Ion-free water for human consumption?

[Dima Klenchin]

In article <53m3hv$alu at data.csw.net>,
   cbenson at CSWNET.COM (H.C. Benson) wrote:

->My interest is in deuterium oxide which contaminates all terrestrial
->water supplies at a ratio ranging from 1:5000 to 1:7000.  It is a puzzle 
->to me why so little research has been done on the deleterious effects of 
->exposure to these concentrations over the human lifespan.
->H. C. Benson			cbenson at cswnet.com

So, what's wrong with heavy water and why would it be deleterious?

- Dima