Spring Break
Trees help clean up mercury pollution in Georgia
ELIZABETH YOUNG
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Over the past decade, a multitude of advisories against consuming mercury-contaminated fish have been issued throughout the state for more than 80 of its lakes, creeks and streams, according to a news release.
The site of an old chemical factory near Brunswick and former gold mines in North Georgia are examples of areas plagued with mercury contamination, according to the release.
A team of University researchers is involved in the first field test using genetically engineered cottonwood trees to remove toxic mercury from the soil.
This technique, called phytoremediation, is a relatively new field that involves using grasses, trees and other plants to remove hazardous materials out of dirt.
"We're taking the mercury that is in toxic form and could potentially wash into rivers and converting it to a less toxic form," said Andrew Heaton, and a member of the research team.
The converted mercury is in the form found in thermometers, and it is the least toxic form of the element, Heaton said.
Since mercury is an element, the tree cannot actually break it down, he said.
This mercury is either drawn into the plant tissue itself or released into the atmosphere, Heaton said.
Richard Meagher, a professor of genetics at the University, and Scott Merkle, a professor of forestry, were the only faculty members on the team involved in engineering the trees.
Meagher, a pioneer in phytoremediation, was the first to demonstrate that a special gene could be inserted into plants that would allow them to remove mercury from the environment.
Meagher then collaborated with Merkle in creating these genetically-engineered trees.
Their project is ongoing, and experimental data indicates that arsenic may be the next toxin to be tested, Merkle said.
"We are hoping to use willows next due to their dense root system and need for wet soil. There is currently work going on with the sweetgum," he said.
Dong Sheng Che was the graduate student that engineered the cottonwood trees, he said. Che could not be reached for comment.
The trees were planted in July 2003 in Danbury, Conn., at the site of a 19th century hat-making factory infamous for the mercury-poisoning of its workers.
The project is a collaboration of the University, Applied Phytogenetics, Inc. of Athens, Western Connecticut State University and the city of Danbury.
In 2001, Meagher participated in a similar project involving transgenic tobacco plants. This will be his first effort involving trees.
