April 9, 2003, 2:00 PM - 4:00 PM, EDT (18:00-20:00 GMT)

This is the first in a series of three seminars on Metals sponsored by the EPA Technology Innovation Office and the NIEHS Superfund Basic Research Program. This event will highlight recent advances in assessing and limiting the bioavailability of metal contaminants. Dr. Joseph Graziano, of Columbia University, will discuss his team’s current research into phosphate treatment of lead (Pb)-contaminated soils. Adding phosphate amendments to soil has been shown to dramatically reduce the absorption of Pb in humans. For example, Pb absorption from a contaminated soil obtained from a former smelter site in Joplin, Missouri, averaged 36% among a group of adult volunteers. However, Pb absorption from an adjacent soil that had been "fertilized" in the field 18 months earlier averaged only 15%. This 57% reduction in Pb bioavailability implies that the Pb hazard at many Superfund sites can be substantially reduced in a very cost effective manner. Dr. James Shine, of Harvard University, is developing a sampling device that can measure the free metal ion concentration of many metals at the same time. The sampler, called the "Gellyfish," functions through the equilibration of immobilized ligands (held in polyacrylamide gel) with the free metal ion concentration in the surrounding solution. This sampler can measure the free metal ion concentration of many metals at the same time. Knowledge of the free metal ion concentration is a critical determinant for understanding metal speciation, and thus understanding the environmental mobility and bioavailability of metals in aquatic ecosystems. This new analytical technique is ready to be demonstrated in a pilot scale application.

• Joseph H. Graziano, Ph.D., The Mailman School of Public Health at Columbia University (jg24@columbia.edu)
• Jim Shine, Ph.D, Harvard School of Public Health (jshine@hsph.harvard.edu)

• Larry Whitson, National Institutes of Health, National Institute of Environmental Health Sciences (whitson@niehs.nih.gov)

Press the "Go to Seminar" button to view the seminar. Please be at this location at the beginning of the conference call.

The seminar is available for download in both Microsoft PowerPoint and Adobe Acrobat formats.