What would we do with a threshold?

[ABELQUIE@ORAU.GOV]

Dear Radsafers-

I have followed the Radsafe discussions for the last several months
concerning the linear non-threshold (LNT) hypothesis, and I am unclear
as to the purpose of such discussion.  That is, what is the real purpose
of all this debate?  Is it primarily to set the record straight (i.e. incorrect
scientific basis for current regs) * or is it to justify setting higher dose
limits, both for radiation workers and the public?  Or does the first lead to
the second?  

First, my position is that the current dose limits are reasonably set (both
occupational and the new 25 mrem/y decommissioning rule).  My belief,
right or wrong, is that the establishment of a threshold is not going to
significantly alter the dose limits.  For example, industry has proven that
occupational radiation workers can consistently keep their doses well
below 2 rem/y*has this level been achieved through unreasonable
constraints on work practices or at extreme costs?  Point being, if a
threshold is proven to exist (let*s say at 25 rem) - what would be the
incentive of increasing the dose limit?  If you know some effect, or
probability of an effect, starts at a given level, isn*t it likely that one would
want to stay as far below that level as possible (within reason,
considering the economics of cost vs. benefit)?  For many, the hormesis
argument falls on deaf ears - they would rather have no more radiation
dose than reasonably achievable, and risk missing the boat on the
potential benefit. If indeed a little radiation does benefit us, I*m content
with the little that I get from the environmental background and necessary
medical applications.

I believe that the primary incentive of arguing for a threshold is to hold the
line against further ratcheting down the dose limits, where these
reductions would not consider costs and benefits.  I am a staunch
supporter of ALARA - reduce dose consistent with economic and other
considerations.  This debate often appears to have two extremes*1)
those who want dose limits indistinguishable from background,
regardless of economic considerations and without much thought about
the benefits of radiation, and 2) those who believe that a threshold exists
for stochastic radiation effects, presumably to increase the dose limits. 
If a threshold is found to exist, I think careful consideration must be given
to how it is implemented in setting regulations. ALARA makes sense.   

Just my thoughts - does not reflect the opinion or position of my employer

Regards,

Eric Abelquist, CHP
abelquie@orau.gov