For more details of this research,
Helps Clean Up Toxic Soils
By Hank Becker
June 19, 2000
When it comes to cleaning up soils
contaminated with heavy and toxic metals, Mother Nature has
Agricultural Research Service plant
physiologist Leon V. Kochian to thank.
Thirteen years of research at the U.S. Plant, Soil and Nutrition Laboratory
at Ithaca, N.Y., makes Kochian an authority on how certain plants take up
essential mineral nutrients and toxic heavy metals--like zinc, cadmium and
nickel--from soils. He has also characterized strategies some plants use to
withstand toxic soils.
Kochian's pioneering research shows how plant species grow on marginal and
toxic-metal-laden soils. He's an international expert on plant responses to
environmental stress, plant mineral nutrition, and how they clean up soils
contaminated with heavy metals and radioisotopes.
Contaminated soil and water pose major environmental, agricultural and human
health problems that may be partially solved by a new technology called
phytoremediation. It uses green plants to remove pollutants or render them
Current engineering-based technologies--such as transporting contaminated
topsoil to landfills--are costly and dramatically disturb the landscape.
Kochian's "green technology" is a cost-effective, plant-based
approach. It uses certain plant species-- known as metal hyperaccumulators--to
"vacuum up" heavy metals through their roots and store them in
above-ground plant tissue. Once concentrated in the easily harvested plant
stems and leaves, these elements can be stored for later use.
Kochian is clarifying how the complex trait of metal hyperaccumulation
involves several different transport and tolerance mechanisms within the plant.
He's working with plants like Thlaspi caerulescens, which thrives on
soils contaminated with high levels of zinc and cadmium, and Amaranthus
retroflexus, which removes up to 40 times more radiocesium from soil than
other plant species tested.
For more details of this research, see the June issue of Agricultural Research.
ARS is USDA's chief research agency.
Scientific contact: Leon V. Kochian, ARS Plant, Soil and Nutrition
Laboratory, Ithaca, N.Y.; phone (607) 255-2454, fax (607) 255-2459,