Re: Does dioxin toxicity increase in the environment??

[DrBillC@aol.com]

  One other note on the buildup of TEQ.
  
  Dick Petersen at Wisconsin notes that the return of trout is due to reduction
  in TCDD concentrations.  He says the critical level in fry for development is
  30 ppt.  Levels were as high as 100 years ago, and now are at about 5.
  
  He noted in a recent interview that levels peaked about 1970 "and have been
  dropping" ever since.  This would not be consistent with degradation of
  higher congeners to TCDD.
  
  Bill Carroll
  Chlorine Chemistry Council