New Jersey company cultivates pollution-eating plants Mustard greens, alfalfa help to clean up ravages of industry

March 30, 1997|By BOSTON GLOBE

MONMOUTH JUNCTION, N.J. - A New Jersey company, Phytotech of Monmouth Junction, is a leader in the emerging field of using plants to remove toxic substances from the soil.

Phytotech was founded four years ago by Rutgers University researchers. It is one of only a handful of companies in the United States getting commercial contracts for phytoremediation.

Last year, in a test of the new approach to cleansing polluted land, Phytotech got nearly 45 percent of the excess lead out of a seriously contaminated yard in Boston by sowing and harvesting a special strain of metal-absorbing greens that comes from India. By next autumn, officials hope, the yard's lead levels will be safe enough for children to play outside.

Besides mustard greens, which it is using along with pumpkin vines to clean up an old Magic Marker factory site in Trenton, N.J., Phytotech is pioneering use of hydroponically grown sunflowers to absorb radioactive metals near the Chernobyl nuclear site in Ukraine and at a uranium plant in Ohio.

Phytotech's work is part of a rapidly growing new technology called phytoremediation, a name based on the Greek root for "growing things."

Around the United States, several dozen academic and agriculture researchers, oil companies and toxic-waste handlers are reporting encouraging results using humble plants such as mustard greens, alfalfa, river reeds, poplar trees and even special weeds to clean up the ravages of industry, agriculture and petroleum production.

In some cases, the plants can digest the poisons and convert them to inert compounds. In Phytotech's Boston experiment and several other projects, the plants are being used only as a medium to absorb metals; the clippings are carefully disposed of.

'Less invasive technology'

Aside from the aesthetic pleasures of bringing green life to the desolate and often toxic "brown fields" that dot urban and industrial America, phytoremediation is intriguing to businesses and environmentalists alike because it can cost half to a tenth as much digging up and burning a contaminated patch of soil.

"So far, it's been very promising," Thomas Plant, a Boston environmental health official, said of the test there. "It's a much less invasive technology. It may take a little longer but cost much less than excavation."

Before the work at the 1,100-square-foot yard began, several areas had readings of 3 to 6 times what the city considers safe. After three crops of mustard greens last year, the worst lead reading was a little over twice the safe level.

"If the results keep looking as positive as they have," Plant said, "hopefully we can apply this in other locations." In many urban areas, lead has accumulated in soil from from old house paint, decades of leaded gasoline exhaust and other sources, creating a big health threat for young children.

Nationally, the potential market for phytoremediation is huge. The United States is facing a bill of $400 billion to $750 billion to clean up hazardous waste sites with conventional technology, according to Charles Plummer of the Agriculture Department's Economic Research Service.

That includes $7 billion over the next five years for sites contaminated by heavy metals - those perhaps most amenable to cleanup by mustard greens and other metal-absorbing plants.

"Phytoremediation takes more time than some traditional or intensive treatments, but the savings of financial and natural resources can offset the time," said Kansas state agronomist Paul Schwab.

Research around the United States has shown dozens of other possible uses for the technology: river reeds that turn airplane de-icer runoff into harmless water and carbon dioxide, poplar trees that suck toxic cleaning solvents and landfill ooze out of ground water, and grains and grasses that clear up spills of fertilizer and herbicides.

There are limits

There are limits, of course, to what plants can do in severely damaged areas, especially those where the pollution reaches deeply into the soil. And even some of the biggest boosters fear phytoremediation is being overhyped.

Gary Banuelos, an Agriculture Department researcher in Fresno, Calif., who has traveled worldwide and done extensive work on using mustard greens to control selenium levels in rich California farmland, said, "It's not a super-drug for decontaminating soil. It's just a tool."

It troubles Banuelos that many of the people doing work in phytoremediation are engineers, not farmers. "You have to treat it just like an agricultural product and think about planting, watering, harvesting. You have to think hard about how you water: If you put down too much water, and the plant doesn't take it, where does it go? Down and into the ground water" - a case of the would-be solution only making the problem worse.

Much research in phytoremediation aims for a better understanding of just how various plants absorb or break down pollutants, as well as better ways to measure the soil improvements they make.

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