RE: Thoughts please! (ICRP 60)

["Tsurikov, Nick" <nick.tsurikov@iluka.com>]

Dear Bjorn,

The potential problem of these models is in their practical application.  An
example would be the FGR13 of US EPA.  The final (if I am not mistaken)
version was published in September 1999 and went without any significant
discussion on Radsafe.

The model itself may be (and, I think, is) correct.  But let us apply a
model to a hypothetical PhD student, who handles very small amounts of
radium in a radiochemistry lab.  We can estimate the probabilities and
possibilities and produce some personal dose estimate, which, in turn, may
be 'translated' into a cancer risk and, from the first sight, will be quite
credible.  Let's say that a personal annual dose is in order of 0.1
mSv/year.  
However, how do we account for the exposure of this student to natural
sources of radiation?  If we'll summarise radon, external exposure, traces
of radionuclides in food, drink and different commodities, the personal
annual dose will be AT LEAST twenty times higher than the exposure due the
'occupational hazard'.  
A difference of "plus or minus 0.1 mSv" in a 'total dose' is, from my point
of view, meaningless.  The difference between 2.0 and 2.1 mSv/year is quite
small and this particular student would receive an additional 0.1 mSv if
he/she decides to come to Australia for a holiday, flying all the way from
Europe or States and back...

> there has not been an integration of a multistep tumor development into it

> (initiation, promotion, progression) - good news for future PhD students.
> Such an integration is the next thing to do - for different kinds of
tumors 
> with different mechanistic event categories -

Another bit of 'good news' for future PhD students - there is another quite
unexplored area: (1) synergistic and (2) antagonistic effects of ionising
radiation and other agents.  
The example for (1) is a dependency between smoking patterns and cancer
incidence for uranium miners (and one of the reasons why the uranium mine
near Roxby Downs in South Australia is absolutely smoke free).  
The example for (2) would be an antagonistic effect between exposure to
Sr-90 and Cs-137 and exposure to large amounts of Stolichnaya vodka -
observed in Chernobyl (joking, joking...).  The antagonism is not
documented, but there will not be a shortage of volunteers...

Kind regards
Nick Tsurikov
Eneabba, Western Australia
nick.tsurikov@iluka.com <mailto:Nick.tsurikov@iluka.com> 
1000+1 radiation links:
http://eneabba.net/ <http://eneabba.net/> 

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