u
N
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SWRHL02r
SOUTHWESTERN RADIOLOGICAL HEALTH LABORATORY
PUBLIC HEALTH SERVICE
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COPY OOl
Copy No. 1
Issued to
O. R. Placak, QIC
SWRHL, Las Vegas, Nevada
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SWRHL-2r
IODINE INHALATION STUDY
FOR
PROJECT SEDAN
July 6, 1962
by
Southwestern Radiological Health Laboratory
U. S. Public Health Service
for
Nevada Operations Office
Atomic Energy Commission
Project Director
Morgan S. Seal, USPHS
Deputy Director
E. L. Fountain, USA, VC
May 20, 1964
Department of Health, Education, and Welfare
Public Health Service
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AUTHOR'S NOTE
The subject matter of this report was presented under the title "Iodine
Uptake by Dogs Exposed to Nuclear Cratering Cloud" at the Seventh An-
nual Western Industrial Health Conference in San Francisco, California
on September 27, 1963 and under the title "Iodine Uptake From a Single
Inhaled Exposure" at the Symposium on the Biology of Radioiodine at the
Hanford Laboratories in Richland, Washington on June 17, 1963,
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ABSTRACT
Beagle dogs and currently accepted physical air sampling equipment
were exposed to the cloud produced by a nuclear cratering experiment
to determine the deposition of radioactive iodine in organs of the biolog-
ical sampler with that collected by the physical sampling devices. Pri-
mary emphasis is directed to the evaluation of such factors as isotopic
ratios, rate of build-up, and the effect of the thyroid gland in concen-
trating iodine. The results, -which indicated the selectivity of the bio-
logical sampler and the inefficiency of the physical samplers, are dis-
cussed.
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ACKNOWLEDGMENTS
The staff of the Southwestern Radiological Health Laboratory is indebted
to several organizations for financial, logistical, and personnel support.
The U.S. Army, Veterinary Corps, supplied both personnel and equip-
ment without -which this project would have been impossible. Valuable
personnel, equipment, and facilities support was also received from the
University of Rochester, from Reynolds Electrical and Engineering
Company, from the Southeastern Radiological Health Laboratory, and
from other units of the Public Health Service. The U.S. Marine Corps
supplied the helicopters and crews, without -which the rapid retrieval of
samples would have been impossible.
The support provided by these organizations and the helpful cooperation
of the personnel assigned to this Study are gratefully acknowledged.
The Atomic Energy Commission, Nevada Operations Office, is due par-
ticular acknowledgment for making available the funds with which this
Study was accomplished.
11
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TABLE OF CONTENTS
ABSTRACT i
ACKNOWLEDGMENTS ii
TABLE OF CONTENTS iii
LIST OF TABLES iv
LIST OF FIGURES iv
Chapter 1. INTRODUCTION 1
Chapter 2. OPERATIONAL PLAN AND FIELD
METHODOLOGY 3
2. 1. Physical Sampling 6
2. 2. Biological Sampling 8
2.3. Dosimetry 11
Chapter 3. LABORATORY METHODOLOGY 13
3. 1. Processing of Samples 13
3. 2. Radioassay of Samples 14
3.3. In Vivo Analysis 20
Chapter 4. RESULTS 23
Chapter 5. CONCLUSIONS 31
APPENDIX Ap-1 thru
Ap-10
DISTRIBUTION LIST
111
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LIST OF TABLES
Table No. Page
Table 1. List of radioisotope standards. 14
Table 2. Efficiencies of the 4" x 4" solid crystal of System 1
and the 9" x 8" well crystal of System 2 for counting
radioisotope standards. 16
Table 3. Qualitative analysis of the body burden of gamma
emitters in a dog sacrificed 24 hours after inhalation
exposure. 22
Table 4. Data from biological samplers, including iodine in
dog thyroids analyzed in vitro. 24
Table 5. Iodine collected by low volume air samplers. 25
LIST OF FIGURES
Figure No. Pag(
Figure 1. Map of the downwind area showing location of
sampling teams. 4
Figure 2. _In vivo spectra of the thyroid of one dog from the
31-mile station. 28
Figure 3. In vivo spectra of the thyroid of one dog from the
42-mile station. 29
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Chapter 1
INTRODUCTION
Many studies both past and current have yielded reasonably reliable es-
timates of the parameters concerning transfer of iodine-131 through the
food chain to the human thyroid. However, relatively little is known
about the means by -which radioiodine produced by nuclear testing passes
through the biosphere to the food of cow and man, about its importance
as an inhalation hazard, or about the relationship between its measure-
ment in environmental samples or dose rate surveys to the radiation
dose produced in man's thyroid. Project Sedan of the Plowshare Pro-
gram provided a fission product source enabling some of these factors
to be studied.
The U. S. Public Health Service, at the request of the Nevada Test Or-
ganization, Atomic Energy Commission, and with their financial support,
designed and conducted a program to measure the inhalable fraction of
iodine released to the close off-site area by the Sedan event. The nuclear
device employed for the event was developed by the Lawrence Radiation
Laboratory, Livermore, California. The device had a design yield of
one hundred kilotons plus or minus ten per cent, and was buried at a
depth of 635 feet in alluvium in Yucca Flat, Nevada.
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It was expected that this iodine inhalation study would provide at least
qualitative and hopefully some quantitative information concerning the
effectiveness of a. biological-physical field study in answering some of
the urgent questions concerning health hazards of iodine, and would per-
haps aid in a preliminary empirical evaluation of the relationship be-
tween external and internal beta-gamma doses which could result from
tests producing a gaseous or near-gaseous nuclear cloud. It was under-
stood that the information obtained would be unique, applying only to the
conditions of the Sedan event. This unique character of the data became
more evident when samples were received, as the expected energy spec-
trum of fission products was contaminated with large amounts of a gam-
ma emitter (W187) associated with the construction of the device. This
contaminant masked many of the isotopes of interest in gamma spectro-
metric analysis of the samples.
A very short lead time allowed only limited calibration and field testing
of many of the methods, equipment, and facilities being used in an ex-
perimental application for the first time. It was realized that this limi-
tation, combined with that provided by the nature of the device, might
render some of the data scientifically invalid. Nevertheless, since
valuable experience and practical information were derived from the
sampling and analytical procedures attempted, they are described
whether or not they yielded scientific data in usable form.
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Chapter 2
OPERATIONAL, PLAN AND FIELD METHODOLOGY
One of the most persistent difficulties encountered in field experiments
is that of effective sampler placement. The concept of manned mobile
sampling stations was therefore employed to reduce the probability of
missing the radioactive cloud without increasing the number of samplers
required to obtain the desired information.
Samplers were concentrated in three mobile units carried in vehicles
equipped with two-way radio. Each unit included two 2-wheel drive,
four-speed transmission, air-conditioned panel trucks for transporting
beagle dogs, and one 4-wheel drive truck carrying generators and phys-
ical sampling equipment. Each unit was manned by a team consisting
of six members, two of •which-were responsible for biological sampling,
two for physical sampling, one for continuous monitoring, and one to
act as team historian. A supply team carrying fuel, water; and back-up
equipment and supplies supported the three sampling units.
Placement of the sampling teams was directed by radio from the Nevada
Test Site (NTS) Control Point. Standby positions were selected prior
to the test day (D) to allow coverage of either of two parallel valleys
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N
.TEAM 3
VT3UEEN CITY SUMMIT
LEGEND
fy SAMPLING TEAM LOCATION
• COMMUNITY
Q ABANDONED BUILDING
• OCCUPIED BUILDING
^ CORRAL
> RESERVOIR
D-« ATTENDED BARRICADE
>-* UNATTENDED BARRICADE
•• PAVED ROAD
— UNPAVED ROAD
OR PASS
APPROXIMATE MILAGE BETWEEN
LANDMARKS IS INDICATED BY
NUMBERS WRITTEN ALONG ROAD
Figure 1. Map of the downwind area showing location of sampling teams.
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within the predicted cloud trajectory. Road surveys and checks for
radio contact were made prior to D-day in the area shown in Figure 1,
and alternate sampling station approaches and escape routes were es-
tablished. A complete dry run of the field operation on D-3 showed
that only minor modifications of the plan were necessary.
Approximately 4 hours before detonation (H-4) the sampling and supply
teams were dispatched to the pre-arranged standby positions. Since
35 minutes were required to place and set up a sampling station, just
before detonation the team closest to ground zero (GZ) was directed by
radio to set up at a position selected on the basis of U. S. Weather
Bureau information. The remaining teams were positioned on the
basis of information received from aerial cloud tracking and ground
monitoring teams, as well as on the visual observations reported by the
first sampling unit. The final sampling positions at approximately 14,
31, and 42 miles from ground zero are shown in Figure 1.
Sampling equipment was activated upon cloud arrival and was turned off
when the cloud had passed,or as soon thereafter as possible. This min-
imized dilution with uncontaminated air, desorption of collected mater-
ial, and contamination with resuspended material. Samples were pack-
aged in the field and were picked up by helicopters summoned by each
team as it began its shut-down operation. This allowed earlier and
perhaps more significant analyses of short half-lived isotopes than
would have been possible by the usual recovery methods. Two members
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of each team accompanied the samples in the helicopter, while the four
remaining members returned the sampling gear to headquarters in the
three vehicles.
A facility for processing and analyzing samples was set up at the field
headquarters to isolate the relatively "hot" samples obtained from this
project from routinely analyzed low-level samples, and to allow as
short a time lapse as possible between collection and analysis. The
facility consisted of a compound enclosing two 40'x8' volume van trai-
lers housing counting room and radiochemistry laboratory, and three
50' x 10' office trailers serving as shops, treatment rooms for animals
and office and storage space. This compound was conveniently located
adjacent to a radiation safety facility maintained for the test site by
Reynolds Electrical and Engineering Co. Helicopters and ground vehi-
cles returning from the field were unloaded and surveyed in this rad-safe
area. Samples and personnel were processed through standard rad-safe
decontamination before entering the headquarters compound.
2. 1 PHYSICAL SAMPLING
The physical sampling equipment at each station comprised four basic
systems. These were the high and low volume air samplers, a cascade
impactor, and a sequential sampler as described below.
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High Volume Air Sampler. - 2 per station
This was a Staplex sampler equipped with 8" x 10" glass fiber
prefilterand 3-1/4" diameter charcoal cartridge (MSA1 Catalog
No. CR-46727), drawing 25-35 cubic feet of air per minute as
calibrated with a Venturi meter.
Low Volume Air Sampler. - 2 per station
This was aGelman vacuum pump drawing air at about 0. 7 cubic
feet per minute through a 47 mm Millipore Type HA prefilter;
a carbon cartridge consisting of a polyethylene tube 8" long by
9/16" I. D. backed by 8-14meshcoconut shell activated carbon,
and a flowmeter. A small-mesh screen wire and a spun glass
plug were inserted into each end of the cartridge to hold the
carbon in place. A Dwyer rotameter calibrated against a wet
test meter was used to measure air flow. All connections were
made with 1/4" Tygon tubing.
Cascade Impactor. - 1 per station
This was the standard Casella impactor for determining par-
ticle size, operated by a Gelman vacuum pump at a flow-rate
of approximately 17 liters per minute. The four glass cover
slip stages were backed by a Millipore filter fifth stage.
1 Mine Safety Appliances Co., Pittsburgh, Pennsylvania
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Sequential Sampler. - 1 per station
This was the Gelman sequential sampler (Model No. 23000)
with Whatman Type 41 filter paper, sampling in 10-minute
periods for each cycle at a flow-rate of 16 liters per minute.
Each set of sampling equipment was mounted on a special wooden rack
which allowed the entire physical sampling array for each station to be
transported, set up, and operated as a single unit powered by three
1. 5 kw generators. The rack was designed so that all samples were
taken three feet above the ground.
When a station was shut down after passage of the radioactive cloud, all
samples were packaged for helicopter transport to the field headquar-
ters. The high volume prefilters were placed in glassine envelopes
which were then taped shut. The high volume carbon cartridges -were
sealed in plastic bags. The cascade impactor was disconnected and
sealed in a plastic bag. A plastic cover was placed over the low volume
filter holder, and the filter holder and carbon cartridge were disconnec-
ted and sealed in separate plastic bags. The elapsed roll of filter paper
from the sequential sampler was detached and sealed in plastic. All
these bagged and sealed samples were then placed in a single large
plastic bag for transport to the field headquarters.
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2.2 BIOLOGICAL SAMPLING
Purebred beagle dogs were used as biological air samplers. These
animals were obtained several weeks prior to the operation and were
housed inkennels at the headquarters compound. To quantitate air sam-
pled by the dogs, and to relate the radioiodine collected with that collec-
ted by the physical air sampling systems, respiratory frequency and
inspired air volume of each animal were determined before the Sedan
event. The measurements were made under simulated field conditions
after the animals •were acclimated to summer desert conditions. The
measurement system utilized Fleisch Pneumotachographs1 of various
flow capacities, built into latex-coated plaster of paris face masks indi-
vidually constructed and fitted to each dog. Pressure differences sensed
by the pneumotachograph -were converted through a battery operated
Sensitive Differential Pressure Transducer, Model 1004A2 containing
the transducer, a control indicating meter, and a recorder driver, to
a tracing on the high torque, spring operated Model AW Esterline
Angus recorder.
To supplement these pre-event breathing calibrations, two animals at
each sampling station wore the breathing apparatus during cloud pass-
age. After the event, respiratory measurements were continued on all
dogs not sacrificed immediately after exposure.
Since time was not available to train the dogs in sampling behavior,
1 Instrumentation Associates, New York
2 Monroe Electronic Laboratories, Inc., Middleport, New York
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they were exposed in cages made of wire mesh. All animals were pre-
pared and caged at the headquarters compound. Two air-conditioned
panel trucks carried ten caged dogs to form the biological sampler
complement at each sampling station.
It was intended that each dog be tranquilized by oral administration of
chlorpromazine upon arrival at the sampling locations to facilitate hand-
ling. However, difficulties encountered in administering the tranquili-
zer prevented tranquilization of animals at the station closest to GZ
and re suited in partial tranquilization of animals at the other two stations,.
Breathing measurement apparatus was connected to two dogs at each
station to operate throughout the sampling period as reference meas-
urements. All dogs were placed on a platform three feet above the
ground in close proximity to the physical sampling devices.
To determine the body burden of activity inhaled during cloud passage,
it was essential to prevent inhalation of resuspended material and in-
gestion of material deposited on the nose and fur. Therefore, four
animals at each station, including one of those wearing the respiratory
measurement devices, were sacrificed as soon as possible after cloud
passage. The area surrounding the nose and mouth of each remaining
animal was washed with a detergent solution to prevent introduction of
additional activity by lapping. The dogs were left in their restraining
cages to prevent lapping of other areas of the body. After intravenous
administration of sodium pentobarbital, sacrifice was accomplished bv
maximal blood withdrawal from the hearts using standard blood donor
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kits to withdraw and receive the blood. Sacrificed animals were sealed
in large polyethylene bags before being loaded into the helicopters with
the caged dogs, the blood samples, and the physical samples for trans-
port to the headquarters compound. Before being readmitted into the
compound, all dogs were decontaminated at the Area 400 Rad-Safe facil-
ity with warm water and detergent, and the neck and chest areas were
shaved. The sacrificed animals were again sealed in clean polyethylene
bags before being taken to the clean area, and the living animals were
returned to the kennels to await in vivo counting of the thyroid and ser-
ial sacrifice.
2.3 DOSIMETRY
Dose rate readings were taken at each station with portable survey in-
struments including the Beckman MX-5 (range 0-20 mr/hr), .the
Eberline E500-B (range 0-2 r/hr), and the Tracerlab TIB (range
0-50 r/hr). Readings were recorded every ten minutes until the cloud
arrived and every three minutes during cloud passage. Integral gamma
dose to each station was determined from Du Pont Type 556 film badge
dosimeters containing high and low range film components. These
badges were attached to the physical sampling gear racks.
One roentgen and 10 roentgen ionization chamber dosimeters and high
and low range film badges were used as personnel dosimeters. These
were standard personnel dosimeters issued and analyzed by the REECo
Radiation Safety Dosimetry Section. The protective clothing used was
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also supplied by REECo Rad-Safe and consisted of standard radex suiting
in addition to respirators with charcoal cannisters. Team members
suitedup in the field just prior to cloud arrival. Respirators were worn
only when the dose rate rose to a pre-determined level. Upon return
from the field, team personnel were decontaminated by standard pro-
cedures at the REECo Rad-Safe facility.
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Chapter 3
LABORATORY METHODOLOGY
3. 1 PROCESSING OF SAMPLES
For the most part, processing of samples prior to counting consisted of
simply repackaging the samples in clean containers when they had re-
turned from the field. Chemical separation of iodine was performed
only on low volume sampler prefilters twelve days after the event. Par-
ticle sizing attempts were not successful.
Dog autopsies were performed through the polyethylene bags to mini-
mize contamination of internal tissues. A midline incision was made
through the bag and skin from larynx to sternum. A skin-and-bag flap
was reflected to expose neck musculature, which was then dissected
with a clean set of instruments to expose the thyroid gland, trachea,
and esophagus. With a third set of clean instruments the thyroid gland
was carefully removed to a small plastic bag in which it was weighed
and counted. The trachea was reflected and the esophagus removed
and sealed in a plastic bag, again using clean sets of instruments for
each operation. After continuing the midline incision from sternum to
pubis, further dissection was carried out in an anterior to posterior
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direction to remove respiratory system, stomach, small intestine,
large intestine, kidneys, and gonads. Each of these samples was sealed
in a pre-weighed plastic container in -which its weight and redioactivity
was determined. Extreme care was taken throughout the sample pro-
cessing procedures to prevent redistribution of activity or cross
contamination of samples.
3. 2 RADIOASSAY OF SAMPLES
Three systems were used for assaying the gamma activity of samples.
The systems were assembled from components on hand, borrowed from
routine programs, or purchased new if time permitted. The urgency
of the Sedan program, the short lead time, and the necessity for return-
ing many system components to their routine duties at other locations
limited the extent of calibration. Also, it was not possible to acquire
the desired spectrum of gamma energies from the standards available.
The three gamma analysis systems are described below and the stan-
dards used for their calibration are listed in Table 1,
Table 1. List of radioisotope standards.
ISOTOPE
I131
Cs137
Zn65
K40
HALF LIFE
8. 08 days
26.6 years
245 days
1 . 25xl09 years
ENERGY
0. 36 Mev
0. 64 Mev
0. 66 Mev
1. 12 Mev
1.46 Mev
Calibration curves for two of the systems are shown in the Appendix,
Part B.
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System 1. 4" x 4" Nal(Tl) crystal assembly with RIDL
400-channel gamma pulse height analyzer.
Most samples analyzed by this system were sealed in the quart
size plastic cheese-tub type container having a 3-3/4" diameter
base. To calibrate for this configuration, counting efficiencies
were determined for various levels of a solution of each stan-
dard. Channel width was set to be 10 Kev. For photopeak
energies below 900-Kev, counts were summed over eight chan-
nels (80 Kev). Above 900 Kev, nine channels (90 Kev) were
summed. The counting efficiencies obtained are shown in
Table 2.
Samples in three additional configurations were analyzed with
the 4" x 4" scintillator-spectrometer system. These were the
MSA charcoal cannister, the hand-packed tube of charcoal, and
the membrane filter from Gelman low volume samplers.
To calibrate for the MSA cannister, a portion of charcoal equi-
valent to approximately 1/8" penetration was removed and im-
pregnated with a known volume of the iodine-131 standard sol-
ution. After slow drying, the impregnated charcoal was mixed
with the uncontaminated granules and replaced in the cannister..
Both the cannister and the container used for drying the char-
coal were counted, showing a 16% detection efficiency for I1 31
in the cannister configuration.
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Table 2. Efficiencies of the 4"x 4" solid crystal of System 1 and the 9"x 8" well crystal of System 2 for
counting radioisotope standards.
ISOTOPE
STANDARDS
I131
Cs137
Zn65
K40
SYSTEM 1.
STD. GEOMETRY
VOL.
(ml)
115
230
345
575
115
230
345
460
115
230
345
460
115
230
345
HT.
(in)
3/4
1-3/8
2
3-1/2
3/4
1-3/8
2
2-3/4
3/4
1-3/8
2
2-3/4
3/4
1-3/8
2
RANGE
SUMMED
(Kev)
80
80
80
80
80
80
80
80
90
90
90
90
90
90
90
COUNTING
EFFICIENCY
(%)
13.5
10.5
8. 62
6.24
14. 1
11.4
9.25
7.80
5.25
4.20
3.40
2.92
2.05
1. 68
1.32
SYSTEM 2.
STD. GEOMETRY
VOL,.
(ml)
200
200
200
200
HT.
(in)
2
2
2
2
RANGE
SUMMED
(Kev)
80
90
80
90
110
130
110
COUNTING
EFFICIENCY
(%)
55.9
59.0
57.5
62.9
27.5
30.9
18.3
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In a similar manner the charcoal from the hand-packed tubes
was calibrated for counting in the quart-sized tub. A detection
efficiency for I131 in this configuration was also found to be
16%, as it was for the membrane filter placed in a 2" diameter
stainless steel planchet, impregnated with the standard I131,
and counted on top of the crystal.
System 2. 9" x 8" Nal(Tl) crystal assembly containing 3"x5"
well with RIDL, 400- channel pulse height analyzer.
A snap-top plastic container having a flat base and a very
slight taper, custom-made by Nalge Co.1 to fit the crystal.
well, was not available for use during the Sedan event. There-
fore, all samples analyzed "in this system followed the geomet-
rical configuration of a 500 ml. plastic bottle 2-3/4" diameter
and 6-1/2" in height. A 200 ml. volume rising approximately
2" above the container base was selected as a volume repre-
sentative of the samples to be counted in this system. The re-
solution of this crystal was poorer than that of the 4" x 4",
spreading photopeaks over a wider range. Therefore, effici-
encies were determined by summing from eight to thirteen
channels depending on photopeak energy. This is shown in
Table 2 with the detection efficiencies obtained.
1 The Nalge Company, Rochester, New York
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System 3. 5" x 6" Nal(Tl) crystal with 3" x 5" well and RIDL
sealer.
This system was used to determine gross gamma activity.
Sample geometry was similar to that in the 9" x 8" well crys-
tal assembly. Two hundred milliliters of standard solution in
500 ml. polyethylene containers were counted and the efficien-
cies calculated. In addition, an efficiency was calculated for
200ml. of a mixed standard solution. Since efficiency is highly
dependent on gamma energy, it was realized that the method
would not give a true efficiency for mixed fission products.
True efficiency would depend on the relative levels of activity
at the various energies. Since it was expected that the lower
energy isotopes would be more prevalent, gross gamma detec-
tion efficiency was determined for a mixture of I1 3 1 and Zn6 5
standard solutions in which the activity of I131 was greater by
a factor of three. This efficiency was found to be 63%.
Physical samples received for counting were MSA charcoal cannisterss
hand-packed charcoal tubes, membrane prefilters, 8" x 10" glass fiber
prefilters, and the Millipore filters and glass cover-slip stages from
cascade impactors. Gamma pulse height analysis of these samples
could not be made immediately because of the high levels of radioactiv-
ity they contained and the complexity of the isotope mixture. Low vol-
ume sampler membrane and charcoal filters were analyzed prior to
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D+5, but at D+5 it was still impossible to obtain information on the high
volume samples. By D+28 the activity in the high volume samples had
decayed to countable levels.
An attempt was made to count grossbeta activity on the membrane pre-
filters and impactor cover-slips by placing each sample on a stainless
steel planchet and counting it in an internal proportional counter. How-
ever, dust particles were blown around the chamber during the gas
purge, causing gross contamination of the equipment. Therefore, these
samples were sealed in polyethylene containers and counted for gross
gamma activity only.
The biological samples received for counting included thyroid, blood,
respiratory system, esophagus, small intestine and contents, large in-
testine and contents, kidneys, and gonads from each dog. Gross gam-
ma activity in these samples was determined as soon as possible after
autopsy. These data were to be used if a gamma pulse height analysis
of each organ could not be made, since it was possible to estimate from
the gamma scans the percentage of gross gamma activity contributed
by the various isotopes of the mixture. By this method, a quantitation
of the isotopes present was obtained in some organs which had not been
gamma scanned. The gross gamma count was also used to indicate the
level of activity on the sample before a detailed pulse height analysis
was attempted.
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One- to five-minute gamma scans were made of all organs except those
so highly contaminated as to produce approximately 100% analyzer dead
time. The larger organs were placed in the tub container and scanned
on the 4" x 4" crystal. The smaller organs were scanned in the well
crystal. A second scan was obtained on all organs one or two days later
and, when possible, a third count was made several days later. All the
thyroid samples •were recounted on D+5 and again on D+22.
3. 3 IN VIVO ANALYSIS
In addition to serial sacrifice and autopsy of exposed dogs followed by
in vitro analysis of organs and tissues, an attempt -was made to follow
the build-up and decay of iodine in the thyroid by in vivo counting. To
do this, a system was constructed in which two 3" x 3" Nal(Tl) crystals
were optically coupled to two photomultiplier tubes, which in turn were
coupled to preamplifiers feeding into the two inputs of a TMC(400-channel)
pulse height analyzer. Each crystal was encased in a 1-1/2" lead
flat-field collimator. In addition, a 2" x 2" Nal(Tl) crystal encased in
1/2" lead sheet was available as a supplementary detector.
Meaningful calibration, effective collimation, and reproducible geom-
etry are necessary features of an in vivo counting system. A reprodu-
cible procedure for the Sedan study was established by making several
trial counts with the available equipment, but insufficient time was
available for further refinements. One of the dogs which had not been
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exposed served as a control. The greatest reproducibility was obtained
in trial counts by placing one 3" x 3" crystal to view the right side of
the neck and the other to view the thyroid from underneath. By using
this method to scan the thyroids of exposed dogs, barely detectable
levels of radioiodine were seen, although tellurium-132 and tungsten-18?
were present. This indicated that the flat-field collimator had allowed
the crystals to view more than just the thyroid (probably the respiratory
system). Therefore in vivo counting data we re used only to indicate the
relative change in iodine content of the animal thyroid as a function of
time.
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Table 3. Qualitative analysis of the body burden of gamma emitters in
a dog sacrificed 24 hours after inhalation exposure 42 miles
from ground zero.
SAMPLE ANALYZED
Thyroid Gland
Respiratory
System
Esophagus
Small Intestine
and Contents
Large Intestine
and Contents
Kidneys
Gonads (testes)'
Blood
DAY ANALYZED
D+2
D + l
D+2
D+l
D + l
D + l
D + l
ISOTOPES DETECTED
I131 I133 Xe133m
W187 Te13Z j!33
Xe133m
W187 Te132 J131
Xe133m Xe135
Wi87 Xe132 I133
Xe133m
Activity exceeded
capacity
W1 87 Te1 32
W187
W187 Te132 I131
I133
I131
counting
I133
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Chapter 4
RESULTS
The high levels of activity, the complexity of gamma spectra, the pres-
ence of unusual contaminants such as W187, and the minimal calibra-
tion of counting equipment all contributed to the difficulty of making a
valid analysis of the data, and reduced the reliability of much of the
data obtained. A discussion of the data analysis procedure and a sam-
ple calculation are included in the Appendix. The results presented in
this section are considered to be reliable for relative comparisons, for
order of magnitude quantitation, and for indicating trends. In view of
the many imponderables, no attempt has been made to determine
probable error.
A qualitative analysis of the organs of a dog which had been exposed at
the 42-mile station and sacrificed twenty-four hours later showed the
body burden contained, at time of count, the isotopes listed in Table 3.
Because of the complexity of the spectra of the various organs, it was
decided to consider the thyroid data primarily. Since only radioiodine
and its daughters are expected in the gamma spectrum of an exposed
thyroid, quantitative estimates could be made. Initial count, recount
after five days, and a:third count after .twenty-two days would assure a
-23-
-------
Table 4. Data from biological samplers, including iodine in dog thyroids analyzed in vitro.
EXPOSURE LOCATION
AND TIME OF
CLOUD ARRIVAL
GZ +14 miles
•H + 1 / 2
Qf-s-f-n nr, 9
GZ +31 miles
H + 1-1/3
c •
GZ +42 miles
H +2
SACRIFICE
TIME .'
(±1/2 hr)
H + 1-3/4
H + 29
H +73
. H+l-1/4
H + 30
H +75
H +:3-l/2
H +28
H +75
DOG
NO.
1 1
16
17
43
? ?
77
37
2
3
28
4
5
14
23
15
33
38
21
26
32
7
12
30
4.1
25
35
40
8
18
24
AVERAGE RATE
OF INHALATION
( ml / mill )
818
2375
744
2153
ons
1 0 1 ?
946
1167
794
1590
70^
368
741
750
1462
1558
980
1058
1507
1262
AQC
1056
1324
2242
1501
1248
1756
1119
629
996 .
VOLUME OF
AIR INHALED
(M3)
A 1 ?. v 1 f) ~ 2
17.8 xlO-2
5.58xlO~2
16.1 xlO"2
A & i vi n ~z
7 RQ-S-I n "2
7.09xlO"2
8. 75xlO-2
5.95xlO-2
11.. 9 xlO"2
q fi4Y i n "2
5. 15xlO~2
10.4 xlO-2
10.5 xlO"2
20. 5 xlO"2
21.8 xlO"2
13.7 xlO"2
14.8 xlO'2
21. 1 xlO"2
; 17.7 XlO"2
5 Q6xl 0 "2
9. 19xlO"2
11.5 xlO~2
i q c; vl n "2
13. 1 XlO"2
10.9 xlO"2
15. 3 xlO"2
9.73xlO"2
5.47xlO-2
8.66xlO-2
NET dpm If
extrapolated to
I131
-----
8.00xl02
4.59xl03
1.47xl03
2. 38xl03
4. 24xl03
6.74xl03
2.83xl03
6.43xl05
6.75xl05
2.97xl05
6.52xl05
8.67xl05
6.00xl05
5.95xl03
1.09xl03
2. 29xl05
6.44xl04
7.50xl04
1. 24xl05
1.26xl05
3. 13xl05
i THYROID
sacrifice time
I133
-----
_____
_____
3 OSxlO4
1.35xl05
1.88xl05
5. 90x1 O4
6. 14xl06
6. 21xl06
2.74xl06
1. 36xl06
1. 59xl06
1.73xl06
1. 37xl05
2.96xl04
2. 33xl05
6.60xl05
7. 57xl05
2.58xl05
2.75xl05
6.85xl05
-------
good quantitation of some of the radioiodines present.
Table 4 presents the in vitro iodine analyses of dog thyroids. The vol-
ume of air sampled by each dog, as determined by the method described,
is also listed. It can be seen that the ratio of I1 3 3 to I131 decreases with
the length of time before sacrifice. The ratios are the same for a given
sacrifice time at both stations, indicating that no appreciable fractiona-
tion of iodine or its precursors occurred as the cloud moved from thirty-
one to forty -two miles.
Table 5 presents the results of the analyses of the low volume air sam-
ples. No I1 31 was detected in these samples, indicating the relatively
negligible amount of that isotope present in the air at the times of sam-
pling. When the activity of I1 3 3 per cubic meter of air determined from
the low volume samples is compared with the I133 activity per cubic
meter of air breathed by each dog sacrificed immediately after expo-
sure, the values of I1 3 3 concentration in air are essentially the same.
Table 5. Iodine collected by low volume air samplers.
Sample
Location
Station 1
GZ +14 mi.
Station 2
GZ +31 mi.
Station 3
GZ +42 mi.
Flow
Collector „
Rate
T^6 (cfm)
Membrane
.71
Charcoal
Membrane
.54
Charcoal
Membrane
.61
Charcoal
Air I133
Sampled Activity*
(M3) (dpm/M3)
7.
1.47
1.
1.
2.07
1.
1.
1. 25
8.
27xl03
26xl04
07xl06
55xl05
31xl06
65xl04
Total I1 31 **
Activity*
(dpm/M3)
2. 09xl04
1. 22xl06
1.40xl06
*Activity has been extrapolated to mid-sampling time.
**Iodine l 31 measured on both membrane and charcoal filters.
-25-
-------
Plots of the initial in vivo counts indicated a barely detectable amount
of radioiodine. This was due to the time lag between inhalation and depo -
sition in the thyroid. However, Te1 3 2 andW187 were present in these
initial plots, indicating that the flat-field collimator had viewed more
than just the thyroid. Therefore, these data were used only to indicate
the change in iodine content of the animal thyroid as a function of time.
A smaller crystal with a higher degree of collimation would have
yielded more useful information.
Figures 2 and 3 are typical spectra obtained from in vivo counting of a
dog from the 31-mile and one from the 42-mile station at the time and
dates indicated. The change in iodine content of the thyroids is appar-
ent. It must be emphasized that the change pictured does not apply
specifically to the thyroid, because other portions of the animals' bod-
ies contributed to the spectra obtained. The qualitative picture shown
was substantiated by the in vitro results.
The majority of the individuals assigned to field teams wore protective
respiratory equipment during cloud passage, or were evacuated from
their stations. One person, however, remained at the 42-mile station
during the entire one-half hour period of operation. He wore no respi-
rator at any time, although he was in and out of his vehicle. Shielding
afforded by the vehicle reduced his external gamma exposure to 525 mr
as compared to the total station exposure of 870 mr. On D+7, an energy
spectrum was determined on this individual at the Walter Reed Army
-26-
-------
Institute of Research in their Whole Body Counting Facility. A 9" x 4"
sodium iodide crystal, and calibration procedures and efficiency values
obtained from counts done on children were used. At the time of this
analysis, the total thyroid burden of I1 31 was calculated to be between
0. 1 and 0. 3 microcuries. On D+l, a thyroid scan •was obtained on this
same individual using the equipment employed for in vivo counting of
dogs. The I thyroid burden was found to be 0. 16 microcuries cor-
rected to mid-time of exposure.
A second individual at the same (42-mile) station wore protective res-
piratory equipment throughout the entire time of cloud passage. His
external gamma exposure was 475 mr. On D+12, he was examined in the
whole body counting facility at New York University. His thyroid bur-
den of I1 31 on D+12 was 8 x 10~4 microcuries.
On D+12, one of the individuals assigned to the 31-mile station was al-
so examined in the •whole body counting facility at New York University.
His body burden of I131 was 1 x 10~3 microcuries on D+12. However,
he wore a respirator throughout the entire period except for that portion
of the time between team evacuation and return for sample pick-up.
His estimated time at the station was twenty-seven minutes prior to
evacuation, during which time his external gamma exposure •was 1025 mr
compared to a station exposure of 2. 9 roentgens.
A fourth individual, a member of the Off-Site Radiological Safety
Program, was examined on the local in vivo system on D+l. His I133
-27-
-------
UJ
H-
cr
H
Z
ID
O
o
10
COUNTED 1732 PDT JULY 7
- COUNTED 1352 PDT JULY 8
- COUNTED III I PDT JULY 9
v\ / \
10
10
10 20 30 40 50 60 70 80 90 100
CHANNEL NUMBER
Figure 2. In vivo spectra of the thyroid of one dog from the 31 -mile station.
-28-
-------
COUNTED 1642 PDT JULY 7
— COUNTED 1235 PDT JULY 8
COUNTED 1002 PDT JULY 9
WI87+|I32
UU_/_L\_
30 40 50 60 70 80 90 100
CHANNEL NUMBER
Figure 3. In vivo spectra of the thyroid of one dog from the 42 -mile station.
-29-
-------
thyroid burden was estimated to be 1. 4 x 10~2 microcuries corrected to
mid-time of exposure. This person's duties took him back and forth
through the cloud in the vicinity of the 42-mile station and, although his
duration of exposure is not known, it has been established that no protec
tive breathing equipment was •worn. His external gamma exposure was
770 mr.
-30-
-------
Chapter 5
CONCLUSIONS
A comparison of the average amount of I1 33 collected by the low volume
samplers (Millipore prefilters plus activated carbon cartridges) with
that found in the thyroids of dogs sacrificed immediately after cloud
passage is of interest. At the 31-mile station, the low volume sampler
showed the average I1 33 content of the cloud to have been 1.2x10 dpm
per cubic meter (see Table 5). Four dogs •were sacrificed at that sta-
tion, and their thyroids were removed and counted separately. The
average value obtained from counting the four thyroids indicated an I1 3 3
content of 1.4x10 dpm in the thyroid per cubic meter of air inhaled.
This concentration value is obtained by dividing total I1 33 in each thyroid
by the total amount of air breathed (sampled) by each dog. A similar
agreement existed at the 42-mile station. Here, the low volume air
sampler indicated an I1 3 3 content in air of 1.4x 106 dpm per cubic
meter, and the average amount found from counting the thyroids of two
dogs was 0. 9 x 10 dpm per cubic meter.
Two interpretations of these data are possible. First, it could be as-
sumed that all I133 inhaled by a beagle dog goes directly and rapidly
to the thyroid and that the physiological system is a completely efficient
-31-
-------
sampling mechanism. This conclusion is quite improbable. One must
therefore accept the second interpretation and assume that the physical
sampling gear currently considered optimum for sampling radioactive
iodine effluents is actually very inefficient, being on the order of 10% or
less. Thus, there is an urgent need for additional studies directed
toward the determination of radioiodine concentration in air which will
lead to the development of truly quantitative sampling methodology,
Of all the radioactive iodine isotopes, I131 has justifiably received the
greatest attention. This is logical when one considers ingestion alone
at times after a release measured in days. The situation is entirely
different when relatively near distances and shorter times are considered
for inhaled material. No I1 31 -was detected in either the prefilters or
the activated carbon cartridges at the 31-mile or 42-mile stations when
they -were counted immediately upon return to the laboratory. The filters
were stored, however, and iodine was extracted chemically at D+12 and
analyzed for I1 31 . The I1 3 1 was then extrapolated back to the mid-time
of the sampling period to give a hypothetical I1 31 content of the cloud.
At the 31-mile station, the hypothetical I131 concentration in air was
1.2x 106 dpm per cubic meter, and at the 42-mile station was
1.4 x 106 dpm per cubic meter. Admittedly, these data are subject to
large errors due to such factors as sampler inefficiencies and incom-
plete chemical extractions. It may be significant, however, that the
averages of the animal thyroids from the 31- and 42-mile stations indi-
cated respectively 5. 9 x 104 and 3. 7 x 104 dpm of I1 31 per cubic meter.
-32-
-------
The presence of I131 is certainly confirmed in the cloud, and is in
agreement with the theoretical fact that at the time of sampling, I131
represents 0.6% of the total iodine activity and I133 represents 11%.
There was probably very little I131 on the physical samples counted
immediately, and that obtained by chemical extraction at D+12 resulted
from the decay of Te1 31 captured on the filters. It can be concluded that
the animal takes a more ra'cxmsaiife- representation of the iodine activities
than does physical sampling equipment because the animal "does its own
chemistry" and deposits these activities in strictly correct ratios in the
thyroid gland.
A comparison of the I1 33/I1 31 ratio found in the dog thyroids with theo-
retical ratios as a function of time supports the validity of this conclu-
sion. At H+l. 5 the I1 33/I1 31 ratio in the thyroids at the 31-mile station
was 23.7. At the 42-mile station the ratio was 24. 4. According to
Glendennen's theoretical calculations, the ratios are 24. 4 at one hour
and 19.6 at three hours after instantaneous fission of U235 .
No obvious correlation or trend was observed between the ratio of total
radioactive iodines in animals' thyroids compared with the total exter-
nal gamma dose at either the 31- or 42-mile stations.
-33-
-------
APPENDIX
Table of Contents
Part Page
A TABLE OF DECAY SCHEMES Ap- 1
B CALIBRATION CURVES FOR TWO GAMMA PULSE
HEIGHT ANALYSIS SYSTEMS Ap- 3
C DATA ANALYSIS Ap- 4
D SAMPLE CALCULATION Bateman Solution for a.
Three-Membered Chain Ap-10
-------
Part A
TABLE OF DECAY SCHEMES
Chain Energy
Member (Mev)
Te13im . 18, .84, .77
Te131 . 15, .94, .45
I131 .36, .64
Sn132—(2.2m>^Sb132—(2. lm)-^Te13 2—(77 . 7h)->I13 2 (2. 3h)
Chain
Member
Te132
I132
Energy
(Mev)
.23
.67, .7
.67, .78, .53, .96, 1.40
Sb133-(4. lm)-^Te133m-(53m)-»Te133—(2
(20.8h)
Xe133m Xe133
(2.3d) (5.27d)
Chain Energy
Member (Mev)
Tei33m >33> >4Q
Te133 .60, 1.00, .40
I133 .53, .85, 1.40
Xe133m .23
Xe133 .08
Ap-1
-------
Sb134—(48s)-^Te134—(42m)-^I134 (53m)
Chain Energy
Member (Mev)
Tl 34
1. 10, .86, . 12, .20, 1.78
j-30% Xe135m—(6.7hk
Sb135—(24s)-^Te135—(1.4mH»I135—I (15. 6h) U Xe135 (9.13h)
Chain Energy
Member (Mev)
I135 1.14, 1.28, .53, 1.72, 1.46, .86,
1.80, 1.04, .42
Xe135m .23
Xe135 .08
Ap-2
-------
10"
2--
O
z
UJ
O
li.
u.
UJ
10'
5'-
I01
WELL CRYSTAL- SYSTEM 2
BELOW 90 KEV, SUM 9 CHANNELS
ABOVE 90 KEV, SUM II CHANNELS
-200 ML.
SOLID CRYSTAL- SYSTEM
BELOW 90 KEV, SUM 8 CHANNELS
ABOVE 90 KEV, SUM 9 CHANNELS
' 115 ML.
I 230 ML.
h—345 ML.
2- —
\>
25
50 75 100
ENERGY (KEV)
125
ISO
PartB. Calibration curves for two gamma pulse height analysis systems,
Ap-3
-------
Part C
DATA ANALYSIS
C-l. DETERMINATION OF IODINE CONCENTRATION IN AIR
In determining the iodine content of the air during cloud passage, the
data from the low volume samplers were used. The activity on these
samples was low enough to allow several gamma scans to be made.
Also, chemical separation of the iodine from the prefilter was carried
out. Two extractions were made on the prefilters approximately five
days apart. The iodine from the first extraction is a function of the
quantity sampled and grown in to H+7, whereas the second extraction
indicates ingrowth alone.
The gamma scan from D-f 4 was used in calculating the I133 in the char-
coal filter. The contribution to this energy region from other photo-
peaks was again assumed to be negligible. Calculation of I131 -was car-
ried out by relating gamma scans from D+27 to data from D + 4.
The quantity of iodine calculated from the membrane filter is the com-
bined activity of the actual iodine sampled and that produced by decay
of its precursors. To determine how much actual iodine was present
in the air at the time of sampling, a different approach -was taken.
Ap-4
-------
Extrapolation of the measured value back to time of sampling is not
valid, since the value actually represents decay and ingrowth of the
isotopes.
Correction for this was made through use of the information provided
by the two chemical extractions on the prefilter. By considering the
formation of radioactive daughters in the decay of the parents for an
n-member decay chain, a relationship can be established, for any time,
between the existing quantity of an isotope, its initial quantity, and the
quantity of its ancestor. This is a straightforward application of the
Bateman equation1 .
The Bateman solution for a chain of n members in which only the parent
substance is present at tQ is:
Where,
-At -At
N = Ce ' + Ce 2 +
n i 2
\\ \, - ,
r
1 (A - A ) (A - A ) (A
2 is i r
A A A -
i 2 n i
2 (A - A ) (A - A ) (A
r ~V
. . . . C e
n
No
kit)
. A^ N" ^
If more than just the parent Substance is present at to, an addition is
made to the above solution; a Bateman solution for an (n-1)-membered
chain with substance i as the parent, a Bateman solution for an
1 Friedlander, G. , and J.W. Kennedy, Nuclear and Radiochemistry,
John Wiley & Sons, New York, 1955, p. 36. ' '
Ap-5
-------
(n-2)-membered chain with the next substance as the parent, etc. A
calculation of the percentage Te131 in air is given in Part D as an exam-
ple of a Bateman solution. For the I133 determination, it was first nec-
essary to find from the second extraction the amount of I13 interfering
in the I1 3 3 region. Then, the quantity of I1 3 3 in the second extraction
was calculated. The Bateman equation was used to derive the Te1 33rn
content at time of first extraction, A straight extrapolation back to mid
sampling time was made to obtain the Te1 33m content of the air at that
time. Application of the Bateman equation to the data from the first ex-
traction gave a relationship between the I133 that existed in the first ex-
traction, the initial I133 in the air at mid-sampling time, and the Te133m
in the air at mid-sampling time. With two quantities known, the I133 in
the air at mid-sampling time •was determined.
If most of the I1 31 had formed at the time of sampling, little or no I1 31
would appear in the second extraction. However, a significant amount
was present, and its existence can be explained upon closer examination
of the decay scheme (See Appendix, Part A). Early references list the
ancestors of I131 as a 3.4-minute Sn and a 23-minute Sb. Current evi-
dence points toward a 1. 6-hour Sn as the fission fragment. Both values
are reported as reliable, but neither one is listed as a metastable form.
Also, Sb, the daughter of Sn, branches on decay to a 30-hour Te and a
24. 8-minute Te. The 30-hour Te in turn branches on decay to the
24. 8 -minute Te and to a 8 . 08 -day iodine.
Ap-6
-------
The more significant parent of the I1 3 1 is the 24. 8-minute Te1 31 which
isformedfrom 85% of the Sb131 decay. Calculations indicate that at
the H+2. 5 mid-sampling time, only a small percentage (approximately
13%) of this Te1 31 had formed. Since it is the preponderant parent and
is of shorter half-life, a small percentage of Te131 would imply an even
smaller percentage of its daughter product. We therefore conclude that
an insignificant amount of I131 was in the air at the time it was sampled.
Absence of I1 3 l in the physical samples supports this conslusion.
C-2. DETERMINATION OF IODINE IN DOG THYROIDS
Quantitative calculation of iodine in dog thyroids was based on the
0.53 Mev peak of I133 and the 0. 36 Mev peak of the I1 3 l . Thereisan
interference from the 0.53 Mev peak in the 0.36 Mev region, but the
contribution of the 0. 36 Mev peak in the 0. 53 Mev region is negligible.
On this basis, and using the data from D+5, which indicated only two
photopeaks, the I133 photopeak could be quantitated.
Data from D+22 provided information on the I1 31 for twelve of the thy-
roids. These quantities were extrapolated backtoD+5to compare them
with the quantities calculated from the D+ 5 data. A ratio of the differ-
ence between the I1 31 values to the sum in the 0. 53 Mev photopeak was
determined to obtain the interference coefficient of the 0.53 Mev peak
in the 0. 36 Mev region. This ratio was determined for the twelve thy-
roids and an average value calculated. The average value for the inter-
ference coefficient was then used to determine the quantity of I131 in the
remaining thyroids.
Ap-7
-------
The amount of I131 and I133 determined in the thyroids was then extrap-
olated back to the time of sacrifice of each animal. This seems to be
the only significant time at which the quantity of radioiodine measured
by this method is meaningful. Before death, there is a build-up of iodine
from decay of precursors in the other organs, and a decrease through
biological elimination and through radioactive decay. After death radio-
active decay is the only process continuing to affect iodine concentration
in the thyroid.
The existence of I1 3 1 in some thyroids of the animals sacrificed in the
field at the end of sampling time indicatedthat the dog thyroid is a more
sensitive sampler for airborne iodine in a mixed fission product cloud
than is standard air sampling equipment. This is due to the advantage
provided by the living system's ability to concentrate and isolate iodine
in the thyroid. This advantage seemed to hold even though the low vol-
ume equipment sampled from eight to forty times the amount of air the
dogs inhaled. The I determinations were carried out twenty-two
days after sacrifice to allow the shorter-lived iodines to decay out and
permit observation of the I1 31 . The amounts remaining at D + 22 were
at the minimum, detection limit, which probably explains why I131 was
not observed in all thyroids counted.
The relatively long half-life of the Te132 (77.7 hours) would assure the
virtual non-existence of its daughter I132 at the mid-sampling time of
H + 2.5. The rate of decay of I134 is such that by the time these samples
Ap-8
-------
were assayed the isotope was not detectable. Quantisation of I1 3 5 was
not attempted because of the multitude of photopeaks exhibited in the
spectrum. Interference among the many photopeaks made any evalua-
tion difficult and perhaps unrealistic.
Ap-9
-------
PART D. SAMPLE CALCULATION OF PERCENTAGE Te131 IN AIR AT MID-SAMPLING TIME
The Bateman solution for a three-member chain is:
,_ -At -At _A t
f e ' e * e ' ]
N = + + A A N°
3 (A - A) (A - A) (A - A) (A - A) (A _ A) (A - A) '
L 2 i' v 3 t' 1 Z1 V 3 27 X 1 37 V 2 3 J
In this instance:
N = Amount of Te1 3 l at any time t
N° = Initial quantity of Sn1 3 * .
t =2.5 hours, lapsed time after release
A, A2/ Aa
= Decay constants for Sn1 31 , Sb131, andTe131, respectively.
Numerical values for the decay constants are:
A = 0.4431
Az = 1.8078
Aa = 1.6632
Numerical values for factors derived from the decay constants are:
-At
(Aa - A) = 1.3647 e ' 5 0.3430
(A3 - At) = 1.2201 e"^* = 0.0116
(A8 - A2) - 0.1446 e~ at = 0.0164
The solution then becomes:
N -f O-3430 0-0116 ' 0.0164 1 4431) n 8078^N«
3 [ (1.3647)(1.2201) + (-1.3647M-0.1446) + (-1. 2201)(0. 1446) J (0.4431) (1. 8078)^
= 0. 1306 N° = 13% N°
-------
DISTRIBUTION LIST
Copy
1-15 SWRHL, Las Vegas, Nevada
16 Terrill, J.G. Jr., DRH, PHS, Washington, B.C.
17 Anderson, E.G., TOB, DRH, Washington, D. C.
18 Snow, D.L., D&R, DRH, PHS, Washington, D.C.
19 Dahl, A.H., RSC, DRH, PHS, Washington, D.C.
20 Moore, R., DRH, PHS, Dallas, Texas
21 Mail and Records, NVOO, AEC
22 Reeves, I.E., NVOO, AEC
23 Test Manager, AEC, Ops. Coord., Mercury- Nevada
24 Allaire, W.W., POD, NVOO, AEC
25-27 Roehlk, O.H., OSD, NVOO, AEC
28 Vermillion, H.G., PIO, NVOO, AEC
29,30 U.S. Weather Bureau, NVOO, Las Vegas, Nevada
31-36 Dunning, G.M., DOS, AEC, Washington, D.C.
37 Test Branch, DMA, AEC, Washington, D.C.
38 Kelly, J.S..DPNE, AEC, Washington, D.C.
39 Hamburger, R., Tech. Ops., DPNE, AEC, Washington, D.C.
40 Ferber, G.D., USWB, MRPB, Washington, D.C.
41 Graves, A.C., LASL, Los Alamos, New Mexico
42 Ogle, W.E., LASL, Mercury, Nevada
43 Jordan, H.S., H-8, LASL, Los Alamos, New Mexico
44 Bacigalupi, C.M. , LRL, Mercury, Nevada
45 Olsen, J.L . , LRL, Mercury, Nevada
46 Rich, B.L. LRL, Mercury, Nevada
-------
Copy
47 Higgins, G. , L,RL,, Livermore, California
48 Fleming, E.H., L,RL,3 Livermore, California
49 Goeckermann, R.H., L.RL, Liivermore, California
50 Potter, G. , L.RL,, Livermore, California
51 Weapons Effects Test Grp., FC/DASA, Sandia Base, New Mexico
52 Chief, Biophysics Div. , AFWL,, KAFB, New Mexico
53 QIC, NERHL, Winchester, Massachusetts
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55 QIC, SERHL,5 Montgomery, Alabama
56 Chief, RHRA, DRH, RATSEC3 Cincinnati, Ohio
57 Fountain, E.L,., USA, MEDS, VSS Chicago, Illinois
58 Wampler, S. , WRA1R -WRAMC, Washington, B.C.
59 Wilson, R.H., Univ. of Rochester AEP, Rochester, New York
60 Gibb, R. , Univ. of Rochester AEP, Rochester, New York
76-100 Author's Copies: M.S. Seal
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