Re: linear hypothesis

["ALDEN N TSCHAECHE" <XAT@inel.gov>]

I guess it's time to chime in on this subject. The American Nuclear
Society and the Health Physics Society both are looking at the validity
of the linear hypothesis (LH). The ANS has had two meetings at which a
number of papers were presented that cast doubt on the LH. In a recent
issue of Nuclear News, Jim Muckerheide summarized information that adds
to that doubt. The Winter meeting of the ANS will contain two days of
papers and panels on the LH. That meeting is in San Francisco on October
30 - November 2, 1995 at the Hilton Hotel and Towers. The LH papers and
panels are on October 31, November 1, 1995.

The HPS Newsletter of June, 1995 is a special issue on the LH. There
were 22 letters, all opposing the LH, in that issue. The HPS is
preparing a position paper on the LH. Hopefully, that paper will be
available shortly.

I received a reply to a letter I wrote to Charlie Meinhold, chair of
NCRP, ICRP and IRPA in which I asked him: "...note that the NRC says:
'The International Commission on Radiation Protection, ... believes
that, in the absence of convicing evidence that there is a dose
threshold or that low levels of radiation are beneficial, the
assumptions regarding a linear nonthreshold dose - effect model for
cancers and genetic effects and the existence of threshold only for
certain nonstochastic effects remain appropriate for formulating
radiation protection standards.'" "Is that statement an accurate
representation of the ICRP position?" Charlie answered, "Yes."

So -- until there is "convincing evidence", that Charlie didn't define,
it appears that the LH will continue to be the ICRP model. What we need
now is a dialog with the ICRP to determine what constitutes "convincing
evidence." It may be that such evidence can never be obtained.
Therefore, those espousing a non-LH model may have their work cut out
for them. Personally, I am no longer willing to permit such a
conservative stance vis-a-vis radiation protection standards. It costs
too much for no observable benefit.

What evidence can we develop that will be convincing, not for the ICRP
necessarily, but for the US regulatory agencies, so that we can get rid
of ALARA at rediculously low doses, and collective dose? Would you be
willing to join an organization set up specifically to eliminate the LH
as the basis for radiation protection standards in the US? If so, please
let me know. Al Tschaeche email: xat@inel.gov phone 208-526-3383, fax:
208-526-7291, address: LITCO P.O. Box 1625, Idaho Falls ID 83415-3406.

*** Reply to note of 10/16/95 07:01

From: Wesley M. Dunn
To: RADSAFE --INELMAIL RADSAFE

Subject: Re: linear hypothesis

Alex makes several good points in his note.  I would like to add
another comment or two:

1) This is =radsafe=, not a discussion among members of the public.
The open discussion discussions that belong here are not necessarily
the same ones we would give members of the public (where the HP is
"The Expert", as opposed to one of several able to give an informed
opinion).  HPs have historically placed a hoard of caveats on any
statements made to non-HPs. (This also responds to Rich's earlier
"ethics" note)

2) The linear-no-threshold model is a MODEL and a HYPOTHESIS.  It
may be true.  It may not be true.  It certainly has not been proven.
One might question whether it is even a consensus opinion AT LOW
DOSES.  (Sorry for the bold, but mailers don't do fonts very well)

Wes

> Date:          Mon, 16 Oct 95 00:13:04 -0500
> Reply-to:      radsafe@romulus.ehs.uiuc.edu
> From:          a.zapantis@qut.edu.au (Alex Zapantis)
> To:            Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
> Subject:       linear hypothesis

> As professional HPs, I believe that it is our responsibility to provide
> advice based on the current accepted state of knowledge. Those of us who
> quote individual studies which include the words "radiation hormesis" in
> their conclusions as a basis for discrediting the linear model remind me of
> the lobbyists who use certain studies into ELF health effects (and ignore
> the majority) to attempt to stop the erection of transmission lines in their
> suburbs.

*********************************************************************
Wesley M. Dunn, C.H.P., Administrator      512-834-6688
Licensing Branch                           512-834-6690 (fax)
(Texas) Bureau of Radiation Control        wdunn@brc1.tdh.state.tx.us
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