More or Less Dioxin??? (was Re: Dioxin Sources

[ttweed@wildrockies.org (Tony Tweedale)]

  sam wrote:
  ----
  Food for thought:  PVC production has almost tripled in the last
  fifteen years.  Yet, dioxin exposure has dropped by over 75% in the
  last decade; I am talking the total biologically available as a
  function of TEQ.  Seems to me that if the PVC industry was the smoking
  
  The reports on dioxin exposure are independent university research efforts or
  government studies (US and Europe), *not* from the PVC industry.
  ----
  aside from phillip's response questioning the 75% drop in exposure; as to
  pvc sources contribution we need to look at a more complete picture than
  what gp has managed to extract from that industry.  pcdd/f attributable to
  pvc come from the complete life cycle, not just the pcdd/f produced at the
  pvc & edc plants.  and since pvc production skyrocketed only recently, how
  much of the increase has gone through its life cycle and been incinerated?
  also, a certain fraction of pcdd/f created at production will not
  contribute to exposure for a long time (ie that portion landfilled, as
  opposed to incinerated or placed into surface waters).
  
  back to the broader question of overall exposure trends: there is very
  little known , actually, given the immensity of the data gathering task!
  thomas & spiro, who head up epa's emissions inventory effort and who
  published a summary of that work, conclude, if i recall, that the well
  known emissions gap (ie not enough known sources to account for observed
  env. & biologic loads) largely disappears w/ certain assumptions.  i wonder
  to what degree the life cycle of pvc i included in either scenario?
  
  in any case, my personal beliefs depend on what's known about the
  mechanisms of action, the hormonal pathways, that tell us that a 75%
  reduction, if true, probably doe not help.  in fact, it may hurt, given
  that we react more strrongly to smaller doses of hormones than to larger
  ones, in many known instances (guilette, vom saal, others).  in short, it
  seems likely we really have had enough already.
  
  
  one other comment, in response to:
  ----
  "Rebecca Leighton Katers" <cwac@execpc.com>:
  >I agree with Mr. Sagady that citizen activists should not waste
  >time dwelling on their "victimhood," but I don't
  >agree with the implication that this
  >victimization is imaginary or insignificant.
  
  as alex responded, he was not saying that victimization is an unimportant
  issue.   he was actually focusing on tactics to aid victims; how to make
  such time more productive than unadulterated complaining about the
  unfairness of the system confronting us.  his record of aiding us with
  extraordinarily useful information is clear.
  
  i've been assuming gp is comfortable with its own explicit decription of
  its methodology in its several year effort at gathering data from edc & pvc
  production facilities!  i would have liked to see some of the data sam
  asked for, but gp's recent reports on this data collection enough level of
  detail to validate to me gp's claims about why the industry was delaying on
  making such data public.  their description of the rigo et al. reports
  methodology, and gp's detailed description of the industry's lies in using
  that report in policy decisions and in public, make me even more
  comfortable w/ gp's efforts here.
  
  
  tony tweedale