Re: Caveman NORM doses

[Chris Davey <cdavey@med.phys.ualberta.ca>]

On Mon, 23 Oct 1995 rick_strickert@pc.radian.com wrote:

> A Radsafer earlier noted:
> 
> >   Remember, the human experience is that the background dose rate has
> >   been decreasing for as long as humans have been a species. (snip)
 
> The long U-238 and Th-232 half-lives limit the equilibrium rates of their
> respective decay products.  Going back 10 million years (well before any
> humans existed) would increase the NORM decay rates (and thus the doses) by
> less than 1 percent, even considering the increased U-235 fraction.  Unless
> exposure through NORM inhalation/ingestion/direct pathways was drastically
> different for the working-class caveman, NORM doses were probably
> comparable to NORM doses today.
Isn't there a lot of radon in caves?

What about earliest life on Earth?  Were amphibians (before dinosaurs..) 
any less sensitive to radiation?
> 
> Based on studies of cosmic ray spallation products, the cosmic ray flux in
> our solar system has been relatively constant over the past billion years.
> 
> Rick
> 
> Richard G. Strickert, Ph.D           |  "Errors using inadequate data
> Radian Corporation, Austin, TX       |   are much less than those using
> 512-310-5259, FAX 512-244-0160       |   no data at all."
> Internet: rick_strickert@radian.com  |     - Charles Babbage (1792-1871)
>  ---> "All written IMHO." <---       |
> 
> 

Just a thought or two.

Chris

RSO	Cross Cancer Institute		Edmonton, Alberta, Canada.