Re: DIOXIN-L digest 547

[DrBillC@aol.com]

  Tony:
  
  Nope.  TCDD.  Greater than 30 ppt, some mortality in sac fry.  Over 100,
  total mortality.  Current Lake Ontario--surprisingly, perhaps--5 ppt (10
  TEQ).  The trout are coming back.  Compare to levels ca. 100 thirty years
  ago.
  
  The article also cites Phil Cook of EPA branch in Duluth who has studied the
  sediment record.  "You see an increase in contaminants until 1970," he said.
   "Then things start coming down pretty fast."
  
  The decay data is recent, and most has so far been done on PCBs.  Hites also
  did some a few years ago.  There was a paper at Dioxin '96 whose author's
  name escapes me right now.  Lots more difficult experiments to do, but it's
  coming.
  
  Bill Carroll
  Chlorine Chemistry Council