Summary (2000-2005)

The University of Arizona Superfund Basic Research Program began in 1990. The theme of the program is development of a risk management process for metals and organic contaminants through toxicologic and hydrogeologic studies and through the development of innovative remediation technologies. The program consists of ten projects (4 biomedical, 6 non-biomedical), two research support cores (hazard identification and technology demonstration), and administrative, outreach and training cores. The chemicals under study are the chlorinated hydrocarbons and toxic metals. The goal of the biomedical research projects is to determine the fate and processing of arsenic in the body and the effects of low level arsenic exposure on skin, kidney and developing tissues. To accomplish this goal researchers are focusing on: (1) the study of the molecular mechanisms of action of enzymes in the human body that modify the toxicity of arsenic species; (2) the elucidation of the major arsenic transport processes within cells of the two tissue/organ systems responsible for its elimination (kidney and bladder); (3) molecular effects of low level exposure to arsenic by examining the expression of key genes induced by arsenic and correlating this with cellular injury; and (4) the molecular determinants of developmental pathways that may lead to morphologic alterations resulting in birth defects, specifically cardiac malformations, as a consequence of arsenic and trichloroethylene exposure. This program has a strong focus in engineering research. Remediation technologies are examining: 1) the use of in situ gene delivery as a mechanism to enhance remediation of co-contaminated soils; 2) biosurfactant enhanced in situ remediation of soils contaminated with metals; 3) the dissolution, bioavailability and remediation of complex, multi-component, dense nonaqueous-phase immiscible organic liquids (DNAPLs) focusing on laboratory-based studies and modeling exercises; 4) methodologies and techniques to guide site evaluations and selection of innovative remediation strategies to stabilize or remove metalloids from abandoned mines; 5) electrochemical remediation of arsenic and chromium using zero-valent iron; and 6) the mechanism and kinetics of transformations of low-molecular weight chlorinated aliphatic compounds in a variety of gas- and liquid-phase electrolytic reactors.