SERDP CU-1166: Quantifying The Bioavailability of Toxic Metals in Soils


  • To investigate the relative bioavailability of toxic metals (i.e., lead, zinc, copper, cadmium, arsenic, chromium, and nickel) in soils, primarily in relation to the human health risk posed by soil ingestion.
  • Calculated health risk is inappropriately based on a reference dose derived from studies that typically use soluble aqueous metal species.
  • Soils can be strong sequestering agents for metals.
  • Insufficient research to provide reasonable initial estimates of relative soil bioavailability for As, Cr, Pb, Zn, Cd, and Ni.

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  • Improved fundamental understanding and predictive capability of the processes that control the long-term immobilization and decreased bioaccessibility of toxic metals in a wide array of DoD soils.
  • Model development and validation studies demonstrated that toxic metal bioavailability can be predicted based on major soil properties [SBAT, Soil BioAccessibility Tool (Excel® 2000 application, User Guide)].
  • Although site-specific data always will need to be considered in final cleanup decisions, results can be used to prioritize sites and to justify site-specific bioavailability studies, thereby avoiding the unnecessary diversion of DoD funds for unwarranted site cleanup.
In vivo swine feeding studies Predicted As(V) bioaccessibility (%) based on soil pH and Fe-oxide content
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In vitro PBET


For more information, contact:
Philip Jardine (, 865-574-8058)