UGA researchers use transgenic trees to help clean up toxic waste site

Contact: Kim Carlyle

706-583-0913
University of Georgia

Can genetically engineered cottonwood trees clean up a site contaminated
with toxic mercury? A team of researchers from the University of Georgia -
in the first such field test ever done with trees - is about to find out.

The results could make clearer the future of phytoremediation - a
technique of using trees, grasses and other plants to remove hazardous
materials from the soil. UGA scientists and city officials in Danbury,
Conn., planted on July 16 some 60 cottonwoods with a special gene at the
site of a 19th-century hat factory in that northeastern city.

"We hope to see a significant difference in the levels of mercury in the
soil within 18 months, perhaps as much as a twofold reduction," said
Richard Meagher, professor of genetics at UGA.

The field test is a collaboration between UGA, Western Connecticut State
University, Applied PhytoGenetics, Inc., of Athens and the City of
Danbury.

While the technology now being used in Danbury does not apply to all
sites, mercury pollution is a pervasive problem in Georgia as it is
elsewhere. The site of a former chemical factory near Brunswick, for
example, is polluted with mercury and other toxic chemicals. Mercury
contamination has been reported around the sites of former gold mines in
north Georgia, and advisories have been issued during the past decade for
mercury-contaminated fish in more than 80 streams, lakes and creeks in the
state.

Meagher's team did the first-ever field trial of a genetically engineered
plant to sequester mercury when it grew transgenic tobacco in a New Jersey
field trial in 2001, but this is the first such trial using trees, whose
larger root systems and year-round life cycle makes them better candidates
for long-term cleaning of polluted soil.

Phytoremediation is a relatively new field and one gaining international
interest. A team of photographers working for National Geographic, for
instance, recently spent considerable time with Meagher capturing on film
his work as part of a four-part documentary that will be aired some time
next winter.

Meagher has for more than a decade been a pioneer in phytoremediation, and
he was the first to demonstrate that a gene called merA can be inserted
into plants and used to detoxify mercury in the environment. While no
plant can break mercury down, since it is an element, less toxic forms can
be created, and that has been the goal of Meagher's lab - to find ways to
let plants or trees grow on polluted sites, draw such heavy metals as
mercury into the plants themselves and then either transpire the much less
toxic forms of the metal into the air where they are quickly diffused or
trap the metal aboveground for later harvest.

The project with Danbury came about because Danbury's environmental
coordinator, Jack Kozuchowski, had in 1977 published an early study that
showed how native plants could transfer mercury from contaminated soils
into the atmosphere. Kozuchowski, aware of Meagher's work, convinced
officials in Danbury that the so-called Barnum Court site in that town
would be a perfect site for a field trial of the genetically engineered
trees that Meagher and his collaborator Scott Merkle developed.

The city was awarded a grant of some $55,162 from the Environmental
Protection Agency to explore use of the technology, and the trial was set
up - though most costs for the work are being born by those involved in
it.

"It is our hope that the research will lead to a cleansing of the Barnum
Court property so the city can transfer the property for development,"
said Mark Boughton, mayor of Danbury.

Meagher's mercury phytoremediation technology is exclusively licensed to
Applied PhytoGenetics, or APGEN as it is called, and that Athens company
has been instrumental in helping set up the field trial. (Meagher is a
consultant to and cofounder of APGEN.)

Postdoctoral associate Andrew Heaton of Meagher's lab and one other of
Meagher's students traveled to Danbury in July to supervise planting the
genetically engineered trees on the site in enclosed plastic containers
buried on the site.

Because the mercury on the site ranges, depending on location, from five
to more than 300 parts per million, trials were set up to measure the
effects of the cottonwood trees on progressively more polluted samples of
soil. Forty-five plots, most planted with four trees each, are located on
the site, which is in a mixed-use urban area and whose total area is less
than an acre. (Some 15 plots have four merA trees, 15 are nonengineered or
"wild-type" trees and 15 received no trees at all, so there are 120 trees
in the field test.)

The form of mercury at the Danbury site is ionic mercury, a species that
can be sequestered and transformed into less toxic metallic mercury in the
transgenic trees and then transpired into the atmosphere. (Several forms
of mercury were used in hat-making in the 19th century, but their toxic
effects often sickened workers and led to the phrase "mad hatter," which
described the process of neurological degeneration that came from working
with the metal. In this part of New England, the symptoms of mercury
poisoning were called the "Danbury shakes.")

Meagher's lab actually has two genes that can effect phytoremediation,
merA and merB, but since the merA is active on ionic mercury, the
cottonwoods trees chosen for the Danbury trial express the merA gene.

"This is a field test, not a cleanup," said Meagher. "And we will be
measuring mercury in both the soil and the trees to see just how much
success we have in reducing the mercury levels in the soil. We are very
optimistic that this technology will work."

While the trees at the site will have to be watered, the costs of that
pale in comparison to traditional clean-up methods - digging up the
polluted soil and hauling it off for storage at another site, possibly
greater than $1 million.

A team of researchers from Western Connecticut State University will be
studying the role of soil microorganisms in the potential clean-up of
mercury on the site. According to the City of Danbury, the field test will
run through the 2004 growing season, and if results are positive,
genetically engineered cottonwood trees will be used to clean the whole
site.

On Tue, 16 Sep 2003 02:10:04 GMT, "David Kendra"
wrote:

transpire the much less
toxic forms of the metal into the air where they are quickly diffused

Great! Let's dump the metal into the wider environment, shall we? This
is a misuse of resources and an attempt to provide a "fix it" approach
instead of tackling the problem at source.

The solution is to stop polluters from putting pollution into the
environment. In the case of polluted land, the polluter must pay to
remove the contaminants from the soil, not allow it to be "diffused"
into the atmosphere!

regards
Marcus

wrote in message
...

On Tue, 16 Sep 2003 02:10:04 GMT, "David Kendra"
wrote:

transpire the much less
toxic forms of the metal into the air where they are quickly diffused

Great! Let's dump the metal into the wider environment, shall we?

just put it back where it came from

Jim Webster

writes

On Tue, 16 Sep 2003 02:10:04 GMT, "David Kendra"
wrote:

transpire the much less
toxic forms of the metal into the air where they are quickly diffused

Great! Let's dump the metal into the wider environment, shall we? This
is a misuse of resources and an attempt to provide a "fix it" approach
instead of tackling the problem at source.

I do hope you aren't british as it would show our education up as
distinctly lacking.

Do you ever give anything more than a moments thought?

The solution is to stop polluters from putting pollution into the
environment. In the case of polluted land, the polluter must pay to
remove the contaminants from the soil, not allow it to be "diffused"
into the atmosphere!

1) What are you going to do about the large areas of (severe) heavy
metal pollution left in the UK by the Romans?

2) Have you ever considered that with heavy metal containing baserocks,
the area around a mine may well have been 'polluted' before any mining
took place?

3) Large areas of the UK midlands have levels of nickel well above the
maximum allowed for sewage sludge use. Why? Because they are derived
from ironstone.

4) Large areas of wales have levels of copper such that the swedes, if
torsten is to be believed, would consider them as 'toxic'.

5) I trust that you use no copper anywhere in your house, for fear of
contributing to this pollution.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
Note: soon (maybe already) only posts via despammed.com will be accepted.

On Wed, 17 Sep 2003 18:13:28 +0100, Oz
wrote:

Do you ever give anything more than a moments thought?

Why are you defending GM "technology" yet again?

Don't you see that allowing plants to "respire" mercury into the
environment might be a bad thing?

regards
Marcus

wrote in message
...

On Tue, 16 Sep 2003 02:10:04 GMT, "David Kendra"
wrote:

transpire the much less
toxic forms of the metal into the air where they are quickly diffused

Great! Let's dump the metal into the wider environment, shall we? This
is a misuse of resources and an attempt to provide a "fix it" approach
instead of tackling the problem at source.




The solution is to stop polluters from putting pollution into the
environment. In the case of polluted land, the polluter must pay to
remove the contaminants from the soil, not allow it to be "diffused"
into the atmosphere!

So you suggest that we should not use this technology to clean up toxic
waste sites? I do not believe many people will disagree that we should
focus on minimizing pollution at it source, but your suggestions do not help
resolve the issues of how to clean up pre-existing sites. What should we do
with the soil that you want the companies to remove? What will we do with
the residue that this creates?

Dave


regards
Marcus

writes

On Wed, 17 Sep 2003 18:13:28 +0100, Oz
wrote:

Do you ever give anything more than a moments thought?

Why are you defending GM "technology" yet again?

Don't you think that it is a good thing to detoxify slightly
contaminated sites?

Don't you see that allowing plants to "respire" mercury into the
environment might be a bad thing?

That depends on how much and how long and whether it has an impact or
not. I rather doubt the concentrations will be high, and may in fact not
be detectable in the wild. In any case I wouldn't be at all surprised if
some existing plants living on Hg contaminated soils do it already.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
Note: soon (maybe already) only posts via despammed.com will be accepted.

On Thu, 18 Sep 2003 00:06:50 GMT, "David Kendra"
wrote:


wrote in message
.. .

On Tue, 16 Sep 2003 02:10:04 GMT, "David Kendra"
wrote:

transpire the much less
toxic forms of the metal into the air where they are quickly diffused

Great! Let's dump the metal into the wider environment, shall we? This
is a misuse of resources and an attempt to provide a "fix it" approach
instead of tackling the problem at source.




The solution is to stop polluters from putting pollution into the
environment. In the case of polluted land, the polluter must pay to
remove the contaminants from the soil, not allow it to be "diffused"
into the atmosphere!

So you suggest that we should not use this technology to clean up toxic
waste sites? I do not believe many people will disagree that we should
focus on minimizing pollution at it source, but your suggestions do not help
resolve the issues of how to clean up pre-existing sites. What should we do
with the soil that you want the companies to remove? What will we do with
the residue that this creates?

Well, dumping the soil pollution as mercury vapour to the
atmosphere´is hardly an option. Only yesterday the US president
announced that mercury emissions to the atmosphere under his
administration's 'clean skies' initiative will need to be decreased by
69 %. So, how do you envision getting EPA to approve a technology
that increases it?

Torsten Brinch writes
Well, dumping the soil pollution as mercury vapour to the
atmosphere´is hardly an option. Only yesterday the US president
announced that mercury emissions to the atmosphere under his
administration's 'clean skies' initiative will need to be decreased by
69 %. So, how do you envision getting EPA to approve a technology
that increases it?

No problem, just leave the ground contaminated.

Your choice, although I doubt the emissions from this sort of scheme
would be significant and probably not in the US anyway.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
Note: soon (maybe already) only posts via despammed.com will be accepted.

"Torsten Brinch" wrote in message
...
On Thu, 18 Sep 2003 00:06:50 GMT, "David Kendra"
wrote:


wrote in message
.. .

On Tue, 16 Sep 2003 02:10:04 GMT, "David Kendra"
wrote:

transpire the much less
toxic forms of the metal into the air where they are quickly diffused

Great! Let's dump the metal into the wider environment, shall we? This
is a misuse of resources and an attempt to provide a "fix it" approach
instead of tackling the problem at source.




The solution is to stop polluters from putting pollution into the
environment. In the case of polluted land, the polluter must pay to
remove the contaminants from the soil, not allow it to be "diffused"
into the atmosphere!

So you suggest that we should not use this technology to clean up toxic
waste sites? I do not believe many people will disagree that we should
focus on minimizing pollution at it source, but your suggestions do not
help
resolve the issues of how to clean up pre-existing sites. What should we
do
with the soil that you want the companies to remove? What will we do
with
the residue that this creates?

Well, dumping the soil pollution as mercury vapour to the
atmosphere´is hardly an option. Only yesterday the US president
announced that mercury emissions to the atmosphere under his
administration's 'clean skies' initiative will need to be decreased by
69 %. So, how do you envision getting EPA to approve a technology
that increases it?

And what option do YOU recommend?

On Thu, 18 Sep 2003 12:07:05 GMT, "David Kendra"
wrote:


"Torsten Brinch" wrote in message
.. .
On Thu, 18 Sep 2003 00:06:50 GMT, "David Kendra"
wrote:
So you suggest that we should not use this technology to clean up toxic
waste sites? I do not believe many people will disagree that we should
focus on minimizing pollution at it source, but your suggestions do not
help resolve the issues of how to clean up pre-existing sites. What
should we do with the soil that you want the companies to remove?
What will we do with the residue that this creates?

Well, dumping the soil pollution as mercury vapour to the
atmosphere´is hardly an option. Only yesterday the US president
announced that mercury emissions to the atmosphere under his
administration's 'clean skies' initiative will need to be decreased by
69 %. So, how do you envision getting EPA to approve a technology
that increases it?

And what option do YOU recommend?

Oh, no particular option, it would depend on the circumstances,
and I am not an expert anyway. I am just not dumb enough to think
it might be a good idea to transform the mercury in the soil to
elemental mercury and vent it as mercury vapour into the atmosphere.

"Torsten Brinch" wrote in message
...
On Thu, 18 Sep 2003 12:07:05 GMT, "David Kendra"
wrote:


"Torsten Brinch" wrote in message
.. .
On Thu, 18 Sep 2003 00:06:50 GMT, "David Kendra"
wrote:
So you suggest that we should not use this technology to clean up
toxic
waste sites? I do not believe many people will disagree that we
should
focus on minimizing pollution at it source, but your suggestions do
not
help resolve the issues of how to clean up pre-existing sites. What
should we do with the soil that you want the companies to remove?
What will we do with the residue that this creates?

Well, dumping the soil pollution as mercury vapour to the
atmosphere´is hardly an option. Only yesterday the US president
announced that mercury emissions to the atmosphere under his
administration's 'clean skies' initiative will need to be decreased by
69 %. So, how do you envision getting EPA to approve a technology
that increases it?

And what option do YOU recommend?

Oh, no particular option, it would depend on the circumstances,
and I am not an expert anyway. I am just not dumb enough to think
it might be a good idea to transform the mercury in the soil to
elemental mercury and vent it as mercury vapour into the atmosphere.

Did you bother to read any of their work to see just how much mercury is
released into the atmosphere via their system verses mercury vapor from
other sources? Probably not. At least they are working on a solution. It
is always easier to criticize someone else's work than to actually be
creative and solve a problem. Keep up the good work Torsten. I always
appreciate you comments :-)

"Torsten Brinch" wrote in message
...
On Thu, 18 Sep 2003 12:07:05 GMT, "David Kendra"
wrote:


"Torsten Brinch" wrote in message
.. .
On Thu, 18 Sep 2003 00:06:50 GMT, "David Kendra"
wrote:
So you suggest that we should not use this technology to clean up
toxic
waste sites? I do not believe many people will disagree that we
should
focus on minimizing pollution at it source, but your suggestions do
not
help resolve the issues of how to clean up pre-existing sites. What
should we do with the soil that you want the companies to remove?
What will we do with the residue that this creates?

Well, dumping the soil pollution as mercury vapour to the
atmosphere´is hardly an option. Only yesterday the US president
announced that mercury emissions to the atmosphere under his
administration's 'clean skies' initiative will need to be decreased by
69 %. So, how do you envision getting EPA to approve a technology
that increases it?

And what option do YOU recommend?

Oh, no particular option, it would depend on the circumstances,
and I am not an expert anyway. I am just not dumb enough to think
it might be a good idea to transform the mercury in the soil to
elemental mercury and vent it as mercury vapour into the atmosphere.

Did you bother to read any of their work to see just how much mercury is
released into the atmosphere via their system verses mercury vapor from
other sources? Probably not. At least they are working on a solution. It
is always easier to criticize someone else's work than to actually be
creative and solve a problem. Keep up the good work Torsten. I always
appreciate you comments :-)

On Thu, 18 Sep 2003 22:57:41 GMT, "David Kendra"
wrote:


"Torsten Brinch" wrote in message
.. .
On Thu, 18 Sep 2003 12:07:05 GMT, "David Kendra"
wrote:


"Torsten Brinch" wrote in message
.. .
On Thu, 18 Sep 2003 00:06:50 GMT, "David Kendra"
wrote:
So you suggest that we should not use this technology to clean
up toxic waste sites? I do not believe many people will disagree
that we should focus
on minimizing pollution at it source, but your suggestions do not
help resolve the issues of how to clean up pre-existing sites. What
should we do with the soil that you want the companies to remove?
What will we do with the residue that this creates?

Well, dumping the soil pollution as mercury vapour to the
atmosphere´is hardly an option. Only yesterday the US president
announced that mercury emissions to the atmosphere under his
administration's 'clean skies' initiative will need to be decreased by
69 %. So, how do you envision getting EPA to approve a technology
that increases it?

And what option do YOU recommend?

Oh, no particular option, it would depend on the circumstances,
and I am not an expert anyway. I am just not dumb enough to think
it might be a good idea to transform the mercury in the soil to
elemental mercury and vent it as mercury vapour into the atmosphere.

Did you bother to read any of their work to see just how much mercury is
released into the atmosphere via their system verses mercury vapor from
other sources?

Yeah. Just to take it further from that, did you bother to realise
that mercury vapour release from 'other sources' is considered to be a
serious environmental problem, one which we certainly do not need a
new technology adding anything to?

snip

Torsten Brinch writes

Yeah. Just to take it further from that, did you bother to realise
that mercury vapour release from 'other sources' is considered to be a
serious environmental problem, one which we certainly do not need a
new technology adding anything to?

I have to say that, outside a localised area, I have come across
anything mentioning Hg as a significant hazard; or any hazard at all,
come to that.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
Note: soon (maybe already) only posts via despammed.com will be accepted.