hay.
aS
Fae
as
a
2.2
We 1
™ A;
A field laboratory end animal quarters were established at Mercury to make observations
and measurements on all animals during the initial 72-he period after inhalation exposures to
’ aed’
: 4
5
ae.
ie
NE:
. a
R,;.
fall-out materials, Upon return of the animals fromthe field, the following procedures were
.
performed:
1, Each animal was decontaminated until external levels of gamma radioactivity were re-
duced to 0.05 mr/hr or less.
2. Bladder urine was expressed manually and collected.
; Re ‘
|
oh
“Lg
3. Each animal was placed in a separate metabolism ciyre.
4. External measuremenis of thyroid gamma-ray activity were made one or more times
daily.
SK ‘
eg
LABORATORY OPERATIONS
5. Urinary excretion was measured, and samples were collected systema"
wes.
‘Jly.
6. At 72 hr postexposure, all animals were sacrificed, refrigerated (dry ice), and shipped
Ae gf?
to the laboratury at the Atomic Energy Project, UCLA, for radioassay of various organs to
<j 7 S%
iv .~
2.3
Ln
NT ed’
y Ly.
f} x ‘\
aS
{ '{
; a
‘ iv tam
wey.
woN ia
determinethe fate of the inhaled fall-out material.
,
INSTRUMENTATION
2.3.1
Inhalation Exposure Equipment
During inhalation exposure tofall-out, all animals were placed in separate restraining
boxes designed to permit he
exposure only and also to prevent simultaneous ingestion of
materials on the ground (see Fig. 2.1). Upon recovery foliowing fall-out exposure, each animal
was cleaned superficially and a plastic collar was secured around the neck. The collars were
employed to prevent neck injuries during transport and the ingestion of iall-out material contamiaating the fur.
Fig. 2.1 —Restraining box for inhalation exposure with shield to prevent ingestion.
2.3.2
Radiation Detection Equipment
Acollimated gamma-ray scintillation counter (Nal crystal) connected to a scaler was
used to measure gammaradiation externally over the thyroid area (see Fig. 2.2). The sensi-
tivity of this equipment was sufficient to register the presence of as little as 0,003 pe of 134 in
the .hyroid with the procedures employed.
Radioassay of urine samples was made with standard counting equipment, using a t.4 mg/
en? mica window for dried samples. This equipment was provided by Project 37.1, and counting procedures established by this group were employed,"
13