Re: [gardeners] toxic marsh
Annetta Green (gardeners@globalgarden.com)
Fri, 29 Jun 2001 20:46:39 -0400
Just curious: which Florida wetlands reclamation project are you discussing?
Dan,
we are discussing the new marshlands being reclaimed at Lake Apopka. There
was a large bird kill that has been blamed on toxic chemicals spilled on the
land between its time being a marsh. It was farmland since the 20's and is
being reflooded in small increments since the first time didn't work.
Anne in FL
zone 9b, sunset 26
----- Original Message -----
From: "Dan Dixon" <dandixon@home.com>
To: <gardeners@globalgarden.com>
Sent: Friday, June 29, 2001 10:33 AM
Subject: Re: [gardeners] toxic marsh
> > From: "Annetta Green" <agreen@cfl.rr.com>
> >
> > what is the half life of DDT? How long can it sit in the ground and be
a
> > viable poison? The research, by state scientists, is showing that the
toxic
> > levels of the farm chemicals, most outlawed now, are what is/has been
> > killing the birds. They found very high levels in the soil, water and
> > birds. They have been trucking out the worst of the soil and are now
trying
> > to let it flood again. I think they are also hoping that the second
> > flooding will dissipate even more of the chemicals to acceptable levels
in
> > the water.
>
> The problem with DDT is that it is a "POP" chemical: it is subject to
> "Persistently Overstated Paranoia." :)
>
> Here is Extoxnet's DDT profile:
>
> http://ace.ace.orst.edu/info/extoxnet/pips/ddt.htm
>
> Half life varies depending on where it is located, between 2-15 years.
> Breakdown chemicals (DDE and DDD) also persistent, however, so overall
> persistence can potentially be very long. My enviro-geologist friend tells
> me that the deeper DDT gets in the ground, the longer it lasts (don't know
> about 50 yrs, though). DDT is relatively immobile in soil, though, so only
> small amounts get carried down really deep. It was banned in the early
70s,
> so it's pushing 30 years since it was last used in the US. Not much DDT
left
> in the environment in this country, I'd guess.
>
> Toxicity to birds is slight to almost none. DDT isnt what's killing the
> birds in FL marsh reclamation, at least not directly. They would pretty
much
> have to eat it raw out of the package to die from it. Contrary to popular
> belief, the eggshell thinning research is not conclusive either, eg, many
of
> the raptor populations thought to be affected were in trouble before DDT
was
> used, no direct mechanism linked to DDT is known, etc.
>
> Just curious: which Florida wetlands reclamation project are you
discussing?
>
> Dan Dixon
>
>