aren
defects,
.
that @ complete appruach to risk assessment at the
time of
exposure must involve the HSEF for cells,
Since the HSEF approach could replace the present approaches using LET,
it has significance with respect to differences in “track structure” seen
with radiations of different “quality".
Some of the severity of cellulac
effect that has been ascribed to LET and track structure differences, may
well be due
to a difference
in dose
to
the cells.
With most,
particularly
planned transfers of chromosomal agents, it has been more or less generally *
accepted that a larger dose will he more effective per unit dose than a
smaller one, apparently with Little or no necessary requirement being
percelved to investigate why.
The interpretation of a “linear, non-threshold” curve (for exposure
and not dose) also changes with the HSEF apprdach.
following any amount of population exposure,
there of course can be
stochastic interactions with health consequences.
amount”,
i.28.,
as little as a single encounter,
the conditions for this are
1) one must
That is to say,
It is true that “any
could be lethal.
However,
first have experienced such an
encounter, and 2) It must be of a size such that the dose
.
transferred is
large enough to have some tangible probability of causing a quantal
response,
REFERENCES
1.
Parker, H. and Roesch, W.C,
X Rays and Gamma Rays.
2.
In Clark, G.L. (€d.) The Encyclopedia of
Chapman and Wall, London; Reinhold, NY, 1963.
Skarsgard, L.D., Kihlman, B.A. et al.
‘Survival,
chromosome
abnormalities and recovery in heavy fun and X-irradtated cells.
Rad...
Res., Suppl. 7, 2U8-221, 1967.
3.
Morstin, K., et al.
,
A probabilistic approach to relate
microdosimetry, biological effects and radiation quality.
Submitted
Se
to Radiation Research,
4,
Rossi, H.H.
Specification of radiation quality.
Radiat. Res. 10,
522-531, 1959.
De
Rossi, H.H.
Energy distribution in
the adsorption of
radiation.
Advances in Biological and Medical Physics, Vol. I1, pp. 27-85, 1967. “%
6.
Rossi, H.W.
Radiation Dosimetry, Vol.
Eds., Academic Press, NY) 1968,
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I (FH. Attix, W.C. Roesch,
Fe