RE: Radiation - net benefit or detriment?

[Bernard L Cohen <blc+@pitt.edu>]

On Mon, 12 Feb 2001, Franta, Jaroslav wrote:

> You wrote :
> 
> 	--The fact that the number of DSBs induced by radiation is linear
> with dose seems obvious. However, it is estimated that chemical and
> thermal effects induce about 200 DSBs per cell per year, whereas 10 rem of
> radiation per year induces only about 4 per cell per year, so the
> contribution of low level radiation to the body's DSB accumulation is
> relatively negligible. This suggests that we consider the positive effects
> of low level radiation - stimulation of immune system, stimulated
> production of repair enzymes, etc - as relevant factors in deciding
> whether the net effect is good or bad.
> <><><><><><><><><><>
> 
> Question :  that being the case, what is so special about radiation damage
> that it manages to evoke an immune response (hormesis), while all those
> other DSBs don't ?
> In other words, would one not expect the "hormetic message of a radiation
> dose" to be swamped, just like it is in the category of damaging effects by
> non-radiation agents ?

	--I am not an expert on these matters, but I see no reason to
believe that stimulated production of repair enzymes or stimulated immune
response are caused by double strand breaks. 

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