SWRHL-14r
        DAIRY FARM RADIOIODINE STUDY
           FOLLOWING THE PIKE EVENT
Delbert S.  Earth,  Chief, and Joel G.  Veater,  Biologist
         Bioenvironmental Research Program
     Southwestern Radiological Health Laboratory
             U. S. Public Health Service
     Department of Health,  Education, and Welfare
                 Las Vegas,  Nevada
                 November 23,  1964
   This study performed under a Memorandum of
            Understanding (No. SF54373)
                        for
       U. S. ATOMIC ENERGY COMMISSION

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                        LEGAL NOTICE

This report was prepared as an account of Government sponsored work.
Neither the United States, nor the Atomic Energy Commission, nor any
person acting on behalf of the Commission:

A.  Makes any warranty or representation,  expressed or implied,  with
respect to the accuracy,  completeness, or usefulness of the information
contained in this report,  or that the use of any information,  apparatus,
method,  or process disclosed in this report may not infringe privately
owned rights; or

B.  Assumes any liabilities with respect to the use of, or for damages
resulting from the use of any information,  apparatus,  method, or
process  disclosed in this report.

As used  in the above, "person acting on behalf of the  Commission"
includes  any employee or contractor of the Commission, or  employee
of such contractor, to the extent that such employee or contractor  of
the Commission, or employee of such  contractor prepares,  dissemin-
ates,  or  provides access to, any information pursuant to his employ-
ment  or  contract with the Commission, or  his employment with such
contractor.
  AUTHORS'   COPY
       059

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                                               SWRHL-14r
        DAIRY FARM RADIOIODINE STUDY

           FOLLOWING THE PIKE EVENT
                         by
Delbert S.  Earth,  Chief, and Joel G. Veater, Biologist

         Bioenvironmental Research Program
     Southwestern Radiological Health Laboratory
             U. S. Public Health Service
     Department of Health,  Education,  and Welfare
                 Las  Vegas,  Nevada
                 November 23, 1964
    This study performed under a Memorandum of
            Understanding (No.  SF 54 373)
                        for

       U. S. ATOMIC ENERGY COMMISSION

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                              ABSTRACT






Following the Pike Event at the Nevada Test Site on March 13, 1964,



a small amount of radioactivity accidentally escaped from the ground.



The resulting radioactive cloud passed over two dairy farms in the



vicinity of Las Vegas, Nevada.  Arrangements were made with the



managers of these farms to cooperate in a study of the uptake kinetics



of I    in dairy cattle under normal dairy farming practices.






Each herd -was separated so that at each farm there were three cows



eating fresh green chop with the remainder of the herd on hay and



stored feed.   Peak levels observed in the  milk of cows on green chop



were 420  picocuries per liter (pc/1) at one farm and  70 pc/1 at the



other with an  apparent decay half-life of approximately four days for



both.  Peak levels in the milk of cows on hay were 70 pc/1 at one



farm and  40 pc/1 at the other.   The  apparent decay half-life at the



farm having the highest levels  was approximately six days.

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                        ACKNOWLEDGMENTS






We wish to extend special thanks to the owners and operators of the



two farms.  In particular, these include Mrs. Eunice Habbart.  Mr



Floyd Miles and Mr.  Nelson Gibson at the Habbart  Farm,  and Mr



Elaine Curtis,  Supervisor,  and Mr. Lynn Duke, Dairy Manager, at



the Latter Day Saints'Welfare Farm.  Without the cooperative help



of these people and their associates, this  study would not have been



possible.  The support and  encouragement of Mr  Robert Thalgott,



Nevada Operations Office, Atomic Energy Commission,  is gratefully



acknowledged.  The liaison and cooperation  of Mr  Ferren Bunker,



Clark County Extension Agent,  and Mr  W  W, White of the Nevada



State Health Department were also of  considerable  assistance in our



investigation.   There were  many friends  and co-workers, too nu



merous to mention, at the Southwestern Radiological Health Labora-



tory who made valuable contributions  and  suggestions throughout the



study.
                                   11

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                        TABLE OF CONTENTS







ABSTRACT                                                        i



ACKNOWLEDGEMENTS                                            ii



TABLE OF CONTENTS                                            iii



LIST OF TABLES                                                 iv



PART I.  INTRODUCTION                                           1



PART II.  SAMPLE COLLECTION                                    5



     A.  Milk Sampling             5



     B.  Feed Sampling             6



     C.  Water Sampling            7



     D.  Air Sampling              8



     E.  Soil Sampling              8



     F.  Beta plus Gamma Dose Rate Survey  8



PART in.  ANALYTICAL METHODS                                 9



PART IV.  DISCUSSION OF RESULTS                               11



     A.  Habbart Farm            11



     B.  LDS Farm                16



PART V.   CONCLUSIONS                                           20



REFERENCES                                                     23



APPENDIX                                                        24
                                   111

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                           LIST OF TABLES








Table 1.  Average production of experimental cows               3



Table 2.  Annual summary of normal feeding  practices for this



          area.                                                  4



Table 3.  Summary of results.                                  <^0
                                   IV

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                                 Part I

                            INTRODUCTION


Radioactivity was accidently released from the underground Pike

Event which took place at the Nevada Test Site at 0802 hours on

March 13,  1964.   A portion of this material passed over the  city

of Las Vegas, Nevada and parts of Clark County.  In particular,

some fallout was deposited on and in the vicinity of two dairy farms

located near Las Vegas.  These two farms were:

                        Latter Day Saints' Church Welfare Farm
                        6206 Munson Road, Las Vegas, Nevada and

                        Mrs. Habbart's Dairy Farm
                        6912 Pecos Road, Las Vegas, Nevada

The location of each farm is shown  in Figure 1 in the Appendix.

Some descriptive information concerning the two farms will be found

in Figures 2 and  3 in the Appendix.  The  milk  census forms consti-

tuting Figures 2 and 3 are representative of the records  maintained

by the Southwestern Radiological Health Laboratory for milk pro-

ducers in Nevada and adjacent states.


This accidental occurrence provided a unique opportunity to study the

uptake of radioiodine into cow's milk under dairy farming management

conditions as practiced at these two farms.  A plan was developed to

conduct a cooperative  study bet-ween the Bioenvironmental Research

Program, Southwestern Radiological Health Laboratory, U.  S.

Public Health Service,  and the local dairy industry with the support

of the Nevada Operations  Office, Atomic  Energy Commission.  The

design of the study -was discussed with Mr. Ferren Bunker, Clark

                                    1

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County Extension Agent representing the University of Nevada   Also



Mr.  W. W  White of the Nevada Health Department was informed of



the proposed study.   General agreement on the objectives listed below



was  obtained.






Four objectives -were established for the study.   The first was to



measure uptake of radioiodine in fresh unpasteurized cow's milk as



a function of time at  two separate dairy farms with two groups of



cows at each farm -- one group eating hay and grain only., and the



other group eating green chop,  hay and grain.  The second was to



measure the effect of green chopping* vegetation on its average



radioiodine content.   As the third objective,  levels of radioiodine in



the air would be measured  continuously at the two dairy farms as a



function of time after a fallout event.   The fourth objective was to



attempt to relate levels of radioiodine  in the  air; on vegetation or on



the ground to subsequent levels which appeared in fresh unpasteurized



cow's milk at the same location.






Arrangements  were made to place three cows at  each farm on green



chop, hay and  grain while the remainder of each  herd was maintained



on hay and grain only.  It was not possible under the prevailing con-



ditions to make arrangements for a larger number •without imposing



an undue hardship on the cooperating farm managers   It should be



noted that before arrangements could be finalized,  all of the lac -



tating cows at  Habbart's were fed one feeding of  green chop on the



morning of March 17. This  was the only time during the  study that
 *This is the terminology used for the standard practice  of mowing



 and machine chopping forage from irrigated fields   Green chop is



 fed to the dairy animals before it dries or spoils.

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either whole herd received fresh green chop.  Prior to the study



no green chop had been fed to any of the cows in either herd.






All animals on green chop at both farms were  Jerseys.  The specific



animals involved in the study were selected by the farm managers



and in addition, all were in the late phase of their milk cycles and



thus -were somewhat below the herd average  in milk production.



Table 1 indicates the average production of the experimental cows.



The  average -was calculated during the study.






           Table 1.   Average production of experimental cows.
Identification
HABBART FARM:
Kay
Goldie
Gretta
LDS WELFARE
FARM:
60
40
30
Last Calving
Date
July 1963
July 1963
July 1963
June 1963
July 1963
Nov 1963
Milk/Day
(Ibs.)
22. 3
27. 0
22. 1
6.3
14. 6
19- 3
Butterfat
(%)
4.4
5.4
4.4
6.0
5.6
5.9
Dry fed cattle usually have a standard diet of hay, silage, and grain.



When silage is fed, the animals are normally fed hay and silage after



each milking and grain during milking.  When the crops reach cutting



size and summer feeding practices begin, fresh green chop replaces



the silage.  The Habbart operation fed hay and grain throughout this



study since the silage had already been consumed.

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Table 2.   Annual summary of normal feeding practices
          for this area
TYPE
OF
FEED
Hay
Silage
Chop
Grain
Estimated total daily feed fibs, /cow)
HABBART
Summer
15

20
10
Winter
15
20

10
LDS
Summer
15

20
6
Winter
12
10-15
--
13-15

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                              Part II




                      SAMPLE COLLECTION
All vegetation and soil samples -were collected in clean plastic bags,



sealed to eliminate cross contamination and loss  of material, and



identified as to  sample type, location, and time of collection (a. m.  or



p.m. ).   Milk and water samples were collected in clean disposable



one gallon containers.






A.    MILK SAMPLING



      Pipeline milking systems are utilized at both farms.  Three



      cows are  milked at approximately the same time.  The milk



      flows from the cow along a central pipe and drains into a



      bulk tank.






      To minimize difficulty and interference with routine operations,



      the three  cows eating fresh green  chop were milked  simultane-



      ously either at the beginning or at the end of each milking per-



      iod.  A one gallon composite sample was collected from both



      the a.m.  and p.m. milkings as the milk passed from the drain



      pipe into the bulk tank.






      Milk from the hay fed animals was collected in the same way,



      except that the composite was a random sample and  was not



      necessarily from the same three animals during each milking.



      It  should be noted that the method  of collecting samples from



      the drain  pipe was not effected until March  18.  Previous samples




                                    5

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      •were drained from the bulk tank and  sometimes included




      composites of different milkings.  All daily milk results re-



      ported are the mean values of the results obtained from the



      a. m.  and the p. m. milkings for that day except when other-



      wise noted.






B.    FEED SAMPLING



      Fresh green chop and dry feed •were  sampled and analyzed for



      radioiodine content.  Also,  fresh vegetation was hand cut from



      the  green-chopping field at Habbart's and analyzed by the same



      methods  to determine the effect, if any, of green chopping on



      the  radioiodine content.  At Habbart's, chop was cut from a



      stand of barley in a field measuring roughly two hundred yards



      by one hundred yards.   The average  height was twenty inches



      of which  sixteen inches were cut for  feed.   Chopping was done



      with a tractor driven forage chopper and blown directly into a



      towed wagon.  Fresh cuts were usually made every other day.



      Soon after each feeding a sample was collected from the trailer



      in which  the chop was loaded.  The field at the  LDS Welfare



      Farm was not fully grown  so the chopping machine  could not



      operate.   Instead,  the  feed was  cut by  hand with a



      scythe.   The area cut was  a small section approximately



      sixty feet square that had grown faster than the rest of the field.



      This section consists mostly of barley with a mixture of al-



      falfa.  The stand averaged thirteen inches and the usual cutting



      was nine inches.   Sample collection was from the feeding trough



      if available.  If it was  all eaten, the  sample was cut in the field



      from an area adjacent to the fresh cutting.






      Most of the samples from the field consisted of one square meter



      of vegetation cut  to the  same level as a chopped sample.  For




                                    6

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      one study,  specific spots were selected to determine if ac-
      tivity was distributed uniformly or had an uneven pattern
      (see  Figure 4).  Other samples were random collections, pri-
      marily of barley.  Alfalfa was collected by the  square meter
      to determine if it had the same retention as barley.  The av-
      erage daily green chop feeding was fifty-five pounds per
      three cows at Habbart's  and  sixty-two pounds per three cows
      at LDS.

      Habbart hay was stacked completely exposed to climatic con-
      ditions.  The cows were fed  this  hay in a bin which extended
      the length of the north side of the corral.  Random  samples
      were taken from this bin and usually represented a cross sec-
      tion of a  bale.  Also, some grain pellets -were collected and
      analyzed.

      Baled hay at the Latter Day Saints' Welfare Farm -was stored
      in large stacks which were covered only with a protective roof.
      Silage was  stored in a trench silo partially covered with a
      polyethylene film.   Samples  were collected from the troughs
      by the same method used at Habbart's.

C.    WATER SAMPLING
      Both Habbart and LDS pipe well water to a trough about the
      size  of a bathtub (in fact, one was a tub).  The water level is
      float regulated  and remains constant at all times.   Samples
      were collected  by immersing gallon containers into the -water
      in such a manner that mostly surface water was collected.

      Rain collectors were placed  at each farm during the experiment.
      On April 1,  1964, there  was a trace of rain.  Also,  there was
      considerable wind and dust throughout the study.

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D.    AIR SAMPLING



      One General Metal Works high volume air sampler was placed



      at each dairy farm.  Mounted on the sampler were a glass fiber



      prefilter and a Mine Safety Appliances Company charcoal car-



      tridge.  Filters and cartridges were changed daily.






E.    SOIL SAMPLING



      Daily  samples were taken by collecting approximately one



      square foot of topsoil from an undisturbed area at each farm to



      a depth of approximately one-half inch.






F.    BETA PLUS GAMMA DOSE RATE SURVEY



      From March 13 to March 17,  dose rate readings were taken



      at each farm with an Eberline Model E-500B portable survey



      instrument.   Dose rate from beta plus gamma  radiation was



      measured both at ground level and three feet above ground in



      the fields where vegetation samples were collected.

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                              Part III



                     ANALYTICAL METHODS
Liquid samples were placed in 3. 5 liter inverted well aluminum


beakers to be analyzed for gamma emitting radioisotopes using a


400-channel analyzer with a 4" x 4" Nal (Tl) crystal detector.   Based


on fifty minute counts,  the minimum detectable level for milk  sam-


ples is 20 picocuries per liter (pc/1) with an associated error  of


+_ 20 pc/1,  or  +_ 10%, whichever is larger.  All values -were corrected


for decay to time of collection.   Samples having less than the mini-


mum detectable level of activity at time of count were not corrected


to time of collection.




Depending upon size, vegetation samples were packaged in  alu-


minum beakers or in 400 ml "cottage cheese" containers.   Since


the sample size was non-standard, it was impossible to give a min-

                131                  2
imum level for I    in  pc/kg or  pc/M .  Instead,  there was assigned


a minimum total activity of 100 pc per sample as the threshold of


detection.  At 100 pc,  the associated  error due to counting  statis-


tics is +  100%.  Since the presence of fresh fission products com-


plicates the calculation (standards for some isotopes are not avail-


able), a value of +100 pc/kg, or +_ 50%,  which ever is larger,  was


assigned as the best estimate of the analytical error for all gamma

                                                        198
analyses of samples other than milk.  The presence of Au    made

                131
the detection of I    impossible  in vegetation samples for about


ten days following detonation.  The accuracy of I    determinations


in soil samples was assumed to  be comparable to that of vegetation

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measurements.

Air sample prefilters -were counted for gross beta activity with a
thin window, large area gas flow proportional probe connected to a
high speed sealer.  The system has an efficiency of approximately
30% for 1. 5 Mev beta particles and background for  this system is
575 _+ 20 counts per minute.  Charcoal cartridges were examined
for gamma emitting radioisotopes  by placing each cartridge directly
on a 4" x 4" sodium iodide crystal coupled to a 400-channel pulse
height analyzer set to view energies from 0 to 2 Mev.   Assuming
no break in the prefilter, the activity  on the cartridge should rep-
resent the  gaseous fission products only.  Detection efficiency for
this geometry is about  18% at 0. 51 Mev.  The minimum detectable
activity is  about 200 pc for any specific isotope.

The analytical  limitations  as described above are depicted graphi-
cally for each datum point in Figures  5 through 11.
                                   10

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                             Part IV



                    DISCUSSION OF RESULTS
A.    HABBART FARM


      Green Chop

               131
      A plot of I    levels in milk from cows eating green chop and


      of I    in the green chop is presented in Figure 5.  From the


      graph,  the following observations may be noted:


                        a.   The  peak daily average milk value was


                            375 pc/1, which was obtained on March 21,


                            four days after the  cows began to eat the


                            green chop.  This average represents the


                            mean value of the a. m. and p. m.  milkings


                            for that day which were 420 pc/1 and


                            330 pc/1.



                        b.   The  milk values decayed with an esti-


                            mated apparent half-life of 3. 8 days.



                        c.   Extrapolation backwards indicates that


                            if the study had been initiated on March 13,


                            the probable maximum value observed


                            would have been approximately


                            700 pc/1 on March  17.



                        d.   The  peak measured green chop value


                            was  4700 pc/kg, which was  obtained


                            on March 19.
                                   11

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                        e.   The green chop values decayed with an



                             estimated apparent half-life of 5. 3 days.





                        f.   The ratio of the  peak average value of



                             I    in milk to the peak value in green



                             chop was 375 pc/1 to 4700 pc/kg, or



                             0.08 pc/1 to 1 pc/kg.






The decay half times are in general agreement with published



results1 > 2»  3» 4.  The milk decay time is  slightly lower than most



values from published studies, but is not significantly different



from the half-time of four days reported for one case3.  The ratio



of pc/1 milk to pc/kg green chop is numerically quite close to the



analogous mean Windscale factor1 of 0. 09.  Considering  the differ-



ences in radioiodine sources, climatic conditions  and  farming prac-



tices for the two different cases,  such agreement  was not expected.






Furthermore,  no profound significance should yet be attributed to



this finding  since the agreement could be due to fortuitous combi-



nations of many unrelated factors.  Clearly, additional experimen-



tation is needed.  It should be pointed out that the  value of 0. 08



calculated from our data actually has a possible range, based on



analytical accuracy of the two values used to calculate  it,  of 0. 05



to 0. 18.






Hay



A plot of I     levels in milk of cows  eating hay and of  I     in the hay



is given in Figure 6.  From the graph, one  may note the  following:



                         a.   The peak measured  milk  value was



                             70 pc/1,  which was obtained on



                             March  16,  three days  after the Pike



                             Event.   Both the a. m. and p. m.





                                     12

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                             milkings for this day were 70 pc/1.
                             Note that the data for March 18 and
                             19 should be disregarded since, as
                             mentioned previously, all cows were
                             fed green chop on March 17-
                         b.   The milk values decayed with an esti-
                             mated apparent half-life of 5. 9 days.
                             Again,  the points on March 18 and 19
                             were disregarded.
                         c.   The peak measured level in hay was
                             1300 pc/kg,  which was obtained on
                             March 15.
                         d.   The activity in the hay was so variable
                             that it was not possible to obtain a
                             good estimate of the decay half-time.
                         e.   The ratio of the peak value of I   in
                             milk to the peak value in hay •was
                             70 pc/1 to 1300 pc/kg, or 0. 054 pc/1
                             to 1 pc/kg.  Based on the analytical
                             accuracy of the two quantities used to
                             calculate the  number 0. 054,  the pos-
                             sible range is 0. 026 to 0. 14.  It is not
                             possible to compare these results with
                             published data since, to  our knowledge,
                             no one else has observed significant
                             I    values in the
                             only stored feed.
I    values in the milk of cows eating
Distribution study
Figure 4 depicts several sampling locations in the field at the Habbart
                                   13

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Farm from which the green chop was being cut.  At each location



a one square meter sample was  obtained as described previously.



The analytical results obtained are also given in Figure 4.  Anal-



yses of these  data shows that the mean value of the field sample of



I.    was 704 + 253 pc/kg on March 27, where the +_ value is the



standard deviation.  The fact that the standard deviation is  less than



the estimated analytical accuracy is evidence that the contamination



of the field in pc/kg •was reasonably homogeneous over  the field.



Furthermore,  the measured I    activity in. green chop on March 27



was 740 +_ 370 pc/kg.  Comparing this to 704 +_ 253 pc/kg indicates



that no  significant I    activity was removed from the vegetation by



the green chopping process.






Calculations from these data  also show that for this particular field



there were 1.  34 +_ 0. 88 kg green vegetation/square meter of sur-



face area.






The mean value of I   on this field on March 27  may also  be cal-



culated to be 743 jf 493  pc/M  .   The large  standard deviation shows



that the activity in pc/M  is  considerably less  uniform  over the field



than is  the activity in pc/kg.  A  possible contributory factor is  the



fact that it was early in the growing season and the barley was not



constant in height over  the field.






Soil
Figure 7 shows the levels of I    found in undisturbed soil samples



at the Habbart Farm.  The apparent decay half-life equals 8. 0 days,



which is precisely the physical half-life of I    .  Interpolation gives



an estimate of 2500 pc/kg for March 27.   Each sample represents



approximately one square foot of surface area.  In additon, the
                                   14

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average soil sample weight was approximately 450 grams.  Therefore,

                                                  2                2
for March 27,  2500 pc/kg corresponds to 1125 pc/ft  or 12, 100 pc/M

                                                                   2

of undisturbed soil.  On March 27, the vegetation contained 743 pc/M .

                                 131
Consequently,  the percentage of I    on the vegetation was  6. 1% of


that on the soil.  In addition,  extrapolation back to March 13 gives a

                        131                2
deposition estimate for I    of 43, 000 pc/M of undisturbed soil.




Comparison of alfalfa to barley


Figure 8 presents I    values for barley and alfalfa at the Habbart


Farm.  The results clearly show that there is no significant dif-


ference between the two.
Miscellaneous samples


Air samples were taken from March 16 through April 10.  All re-


sults for I    were below the limit of detection of our analytical


instruments,  indicating  that there were no significant secondary


aerosols after the passage of the radioactive cloud.



From March  14, to March 17, beta plus gamma surveys at the


fields where the vegetation samples were collected registered 0. 02


to 0. 03 mr/hr, which is normal background for this area.  Grain


supplement food pellets  fed to cows at the Habbart Farm were

              131
analyzed for I   content -with negative results.   This was to be ex-


pected since these pellets were protected by storage.



The analysis of water samples collected from the cows' watering


trough gave a peak reading for I    of 100 pc/1 on March 15.  The


levels were quite variable for the period March 15 to March 29f


averaging approximately 50 pc/1.   It is  not likely that the well pro-


viding water for the cows was contaminated since it is a deep arte-


sian well.  Thus the most likely explanation for these findings seems




                                   15

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to be that the cows •were contaminating the water with their saliva
and bits of uneaten food.

B.    LDS FARM
      Green Chop
      A plot of I    levels in milk of cows eating green chop and
      of I    in the green chop is presented in Figure 9.   The
      following observations may be made:
                        a.  The peak daily average milk value was
                            65 pc/1, which was obtained on March 20,
                            three days after the cows began to eat
                            the green chop.  This average represents
                            the mean value of the a. m.  and p. m.
                            milkings for that day which were
                            70pc/l and 60 pc/1.
                        b.  The milk values decayed with an estima-
                            ted apparent half-life of 4. 0 days.
                        c.  Extrapolation backwards indicates that if
                            the study had been initiated on March 13,
                            the probable maximum value observed
                            in milk would have been approximately
                             110 pc/1 on March 17.
                        d.   The peak measured green chop value  -was
                             1700 pc/kg, which was obtained on March 21
                         e.   The green chop values decayed with an
                             estimated apparent half-life of  5. 3 days.
                        f.   The ratio of the peak average value of
                              131                              *
                             I   in milk to the peak value in green
                             chop was 65 pc/1 to 1700 pc/kg, or
                                   16

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                              0. 038 pc/1 to 1 pc/kg.  The possible
                              range on this number may be  calcu-
                              lated to be 0. 018 to
The decay half times are in good agreement with the results ob-
tained at the Habbart Farm.  However, the most likely ratio of
pc/1 of milk to pc/kg of green chop here is less than one -half the
one calculated for the Habbart Farm.  A possible contributory
factor5 is the  relatively much lower average milk production of the
L.DS cows on green chop vs.  that of the Habbart cows on green chop
(see Table 1).  The green chop I    values here seemed to be lower
by about  a factor of three than the values obtained at Habbart1 s  Farm.

Hay
A plot of I    levels in milk from cows eating hay is given in Figure  10.
Levels of I    in the  hay are shown in Figure 11.   From these graphs
one may  note the following:
                          a.   The peak measured milk value was
                              30 pc/1, which was  obtained on March 21,
                              eight days after the Pike Event.   Both
                              the a.m. and p.m.  milkings for this day
                              were 30
                          b.   The peak measured level in hay was
                              630 pc/kg, which was obtained on
                              March 20.

                          c.   The values are so erratic as to make any
                              calculation of decay half time for either
                              milk or hay unreliable.

                          d.   The ratio  of the peak average value of
                              I   in milk to  the peak value in hay was
                              30 pc/1 to 650 pc/kg, or 0.046 pc/1 to
                                    17

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                              1 pc/kg.  The possible range on this

                              number may be calculated to be 0. 010 to

                              0. 15.


The above results correspond reasonably well with the ones found at

the Habbart Farm, but in general the levels are lower by about a

factor  of two.

T1^!  ,
1	deposition per square meter

On several days one square meter  samples of green chop were taken.

From the weights of these samples it was  calculated that  at the LDS

Farm there were  1.08 + 0.42 kg green vegetation per square meter of

surface area.  This agrees with the corresponding value of 1. 34 jf 0. 88

for the Habbart Farm.


Soil

The values obtained were too variable to admit the determination of

a reasonable half-life  of decay.   The value obtained for March 26 was

500 pc/kg.   The average soil sample weight was approximately 485 grams

Consequently, for March 26, 500 pc/kg corresponds to  242 pc/ft2  or

2610 pc/M2 of undisturbed soil. On March 26 the vegetation contained
                                    131
600 pc/M2  .  Thus the percentage of I    on the vegetation was 23% of

that on the  soil.  This is considerably higher than the value of 6. 1%

calculated for March 27 at the Habbart Farm. A possible contributory

factor  for this difference may be that at the LDS Farm the forage growth

was somewhat spotty and the areas where  the forage was  cut had higher

and more dense growth than the surrounding areas in the  same field.

If  one assumes that the soil levels  at the LDS Farm decayed with a
half-life of 8. 0 days it is possible to extrapolate back to March 13,
                *                                               13
the day of the Pike Event. This calculation leads to a value for I
8050 pc/M2 of undisturbed soil.  This is lower by approximately a
                                    18

-------
factor of five than the corresponding value obtained at the Habbart
Farm.

Miscellaneous samples
Air samples were taken from March 16 through April  10.  All results
for I    were below the limits of detection of our analytical instruments

On March 14 through 17, beta plus gamma surveys at the fields -where
the vegetation samples were collected registered 0.02 to 0.03 mr/hr,
which is normal background for this  area.
The analysis of water samples obtained from the cows' watering
trough gave low,  variable levels of I    , averaging approximatel
25 pc/1 for the period March 15 through March 29.
                                   19

-------
                                 Part V



                            CONCLUSIONS






A brief summary of some of the results pertinent to the first objec




tive is given in Table 3.






Table 3.  Summary of results.
TYPE OF
SAMPLE
Milk from
cows on
green chop
Milk from
cows on
hay
Green chop
(wet)
Hay
HABBART FARM
Max.
Value
I131
375*
pc/1
70*

4700
pc /kg
1300
pc/kg
Time to
reach max.
(days)
4
3

-
-
Decay
half -life
(days)
3. 8
5.9

5. 3
	
LDS FARM
Max.
Value
I131
65*
pc/1
30*

1700
pc/kg
630
Time to
reach max.
(days)
3
8

-
-
Decay
half -life
(days)
4, 0
	

5. 3
	
* Average of a. m.  and p. m. milkings.






This  summary plus the appended graphs show the measured uptake and



decay of I    in the study cows under the conditions  of this  investi-



gation.   Probably the most  significant quantities in Table 3 are the



decay half-lives.  Even though each specific reported value could be



in error by as  much as plus or minus one day, it seems likely that



there may be a significant difference between  the decay in the milk



from cows on green chop and the decay in the  milk from cows on hay,
                                20

-------
The observed time of 8 days for the level of I    to reach a max-


imum in the milk of cows on hay at the LDS Farm could -well be in


error by a considerable amount since the measured maximum value


of 30 pc/1 was quite close to our analytical detection limit.




Within the limits of accuracy of our analytical techniques it is con-


cluded that the process of green chopping forage does not remove an


appreciable amount of T




Since the air levels of I    were below the limits of detectability of


our analytical methods, the third objective of the study was not


achieved.



                                     131
Relationships between peak levels of I    on  cow's feed and peak


levels appearing in fresh unpasteurized milk at the same location


have  been calculated and presented.  As was shown there is consid-


erable variance to be expected  in such relationships since they are


determined as the  quotient  of two quantities,  each subject to its own


analytical error.  Since the external beta plus gamma measurements


were background throughout the study it was  not possible to calculate


relationships  between these readings and subsequent milk levels of


i131.




It appears that, by a factor of 2 to 5,  there was a significantly higher


deposition of I    on the Habbart  Farm than on the LDS Farm.  Since


these farms were only five  miles apart in a broad valley -with no sig-


nificant topographical features  separating them, this  finding casts


some doubt on the validity of the assignment  of contamination values


to broad geographical areas based on a single reading at any one


location.
                                21

-------
Levels of I     in milk of cows on dry feed only were significantly


higher than have been reported in other studies,   This difference


undoubtedly was due to the common practice in this geographical


region of storing baled hay in the open.




Extreme caution should be exercised in attempting to use these


data in extrapolating past or  possible future situations.   It is


apparent that there is considerable variance found even in direct


measurements as exhibited in Figure 4.   240 pc/M2  of I    was


found in  a field approximately 200  yards from a location  where a


value of  1700 pc/M2  was measured.  Practices of attempting to


estimate I    levels -which will be  found in milk from external


gamma or beta plus gamma dose rate readings are particularly


subject to question.   For example,  utilizing such relationships in


this instance would have  led to the conclusion that there -would have

                     131
been no measurable I    milk levels found whereas our  data  mdi


cate that levels could actually have reached values near 700 pc/1


had the study been started at  an  optimum  time.




Each different source of  radioiodine can produce  activity  of different


characteristics which is  then further modified by release conditions,


meteorological conditions, local climatic conditions  and  local dairy


farming practices.  Thus,  generalizations which  purport  to apply to


any and all  situations are fraught with uncertainty
                                 22

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                             REFERENCES






1-  Booker, D.  V., Physical Measurements of Activity in Samples



    from Windscale,  A.E.R.E. HP/R  2607,  October, 1958.






2.  Soldat,  J. K. ,  The Relationship Between I1 3l  Concentrations in



    Various Environmental Samples, Health Physics, 9:1167-1171,  1963






3.  Knapp, H. A. ,  Iodine-131 in Fresh Milk and Human Thyroids Fol-



    lowing a Single Deposition of Nuclear Test Fallout,  TID-19266,



    June 1,  1963.






4.  Bustad, L,. K, , D.  H. Wood,  E. E. Elefson, H. A. Ragan and



   R.  O.  McClellan, 1-131 in Milk and Thyroid of Dairy Cattle Fol-



    io-wing a Single Contamination Event and Prolonged Daily Adminis-



    tration, Health Physics, 9:1231, 1963.






5.  Squire, H.  M. , L.  J.  Middleton, B.  F. SansomandR. C. Coid,



    The Metabolism in Dairy Cows of Fission Products,  Progress in



    Nuclear Energy,  Series  VI 3:69-90, 1961.
                               23

-------
                               APPENDIX

Figure                                                          Page
 1.  Locations of study farms.                                  A-l

 2.  Milk census data collected at the Habbart Farm.            A-2

 3.  Milk census data collected at the Latter Day Saints'
     Welfare Farm.                                             A-3

 4.  Area Sampling of Habbart's  field for I    activity on
     March  27.                                                  A-4

 5.  I'    in Habbart green chop and I    in milk from cows
     eating green chop.                                          A-5

 6.1     in Habbart dry hay and  I    in milk from cows
     eating dry hay.                                             A-6

 7.1     in undisturbed soil at the Habbart Farm.               A-7

 8.  Comparison of I   in alfalfa vs. barley at the Habbart
     Farm.                                                      A-8

 9.1"    in LDS Welfare green chop  and I    in milk from
     cows eating green chop.                                    A-9
10.  I     in milk collected from cows eating dry hay at the LDS
     Welfare Farm.                                             A-10
11.  I     in hay from the LDS Welfare Farm.                    A-ll

         Note:  The following  symbols are used in the  Appendix:

                        Upper Analytical Limit
                       Actual or  Averaged Value Q
                       Lower Analytical Limit   I

         For plotting purposes,  a value of not detectable is
         plotted as half the  value of the lower detection limit
         e.g., the lower detection limit for I   in milk is
         20 pc/1,  any value  below this is considered not de-
         tectable  and is plotted in the following graphs at 10 pc/1.
                                 24

-------
                  LDS WELFARE FARM
GREATER
LAS
VEG
                             HABBART FARM
             Figure 1. Locations of study farms.

-------
Population: (Indicate
male or female; list
children individually)
Adults:
(2) 1 Male(s)
(4) 2 Female(s)
Children:
(6) 1
(7) 1
(8) 1
(9)
(10)
(11)
(12)
(13)
Age
(yrs)
Over 18
Over 18
10 yrs.
5 yrs.
3 yrs.
Raw milk
consumed daily
(in quarts)
(3) 1
(5) 1
Pasteurized Milk
ti 11
ii it
Home use
milk (qts
than drin
(17) To
(18) Ga
Home
Comr
None
Crop(s
(14) Total Adults : 3 (16) Total quarts raw milk
(15) Total Children: 3 consumed daily: 2
                        MILK CENSUS FORM
(1)  Code: Fig. 2
Name    : Eunice Habbart
Address: 6912 Pecos Road
Location: Las Vegas, Nevada
                                              Date    3-17-64
                                              County (or area) Clark
                                                           Barley
                                                           Oats
Cattle:  Number of Milk Cows:  27
                                    Breed(s):  Jersey, Guernsey and
                                              Holstein
Normal feeding practices:
(19) Dry feed
(20) Pasture
(21) Grain
(22) Concentrate
Inclusive dates
From
Nov.
Beef c
Dec.
Dec.
To
March
Dec.
Dec.

Type
Alfalfa hay


Source
Commercial & field
	 w.
r
Milk:
(23) Milk shipped to dairy 120 gals/day; Days of milk pickup Mon.  Sat.
     Name of dairy and location: Hinies    Wed. Fri.  Time: varies
      626 Las Vegas Blvd So., Las Vegas,
(24)
     Nevada.
                                      T25)  Grade of milk:
                                            (A, B, or C)
                                          Well
                                         "Well"
Water Supply:
(26)  Domestic use: Surface	Municipal_
(27)  Cattle source: Surface	Municipal^
     Other uses: (i.e.,  irrigation,  etc.)
(28)  Remarks:  Quality of pasture?  Home pasteurization?
                 pasture.  No pasteurization at home.
_X_ Depth
 X Depth
Artesian
Artesian
                                                  Irrigation
                                                              Good
                                Data collected by: Joel G. Veater
Figure 2.  Milk census data collected at the Habbart Farm.
                                A-2

-------
                       MILK CENSUS FORM
(1)  Code: Fig. 3
Name    : LDS Welfare Farm
Address : 6206 Munson
Location: Las Vegas, Nevada
                                        Date   3-17-64
                                         County (or area) Clark
Population:  (Indicate
male or female; list
children individually)
Adults:
(2)   4  Male(s)
(4)   4  Female(s)
Children:
 (6)
 (7)
 (8)
 (9)
(10)
(11)
(12)
(13)
    2
    1
    1
    2
    2
    2
                   Age
                   (yrs)
Over  18
Over  18

16 yrs.
15  "
14  "
10  "
 6  "
 4  "
         Raw milk
         consumed daily
           (in quarts)
                           (3)
                           (5)
4
2

3
1
1
1/2
1/2
1/2
Home uses of raw
milk (qts. /day)other
than drinking:
  (17) Total	
  (18) Garden:
   Home
   Commercial XX
   None
  Crop(s):
Hay
Grain
Silage
Pasture
(14) Total Adults  :    8
(15) Total Children:   10
                          (16) Total quarts raw milk
                              consumed daily:   12-1/2
Cattle:   Number of Milk Cows:  100   Breed(s):  Jersey and Holstein
Normal feeding practices:
(19)  Dry feed
(20)  Pasture
(21)  Grain
(22)  Concentrate
                         Inclusive dates
                         From
                    Dec.
                              To
           April
                    Beef only
                    Dec.
           Dec.
                                             Type
   Hay & Silage
                                                     Source
Milk:
(23)  Milk shipped to dairy 260 gals/day; Days of milk pickup Mon.Wed.
(24)  Name of dairy  and location:  Arden   Fri. Sat.  Time:  a. m.
      1000 N. Main,  Las Vegas,  Nevada  (25)
Water Supply:
(26)   Domestic use: Surface
(27)   Cattle source: Surface
                                        Grade of milk:
                                         (A, B, or C)
                          Municipal
                     	Municipal
Other uses: (i. e. , irrigation,  etc. )_
           Quality of pasture?
            pasture.
                      Well_X_ Depth 200 ft.
                      Well X  Depth 200 ft.
(28)   Remarks:
              Home pasteurization?  Good
    No home pasteurization.	
                                 Data collected by:  Joel G. Veater
Figure 3.  Milk census data collected at the Latter Day Saints'
           Welfare Farm.       A-3

-------
       (X)
        240 pc/M
        720 pc/kg
                    (X)
                     240 pc/M
                     480 pc/kg
                                                             (X
                                                       920 pc/M
                                                      £670 pc/kg
                                   920 pc/M
                                   650 pc/kg
                                  (X)
                (X)
                 800 pc/M
                 670 pc/kg
                                  1700 pc/M
                                  1300 pc/kg
                            295 pc/M
                            590 pc/kg
                            (X)
830 pc/M
550 pc/kg
X
Description:

   Eight samples were taken from the field from which green forage was
   chopped.  Each (X) represents one square meter.
      Figure 4.  Area sampling of Habbart's field for I
                March 27.
                                                    131
                                               activity on

-------
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                                                             >ry he
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                                329
                                  TIME:  MONTH/DAY 1964

                                 ibbart
                        eating dry hay.          A-6
Figure 6.1    in Habbart dry hay, and I    in milk from cows

-------
                                                4/5
4/7
                    TIME: MONTH/DAY 1964
           ,131
Figure 7.  I    in undisturbed soil at the Habbart Farm.

-------
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                              TIME: MONTH/DAY 1964



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                     Habbart Farm.
                                      A-8

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3/19
3/21        3/23      3/25       3/27

       TIME:  MONTH/DAY 1964
3 29
3/31
            Figure 9.1    in LDS Welfare Farm green chop, and I    in milk

                       from cows eating green chop.
                                          A-9

-------
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3/17
3/19
3/21       3/23       3/25       3/27

     TIME: MONTH/DAY 1964
3/29
3/31
                 ,131
     Figure 10.  I    in milk collected from cows eating dry hay at the
                 LDS Welfare Farm.
                                   A-10

-------
   1000-
    100-
nt
t-,
oo
o
u
a
     10-
            i
       3/19
3/21
3/23       3/25        3/27



    TIME: MONTH/DAY 1964
3/29
                           131
              Figure 11.  I    in hay from the LDS Welfare  Farm.
                                      A-ll

-------
                        DISTRIBUTION LIST


 1-15   SWRHL, Las Vegas, Nevada

     16   James E. Reeves, Manager,  NVOO, AEC, Las Vegas, Nev.

     17   Robert H.  Thalgott, NVOO, AEC,  Las Vegas, Nevada

     18   Col.  E.  G.  Halligan, DASA, NVOO,  AEC,  Las Vegas, Nev.

     19   Otto H. Roehlk, OSD, NVOO, AEC,  Las  Vegas,  Nevada

     20   Gordon M.  Dunning,  DOS, USAEC,  Washington,  D. C.

     21   JohnS. Kelly, DPNE, USAEC,  Washington, D. C.

     22   Phillip W. Allen,  USWB, NVOO, AEC, Las Vegas, Nev.

     23   Frank D. Cluff, USWB,  NVOO, AEC, Las Vegas,  Nev.

   .  24   G. D. Ferber, USWB, MRPB (R-3.3), Washington, D. C.

     25   Ernest C. Anderson, TOB, DRH, PHS, Washington, D. C.

     26   James G. Terrill, Jr. ,  DRH,  PHS,  Washington, D.  C.

     27   Bernd Kahn, DRH, RATSEC,  Cincinnati, Ohio

     28   Arve H.  Dahl, DRH, PHS, Rockville, Maryland

     29   Raymond Moore,  DRH,  PHS,  Region VII,  Dallas,  Texas

     30   Northeastern Radiological Health Lab. , Winchester, Mass.

     31   Southeastern Radiological Health Lab. , Montgomery,  Ala.

     32   Bryce L. Rich, LRL, Mercury, Nevada

     33   Robert H.  Goeckermann, LRL, Livermore, California

     34   John W.  Gofman,  LRL,  Livermore,  California

     35   Charles  I. Browne, LASL,  Los Alamos,  New Mexico

     36   William  E.  Ogle,  LASL, Mercury,  Nevada

     37   Alvin C. Graves,  LASL, Los Alamos, New Mexico

     38   Harry S.  Jordan,  LASL, Los Alamos, New Mexico

     39   Victor M.  Milligan, REECo,  Mercury, Nevada

     40   Clinton S.  Maupin, REECo, Mercury,  Nevada

     41   Brig. Gen. Delmar L. Crowson, Director, DMA, USAEC,
                             Washington, D.  C.

     42   Mail & Records, NVOO,  AEC,  Las Vegas, Nevada

43- 150   Author's copies

-------
OPTIONAL K»M NO. 10
1010-104
UNITED STATES GOVERNMENT                      U.S. PUBLIC HEALTH SERVICE-BSS
Memorandum

TO    : Initial Recipients of Report, SWRHL-14r     DATE:  July 29, 1965
FROM
_Chief, Bioenvironmental Research Program
• Southwestern Radiological Health Laboratory
SUBJECT: Erratum to SWRHL-14r,  "Dairy Farm Radioiodine Study Following the Pike
       Event"  (Dated November 23, 1964)


 Correct the second figure on  line three  of page 17  to read 0.10  instead of

 0.010.  This was a typographical error.
                                             D.S. Barth

-------