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Re: Linear Hypothesis IS the Cause of P -Reply



Joyce Davis wrote:
> 
> A few thoughts (opinion) in response to Al Tschaeche's latest posting
> and this thread in general.
>   If we set a purely threshold limit, the public, suspicious of
> government, scientists, institutions, etc., will ask.  

I don't think the general public would ask.  But the anti nukes would
for sure.  We must remember to "bulletproof" our reasons when we get 
rid of the LNTH so the antis can't have a case.

>    If the LNT is seen as giving an upper limit on risk, I think it
> can be helpful in at least defining to the public how "small" the
> largest  "small" effect is.  If we leave people with the idea that
> the effects of radiation, a menace undetectable to the senses, are
> "unknown", we leave the door open for all sorts of monsters to enter.

Unfortunately this argument is hoist on its own petard.  It's all well
and good to talk about "upper limits of risk."  However, that doesn't
help the people who "play the lottery."  They will still think a little
radiation, no matter how small, WILL KILL them.  Getting rid of the LNTH
and saying "a little radiation is safe and will not kill you because we
have no evidence that it will" should be acceptable to more "lottery"
people than the upper limit of risk idea.

>      By putting an upper limit on the risk with the LNT assumption we
> can at least hope to stop the idea that there may be a major
> undiscovered effect lurking at very low doses.  (There are people who
> believe that very dilute medicines are more powerful than
> concentrated ones!).

We've done that for years and look where it's gotten us!  The effect
lurking at very low doses is beneficial and we should say so!

>     In short, at the present time (convince me otherwise), I think
> the LNT is useful in 2 contexts: standards setting and establishing
> an upper limit on quantified risk.  

Sorry, one can't convince another of anything.  All one can do is
present facts and let the other interpret the facts however (s)he will. 
The fact is: the antis use the LNTH to convince the public that a little
radiation WILL KILL them.  The LNTH probably was useful in setting
standards 40 years ago.  But we have much more information now about the
beneficial/adaptive effects of low doses and no more information that
low doses are harmful.  Why can't we use this information to throw out
the LNTH?  Establishing an upper limit of risk is useless in light of
how the antis use the LNTH.  So I don't agree that the LNTH is useful
for anything now (except to the antis).

In other contexts, I think it is
> more than useless; it is misleading, counterproductive, and all
> things Al said about its influencing the demise of the rad world as
> we know it. Quantitative risks derived from the LNT should NOT be
> used in risk assessments that purport to show what the actual effects
> of some radiation-producing action on actual people are, have been,
> or will be.

Do I sense agreement here?  

How would you suggest we get rid of the LNTH in all contexts except the
two you cite and still keep the antis from corrupting the part of the
LNTH that remains?  To me (as is sung in Oklahoma) "it's all or
nothing.  Is is all or nothing for you?  It can't be in between: it
can't be half; no half and half (and here I must deviate from the song)
an hypothesis will do."  

>       As HPs and rad scientists, we should not let simplistic use be
> made of risk extrapolations by those who put together NEPA
> statements, PRAs, and similar public documents.  

So how many times in the past have you seen "us" make sure the EPA, NRC,
DOE, etc. don't use the LNTH simplistically?  

Make sure every risk
> assessment has uncertainties stated.  Make it clear that the LNT
> extrapolation is an upper limit only; the actual value is somewhere
> below that; it may be zero, it may be an itsy bitsy (de minimis)
> detriment; it may be a benefit (also small).

I refer you to my Correspondence in Health Physics, Vol. 54, No.5 May
1988, pg 565, "Tell Policymakers That Low Doses of Ionizing Radiation
May Have Zero Risk of Harm" and the response on Pg 566 of the same
journal issue from the EPA "Science, Evidence and Regulation," followed
by an Editorial in Radiation Protection Dosimetry, Vol. 25, No. 1, 1988
pp 3-4, "Science in Radiation Protection."  As long as the LNTH remains
in existance, no matter for what reason, regulators will pursue ALARA,
the antis will corrupt the meaning, and the nuclear industry will go
out, "not with a bang, but a whimper."  And its whimpering a lot right
now.

>      Until we can get a better handle on the quantitative detriment
> of low doses or prove to a reasonably high degree of certainty that
> low doses have a zero or beneficial effect, I suggest we put our
> efforts into ensuring that the right risk assessments be used in the
> right manner, not in declaring one way of estimating risk verboten.

Why do we need to prove to a reasonable high degree of certainty that
low doses have a zero or beneficial effect?  Why doesn't the "other
side" have to prove that there is a definite, measurable and significant
harmful effect before the numerical value (5 rem per year) is lowered? 
It seems to me that we have put radiation in the position of being
guilty until proven innocent.  That's not the way this country was
founded.  Something ought to be assumed safe until proven unsafe, not
the other way around.  Something's out of whack when people in the legal
profession assume guilt, not innocence ( my opinion :-)).

  
> And maybe, just maybe, the public will begin to understand a little
> better.

Not until the LNTH is killed, eliminated, expunged and expurgated.

>     Don't you think that if the entire HP community, nuclear
> industry, and regulatory agencies came out today for a threshold at 5
> rem per year and a prohibition on the use of the LNT, many in the
> public would interpret it, not as the triumph of reasonableness but
> as another conspiracy of the power elite to make money at the expense
> of the powerless citizen, exposed to invisible rays?

No I don't.  Let's do it and see.

Not only the opinion of Al Tschaeche xat@inel.gov
> 
> Only the opinion of  J. P. Davis
> joyced@dnfsb.gov