Re: Dioxin Controversy

["Protect All Children's Environment" <pace@mcdowell.main.nc.us>]

  I have read several studies of pesticides that cause greater harm at low
  levels than high (are more carcinogenic at lower doses) as well as several
  that indicate greater harm to females than males.
  The later was not revealed until it was discovered that tests were being
  conducted on male rats only as the "complicated reproductive system of the
  female rat confused the results".  Could this be the case with "dioxin"
  generically speaking?
  
  ----------
  > From: Susan K. Snow <sksnow@1stnet.com>
  > To: Multiple recipients of list <dioxin-l@essential.org>
  > Subject: Dioxin Controvery
  > Date: Wednesday, August 13, 1997 1:40 AM
  > 
  > The following was posted recently to the "WASTENOT Organic Waste
  > Collection, Processing, Composting," online discussion list.  The author
  > is Gary A. Breitenbeck of Louisiana State University.  
  > implications of  TCDD appears to be that of Arthur and  Frea (1989, J.
  > Environ. Qual. 18:1-11).   In addition to fate and transport, they
  > briefly review the toxicological effects  (acute toxicity, chronic
  > toxicity, teratogenicity, mutagenicity and  carcinogenicity) known at
  > that time.   A great deal of the controversy regarding the toxic effects
  > of TCDD appears to arise from the fact that the effects of this compound
  > are highly species-specific as well as dependent on the sex of the test
  > animal and the route of exposure.  Findings from studies using human
  > subjects exposed to high (in some instances, extremely high)
  > concentrations of TCDD are inconsistent, but most indicate that risks to
  > the general population are very low.