Phosphate-Induced Bioavailability Reduction of Lead in Contaminated SOILS.

Lead contamination in soils is of major concern due to its toxicity to humans and animals. This is because ingestion of Pb-contaminated soils is a significant exposure pathway to humans, especially for children. Soil amendments can be used to reduce the bioavailability and mobility of toxic metals including Pb in contaminated soils. Phosphate-induced Pb immobilization is considered a cost-effective and environmentally benign remediation technology to stabilize Pb in contaminated soils, therefore reducing the health risk of Pb exposure to humans. This presentation will discuss the mechanisms of P-induced Pb immobilization as well as its effectiveness in reducing the health risk of Pb exposure to human measured via various in vitro and in vivo methods. Formation of pyromorphite and its extreme low solubility makes P-induced Pb immobilization effective in reducing Pb bioavailability in soil. However, its long-term effectiveness still warrants further investigation. This presentation is prepared in honor of late Dr. Willard Lindsay who served as major supervisor for my M.S. and Ph.D degree at Colorado State University