- 1B =
’
Cc,
NN
The Hot Particle Problem
It is important to recognize that the ICRP has given
NO culsance with respect to nonuniform irradiation of the lung
by insoluble alpha-emitters such as insoluble plutonium
particles.
In its Publication 9, the ICRP states:
...In the meantime there is no clear evidence to show
whetner, with a given mean absorbed dose, the biological
risk associated with a non-homogeneous distribution is
greater or less than the risk resulting from a more
Girtiuse cistribution of that dose in the lung. 29
in etiect, the ICRP is saying that there is no guidance as
£9 the risx lor non-homodqeneous exposure in the lunc, hence
the MPLB are meaningless for insoluble slutonitn
Tae NCRP offers the following ana sixsilar statement
with restect to these particles:
{210) The NCRP has arbitrarily used 10 percent of
tne volume of the organ as the significant volume for
izradiation of the gonads.
There are some casas in
waick choice of a significant volume or area is
virtually meaningless.
For example, if a single
barticle of radioactive material fixed in either lung
Or iwmph neces may be carcinocenic, the averaging
ci écss ¢ither over whe lung or even over one cusic
ceantineter mav have little to do with this case. 30
Tnis hot sarticle problem is also well recognized in
tne bioslecical community.
29/
IcRP
30/
CRP Paport No.
The following is extracted froma
Publication 9, Op.
39, Oo.
cit., p.
cit., pp.
4.
79-30.
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