From: dietz@dls.net   
      
   Henry Spencer wrote:   
      
   > When it's removed from the air, nothing replaces it.   
      
   Naturally, there should be a (very) small production from   
   spontaneous fission of U238, and fission of U235 from   
   background neutrons (mostly from (alpha,n) reactions   
   on light elements, I think).   
      
   	Paul   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)