=
LIFE SCIENCES
Mar. 15, 1971
inhalation exposure to ??*Rn and daughter products from the accumulated 2!"Pb body burden are given. The effect of the viola-
tion of the assumption that there was no significant 2!"pp contributions from sources other than 7?’Rn daughters on the model,
and the results are considered. (UK)
8681
DERIVATION OF WORKING LIMITS FOR CONTINUOUS
RELEASE RATES OF '*] TO ATMOSPHERE.
Bryant, Pamela M.
(United Kingdom Atomic Energy Authority, Harwell, Eng.),
Health Phys.; 19: 611-16(Nov 1970).
Working limits for continuous release ratcs of '¥1 to atmo-
sphere are derived by the specific activity method and, with
appropriate modification, by the direct foliar contamination
method used for '8!I involving the grass-cow-milk-infant crit-
ical pathway. Limitations of the methods-are discussed. It is
concluded that derived working limits calculated by the specific
activity method are appropriate for design purposes in connection with planned continuous release rates of "I. As an illustra-
tive example, the derived working limit is 270 mCi/duy for a
chimney of effective height 60 m, assumed to be the only source
of 1°7 in the area and situated at 400 to 500 m from the nearest
pasture. In some environmental situations, e.g., near the sea,
the derived working limit might be up to ten times greater than
this due to a high average stable iodine (!2"1) concentration in the
atmosphere. (auth) (UK)
8682 ~ DOSIMETRY OF PROTON RADIATION FIELDS IN
SPACE WITH NUCLEAR EMULSIONS. Schaefer, H.J. (Naval
Aerospace Medical Inst., Pensacola, Fla.); Sullivan, J. J.; Richmond, R.'G. Health Phys.; 19: 663-70(Nov 1970).
The bulk of the astronauts’ radiation exposure in space is due
to trapped protons in the South Atlantic Anomaly or, on a deep
space mission, in the radiation belt itself. The energy spectrum
of the proton flux in both cases is a broad continuum from zero
to several hundred MeV, with low energy protons and protons
ending in tissue carrying a substantial fraction of the total dose.
As demonstrated with the emulsion data of the Earth-orbital mission Apollo VI, a method using grain counting of tracks traversing
the emulsion combined with a count of those ending in it (zero energy) provides sustained accuracy over the entire energy range.
Within certain limits, the counts of ending protons at various locations in the space vehicle are proportional to the corresponding
total doses. Highly structured directional patterns that are generally characteristic for the low energy particles were analyzed
in detail from the unmanned Apollo VI mission during which a
total proton dose of 1.56 rad was observed within the vehicle.
The fact that low energy protons with their comparatively high
LET contribute substantially to the total dosc is reflected in
large microdosimetric fluctuations of the absorbed energy in
tissue, with Bragg peaks of ending tracks occurring only in a
few percent of the total cell population even at dose levels of
50 to 100 rad. (auth) (UK)
8683
COMPUTER CALCULATION OF RADIATION ATTENUATION AROUND A MEDICAL CURIETRON-TYPE RADIOACTIVE
PROBE. Costa, A.; Dutreix, Andree (Institut Gustave Roussy,
Villejuif, France), J. Biol. Med. Nucl.; 5: No. 20, 22-6(May-Jun
1970),
(in French).
The Curtetherapy Service of the Gustave Roussy Institute uses
an apparatus commercialized under the name Curietron, by the
A.G.S, Company. Thia unit allows permanent storage of miniaturized '"Cg sources and their automatic transfer by remote
control in a radium holder, The design of the Curietron and the
choice of “7Cs comply with the IAEA rules on the safety and protection of hospital staff. A programmeof dose calculation for a
computer, in FORTRAN IV, was established to determine the
form of the isodose around a rectilinear prohe, taking into account the presence of metal bearings between the grains of !7Cs,
833
squamous cell epithelhoamas located in regions with curved or irregular surfaces covering bony or cartilaginous planes (alae
nasi, aunele, etc.) (hr rance)
8685
DOshk AND LET DISTRIBU LIONS IN SMALL-ANIMAL
SIZED CYLINDERS FOR A FISSION NEUTRON SPPC TRUM.
Willhoit, Donald G.; Jones, Provee D. (Oak Rulge National Lab.,
Tenn.)., Radiat. Res.; 44: 263-72(Nov 170,
Monte Carlo sampling techniques were used tu produce ucutron
histories in tissue geometries corresponding in siec to the miuuse,
rat, and guinca pag. Dose and LET distributions were evaluated for
60,000 to 50,000 normally uvident neulrons having an energy dis =
tribution curraspunding to that of the Health Phy sies Research Keactor (HPRR) spectrum. Fur these geomctrics, Ju ol the dose
delivered by recoil nucle: was from elastic scattermw with iG,
C,and N, The dose averae d over the volume of cach animal was
94, 84, and 78. of kermafur tissue fu, free space (028 LUT eng
eg neutron! cin? fur Ue mouse, tat, and gumea pig, respectively.
Forthese geometries, unilateral exposure results uo maxinium to
minimum dose ratios greater than 1.00, which according to the
ICRU recommendations are classified as nedunitorm tri aduetian
condition, These data indicate that rotation of the animals in the
held would result ma unifyrm (variation less than 15%) irradiation
condition, The distribution of duse as a tunetion of LET was not
markedly dependent on depth in the animal geometries. The dose
median LET was estimated to be about 59 ke\ 2 for these tcometries for the IPRR neutron spectrum, fauth)
8686
GAMMA-RAY DOSE DISTRIBUTIONS IN EX PERNALLY
IRRADIATED CYLINDERS, Hubbard, Lincoln B.
(Qak Ridge National Lab,, Tenn. Knoavilte Coll, Tenn.).
Radiat. Res.; 44: 4-12
{Oct 1970),
Ap approxipiite model was presented for the arradiauion of aniform cylinders by external, broad-beam y rays. In the model, the
point doses lor unilateral and bilateral irradiations were simple
expressions of Clementary tuuctions, Che cange tram maximum
to minimum dose values was shown to be abot halt as groat lor
bilateral urradiation as compared with unilateral irradiation, Thus,
if the unilateral irradiation was considered nonumttorm, then the
bilateral irradiation was at best moderately unilorm, The dose
distributions for unilateral and bilateral irradiations have very
dillerent prope rtics. These distributions were discussed, and
their effects on cxperimental design were nuted, The surface
average, voluine average, and midline dose were compared lor
these irradiations. (auth)
8687
TECHNIQUES FOR MFASURING GAMMA RADIOACTIVITY IN THF RLMAN BODY. Clemente, Gianlelice (CNFN,
Rome), G, Fis. Sanit. Prot. Radiaz.; 12: 200-13(Jwl-Sep 1968).
(In Italian), (RT PROL-(69)6),
All the principal geometries used for external scintuiition de-
tector measurcments of y activity in the human body were crvamined critically. For all geometries the principal advantages and
disadvantages were analyzed as a function ul the type of measurement made. Applications of partial-body and whole-body scanning
and other external measurements for radiation protection programs
and medical studies are considered, The best working conditions
are outlined. (tr-auth)
Radiation Protection
Reser also to abstracts 8755, 8793, and 9540.
8688
(SZS—6/70) METHODS OF APPLICATION OF
GAMMA EMITTERS IN CONTACT THERAPY WITH REGARD
TO RADIATION PROTECTION,
THE NE LD FOR MFASURING
THE RADIATION BLRDEN OF THE BLADDER AND TEC TUM
(France)
WITH THE GAMMA METER IN GYNT COLOGLE AL CONTACT
8684
COMPUTER DOSIMETRY OF THE RADIOIRIDIUM
CASTINGS. Sinistrero, G.; Ragni, G.; Benedetto, A.
(Turin
Unw.), J. Radiol. Electrol, Med. Nuch; 51: 399-102(Tun-Jdul
GOLD-SELDS IN CONTACT THERAPY WITH SPFUTAL REGARD
1970),
(In French).
.
The castings used were 0.5 and 1 em thick and rectangular
Shaped; the isodoses were studicd in two planes: a plane parallel
to the longest side and a plane parallel to the shortest side. PerCentage depth dose and isodose curves were calculated at quarter
Millimeter intervals; along each isodose curve values were valCulated every millimeter, It appeared that under such conditions
the superficial dose tended to be small. It was thus possible to
Use spheres of higher activitics (between 2 and 3 miCi/sphere),
The wires were first used for the castings and then for implanta-~
“ons whentheir activities had decreased. These castings were
Sed to treat basal cell epitheliomas, which were not verythick
but were very extensive (more than 4 cm in diameter', interNeédiate metaplastic epitheliomas, and se a tow differ nnty ot
THERAPY TO AVOID RADIATION DAMAGE.
APPLICATION OF GAMEMA EMITTERS
METHODS OF
PRCPAGLY
RADIO-
TO RADIATION PROTECTION, THE SITUATION AND TEL
TREND OF CONTACT THERAPY IN THE TREATMENT OF
GI NECOLOGIC CARCINOMAS.
Mecbius, W., Glaser,
sehutyz, Berlin
Dep. NTIS (US
Mar 1970.
Pitze, R.; Grossinann, TW,
[otf
(Staatliches Zentrate fuer strohten-
st Germany).
Sales Only).
"5p.
Un German),
Separate abstracts were prepared lor the tour sectrons ot
this report. (ERB;
For abstracts of wunividuad vections sev. 8679, Shot, SP, cate
870,
8689
(SZ8—6-7), op 19-27)
Vi THODS OF APPLIC A TIO’.
OY GAMMA EMITTERS, ESTO TALLY RADEO-GO ni? Sk RJIN
CONTACT THERAPY AUPITSVRCOUL REGARD Tor Ab to
'
.
PDE Pp ere se