Re: x-rays, IRB, rad-safty, consents, r

[JMUCKERHEIDE@delphi.com]

Paul,

> Bonjour mes amis

Very cosmopolitan this morning; must have had a great weekend!?

> Jim Muckerheide wrote in part:
> 
> >Of course this begs the question of whether 1 rad to 1 gram, and 1
> >rad to the whole brain, are equivalent when dealing with dose risks,
> >and the matter of the need to look at  radiation differently than
> >other toxins. 
> 
> Jim:
> 
> Radiation is not  a toxin. Mutagenic agent is another story.

I reduced this rather loosely and inartfully. I agree in all you say here as
matter of technical considerations. I was really thinking of this as the
matter of "explaining risks" understandably to a patient, using radiation
measures. Still, cellular radiation damage is equivalent to many if not most
toxic effects. 

> I don't recall anyone ever remotely suggesting that 1 rad to one gram
> carried an equivalent risk to one rad to the whole brain or any other
> similar tissue. That argument looks suspiciously like a strawman 
> created for the purpose of being knocked down. 

I'm just referring to difficulties I've encountered trying to clarify
radiation doses as energy/unit mass as opposed to total energy, combined with
Vic Bond's strong case for measuring radiation as total imparted energy at the 
appropriate biological level of interest (including the mathematical
derivation that addresses the concept with rigor in units, quantities and
effects). 

> The implied arguement that two individuals of different masses
> receiving the same effective dose equivalent would experience
> different risks is a legitimate.  But in view  of all the other
> uncertainties and variables, its not really a significant issue.

Wasn't thinking of different individuals/masses. Is the total imparted energy
to a larger individual due to a larger mass at the same rad/rem dose really a
higher risk? Would not seem obvious.  

> Non?

Sounds good to me.
 
> Regards
> 
> Paul Frame

Thanks.

Regards, Jim