I believe she is referring to Radon.  Whether it occurs in groundwater or not I 
don't know.  It does outgas and collect in basements, etc...

Dan 

http://en.wikipedia.org/wiki/Radon

Radon (pronounced /ˈreɪdɒn/) is the chemical element that has the symbol Rn and 
atomic number 86. Radon is a colorless, naturally occurring, radioactive noble 
gas that is formed from the decay of radium. It is one of the heaviest 
substances that are gases under normal conditions and is considered to be a 
health hazard. The most stable isotope, 222Rn, has a half-life of 3.8 days and 
is used in radiotherapy. While having been less studied by chemists due to its 
radioactivity, there are a few known compounds of this generally unreactive 
element.

Radon is a significant contaminant that affects indoor air quality worldwide. 
Radon gas from natural sources can accumulate in buildings and reportedly 
causes 21,000 lung cancer deaths per year in the United States alone.[1] Radon 
is the second most frequent cause of lung cancer, after cigarette smoking, and 
radon-induced lung cancer is thought to be the 6th leading cause of cancer 
death overall.


> -----Original Message-----
> From: Marshall Dudley [mailto:[email protected]] 
> Sent: Wednesday, June 04, 2008 9:06 AM
> To: [email protected]
> Subject: Re: distilled water harmful, was Re: CS>Re: food prep with cs
> 
> Clayton Family wrote:
> > I like certain water- minneapolis city water (mississippi 
> river water, 
> > processed with a newish state of the art facility) put 
> through an RO 
> > machine, or failing that, distilled.
> >
> > the well water up here has radioisotopes in it; there is 
> less in the 
> > river water, even downriver from the power plant. I just do 
> not like 
> > chlorinated water, but I do like it a little better than water with 
> > algae or parasites. So the RO takes out alot.
> What isotopes?
> 
> Marshall
> 
> 
> 
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