(McLean, VA, 12 October 2004) -- At the 2004 Virginia Biotechnology Summit, Edenspace Systems Corporation announced today that the U.S. Department of Housing and Urban Development (HUD) has awarded the company an eighteen-month, $400,000 grant to demonstrate new phytoremediation techniques for urban yards.

The objective of the project, which will include a demonstration at ten Baltimore homes in the summer of 2005, is to validate low-cost, effective ways of reducing the health hazards posed by lead in residential soils. Lead can affect children's developing nervous systems, resulting in learning disabilities and a reduced IQ. In adults, lead exposure at high levels has been shown to cause headaches, kidney damage, high blood pressure, digestive problems, mood changes, sleep disturbances, problems with memory and concentration, joint and muscle pain, nerve disorders, and fertility problems.

HUD's Lead Hazard Control Grant Program, which sponsors the Edenspace project, conducts technical studies on specific topics related to the evaluation and mitigation of residential lead hazards. The program seeks to protect young children, particularly those from low-income families. In 1991, the Secretary of Health and Human Services called lead "the number one environmental threat to the health of children in the United States" In 2004, HUD estimates that 26 million dwellings still have significant lead-based paint hazards, including 5.7 million with young children.

Decades of peeling exterior paint, car exhaust from leaded gasoline along streets and highways, and pollution from lead smelters and other industries have deposited lead in the yards around homes where it is a major source of lead exposure in children and adults. The U.S. Environmental Protection Agency (USEPA) estimates that 12 million homes have lead in their yards at levels exceeding the 400 parts per million (ppm) standard for play areas, while 4.7 million homes exceed the 1,200 ppm standard for the rest of the yard. While landscaping, paving, laying sod or gravel, and other interim control techniques can reduce exposure hazards, the only permanent method currently used to remove lead is excavation and replacement of the soil. This method can cost thousands of dollars for a small yard and is inconvenient to homeowners.

A new technique called phytoremediation uses living plants such as turf grass to remove lead from soil. Advantages of this approach for urban yards include permanent reductions in soil lead; low cost; ease of use; and compatibility with ongoing uses of the property. Potential drawbacks include the need for lawn care and disposal of grass clippings. In addition, a chelating agent used to promote lead uptake by plants, ethylenediaminetetraacetic acid (EDTA), can persist in some soils and allow migration of lead in sandy, well-drained soils.

Dr. Mark P. Elless, Senior Scientist at Edenspace and the project's Principal Investigator, noted that the new project will demonstrate improved phytoremediation methods to remove lead from urban yards, evaluating costs, treatment time, and other factors based on the use of recently-identified biodegradable compounds, such as citric acid and other organic acid derivatives, that reduce migration concerns. In a 2003 project studying depleted uranium and lead in firing ranges for the U.S. Army TACOM/ARDEC, these biodegradable substitutes, termed transient phytoextraction agents (TPAs), provided comparable removal performance with superior migration control. The current demonstration will build on work conducted under this and other projects, demonstrating TPA-assisted phytoremediation as a cost-effective method to reduce the health risks posed specifically by paint-derived lead in residential soils.

Several TPAs will be tested in residential soils from cities around the country, representing a variety of soil pH levels, fertility, salinity, organic matter content, and moisture holding capacity. Planned soil sources include Baltimore, MD; Cambridge, MA; Chicago, IL; Cleveland, OH; Denver, CO; El Paso, TX; Herculaneum, MO; Indianapolis, IN; Las Cruces, NM; Miami, FL; Philadelphia, PA; St. Louis, MO; Trenton, NJ; and Washington, D.C. Performance of each TPA will be correlated with soil type in a database that will be published in 2005. TPA performance will then be validated in the Baltimore field demonstration.

The Edenspace project team includes Dr. April L. Ulery, Associate Professor at New Mexico State University, who has collaborated with Edenspace in pioneering TPA research; the Coalition to End Childhood Lead Poisoning, which will assist in the Baltimore field demonstration with technicians trained by B'More Green, a grass-roots community program; and Professor Niall Kirkwood of the Harvard Graduate School of Design and Director and Harvard Center for Environment and Technology, who has participated in lead hazard control and phytoremediation projects in the U.S. and abroad.

Mr. Bruce W. Ferguson, President and CEO of Edenspace, said, "We feel the team we have assembled will provide a very balanced and rigorous approach that uses university, community and commercial resources in addressing this important environmental challenge."

Headquartered in Dulles, Virginia, Edenspace Systems Corporation is a commercial leader in the use of live plants to improve human health, protect property values and clean the environment. Its techniques employ plants to detect, concentrate and remove lead, arsenic, radionuclides, chlorides (salts), hydrocarbons, and other minerals in water and soil. With expertise in plant science, soil science, genetics and agronomy, Edenspace is developing new markets for the restoration and enrichment of our surroundings.

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A photograph of oranges, a natural source of citric acid, on a lawn is attached as a jpeg file [download large: 192KB] [download small: 52KB]. Phytoremediation of lead requires application of TPAs such as citric acid to turf grass roots and surrounding soil. Additional information on the distribution and health effects of lead in the soil may be found at HUD and EPA. To learn more about Edenspace Systems Corporation, as well as to review other recent news releases, please visit our web site at www.edenspace.com.