Accomplishments & Future Developments

Arizona's unique opportunity
Arizona is in a unique position to become a leading regional center for the development of innovative technologies and related risk assessment methods. The Southwest Hazardous Waste Program tests potential methods and technologies both in the laboratory and at field sites so as to make scientific data available to individuals in the areas of hazardous waste regulation, environmental restoration, and the prevention of human health effects. Information learned in Arizona can be applied to hazardous waste sites and environmental pollution issues both nationally and internationally.

Hazardous waste cleanup in the U.S. is estimated at $500 billion over the next two decades
Making this cost effective is important for the nation and for Arizona's environmental health. For example, implementation of the new arsenic drinking water standard will cost about $1 billion in capital costs and $60-90 million per year operation costs. As another example, improper disposal of chlorinated organic compounds has resulted in extensive contamination of groundwater. Using existing technologies, it will take another 20-50 years to cleanup the TCE contamination at the Tucson International Airport -- that's just one Superfund site.

Reaping the rewards of research
Arizona and other Southwestern states can reap the rewards of 15 years of research by the Southwest Hazardous Waste Program at The University of Arizona. This Program is examining health implications of exposure to toxic substances and designing innovative technologies that will, effectively and economically, remove toxicants from soil, water, and air. The Superfund Basic Research Program at the University of Arizona has received funding to continue research for another five year period, beginning April 1, 2005 and continuing through March 31, 2010. Over this five year period, the program will receive approximately $14 million for continued study on arsenic, cholrinated solvent and mine tailings contamination.

Translating years of study into solutions 1995 - 2004

• Established a correlation between exposure to high levels of TCE in drinking water and congenital heart defects. Since TCE is found in water supplies throughout the United States, the impact of these findings reaches far beyond Southern Arizona. In addtion, the toxic effects of perchloroethylene (PCE) are being modeled after these TCE studies.
• Determined that TCE exposure in vitro blocks required cell invasion in the heart.
• Determined how fast arsenic, mercury, cadmium, and lead are moving from Pinal Creek downstream to Roosevelt Lake. These contaminants threaten a major source of the Phoenix water supply. Water is a precious resource in Arizona and the UA research team is working with government agencies to keep our water safe.
• Demonstrated the effectiveness of biosurfactants for removing toxic metals from soil. Biosurfactants, produced naturally by microorganisms, function similarly to synthetic cleaning agents found in detergents. Lab results show 80-100% removal of single metals including cadmium and lead from artificially contaminated samples. Unlike many existing clean-up technologies, using microorganisms is environmentally benign.
• Designed, tested and patented a clean-up technique that uses a palladium-coated iron powder catalyst to destroy TCE and PCE in groundwater. Several consulting firms in the Southwest currently use this technology. UA researchers are in the forefront of developing new technologies to maintain safe drinking water.
• Accomplished purification of enzymes that reduce various forms of arsenic in the body. More specifically, MMA(V) reductase was purified and sequenced. Sequencing indicated that MMA(V) reductase and glutathione S transferase omega (GSTO) are identical proteins. The glutathione S transferases are of major importance for metabolizing xenobiotics in humans.
• Determined that arsenic effects the association of specific protein complexes in the signaling cascade. Low-level arsenic causes the accumulation of protein debris which can cause a variety of cellular defects (e.g. cell cycling, differentiation, cancer).
• Conducted pilot-scale (demonstration) tests to evaluate the performance of two innovative source-zone remediation technologies—enhanced solubilization using cyclodextrin and in-situ chemical oxidation using potassium permanganate. As a result of the potassium permanganate demonstration tests, full-scale remediation of the source zone at the Air Force Plant 44 site is being implemented.
• Developed mechanistically based kinetic models to describe arsenic and chromium removal in flow-through systems.
• Determined that gas-phase solvents like those in waste streams derived from soil vapor extraction can be rapidly destroyed via thermocatalytic reduction on a variety of metal catalysts. Hydrogen gas is a suitable reductant for the process. Half times for solvent destruction are on the order of a few seconds.

• To clarify the toxic effects of low-level arsenic in a human bladder model and provide potential biomarkers for arsenic-induced bladder injury.
• To understand the molecular mechanism by which arsenic causes its deleterious effects on the vascular system and how the activity of annexin II contributes to arsenic toxicity.
• To identify the mechanism(s) of action of trichloroethylene (TCE) and its metabolites trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) in the developing heart.
• To evaluate the developmental effects of arsenic in the lung and the effect of folate on these developmental effects.
• To fully characterize the genetic variability of all known genes involved in arsenic biotransformation in a diverse group of ethnically defined, globally collected human samples of arsenic-exposed individuals.
• To treat contaminated soil vapor and groundwater with an emphasis on destruction of the target pollutant, rather than capture and disposal.
• To better understand the dissolution behavior of dense nonaqueous-phase, immiscible organic liquids in subsurface systems.
• To address shortcomings and provide advances in three critical areas: arsenic treatment technologies, arsenic residuals assessment, and arsenic residuals stabilization.
• To develop a feasible re-vegetation strategy for the phytostabilization of metal contaminants in mine tailing piles in arid and semi-arid ecosystems.