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Articles in English
Arsenic hyperaccumulation in ferns: a review
The Chinese Ladder fern Pteris vittata, also known as the brake fern, is a highly efficient accumulator of arsenic.  P. vittata grows rapidly and can absorb up to 2% of its weight in arsenic.  It can extract arsenic from soil even where the level is low, for example 6 ppm, which is normal for many soils. When it grown on soil with 100 ppm not only did it absorb more arsenic, but it grew 40% larger than normal.
[ link to complete article, page 8 ] [ brief abstract ]
Beyond Food and Drugs, Biotech Fights Pollution

July 03, 2005 — By Paul Elias, Associated Press

On the site of a former hat factory in Danbury, Conn., a stand of genetically altered cottonwood trees sucks mercury from the contaminated soil. Across the continent in California, researchers use transgenic Indian mustard plants to soak up dangerously high selenium deposits caused by irrigation of the nation's bread basket.  Still others are engineering trees to retain more carbon and thus combat global warming....
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Phytoremediation: novel approaches to cleaning up polluted soils
Ute Krämer - from Current Opinions in Biotechnology, 16:133-141 (2005) .
Environmental pollution with metals and xenobiotics is a global problem, and the development of phytoremediation technologies for the plant-based clean-up of contaminated soils is therefore of significant interest. Phytoremediation technologies are currently available for only a small subset of pollution problems, such as arsenic. Arsenic removal employs naturally selected hyperaccumulator ferns, which accumulate very high concentrations of arsenic specifically in aboveground tissues. Elegant two-gene transgenic approaches have been designed for the development of mercury or arsenic phytoremediation technologies. In a plant that naturally hyperaccumulates zinc in leaves, approximately ten key metal homeostasis genes are expressed at very high levels. This outlines the extent of change in gene activities needed in the engineering of transgenic plants for soil clean-up. Further analysis and discovery of genes for phytoremediation will benefit from the recent development of segregating populations for a genetic analysis of naturally selected metal hyperaccumulation in plants, and from comprehensive ionomics data – multi-element concentration profiles from a large number of Arabidopsis mutants.

chemical reactions
 Above:  Chemical reactions in transgenic phytoremediation:
(a) detoxification and volatilization of organomercurials.
(b) Arsenate detoxification and immobilization.
(c) Selenite detoxification.
AdoMet, S-adenosylmethionine; GSH, glutathione (reduced); GS-SG, oxidized glutathione; Me, methyl; SMM, S-methylmethionine.

Danforth Plant Science Center ResearchFrom Green to Clean

Merging Genes Could Create Plants That Clean Contaminated Ground
- Rachel Melcer, St. Louis Post-Dispatch, March 18, 2004

St. Louis - In a Creve Coeur, Mo., laboratory, biochemists Joe Jez and Tom
Smith are working toward a day when plants and trees will replace
earthmovers and landfills in cleaning contaminated industrial sites. The
duo, who work at the Donald Danforth Plant Science Center, are advancing a
method of phytoremediation, a broad term that refers to using green plants
to absorb or break down contaminants in soil, sludge, sediment and
groundwater.
Jez has identified a gene that allows certain plants to thrive in soil
contaminated with cadmium, a toxic heavy metal. Smith has found a
different gene that helps some bacteria to capture and transport zinc,
which is important for nutrition but can be threatening at high
concentrations. They would like to augment and transfer both traits to
large, fast-growing plants and trees, enabling them to store various
heavy-metal pollutants absorbed from the ground. The plants could be
harvested and incinerated, leaving a relatively small amount of ash for
proper disposal. <more>

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Use of plant roots for phytoremediation and molecular farming

by Doloressa Gleba, Nikolai V. Borisjuk, Ludmyla G. Borisjuk, Ralf Kneer, Alexander Poulev, Marina Skarzhinskaya, Slavik Dushenkov, Sithes Logendra, Yuri Y. Gleba, and Ilya Raskin

"Alternative agriculture, which expands the uses of plants well beyond food and fiber, is beginning to change plant biology. Two plant-based biotechnologies were recently developed that take advantage of the ability of plant roots to absorb or secrete various substances." 
Proc. Natl. Acad. Sci. USA: Vol. 96, No. 11, 59735977, May 25, 1999

  [ link to article ]
Engineered Arabidopsis plants (left and center) thrive on arsenic compared to normal plants (right).Genes improve green cleaning:  
Engineered organisms could make toxic clean-ups safer and speedier.
   by Kendall Powell.

"Researchers have created a plant that safely takes up the toxic element arsenic, and hope to use it to restore soils that are too contaminated for human use. Genetic techniques could also produce new
biological tools to absorb other chemical pollutants." 

Right:  Engineered Arabidopsis plants (left and center) thrive on arsenic compared to normal plants (right).

Nature Science Update, 7 October 2002.

  [ link to article ]
Phytoremediation: A Growing Field with Some Concerns
   by Harvey Black.

"Phytoremediation -- the use of trees and plants to help clean up toxic waste sites -- is not only a growing science; it's also a growth industry." TheScientist 13 (March 1, 1999): 1. (page requires free registration to view)

  [ link to article ]
A Citizen's Guide to Phytoremediation  [ pdf file, 88 kb ]
 United States Environmental Protection Agency, Technology Innovation Office.

"Growing and, in some cases, harvesting plants on a contaminated site as a remediation method is an aesthetically pleasing, solar-energy driven, passive technique that can be used to clean up sites with shallow, low to moderate levels of contamination. This technique can be used along with or, in some cases, in place of mechanical cleanup methods." 
USEPA, Office of Solid Waste and Emergency Response (5102G), EPA 542-F-98-011, August 1998

  [ link to article ]
 
Phytoremediation and Indoor Air Quality:  Plants Clean the Air

In the modern workplace, polluted city air combines with limited ventilation and office-use chemicals to cause indoor air pollution.  Well-maintained house plants may be a partial solution to this problem.
 
 

Plants Actually Clean the Air!, 
   Sheri Dorn, Virginia Cooperative Extension.

"Despite all of today's present technology, it seems that foliage plants and trees may be the best means of improving outdoor air quality.  They are capable of removing gas and particulate pollutants from the air, reduce energy expenditures, lower air temperatures, and make our communities more attractive places to live."

Houseplants to Fight Pollution
   Virginia Peart, University of  Florida Cooperative Extension Service 

"Houseplants under some conditions can effectively remove benzene, formaldehyde, CO and nitrogen oxides (undesirable products of burning tobacco and wood). In a NASA research project, Spider plants were placed in closed chambers with 120 ppm carbon monoxide (CO) or 50 ppm nitrogen oxide (NO2)."
Florida Cooperative Extension Service publication FCS 3208
Elements of MurderHuman Consequences of Toxin Exposure

The Elements of Murder
A History of Poison,  by John Emsley.

This book describes the human consequenses of exposure to a few of the most infamous elemental toxins.  It is a well-researched overview with many unfortunate historical examples of mass and individual poisonings.   Mr. Emsley focuses on mercury, arsenic, antimony, lead, and thallium, all of which are targets of phytoremediation efforts.  In addition to poisonings and toxicology, the author discusses the natural occurrence of these elements and how human activities contribute to their distribution in the environment.
Biotecnologia en la Disoluciony Recuperacion de Metales [HTML file, 47kb ]

Biól. José J. Guerrero Rojas, Los Rhododendrons Nº 246 - Urb. VIPOL- Correo Vipol - Callao 03 - Peru.

 
Les plantes pour l'extraction des métaux lourds dans les sols

par Nathalie Ross, M.Sc.

l’Ecologie de la restauration 

Gabriel BERNARD
Reviews in other languages

A review in Portuguese formerly was posted here, but the link has disappeared.  If you know of reviews in other languages, please let me know so I can add them.

 
Bioremediation and Phytoremediation Glossary

by Steve Bentjen

"This is a glossary of terms related to bioremediation (biological treatment) and phytoremediation (remediation using green plants) of environmental pollutants.  Links to other environmental glossaries are at the bottom of the page."
 
Research Bibliographies on Phytoremediation
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Last update:  December 20, 2005