New Plants Being Developed That Eat Toxins and
Cleanse Polluted Soil ... But What are the Risks?
by www.SixWise.com
Nature is full of amazing things, like "extromphiles"
that live in toxic waste sites and may hold the cure to cancer,
and the 400,000 Mexican free-tail bats that live in Carlsbad
Caverns (New Mexico) and eat several tons of bugs each
night.
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Plants can naturally remove toxins that industry leaves
behind from our soil and water, but it can takes years
-- even decades -- for them to be effective. With genetic
engineering, researchers were able to create plants
that could clean up waste 100 times faster -- but with
unknown consequences.
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Nature also produces plants that can naturally clean up contaminated
soil and ground water in a process known as phytoremediation.
Certain plants are able to withstand soil toxins such as heavy
metals, and actually uptake them into their roots. The plants
are able to breakdown the toxins into harmless byproducts
that they either keep in their roots, stems and leaves or
release into the air.
Cleansing soil that has been polluted by industry or accidents
in this manner has shown promise since the early '90s. However,
though effective, it's a relatively slow process (and it shuts
down during the winter), which makes it impractical for many
remediation sites -- which may be under deadlines imposed
by federal regulators -- to use phytoremediation for cleanup.
In order to speed things up a bit, scientists have been working
on tweaking plants to clean soil even more effectively (i.e.
faster). And now they think they've done it.
Plants With Animal Genes
Researchers from the University of Washington have genetically
engineered lab-grown poplar plants that show great promise
for cleaning up trichloroethylene, an industrial degreaser
that commonly contaminates groundwater.
The genetically modified (GM) plants took up as much as 91
percent of the trichloroethylene from a liquid solution, while
unaltered plants took up just 3 percent. The GM poplars also
broke down the toxin into harmless byproducts 100 times faster
than unaltered versions.
On top of that, the GM plants were also found to uptake more
of other environmental toxins, including:
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Chloroform, a byproduct of disinfecting drinking water
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Carbon tetrachloride, a solvent
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Vinyl chloride, a plastics chemical
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Benzene
"It is our hope that by developing trees that can remove
carcinogens from the water and air in a fast and economical
way, people will be more likely to use [the land] than abandon
the property as too expensive to clean up," said Sharon
Doty of the University of Washington, the study's lead author,
in a National Geographic News article.
However, there's a catch. The researchers implanted the poplar
plants with a gene from rabbits' livers that produces cytochrome
P450 -- an enzyme that poplars use to metabolize contaminants.
While both plants (including poplars) and animals contain
P450, it's not expressed naturally in poplars at the rate
found with genetic modification.
The problem with using GM plants for remediation is that
it's never been done before and the risks are unknown. Plants
spread naturally in the wild, which means that GM genes could
easily spread uncontrollably, with perhaps unseen, negative
consequences.
"I think we're playing to some extent a game of roulette
here," said Doug Gurian-Sherman with the Union of Concerned
Scientists in Washington, D.C in National Geographic News.
"If they [GM genes] do [escape and] cause problems,"
he said, "we're pretty much going to be stuck with them."
In 2005, a similar controversy arose when Japanese researchers
inserted a human liver gene into rice. The gene produces an
enzyme, CYP2B6, which breaks down chemicals in the human body.
The GM rice was intended to be resistant to herbicides and
to breakdown other pollutants.
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The USDA has given approval for a 3,000-plus acre crop
of rice that contains human proteins to be grown in
Kansas.
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At the time, the anti-GM Institute of Science in Society
expressed concerns that the enzyme could end up back in humans,
where it could potentially trigger new viruses or cancers.
Taking things a step further, the U.S. Department of Agriculture
has given preliminary approval to Ventria Bioscience, the
producer of rice that contains human proteins found in breast
milk and saliva, to plant the GM rice on more than 3,000 acres
in Kansas.
The company is intending to market the rice as a treatment
for diarrhea and stomach bugs, and put it in drinks, deserts,
yogurts and muesli bars. It will be the first product to contain
both human and plant genes.
While the idea of using GM plants to clean up contaminated
soil has stirred plenty of controversy, using
them directly in food has created even more.
While the USDA says the rice can be grown with "virtually
no risk," others are not so sure.
Says Friends of the Earth campaigner Clare Oxborrow, "Using
food crops and fields as glorified drug factories is a very
worrying development. If these pharmaceutical crops end up
on consumers' plates, the consequences for our health could
be devastating."
Recommended Reading
Are
Genetically Modified (GM) Foods Dangerous? The Essentials
on Both Sides of the Debate
Codex:
What Exactly is it and How Does it Impact Your Health Freedom?
Sources
Proceedings
of the National Academy of Sciences October 16, 2007
The
Daily Mail March 6, 2007
National
Geographic News October 15, 2007
Eurek
Alert October 15, 2007
Telegraph
April 25, 2005