occasionally hunted under the provisions of a collection permit
issued by the Nevada Fish and Game Commission. Rabbits and game birds are
also collected.
Samples from desert bighorn sheep are also collected through the cooperation
of personnel of the Desert National Wildlife Range and the participants in
the annual hunt in this area. In recent years, the levels of gamma emitting
radionuclides in the tissues have been of low magnitude and are usually
below detectable limits of the Center's analytical equipment.
In the fall of 1970, water samples were collected from seven natural springs
on the Desert National Wildlife Range. The results of gamma spectroscopy
analysis were negligible on all samples and the tritium levels did not
exceed 400 pCi/1.
Figure 1 presents the average 90Sr content of the ash of bones collected
from deer on or near the NTS, from cattle on the NTS and from desert bighorn
sheep on the Sheep Range. The data presented were collected from 1964 to
1971.
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20
CD
u.
CO
o
O
Q.
I
CO
111
z
o
m
10
0
DEER
BEEF
BIGHORN SHEEP
1=1
1964
1965
1966
1967
1968
1969
1970
1971
90
Figure 1. Comparison of Sr in Bones of Deer, Beef and Bighorn Sheep
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The 90Sr data on the three species through 1963 were reported previously
I ' '. In general, all three species have shown a downward trend since
1964 and this is assumed to be directly associated with the cessation of
atmospheric testing in 1962. In 1964 the range in bone ash samples from
desert bighorn sheep was 3.9-13.4 pCi/g of ash with an average of 9.7 pCi/g
of ash and in 1971 the range was 1.0-12.0 pCi/g of ash with an average of
5.8 pCi/g of ash.
Strontium-90 has a long half-life (27.7 years) and resembles calcium in its
biological behavior, so the critical organ is bone. As it decays by beta
emission, there may be damage to the bone marrow, which is one of the blood-
forming sites within the body.
Radiation protection guides have not been specifically established for desert
bighorn sheep, but have been established for man. These standards may be
applied if it is assumed that desert bighorn sheep are no more sensitive
to the effects of radiation than man. The radiation protection guide for
90Sr in man has been established by the National Committee for Radiation
Protection as 2 uCi in the critical organ, i.e. bone, for occupational
exposure. The radiation protection guide for members of the general popu-
lation is l/30th of this value or 6.7 x lO4 pCi. Standard man contains
7,000 grams of bone in his body which will yield approximately 2,330 grams
of ash. For standard man 6.7 x lO4 pCi of activity corresponds to 28 pCi
per gram of ash.
As shown in Figure 1, levels of 90Sr found in the bone ash of desert big-
horn sheep and other ruminants living on and around the NTS are a fraction
of the 28 pCi/g of ash level.
Experimental Dairy Farm
The experimental dairy farm was established in 1964 to study the transport
of radioiodine through the soil-forage-cow-milk-food-chain. Data obtained
from studies conducted there were used to formulate a model for calculating
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the dose to man drinking milk from cows exposed to fresh fission products
under a variety of conditions and exposure levels.
The research dairy farm is located in the northern end of the NTS, 120 miles
byroad from Las Vegas. It consists of 16 1/2 acres of croplands which are
irrigated from a 5,400-foot well. Crops grown are alfalfa and rye, which
furnish forage for the dairy herd of 30 animals (26 Holstein and 4 Jersey
cows). Standard irrigation, fertilization, and harvesting practices are
used * . During 1970 the croplands provided 170 tons of green chop and
50 tons of hay.
The cows are maintained in a dry lot the year around. They are not allowed
to graze; all forage is brought to them. Commercial husbandry practices
are followed with the dairy herd, except that individual bucket milkers are
used to prevent cross contamination and to allow the collection of data from
individual cows. The cows are milked on a 9- and 15-hour schedule, in order
(7 8)
to reduce the manpower requirement v * .
Despite the unusual milking hours and extensive participation in experi-
ments, the cows average over 13,000 pounds of milk per lactation with an
average butterfat percentage of 3.5. The Nevada Dairy Herd Improvement
Association's monthly ratings have placed the herd as high as No. 1 on
butterfat percentage and third on milk production.
In addition to furnishing feed for the cows, the crops are used for experi-
mental purposes. They were used for studying the uptake and retention of
radionuclides by the plants and for the investigation of the uptake of
radionuclides by the cows from ingestion of the plants. Aerosols of
radioiodine were generated over the crops which were then harvested in the
normal manner. A weighed amount of this forage was fed to the cows in the
experimental feeding pens. A sample of each cow's ration was analyzed for
radionuclide content prior to feeding. The uneaten residue was also
weighed and the total radionuclide intake of the .cow was determined. At
each milking, each cow's production was weighed and sampled for analysis.
The percentage of the radionuclide transferred to the milk was then derived.
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Other experiments were carried out in association with Plowshare cratering
experiments. Forage was placed downwind of these experiments and subse-
quently returned to the farm and fed in the same manner as above, except
that baled hay was chopped before feeding to ensure that a homogeneous ration
was fed and that a representative sample was collected.
There is a microplot area at the farm with 1/8 to 1/4 acre study plots which
are used to grow a variety of forage, grain and vegetable crops. The wheat
yield in 1970 was approximately 40 bushels per acre. Vegetables that have
been grown include onions, radishes, potatoes, beets, sugar beets, lettuce,
Swiss chard, beans, English peas, cow peas, melons, sweet corn, and tomatoes.
These plots have been used to study the uptake of aged radionuclides by the
crops from the soil which contains ejecta from the Sedan crater. The leach-
ing effect of irrigation water on these radionuclides has also been studied.
The dairy cows have been used for metabolism studies of various radionuclides.
In these studies, following the oral or intravenous administration of the
selected radionuclide, the cows were placed in special metabolism stalls
for a period of 8 to 14 days. During this time, milk and blood samples
were collected every six hours. The entire fecal and urinary output was
collected and sampled every 12 hours and the thyroids were counted period-
ically. In this way the pathways of excretion for the radionuclide were
determined. In addition, cull cows and steer calves were given similar
doses and after varying periods of time they were sacrificed. Each organ
and all tissues were sampled to determine the distribution of the radionu-
clide within the body. Radionuclides studied in this manner have included:
3H. 123I; 131I; 7Be. 181W; 202T1. 203Hg. 86Rb; 59Fe; 187W; and 203pb>
8
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CONCLUSION
The radionuclide burdens found in the tissues of domestic and wild rumi-
nants on and near the NTS continue the decline observed each year since
the cessation of atmospheric testing. On the basis of guidelines currently
used, levels found present no significant hazards to the animals themselves
or to humans consuming their flesh. Surveillance activities will be con-
tinued in order to determine any changes in the present situation.
Studies defining critical metabolic pathways of ingested radionuclides
which are likely to appear in the environment following nuclear detonations
provide valuable data for use in hazard evaluation. Such studies are of
particular importance when conducted with dairy cows as dairy products con-
tribute a significant portion of the total diet for infants and children.
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REFERENCES
1. Smith, D. D. 1970a. Management Histoiy o& the. AEC 8eei$ HeAd 1 Jane.
1964 - 1 Jane. 1969. SWRHL-80r. Western Environmental Research Labora-
tory, Las Vegas, Nevada.
2. Fountain, E. L. 1961. 0^-Site. Animal Investigation PAoje.ct
Annual Re.poAt. United States Atomic Energy Commission, Office Test
Operations, Las Vegas Branch, Las Vegas, Nevada.
3. Smith, D. D. and K. R. Giles. 1970. Animal. Investigation
1969 Annual Re.po*t. SWRHL-102r. Western Environmental Research Labora-
tory, Las Vegas, Nevada.
4. Fountain, E. L. 1962. Mu.dLe.aA. Test PiogAam as it is ReŁate.d to the.
VeseAt Bighoin Sheep. Desert Bighorn Council Trans. 6:62-67.
5. Kramp, R. C. 1965. PneJUminajiy Re.poAt on 90St LeveŁa xln Hocfe. Joints
o& VeseAt Bi.ahotin Sheep and Mule. Ve.eA. Desert Bighorn Council
Trans. 9:87-92.
6. Daley, E. M. and D. D. Smith. 1969. Agronomic A&pe.cts o& the. Expe/u.-
mental V&iny Fasun, January 1966 - Ve.cmbeA 1968. SWRHL-63r. Western
Environmental Research Laboratory, Las Vegas, Nevada.
7. Smith, D. D. and R. E. Engel . 1969. PAogiesA Re.poit Ł0*. tne. l$i.oe.n\j
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DISTRIBUTION
1 - 20 National Environmental Research Center, Las Vegas, Nevada
21 Mahlon E. Gates, Manager, NVOO/AEC, Las Vegas, Nevada
22 Robert H. Thalgott, NVOO/AEC, Las Vegas, Nevada
23 Richard M. Pastore, NVOO/AEC, Las Vegas, Nevada
24 Henry G. Vermillion, NVOO/AEC, Las Vegas, Nevada
25 Donald W. Hendricks, NVOU/AEC, Las Vegas, Nevada
26 Elwood M. Douthett, NVOO/AEC, Las Vegas, Nevada
27 Paul B. Dunaway, NVOO/AEC, Las Vegas, Nevada
28 Ernest D. Campbell, NVOO/AEC, Las Vegas, Nevada
29 - 30 Technical Library , NVOO/AEC, Las Vegas, Nevada
31 Chief, NOB/DNA, NVOO/AEC, Las Vegas, Nevada
32 Robert J. Catlin, Office of Environmental Affairs, USAEC, Washington, D.C.
33 Martin B. Biles, DOS, USAEC, Washington, D.C.
34 Tommy F. McCraw, DOS, USAEC, Washington, D.C.
35 Assistant General Manager, DMA, USAEC, Washington, D.C.
36 Gordon C. Facer, DMA, USAEC, Washington, D.C.
37 John R. Totter, DBM, USAEC, Washington, D.C.
38 John S. Kirby-Smith, DBM, USAEC, Washington, D.C.
39 L. Joe Deal, DOS, USAEC, Washington, D.C.
40 Charles L. Osterberg, DBM, USAEC, Washington, D.C.
41 Rudolf J. Engelmann, DBM, USAEC, Washington, D.C.
42 Harold F. Mueller, ARL/NOAA, Las Vegas, Nevada
43 Gilbert J. Ferber, ARL/NOAA, Silver Spring, Maryland
44 Stanley M. Greenfield, Assistant Administrator for Research & Monitoring,
EPA, Washington, D.C.
45 William D. Rowe, Deputy Assistant Administrator for Radiation Programs,
EPA, Rockville, Maryland
46 Dr. William A. Mills, Dir., Div. of Criteria & Standards, Office of
Radiation Programs, EPA, Rockville, Maryland
47 - 48 Charles L. Weaver, Dir., Field Operations Division, Office of
Radiation Programs, EPA, Rockville, Maryland
49 Ernest D. Harward, Act. Dir., Div. of Technology Assessment, Office of
Radiation Programs, EPA, Rockville, Maryland
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Distribution (continued)
50 Gordon Everett, Dir., Office of Technical Analysis, EPA,
Washington, D.C.
51 Library, EPA, Washington, D.C.
52 Bernd Kahn, Chief, Radiochemistry & Nuclear Engineering, NERC, EPA,
Cincinnati, Ohio
53 Kurt L. Feldmann, Managing Editor, Radiation Data & Reports, ORP, EPA,
Rockville, Maryland
54 Dr. J. Frances Allen, ORM, EPA, Arlington, Virginia
55 Regional Admin., Region IX, EPA, San Francisco, California
56 Regional Radiation Representative, Region IX, EPA, San Francisco,
California
57 Eastern Environmental Radiation Laboratory, EPA, Montgomery, Alabama
58 William C. King, LLL, Mercury, Nevada
59 Bernard W. Shore, LLL, Livermore, California
60 James E. Carothers, LLL, Livermore, California
61 Howard A. Tewes, LLL, Livermore, California
62 Lawrence S. Germain, LLL, Livermore, California
63 Paul L. Phelps, LLL, Livermore, California
64 Charles I. Browne, LASL, Los Alamos, New Mexico
65 George E. Tucker, Sandia Laboratories, Albuquerque, New Mexico
66 Harry S. Jordan, LASL, Los Alamos, New Mexico
67 Arden E. Bicker, REECo, Mercury, Nevada
68 Savino W. Cavender, REECo, Mercury, Nevada
69 Carter D. Broyles, Sandia Laboratories, Albuquerque, New Mexico
70 Melvin L. Merritt, Sandia Laboratories, Albuquerque, New Mexico
71 Richard S. Davidson, Battelle Memorial Institute, Columbus, Ohio
72 R. Glen Fuller, Battelle Memorial Institute, Las Vegas, Nevada
73 Steven V. Kaye, Oak Ridge National Lab., Oak Ridge, Tennessee
74 Leo K. Bustad, University of California, Davis, California
75 Leonard A. Sagan, Palo Alto Medical Clinic, Palo Alto, California
76 Vincent Schultz, Washington State University, Pullman, Washington
77 Arthur Wallace, University of California, Los Angeles, California
78 Wesley E. Niles, University of Nevada, Las Vegas, Nevada
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Distribution (continued)
79 Robert C. Pendleton, University of Utah, Salt Lake City, Utah
80 William S. Twenhofel, U. S. Geological Survey, Denver, Colorado
81 Paul R. Fenske, Desert Research Institute, University of Nevada,
Reno, Nevada
82 John M. Ward, President, Desert Research Institute, University of
Nevada, Reno, Nevada
83 - 84 Technical Information Center, USAEC, Oak Ridge, Tennessee (for
public availability)
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