Re: Son of ALARA!

[Muckerheide <muckerheide@mediaone.net>]

Keith,

"Bradshaw, Keith" wrote:
> 
>         Dear colleagues
> 
>         A single alpha particle track through a single cell nucleus averages
> 23000 ionisations, 200 DNA single-strand breaks and 35 double-strand breaks.
> Most cells this happens to die, and a large percentage of survivors carry
> chromosome aberrations.  I'm sorry, but I still need a lot of convincing to
> see this as beneficial.

Setting aside your specific numbers and addressing your description:

First: Consider that there are Millions of times more ssb's and dsb's
from normal oxidative metabolism (plus heat, stress, etc.) than from
the normal range of background radiation. There are 30,000 DNA adducts
at any given time in every cell, and likely more than 10 times that at
high stress times (exercise, hot foods/drinks, etc.). Note that DNA
damage is not directly related to carcinogenesis in biology.  But, the
breakdown of the damage repair system is related: anti-oxidants, etc.
to reduce oxy damage; DNA repair enzymes, immune functions, etc., to
repair DNA; and apoptosis etc. to remove cells with mis-/un-repaired
damage to DNA (mutations, of which about 1/day/cell are accumulated).

Second: Consider that radiation causes "local" hits (single cell as
you describe, but more often multi-cell) and the signal transduction
stimulates responses that generally improve anti-oxidant and related
protective capabilities; enzymes, proteins, gene expression, etc.; and
apoptosis, etc. that improve general molecular, cellular, and tissue
responses, not only to the small (trivial) number of radiation-induced
DNA/cellular damage events, but more importantly to the vast number of
normal metabolism events. As long as you are physiologically and
immunologically healthy ("young") this "improvement" is small or
trivial since you keep your DNA damage under control. But with various
environmental challenges, failure to maintain good conditions (diet,
etc.), and normal aging, the loss of functions is substantial, and
cancer can result. But LDR stimulation enhances these functions. It's
been demonstrated for a century, and now molecular biology documents
specific responses, and LDR effects real "whole" organisms, including
curing cancer in humans, provides another verification of the
underlying biology of the cell/organism.

(There is more evidence that the cell/organism can't function without
ionizing radiation as the engine - electrons, like the planet couldn't
function without radioactivity. That's a little less demonstrable and
understood at this time. Serious science could address the evidence
quite readily, but "rad research" policy hasn't supported that either :-)

Regards, Jim
muckerheide@mediaone.net
Radiation, Science, and Health
Center for Nuclear Technology and Society at WPI
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