Biologists have been working for a decade with plants and bacteria that absorb and break down toxic pollutants, a process known as bio- or phytoremediation. The emerging challenge in this field is to blend different plants through genetic engineering--by taking a gene from a fern that captures arsenic, for example, and putting it in a larger plant with a greater absorption capacity--creating more efficient cleanup “machines” that are adapted to different types of toxic areas.
The Promise: The traditional method of cleaning up toxic sites--digging out the chemicals and putting them in special landfills--is an expensive, disruptive process. Supporters see harnessing the natural abilities of bacteria and plants as a cost-effective, environmentally friendly way to remove radioactive waste, DDT, and other poisons from groundwater and brownfield sites.
The Peril: Researchers are still unsure if some poisons accumulated by the plants would evaporate through the leaves, transferring the pollution problem to the air. If the plants happened to be recycled as garden mulch, wood chips, and other products, they would take the poisons with them to unsuspecting citizens’ backyards. Critics also argue that phytoremediation will only put a small dent in our industrial pollution problem. “Requiring all manufacturers to be responsible for ‘end of life’ care of their products or putting double hulls on oil tankers are less glamorous than taking a gene from ferns and putting it into poplars, but these actions would do much more to reduce pollution,” says Dr. Jim
Diamond, a member of the Sierra Club’s Genetic Engineering Committee.