Health problems associated with exposure to arsenic (As) from chromated copperarsenate (CCA)-treated wood continue to command world attention. It has beendemonstrated that, in addition to As, chromium (Cr) and copper (Cu) also leach at levelspotentially toxic to aquatic organisms. Although considerable progress has been made instudying the toxicity of As, the harmful effects of these three elements in mixtures, leachedsimultaneously are currently unknown. The lack of this information remains one of the majorobstacles to assess the potential effects of CCA-treated wood on human health. Our longtermgoal is to characterize and ultimately reduce the human health risks associated withexposure to CCA. The principal objective of this research is to understand the leaching andhuman physiological effects (cell behavior and metabolism) of As, Cr, and Cu associated withCCA-treated wood. The objective will be accomplished by pursuing the following specificaims: (1) Investigate the leaching characteristics of all three toxic elements, As, Cr, and Cufrom CCA-treated wood and from the affected soils; (2) Evaluate the effects on aspects ofcell physiology of As, Cr, and Cu alone or in mixtures using a model based on human nervecell cultures (cell lines such as NSC-34, SH-SY5Y, CATH.a, D384 and SK-N-MC); and 3)Determine the effects of soil properties on the cell effects of soil leachate. This study will beguided by the following hypotheses: (1) The potential physiological effects of the leachatesassociated with CCA-treated wood to human beings is affected by the presence of the threemetals derived from CCA and interactions between them and low concentrations of As, Cr,and Cu in these leachates will affect critical aspects of cell metabolism; and (2) The leachingand potential effects of these elements from soils affected by CCA are altered by soilproperties. It is expected that this research will provide new and essential information forassessing the effects of the leachates associated with CCA on human beings. These resultswill allow improved predictions of leaching of As, Cr, and Cu from CCA-treated wood andtheir transport through soils and, ultimately, evaluations of possible human health impactsassociated with the release of these elements. Our results will, therefore, enable us to moreaccurately assess the environmental and human health impacts of As, Cr, and Cu pollutionresulting from CCA applications.