Re: LNT and Epidemiology

[Al Tschaeche <antatnsu@pacbell.net>]

Eric, I attended the same BEIR VII meeting.  If you remember, I asked the
questions: "Are all your data from in vitro experiments, or are some from
in-vivo experiments?"  His answer: "All from in-vitro."  I then asked:
"Where are the data that demonstrate one can extrapolate from in-vitro to
in-vivo situations (or words to that effect)?"  He hesitated a bit and then
said: "That's a hard question."  There was no answer to my second question.
However, I think all the BEIR VII committee members got the inference that,
although Ward's in-vitro data seem to indicate a difference between
radiation-induced damage and spontaneous (e.g., non-radiation-induced
damage), there are no in-vivo data that demonstrate such differences really
occur in humans.  The same theme carried through to the next day when Antone
Brooks, Washington State University,  presented a paper on all the research
DOE is doing vis-a-vis LNTH, and I presented a paper on the data available
for hormesis, adaptive response and the need for a new paradigm describing
low dose effects.  During the question session on my paper I asked Antone
how long it would be before the DOE had data that demonstrated in-vitro
experimental data were really representative of what goes on in-vitro.  He
hesitated and then said, "A long, long time."  Again, I think the BEIR VII
committee members got the thrust of my question and the answer.  That is:
we must be certain that the in-vitro experimental results represent reality
in-vitro.  An assumption that they do, well, you know what an ass u me might
result in.

What all of this says to me is that in-vivo experiments may be useful, but,
until we know on the basis of experimental data that the in-vitro
experiments reflect reality in a living human, it may be very risky to try
and extrapolate and conclusion from in-vitro data to humans.  I would not
necessarily agree, on the basis of the Ward paper, with the conclusion that
radiation induced damage is different in humans from spontaneous damage.

With respect to your other point, I have no difficulty in cleanup for
reasons other than safety.  However, the public must be told that the
cleanup we are doing will yield no measurable health and safety benefit. If
the public wants to spend billions to clean up the oceans so some
researchers can research, fine.  But they should know the difference between
cleanup for health and safety purposes and cleanup for research, or other,
purposes and be willing to spend the billions for those other purposes.

Have a happy New Year, all.  Al Tschaeche, CHP antatnsu@pacbell.net

ERIC GOLDIN wrote:

>        I heard an
>      excellent presentation by Dr. John Ward of UC San Diego at the
>      recent BEIR VII meeting in which he described the types of DNA
>      damage from both radiation induced free radicals and from
>      metabolically induced free radicals.  Ward contends that at least
>      some significant percentage of the radiation induced damage is
>      physically different from the spontaneous damage (and he has the
>      molecular biology studies to support this).  These multiply
>      damaged sites are not repaired as easily or effectively as simple
>      damage locations for which routine cellular repair mechanisms
>      operate.
>
>          On another related note, the comment is occasionally made that we
>
>      are spending far too many millions of tax dollars cleaning up
>      sites that present no significant risk to the public.  While it
>      is true that we are spending a fortune that could be used
>      elsewhere, we should keep in mind that there are sometimes good
>      reasons to clean places up.  For example, I heard a presentation
>      a few years ago in which some important oceanographic research
>      relied on the detection of extraordinarily low levels of trace
>      radioactive species (tritium and C-14) in ocean water.  If we
>      don't keep our environment as clean as reasonably achieveable
>      (huh?) then we may render such research impossible.
>
>      My opinions only,
>      Eric Goldin, CHP
>      <goldinem@songs.sce.com>
>
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