Re: how many sensitive cells?

[JMUCKERHEIDE@delphi.com]

Wade states, correctly but not far enough:

> Les and all:
> In my view present MPE's are set under the assumption that a single
> event at the cellular level can give rise to cancer. From this
> assumption arises the concept of collective dose and the policy of
> ALARA.
> 
> The use of specific energy (dose/gram) also rests on this unsupported
> assumption. 

The assumption is not just unsupported, it has been wholely refuted, in
physiology, cellular biology, and molecular biology. 

>Further it would make no difference if total energy was used
> instead because the assumption has no biological basis.

...and is contradicted by the biological evidence.
 
> I have shown in my March HP paper that this assumption is promulgated by
> UBIN, in spite of the existence of much contradictory evidence.
> 
> The bottom line is that risk should be related to measurable physical
> quantities such as fluence and energy, not on quantities which cannot be
> measured such as Sv and Gy.

I'd think that "risk" can't be directly related even to physical quantities
(energy deposition) vs Sv/Gy energy-concentration units that are not additive. 
Actual "risk" must be related to quantifiable adverse conditions/effects. Even 
fluence and energy have different adverse effects on different cells and
organisms. And even dosimetric "adverse effects" (like counting chromosome
aberrations or sister chromatid exchange) do not produce adverse effects to
health (from organism to human experiences - see eg, the Windscale workers
with cellular evidence of dose but no adverse affects). 

This is consistent with many effects, including exercise which produces vast
cellular and DNA damage, from which the biological response strengthens the
cell and organism. This is proven also in all biological classes for low-dose
radiation, including detrimental effects of below-normal natural radiation,
from 100s of confirmatory studies with paramecia and other organisms, to
animal experiments, to consistently high lung cancer, stomach cancer, and
total cancer, in low-dose/low-radon areas. 

> Wade

Thanks again Wade.

Regards, Jim Muckerheide
jmuckerheide@delphi.com
Radiation, Science, and Health, Inc.