Air Date: Week of December 7, 2001

Living on Earth's Cynthia Graber reports on how tobacco might help clean up pollution from TNT.

Transcript

CURWOOD: Just ahead: evidence that smoldering fires and dusty debris from Ground Zero are the source for an outbreak of respiratory problems in lower Manhattan. First, this Environmental Technology Note from Cynthia Graber.

GRABER: Weapon production and weapon use can leave behind chemicals and explosives that are deadly to plants and animals. TNT is one of the most toxic of these chemicals, and one of the most difficult to get rid of. At the moment, the only way to treat soil contaminated with TNT is to excavate and burn it, a process that creates air pollution and leaves behind contaminated ash. So scientists went looking for an alternative and they found that some plants, such as tobacco, have the natural ability to take up low levels of TNT from the environment and then turn it into harmless organic molecules. The problem is TNT is so potent that at high levels it will stunt the growth of roots and leaves and eventually kill the plant. So genetic engineers at the University of Cambridge, in England, introduced a bacterial enzyme into tobacco plants that allows them to flourish in highly polluted water and soil. At the same time, they remove and destroy nearly all the TNT around. The lab tests have shown good results with tobacco plants, so the researchers plan to try the technique with poplars. Their deep root system would allow the trees to more effectively reach and destroy all the TNT in the soil. That's this week's Technology Note. I'm Cynthia Graber.

CURWOOD: And you're listening to Living on Earth.