09-21-1994 12:13
5162825311
BNL-MED. DEPT.
P. 006
+1-
will not be known precisely.
The dosimetry device, records the doge
or done rate,
which may not reflect accurately, because of shielding and energy dependence of the
device, the deposition of radiant energy at the site of interest,
ely the bone
marrov and the lining of the intestinal tract.
The problems associated with predicting medical effects from pHysical’ estination of dose can be further illustrated as follows: it 1s apparent [that done
estimntes available will be air doses.
The dose received by the aint
is of academic
interast only, since the degree of effect in living things is due tol
the deposition
of energy and its distribution in the critical tissues.
Accordingly| one must know
the depth dose nattern or sore precisely the pattern of absorbed Joss
in sensitive
critical tissnes.
freat length
This problem has been explered experimentally at
and is deseribed in detail in references (17).
More need not te said
here other
than the fact that the uniform fleld cf radiation coming at an indiviflual fron
all directions is sore effective per r in air than dose of radiation
quality.
pf directional
In urban areas there may he shielding from the fallout fielf
or inhomogeneities in the field due to drift in dry windy areas.
With
by buildings
the prompt
radiation shielding may te significant and the proximity of large buildings may ser~
Jously influence scatter ani perturb the uniformity of the radiation.]|
Lastly a
fallout field may be made unidirectional by heavy shielding from buildinge on one
side,
Thus estimntas of dose calculated from dose rates or derived frbm an inte-
frating type of dosimeter that adds up to the total dose received, or Form position
of an individual during exposure, cannot be accepted as the best indexfof the pro~
-bable fate of this individual, or as the final guide to treatment.
interested in the individual from the
The
stardpoint of sorting casualticp
physicien is
with some
chance of survival ard those for whom nothing can be dene, and of squa
importance
the troop commander is interested in the
froupa of
over all prognosis of large
individuals in order to make plans for disposition and replacement.
ese two
different desires cannot be completely met by physical estimates of doge.
ever, nature has been helpful.
The manifestations of radiation injury
How
Wary vith