Submitted to: International Bioavailability Workshop
Publication Type: Abstract only
Publication Acceptance Date: 1/10/2003
Publication Date: 2/4/2003
Citation: Interpretive Summary:
Technical Abstract: Reducing risks associated with Pb in soil has typically been accomplished by soil removal, covering, or dilution by mixing with uncontaminated soil. The In-place Inactivation and Natural Ecological Restoration Technologies (IINERT) Soil-Metals Action Team was established in November 1995. Its primary goal was to examine in situ remediation alternatives that are persistently effective and low cost, yet provide equivalent or better protection to human health and the environment compared with conventional methods. A field experiment was started in 1996 at an urban Pb-smelter contaminated site in Joplin, MO, USA. The objective was to help accomplish the two-fold mission of the team: 1) develop and demonstrate in situ treatment technologies that reduce and eliminate the risks to human health and the environment of metals in soil and 2) achieve regulatory and public acceptance of these technologies. The data that has been developed from this cooperative research effort will be summarized and discussed. Evaluation of both the change in soil Pb geochemistry and its bioavailability [in vivo (using rats, swine, and humans) and in vitro] were measured over time. Results from this field evaluation illustrate the reduction in soil Pb, Zn and Cd availability to plants, and reduction of soil Pb bioavailability to mammals. Soil Pb was altered to pyromorphite during the 3 year test based on spectroscopic and chemical evaluation; increased adsorption also contributed to reduced Pb bioavailability of soil Pb where high Fe biosolids compost was applied. Each animal and in vitro chemical testing showed reduction in the bioavailability of soil Pb to mammals. This test demonstrates that reduction in soil Pb risk can be accomplished without soil removal.