EPA-600/3-77-076
June 1977                                 Ecological Research Series

                      TRITIUM  RETENTION BY COWS
             AND  STEERS AND TRANSFER TO MILK

                                Environmental Monitoring and Support Laboratory
                                       Office of Research and Development
                                      U.S. Environmental Protection Agency
                                             Las Vegas. Nevada 89114

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                RESEARCH REPORTING SERIES

Research  reports  of the  Office  of  Research  and  Development, U.S.
Environmental Protection Agency, have been grouped into five series. These
five broad categories were established to facilitate further development and
application of environmental technology. Elimination of traditional grouping
was consciously planned  to  foster technology  transfer and a maximum
interface in related fields. The five series are:

    1.  Environmental Health Effects Research
    2.  Environmental Protection Technology
    3.  Ecological Research
    4.  Environmental Monitoring
    5.  Socioeconomic Environmental  Studies

This report has been assigned to the ECOLOGICAL RESEARCH series. This
series describes research on the effects of pollution on humans, plant and
animal species, and materials. Problems are assessed for their long- and
short-term influences.  Investigations  include formation,  transport, and
pathway studies to determine the fate of pollutants and their effects. This work
provides the technical basis for setting standards to minimize undesirable
changes in living organisms in the aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical
Information Service, Springfield, Virginia 22161.

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                                             EPA-600/3-77-076
                                             June 1977
       TRITIUM RETENTION BY COWS AND STEERS
               AND TRANSFER TO MILK
                        by
  A. L. Mullen, A. A. MoghissiJ J. C. Wawerna?
B. A. Mitchell, E. W. Bretthauer, and R. E. Stanley
  Environmental Monitoring and Support Laboratory
             Las Vegas, Nevada  89114
                 ^Present Address
       Office of Interdisciplinary Programs
          Georgia Institute of Technology
              Atlanta, Georgia  30332
                 2Present Address
             Criminalistics Laboratory
     Las Vegas Metropolitan Police Department
             Las Vegas, Nevada  89106
  ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY
        OFFICE OF RESEARCH AND DEVELOPMENT
       U.S. ENVIRONMENTAL PROTECTION AGENCY
             LAS VEGAS, NEVADA  89114

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                                  DISCLAIMER

     This report has been reviewed by the Environmental Monitoring and Support
Laboratory-Las Vegas, U.S.  Environmental Protection Agency, and approved for
publication.  Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.

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                                   FOREWORD

     Protection of the environment requires effective regulatory actions which
are based on sound technical and scientific information.  This information must
include the quantitative description and linking of pollutant sources, trans-
port mechanisms, interactions, and resulting effects on man and his environ-
ment.  Because of the complexities involved, assessment of specified pollutants
in the environment requires a total systems approach which transcends the media
of air, water, and land.  The Environmental Monitoring and Support Laboratory-
Las Vegas contributes to the formation and enhancement of a sound integrated
monitoring'data base through multidisciplinary, multimedia programs designed
to:

     •    develop and optimize sustems and strategies for moni-
          toring pollutants and their impact on the environment

          demonstrate new monitoring systems and technologies by
          applying them to fulfill special monitoring needs of
          the Agency's operating programs

     This report presents the results of an investigation designed to evaluate
the short- and long-term behavior of tritium in beef animals and dairy cows
with emphasis on the resultant hazard to humans consuming meat and dairy
products.  It is hoped that this information will be of use to those individ-
uals who must assess hazards from accidental release of tritium, designers of
nuclear waste processing facilities and those responsible for nuclear reactor
site selection.  Additional information regarding this study may be obtained by
contacting the Exposure Dose Assessment Branch of the Monitoring Systems
Research and Development Division.
                                        Georg'e &. Morgan^
                                            Director
                       Environmental Monitoring and Support Laboratory
                                            Las Vegas
                                     iii

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                                   ABSTRACT

     Eight lactating dairy cows and three steers received a single oral ad-
ministration of tritiated water.  Milk and blood from the lactating cows and
blood from the steers were periodically collected and analyzed for tritium
content.

     The tritium content of whole milk decreased with time giving a curve
expressed as a three component exponential which yielded half-times of 3.04 d
0.09, 11.1 ± 2.58, and >120 days.  Tritium in the blood serum of steers de-
creased with half-lives of 4.05 ± 0.21 and 40.4 ± 9.82 days.

     Additional study of the milk to assess tritium incorporation in the
various fractions showed half-times of 2.93 ± 0.14 and 43.7 ± 4.28 days for
milk serum; 2.08 ± 0.56 and >50 days for milk protein; and 3.28 ± 0.35 and
60.7 ± 43 days for butterfat.
                                      IV

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                                   CONTENTS





                                                                      Page





FOREWORD                                                                iii





ABSTRACT                                                                 iv





LIST OF FIGURES                                                          vi





LIST OF TABLES                                                          vii





ACKNOWLEDGMENTS                                                       vi i i





INTRODUCTION                                                             1





CONCLUSIONS                                                              2





RECOMMENDATIONS                                                          2





METHODS                                                                  2





RESULTS                                                                  4





DISCUSSION                                                               14





REFERENCES                                                               15

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                               LIST OF FIGURES

Number

  1.      Average concentration of tritium in whole milk
            following a single oral administration of 100 mCi
            of tritiated water to four dairy cows.

  2.      Average concentration of tritium in milk components
            following a single oral administration of 200 mCi
            of tritiated water to four dairy cows.

  3.      Average concentration of tritium in blood serum
            following a single oral administration of triti-
            ated water to dairy cows and beef animals.

  4.      Average concentration of tritium in blood serum
            following a single oral administration of 65 mCi of
            tritiated water to three beef cattle.
                                     VI

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                                LIST OF TABLES

Number                                                           Page

  1.      Tritium Concentration in yCi/1 of Water Or Its            5
          Equivalent in Whole Milk and Components Following
          A Single Oral Administration of 100 millicurie of
          Tritiated Water

  2.      Tritium Concentration in yCi/1 of Water Or Its Equiv-     7
          alent in Milk Components Following A Single Oral
          Administration of 200 millicurie of Tritiated
          Water

  3.      Tritium Concentration in Blood Serum of Dairy Cows       10
          Following A Single Oral Administration of 100
          millicurie of Tritiated Water

  4.      Tritium Concentration in Blood Serum of Dairy Cows       10
          Following A Single Oral Administration of 200
          millicurie of Tritiated Water

  5.      Tritium Concentration in Blood Serum of Beef Cattle      12
          Following A Single Oral Administration of 65
          millicurie of Tritiated Water
                                     VII

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                                ACKNOWLEDGMENTS
     The authors wish to express their appreciation to S. R. Lloyd, B. Johnson,
L. Dana, J. Titus, R. Hope, and the other personnel of the U.S. Environmental
Protection Agency Experimental Farm for their assistance during the experi-
mental phase of this study, and to R. R. Kinnison and P. Fort  for  the sta-
tistical analysis of the data.
                                     vnx

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                                 INTRODUCTION

     As an isotope of hydrogen, tritium is incorporated into essentially all
components of biological systems.  Tritium is produced as a result of nuclear
fusion and, to a certain extent, nuclear fission explosives, including  those
used in the nuclear stimulation of natural gas formations  (Moghissi and Carter,
1973).  Tritium is also produced in all nuclear power reactors both as  fission
and activation products.  Due to the presence of large quantities of tritium in
the initial stages of operation, it is expected that tritium production in
fusion reactors will be substantially higher than in fission reactors.  Because
of the problems associated with separation and disposal of tritium from nuclear
waste, dilution is presently used as the disposal method for this radionuclide.
However, it is expected that in the foreseeable future tritium will be  sepa-
rated and contained.

     Cow"s milk is recognized as one of the major routes of the  intake  of
radioactive pollutants into the human body.  Attempts to study tritium  metab-
olism in bovines have been numerous.  Black et al.,(1964) studied the turnover
rate of tritium in a total of 17 lactating and nonlactating cattle.  They
observed no difference in the turnover rate of tritium in body water  (T ) in
nonlactating as compared to lactating animals.  Their T  values  ranged  rrom 2.8
to 4.1 days with an average of 3.5 days.  However, Aschbacher et al., (1965)
studied a number of physiological parameters in dairy cows using four lactating
and two nonlactating animals.  They observed T  values for tritium of 3.0 days
for lactating and 5.2 days for nonlactating cows.

     The incorporation of tritium into the organic fraction of milk subsequent
to the intake of tritiated food has also been repeatedly studied.  Lubran and
Corsini  (1960) and Glascock and Wright  (1962) studied tritium transfer  into
certain components of milk subsequent to the intake of tritiated triglycerides.
These authors clearly showed the importance of considering the chemical form of
tritium intake when determining the composition of tritiated compounds  in milk.
In a series of papers Kirchmann et al., studied tritium behavior in dairy cows
(Kirchmann et al., 1969; Kirchmann et al., 1971; and Van den Hoek and Kirch-
mann, 1971).  These authors observed values of 3 to 5 days for the T  of
tritium in lactating cows.  They also observed an increase of tritium concen-
tration in milk solids if tritiated grass was fed to the cows when compared to
intake as tritiated water.  Values for the biological half-life  of tritium in
milk solids were compared to those in body water.

     Potter et al.,(1972) also studied tritium behavior using one dairy cow.
They observed a two-component exponential excretion rate corresponding  to half-
lives of 3.1 and 40 days, respectively.  They also showed a substantial incor-
poration of tritium into the organic component of the milk.

     Due to concern over the continued release of large quantities of tritium

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into the environment and because of the lack of consistent information on the
behavior of tritium in components of man's food chain, this study was under-
taken in dairy cows and beef animals to evaluate both the short- and long-term
behavior in one of the more significant sources of exposure.
                                  CONCLUSIONS

     1.   Little significant difference was noted in the rate of tritium in
body water turnover in lactating dairy cows versus steers.

     2.   Although whole milk is the major route of exposure of humans consum-
ing tritiated dairy products, additional information on the turnover rate of
tritium in milk solids is necessary before an accurate determination of radi-
ation dose can be made.
                                RECOMMENDATIONS

     In the event of contamination of agricultural areas with tritium, the
potential hazard to humans ingesting tritiated dairy products must be carefully
evaluated.  As more knowledge is gained of the metabolism of specific tritiated
compounds, it may be found that incorporation of tritium into nucleic acid, via
deoxyribonucleic acid  (DNA), may influence all aspects of biological activity
and have greater effect than previously ascribed.  Further studies with  a
biological receptor are necessary to accurately estimate exposure/dose result-
ing from the consumption of tritium.
                                    METHODS

     These studies were carried out at the Nevada Test Site on the experimental
farm operated by the U.S. Environmental Protection Agency for the U.S. Energy
Research and Development Administration.  The dairy animals selected for  the
study were either Holstein or Jersey cows 3 to 9 years of age, were in their
30th to 100th day of lactation, and were producing 20 to 31 kilograms  (kg) of
milk per day.  The beef animals were 4- to 6-year-old Hereford steers.  All the
animals were allowed free access to water and alfalfa hay.  In addition,  the
dairy cows received a pelleted commercial dairy feed containing 16% protein.

     The cows were milked with a milking machine, and blood samples from  the
cows and steers were taken by jugular venipuncture.  Tritiated water was
administered to each animal following collection of milk and/or blood for
background activity determinations.  The tritiated water was placed in gelatin
capsules containing starch and administered orally using a balling gun.   Milk
samples were collected twice daily from the dairy animals, and blood samples

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were collected from all animals hourly for the first 12 hours and then at
longer intervals during the remainder of the project.  Milk samples were stored
in 4-liter polyethylene containers to which 10 milliliters  (ml) of formaldehyde
was added to retard spoilage.  Blood samples were centrifuged and the serum
portion was removed for tritium analysis.  All samples were processed for
analysis within 24 hours.

     This study was conducted as a series of three consecutive experiments.
The milk transfer portion of the study utilized two groups of four lactating
dairy cows  (three Hoisteins and one Jersey) in each group.  Each of the cows
was given a single 100-millicurie(mCi) dose of tritiated water.  The milk  from
this group was analyzed for tritium activity in the whole milk.

     The total activity in the milk was determined directly by liquid scin-
tillation counting utilizing an internal standard.  The scintillation liquid
consisted of p-xylene containing 7 grams (g) of 2,5-diphenyloxazole  (PPO)  and
1.5 g of bis-(o-methylstyrylbenzene)  (bis-MSB) per liter mixed with Triton N101
(Rohm and-Haas, Philadelphia, Pennsylvania) in a volume ratio of 2:1.  This
mixture could incorporate up to 10 ml of water or milk in a 25-ml vial  (Lieber-
man and Moghissi, 1970).  Counting efficiency was determined by using an inter-
nal standard with identical system properties  (Moghissi and Carter, 1968).  The
whole milk was mixed thoroughly and two aliquots of each sample were prepared
with one of them having a known quantity of tritium added.

     The second group of dairy cows received 200 mCi of encapsulated tritiated
water each.  Milk from these cows was separated into milk, serum, butterfat,
and protein fractions and the tritium activity of each fraction was determined.

     Milk serum was separated by the addition of trichloracetic acid  (15
g/100 ml).  The presence of about 100 milligrams(mg) of hydrogen ions per  gram
in the acid was regarded as acceptable and within expected errors.  The mixture
was allowed to stand for about 30 minutes and filtered, and the filtrate was
distilled.  The tritium activity in the distillate was determined by liquid
scintillation counting.

     Cream was separated from the milk by cryogenic centrifugation.  Fat was
separated from cream using heat and 100 ml of Triton and 25 grams of hexameta-
phosphate per liter of cream as described by Horowitz  (1970).  The purity  of
the fat was checked using the Babcock test  (Hausler, 1972).

     The proteins were separated from the milk serum and dried for several days
in an oven at a temperature of 40° C.  The dried protein was weighed and the
organically bound tritium separated by combustion  (oxidation) in a Parr bomb.
After the water of combustion was collected, its tritium content was determined
by liquid scintillation counting (Moghissi et al./ 1975).

     After installation of a large scale azeotropic distillation system  (Mo-
ghissi et al. , 1973), the protein and serum separation was repeated using  this
procedure and the results indicated a reasonable agreement between the two
methods.

     In order to determine the difference in blood tritium levels between

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lactating and nonlactating animals, three Hereford steers were each adminis-
tered 65 mCi of tritiated water in the same manner as the dairy cows.  Blood
was collected from all three groups of cows and the serum portion analyzed by
direct liquid scintillation counting.

     The data were analyzed by performing a nonlinear least squares regression
on a sequence of successively more complex mathematical models in the class of
sums of exponential terms functions.  The best of the regression functions was
chosen using the general linear hypothesis test and half-lives were calculated
from the exponential coefficients of the best-fit regression.
                                   RESULTS

     The individual values for whole milk are shown in Table 1 for the four
cows receiving 100 mCi of tritiated water.  The half-lives for tritium transfer
to whole milk are presented graphically in Figure 1.  This figure represents
the mean of the whole milk concentration values listed in Table 1.  Tritium in
the whole milk of cows appears to decrease with a 3.04 ± 0.09-day half-life
during the 20 days following oral administration of 100 mCi of tritiated water.
The transfer of tritium to milk then changed to exhibit a slope with a half-
time of 11.1 ± 2.58 days followed by a much longer half-time of >120 days.

     In order to determine the biological half-time of tritium in the different
milk components, a second experiment was conducted in which each of the dairy
cows received 200 mCi of tritiated water.  The results of this experiment are
shown in Table 2 and Figure 2.  The initial half-times shown by the milk com-
ponents indicate little difference between the milk serum and the butterfat
with half-times of 2.93 ± 0.14 days and 3.28 ± 0.35 days, respectively.  The
protein fraction of the milk exhibited a considerably shorter half-time of
2.08 ± 0.56 days.  The longer half-time portion of the curves showed the
normal variance of results with time and lower activity.  The shortest half-
time was indicated by the tritium activity in the serum portion of the milk.
This was found to be 43.7 ± 4.28 days.  The results of the protein analysis
showed that a relatively constant incorporation of tritium into protein oc-
curred during the 2nd and 3rd months after administration, followed by a half-
time of >50 days for the remainder of the study.  The incorporation of tritium
into butterfat decreased with a longer half-time of 60.7 ± 43.0 days and then
increased during the latter part of the study.

     The blood levels of tritium were similar for both the lactating dairy cows
and the beef animals during the first 12 hours after administration as shown in
Tables 3 and 4 and Figure 3.  The tritium levels in blood serum from beef
cattle shown in Table 5 were averaged and the half-lives determined to be
4.05 ± 0.21 days and 40.36 ± 9.82 days as shown in Figure 4.

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TABLE 1.  TRITIUM CONCENTRATION IN yCi/1 OF WATER OR ITS EQUIVALENT IN WHOLE MILK AND COMPONENTS FOLLOWING
          A SINGLE ORAL ADMINISTRATION OF 100 mCi OF TRITIATED WATER

                                                MILK
r-POSt
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
16
18
20
22
24

H-21
251
209
178
156
128
98.1
80.2
63.2
51.6
41.2
33.2
28.0
21.9
16.6
13.2
9.33
5.30
3.76
1.78
1.40

H-90
283
277
218
189
158
124
105
86.5
69.4
49.1
48.1
40.7
31.3
25.0
20.4
13.3
8.64
6.00
2.90
2.45

H-171
344
376
332
274
244
176
138
116
98.8
69.2
57.6
51.9
39.0
30.9
23.6
16.2
9.94
6.46
3.50
2.00

J-175
428
405
314
276
232
182
142
116
103
76.8
63.2
54.6
41.0
35.2
27.1
17.6
10.4
6.76
3.20
2.29

Day-Post
26
28
31
34
37
40
43
49
56
63
70
77
84
91
98
105
112
119
126
154
161
H-21
0.929
0.792
0.378
0.202
0.132
0.888
0.105
0.040
0.030
0.038
0.028
0.029
0.027
0.030
0.030
0.024
0.029
0.025
0.051
0.069
0.054
H-90
1.62
1.10
0.601
0.333
0.223
0.122
0.139
0.058
0.040
0.042
0.038
0.045
0.043
0.033







H-171
1.64
1.10
0.590
0.376
0.294
0.158
0.181
0.068
0.065
0.075
0.888










J-175
1.71
1.05
0.48
0.330
0.210
0.120
0.160
0.076
0.057
0.071
0.063
0.045
0.043
0.047
0.038
0.033
0.030
0.030
0.060
0.069
0.029

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       10
 0)
 U
 a.
       10
        -5
       10
                    20
40
 60

DAYS
80
100
Figure 1.  Average concentration of tritium in whole milk following a single
           oral administration of 100 mCi of tritiated water to four dairy
           cows.

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TABLE 2.
TRITIUM CONCENTRATION IN yCi/1 OF WATER OR ITS EQUIVALENT IN MILK COMPONENTS FOLLOWING A
SINGLE ORAL ADMINISTRATION OF 200 mCi OF TRITIATED WATER

d
0.3
1
1.4
2
2.4
3
4
5
6
7
9
11
14
16
22
24
29
31
37
45
52
59
65
72
79
86
93
100
107
114
120
Serum
' H*-16
181
354
261
206
188
142
160
139
91.8
72.7
39.0
22.0
6.98
2.97
0.385
0.225
0.217
0.098
0.027
0.020
0.034
0.067
0.013
0.011
0.010
0.010
0.006
0.003
0.004
0.009
H-132
144
	
403
284
290
242
267
244
169
153
95.0
54.0
27.0
17.2
4.45
3.04
1.27
0.720
0.091
0.019
0.016
0.039
0.023
0.022
0.006
0.004
0.003
0.057
0.063
H-135 J**-175
322
300 426
235 358
206 315
210 314
237 310
203 248
147 "180
124 145
75.0
43.4 26.2
22.5 20.7
16.0 8.00
2.19 1.44
1.85 0.770
0.750 	
0.450 0.300
0.053 0.042
0.039 0.030
0.023 0.019
0.090 0.025
0.026 0.013
0.016 0.015
0.013 0.009
0.010 0.008
0.014 0.007
0.019 0.003
0.005 0.005
0.009 0.010
Protein
H-16
73
159
145
123
114
95.1
69.6
50.6
44.7
35.3
15.2
4.38
7.03
3.27
2.72
0.956s
1.04
1.29
0.407
0.426
0.584
0.678
0.243
0.499
0.154
0.119
0.103
0.043
0.072
0.060
0.048
H-132
112
94.4
	
151
152
119
43.0
16.1
12.1
4.42
2.56
0.717
0.664
1.14
1.10
0.684
0.626
1.09
0.866
1.60
0.480
0.252
0.444
H-135
245
138
— ..
154

106
54.5
47.0
10.37
9.78
8.29
3.52
4.95
1.43
1.32
0.970
0.588
0.653
0.481
0.452
0.884
0.583
0.118
0.057
0.086
0.132
J-175
98.8
135
283
177

118
102
94.5
25.0
3.26
2.52
2.55
1.49
1.05
0.910
1.82
2.06
0.822
1.05
1.08
0.596
0.099
0.056
0.082
0.076
0.114
Fat
	 H-16
24.0

__—
78.9

72.0
87.6
75.5
37.7
26.5
14.7
6.86
4.32
2.42
1.66
0.429
0.336
0.151
0.085
0.061
0.065
0.033
0.032
0.030
0.026
0.047
0.040
0.090
0.023
H-132
110

100
70 9
93.5
65.2
53.1
39.0
28.7
16.6
12.0
6.79
2.58
1.60
0.687
0.178
0.060
0.086
0.153
0.059
0.052
0.227
0.258
0.396
0.421
H-135
17.9
83 8


-it. o
75.6
56.3
42.0
33.5
22.6
20.2
9.39
5.96
1.66
0.955
0.510
0.162
0.093
0.066
0.052
0.066
0.051
0.034
0.033
0.038
0.154
0.149
0.038
0.025
11 9


72 i

68.5
60.5
53.8
39.9
37.2
23.8
8.99
4.40
1.04
0.661
0.398
0.189
0.673
0.078
0.054
0.055
0.070
0.039
0.043
0.048
0.053
0.111
0.080
0.150
0.037

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     TABLE 2.  TRITIUM CONCENTRATION IN uCi/1 OF WATER OR ITS EQUIVALENT IN MILK COMPONENTS FOLLOWING A
               SINGLE ORAL ADMINISTRATION OF 200 mCi OF TRITIATED WATER (Continued)
Time
d
128
135
137
142
144
149
156
158
163
177
185
191
199
205
215
226
233
240
247
254
261
269
275
282

H*-16
0.002
0.006
0.004
0.017
0.011
0.010
0.010
0.002
0.005
0.003
0.002
0.003
0.005
0.004
0.002
0.001








Serum
H-132
























H-135
0.008
0.004
0.003
0.003
0.002
0.006
0.004
0.005
0.003
0.002
0.002
0.003












J**-175
























Protein
H-16 '
0.041
0.057
0.054
0.047
0.041
0.033
0.017
0.013
0.016
0.039
0.029
0.024
0.030
0.039
0.0278
0.0207








H-132
























H-135

0.101
0.101
0.088
0.066
0.035
0.026
0.035
0.051
0.054

0.041
0.023
0.0297
0.0315
0.026
0.015







Fat
J-175

0.141

0.094
0.071
0.034
0.032
0.017
0.026

0.026
0.022
0.032
0.043
0.017
0.024

0.013
0.017
0.016




H-16
0.011
0.028
0.048
0.022
0.021
0.022
0.020
0.014

0.015

0.016
0.021
0.016










H-132
























H-135
0.022
0.022
0.034
0.026
0.031
0.026
0.019
0.013


0.012
0.045

0.016

0.024
0.099








J-175

0.034
0.036
0.021
0.024
0.017

0.013

0.009
0.009
0.014
0.023
0.028

0.023
0.014
0.035
0.057
0.064
0.045
0.036
0.018
0.017
00
      *H = Holstein
      **J » Jersey

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    10
    10
    10
u   10
a.
     -2

    10
     -3
    10
o MILK SERUM' T|.J =2.93±0.14 d

e PROTEIN :Tb= 2.08±0.56d

• BUTTERFAT: Tb=3.28±0.35d
                                                                  ©PROTEIN:
                                                                 • BUTTERFAT: T^60.69±43.04 d


                                                                 OMILK SERUM: T^=43.69±4.28d
                                                  o  o
               20
     40
60
80
100
120



DAYS
140
                                                                                160
                                                                      180
200
220
  Figure 2.  Average concentration of tritium in milk components following a  single oral administration

              of  200 mCi of tritiated water  to four  dairy cows.

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TABLE 3.   TRITIUM CONCENTRATION IN BLOOD SERUM OF DAIRY  COWS  FOLLOWING
           A SINGLE ORAL ADMINISTRATION OF 100 mCi OF TRITIATED WATER
Time
h
1
2
3
4
5
6
7
8
9
10
H-21
yci/i
124
232
259

250
238
242
248
335
229
H-90
yCi/1
250
318
303
330
298
295
305
294
291
279
H-171
yCi/1
136
326
410
426
412
430
428
427
437
404
J-175
yCi/1
112
374
406
414
417
411
440
441
410
423
TABLE 4.  TRITIUM CONCENTRATION IN BLOOD SERUM OF DAIRY COWS FOLLOWING
          A SINGLE ORAL ADMINISTRATION OF 200 mCi OF TRITIATED WATER
    Time
     d
H-116
yci/i
H-132
yCi/1
H-135
yci/i
J-175
yci/i
     1/24
     2/24
     3/24
     4/24
     5/24
     6/24
     7/24
     8/24
     9/24
    10/24
    11/24
    12/24
     2
    16
    24
173
313
308
354
378
329
369
356
372
247
331
343
 38.
  2.98
  0.629
240
320
355
403
391
418
406
397
384
365
377
401

 16.2
  2.87
150
197
306
334
340
394
359
359
362
340
362
375
 58.3
  9.93
  2.74
272
425
505
437
507
495
488
491
457
449
507
492
 87.6
  8.70
  1.52
                                 10

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      10
  QC
  LU
  CO
  Q
  O
  2    i
  «o  10
                                                  (lOOmCi)
              1     234    5     67    89     10   11
                                                   (200mCi)
  U
   a.
       10
   1     23456
                                                   89    10    11
                                                  (65mCi)
Figure 3.
    123456789    10    11

                            HOURS

Average concentration  of tritium in blood serum following a single
oral administration of tritiated water to dairy cows and beef
animals.

                           11

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TABLE 5.  TRITIUM CONCENTRATION IN BLOOD SERUM OF  BEEF  CATTLE  FOLLOWING
        A SINGLE ORAL ADMINISTRATION OF 65 mCi OF  TRITIATED WATER
Time
d
1/24
2/24
3/24
4/24
5/24
6/24
7/24
8/24
9/24
10/24
11/24
12/24
1
2
8
16
23
28
30
65
72
79
86
93
106
114
121
128
135
139
142
144
149
156
158
163
Cow #662
VCt /I
___
127
165
174
181
215
218
203
184
206
202
210
208
135
110
28.3
11.4
5.45
1.92
0.071
0.064
0.056
0.044
0.028
0.065
0.029
0.038
0.028
0.023
0.015
	
0.018
0.020
0.009
0.015
0.010
Cow #669
UCi/1
___
118
126
191
219
223
256
239
239
255
240
265
221
122
144
37.3
12.1
5.51
2.09
0.096
0.063
0.076
0.039
0.078
0.067
0.023
0.030
0.021
0.018
0.018
0.018
0.017
0.022
0.011
0.021
0.009
Cow #675
yCi/1
72
194
165
184
194
202
216
206
207
212
214
215
216
173
105
	
11.2
4.84
2.21
	
0.065
0.075
0.047
0.031
0.030
0.030
0.020
0.018
0.025
0.017
0.022
0.045
0.084
0.012
0.010
0.009
                                    12

-------
          10
     O
     O
     g
     GO
     ^     0
     *!    10
    'a.
U)
           -1
          10
                                                         =4.05 ± 0.21 d
                 246

                     HOURS
8    10   12
20
40
 60

DAYS
                                                80
                                       100
                                      120
     Figure 4.  Average concentration of tritium in blood serum  following a single oral administration of
                65 mCi of tritiated water to three beef cattle.

-------
                                   DISCUSSION

     Results of this  study  show that  the turnover  rate  of tritium in  the  body-
water pool of lactating  dairy  cows is not appreciably different from  nonlac-
tating beef animals at 3 days  and  4 days, respectively.   The tritium  turnover
rate 60 days after ingestion showed even less  difference, 44 days for lactating
dairy cows and 40 days for  beef animals.  This result is similar to that  noted
by Black et al.,(1964) who  found the  average half-life  for body water in
lactating cows to be  3.54 ± 0.10 days and that in  nonlactating cattle to  be
3.40 ± 0.18 days over the course of a 15-day study following intravenously
administered tritiated water to dairy cows and steers.   The greater differences
in T  noted by Aschbacher et al.,(1965)  3 days for nonlactating and 5 days for
lactating cows may have  been due to the  use of fat,  nonlactating,  nonpregnant
cows/ whereas the present study and Black's study  utilized steers.  There may
be differences in the rate  of  tritium turnover between  the two experimental
groups due to the differences  in formation and turnover  of muscle by  steers
versus adipose tissue by nonlactating cows.

     The difference in the  rate  of incorporation of  tritium into proteins as
compared to its incorporation  into non-exchangeable  portions to form  stable
carbon-tritium lipid  bonds  is  indicated  by the shorter T  of 2.08 and about 50
days for protein in milk as compared  to  T  of  3.28 and  61 days for butterfat.
The concentration of  tritium in  fat was  noted  by Schirch and Mason (1963)  while
investigating concentrations in  humans chronically exposed to tritium.

     Moyer and DuVigneaud (1972) found the appearance of tritium in protein was
maximal after 1 day following  intravenous administration to rats,  but fell to
about 20 percent of the peak level  by day 5.   Tritium incorporated into serum
fatty acids became maximal during  day 1  and remained relatively constant  until
the 12th day, whereas, the appearance of tritium in  serum cholesterol increased
over a period of 12 days.   It would appear that the  complexity of  the chemical
transformations of tritium  (Smith  and Taylor,  1969)  does not allow a  simple
conclusion to be drawn concerning  the fate of  ingested tritium.

     The relatively long half-time  of >120 days for  the  transfer of tritium to
whole milk indicates  that milk may  be the major contributor to the radiation
dose of humans consuming tritium-contaminated  dairy  products.   However, al-
though milk solids constitute only  1/10  of the total volume of milk,  the
radiation dose resulting from consumption of butterfat and cottage cheese may
exceed that from whole milk due  to  the longer  biological half-lives and in-
corporation of tritium in fat,  protein,  and carbohydrates.   It will be neces-
sary to establish the turnover of  tritiated milk solids  in humans  before  it
will be possible to accurately estimate  the radiation dose resulting  from the
consumption of tritium-contaminated dairy products.
                                      14

-------
                                  REFERENCES
Aschbacher, P. W., T. H. Kamal and R. G. Cragle.  1965.   "Total body water
     estimations in dairy cattle using tritiated water."  J. Animal Sci.
     24:430.

Black, A. L., N. F. Baker, J. C. Hartley, T. E. Chapman and R. W.  Philips.
     1964.  "Water turnover in cattle."  Sci. 144:876.

Glascock, R. F., and E. W. Wright.  1962.   "Some Examples of the Use of  Radio-
     isotopes in Biochemistry."  Uses of Radioisotopes In Animal Biology  and
     the Medical Sciences.  Vol. 1. Academic Press, New York.  p.  185.

Hausler, W. J., Jr., ed.  1972.  Standard Methods for the Examination of  Dairy
     Products.  Am. Pub. Health. Assoc.  Washington, D.C.  p. 225.

Horowitz, W., ed.  1970.  Official Methods  of Analysis of the Association of
     Official Analytical Chemists.  Assoc.  of Official Anal. Chem. , Washington,
     D.C.  1015 pp.

Kirchmann, R., A. Lafontaine, J. Van den Hoek and G. Koch.  1969.  "Transfer
     and distribution of tritium among the  main components of milk produced by
     cows having ingested contaminated water."  Cpmp. Rend. Soc. Biol. 63;1459.

Kirchmann, R., J. Van den Hoek and A. Lafontaine.  1971.  "Transfer et incor-
     poration du tritium dans les constituants de 1'herbe et du lait en  condi-
     tions naturelles."  Health Phys.  2^:61.  July, 1971.

Lieberman, R., and A. A. Moghissi.  1970.   "Low-level counting by  liquid  scin-
     tillation.  II.  Applications of emulsions in tritium counting."  Int. J.
     Appl. Radiat. Isotopes.  21:319.

Lubran, M., and G. Corsini.  1960.  Mineiva Nucl.  4_:130.

Moghissi, A. A., and M. W. Carter.  1968.   "International standard with  identi-
     cal system properties for determination of liquid scintillation counting
     efficiency."  Anal. Chem. 40;812.

Moghissi, A. A., and M. W. Carter.  1973.   Tritium.  Messenger Graphics,
     Phoenix, Arizona,  p. 3277.

Moghissi, A. A., E. W. Bretthauer and E. H. Compton.  1973.  "Separation  of
     water from biological and environmental samples for  tritium analysis."
     Anal. Chem. 45:1565.
                                      15

-------
Moghissi, A. A., E.  W.  Bretthauer,  E. L. Whittaker and D.  N.  McNeils.   1975.
     "Oxygen bomb combustion of environmental and biological  samples for tritum
     analysis."  Inter.  J.  Appl.  Isotopes.

Moyer, A. W.,  and V.  DuVigneaud.   1972.  J. Biol. Ghent.  143;373.

Potter, G. D., G. M.  Vattuone and D. R. Mclntyre.  1972.   "Metabolism of triti-
     ated water  in  the  dairy cow."   Health Phys. 22;405.

Schirch, L. v.,  and M.  Mason.   1963.  J. Biol. Chem. 238:1032.

Smith, T. E.,  and R.  T.  Taylor.   1969.  "Incorporation of  tritium from triti-
     ated water  into carbohydrates, lipids, and nucleic  acids."
     UCRL-50781. 24 p.

Van den Hoek,  J., and R.  Kirchmann.  1971.  Radioecology Applied  to the Pro-
     tection of  Man and His Environment.  Comm. of European Communities,  p. 1.
                                       16               *U.S. GOVERNMENT PRINTING OFFICE: 1977-784^60

-------
                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.
  EPA-600/3-77-076
                                                           3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
       TRITIUM RETENTION BY COWS  AND STEERS
       AND TRANSFER TO MILK
                                                           5. REPORT DATE
                                                             June 1977
                                   6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
   A.  L. Mullen, A.  A.  Moghissi, J. C. Wawerna,
   B.  A. Mitchell, E. W.  Bretthauer and R. E.  Stanley
                                                           8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
   Environmental Monitoring and Support Laboratory
   Office of Research  and Development
   U.S. Environmental  Protection Agency
   Las Vegas, NV  89114
                                   10. PROGRAM ELEMENT NO.
                                       1FA628
                                   11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
  U.S.  Environmental Protection Agency-Las Vegas,  NV
  Office of Research and Development
  Environmental Monitoring and Support Laboratory
  Las Vegas, NV  89114	
                                    13. TYPE OF REPORT AND PERIOD COVERED
                                     FINAL  FY70-71
                                    14. SPONSORING AGENCY CODE

                                     EPA/600/07
15. SUPPLEMENTARY NOTES
16. ABSTRACT

        Eight lactating  dairy cows and three  steers received a single  oral ad-
  ministration of tritiated water.  Milk and blood from the lactating cows and
  blood from the steers were periodically collected and analyzed  for  tritium
  content.
                                               /
        The tritium  content of whole milk decreased with time giving a curve
  expressed as a three-component exponential which yielded half-times of 3.04 ±
  0.09, 11.1 ± 2.58,  and >120 days.  Tritium in the blood serum of  steers de-
  creased with half-lives of 4.05 ± 0.21 and 40.4 ± 9.82 days.

        Additional study of the milk to assess  tritium incorporation in the
  various fractions  showed half-times of 2.93  ± 0.14 and 43.7 ± 4.28  days for
  milk serum; 2.08  ± 0.56 and >50 days for milk protein; and 3.28 ± 0.35 and
  60.7 ± 43 days for butterfat.
                  O££CP.:PTO?!£
        KEY WORDS AND DOCUMENT ANALYSIS

                      Jb.lDENTIFiERE/OPEN ENDED TERMS  !C.  COSAT! I >dd/Group
   Beef
   Biochemistry
   Cattle
   Dairy Cows
  DISTRIBUTION STATEMENT
   RELEASE TO  PUBLIC
Dairy Products
Isotopes
Radiation chemistry
Radiobiology
Tritium
j Tritium retention
j Tritium transfer
'•. Nevada Test  Site
                       19. SECURITY CLASS (This Report)
                        UNCLASSIFIED
I 02E
j 06A
| 06H
j 06R
' 07E
 18B

aiTNoTo F~PAG'ES~
        28
                                              20. SECURITY CLASS (This page)
                                               UNCLASSIFIED
                                                                         22. PRICE
EPA Form 2220-1 (9-73)

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