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Salad Greens Scarf Selenium

Dr. Norman Terry's research has gotten a bit more spicy of late. The UC Berkeley professor of plant biology is a leader in the field of phytoremediation, or the use of plants to clean up heavy metals and other toxic materials from contaminated soil. His research has shown that many common crops, including rice, cabbage, and everyone's favorite vegetable, broccoli, absorb selenium into their root systems, converting it to innocuous dimethyl selenide, which is then released into the atmosphere.

Lately Terry and his colleagues been focusing on Indian mustard, which he says seems to be more effective than the others in selenium removal, and he is also experimenting with genetic engineering techniques, which he hopes will double, or even triple, the plants efficiency in removing selenium, cadmium and possibly other heavy metals.

Another promising plant is pickleweed, which can tolerate high salinity and pollution levels, and removes up to 500 milligrams per square meter of selenium, the highest rate of any of the species he's tested. The plant, common in wetlands, is unfamiliar to most Americans as a culinary delight, but, says Terry. "The French like it as a salad."

Virtually none of the toxins actually remain in the plants themselves, but it's not likely that you're going to see Terry's crops on the menu at your local bistro. (Terry does, however, hold out the possibility that they could be used to feed livestock.) He thinks the technique will be most valuable in cleaning up large areas with relatively low levels of contaminants - the plants are easily cultivated and their extensive root systems probe every nook and cranny where the toxins may lurking.

Most of his work so far has been in the lab, although a test planting in an artificial wetland near the town of Corcoran in Kings County is showing good early results. A few plants, such as lettuce and onions, failed to extract much selenium, but others, like the pickleweed and mustard, are proving their worth.

"We're moving right along on several fronts," he says. "We've had a few misses, but it seems like the technique is working."

Contact: Norman Terry (510) 642-3510

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