I have had an active environmental chemistry research program since 1973. My research is best described as the use of modern analytical chemistry instrumentation to answer questions about the fate of trace chemical substances in the environment. Atomic spectroscopy is used to measure metal concentrations in soil and water samples, and chromatography is used to identify, and quantify, organic substances in the environment.

The projects I have worked on fall under one of two general categories: water chemistry issues, and the impact of energy production on the environment. All my research projects involve collecting field samples that are returned to the laboratory for analysis by the appropriate instrumental technique.

Advanced mathematical analysis of the chemical data is often required before meaningful statements of environmental quality can be made. This requires my students to be proficient in multivariate statistics, as well as analytical chemistry.

Here is a partial list of completed and current projects in northern Arizona:

Geochemistry of Grand Canyon springs
I have been testing the water from Grand Canyon springs for major, minor and trace chemical substances since 1973. This is an ongoing effort to understand the relationships between water and minerals in an environment with very little water. This research has recently taken on elevated significance because of the potential impact south rim water development projects will have on fragile ecosystems of the Grand Canyon.

Water Quality of Oak Creek
This was a six-year study of the Oak Creek watershed (co-directed with Dr. Gordon Southam) to identify non-point source pollution sources and levels. Data from this project was used by the Arizona Department of Environmental Quality to prepare revised guidelines for effluent emissions into Oak Creek.

Paria River Water Quality
This was a three-year study, where we measured concentrations of trace metals in the water and sediments of the Paria River watershed. The purpose of this project was to determine if abandoned mines in the area were impacting water quality in the Paria River, and ultimately, the Colorado River.

Arsenic Speciation in Montezuma Well
Groundwater arsenic is a significant environmental problem in many parts of the world. Arizona has some natural springs with arsenic levels in excess of 100 mg/L, which is twenty times greater than the World Health Organization recommend level for drinking water. Over a million people, world wide, suffer from acute arsenic poisoning that was acquired from their drinking water. Montezuma Well contains arsenic at a level of about 117 mg/L, and is an isolated travertine spring with a very well characterized ecosystem. We are collecting organisms from all trophic levels, as well as water and sediment samples, to understand how arsenic in moved throughout this ecosystem. We hope to discover processes that can detoxify arsenic by identifying how arsenic is transformed from arsenate (the predominate mineral form) to the various organic complexes that exist in living organisms.

Atmospheric Deposition of Heavy Metals from Mohave and Navajo Power Plants
We have conducted several studies on the atmospheric deposition of heavy metals near the Navajo and Mohave power plants. Heavy-metal fallout from these coal-fired power plants is significant, and does affect the trace metal content of plants and shrubs growing near these two power plants. Our most recently concluded project showed that lead deposition from the Mohave power plant is significant—and that the surface-soil lead originated in coal mined at Black Mesa, 320 miles to the east!

Recent student recognition of this research:

• Jens-Uwe Kuhn was recognized, by the environmental chemistry division of the American Chemical Society, with the 2000 award for top environmental chemistry graduate students in the United States.
• Kim Givler and Jens-Uwe Kuhn shared the honor of presenting the best student paper in the environmental chemistry division at the International Chemical Congress of Chemical Societies of the Pacific Rim. The meeting was held in Honolulu, HI, in December 2000.
• Anne Marie Compton was recognized, by the environmental chemistry division of the American Chemical Society, with the 2001 award for top environmental chemistry graduate students in the United States.
• Jeevanthie Senanayake's thesis research, looking for evidence of arsenic in the diet of the southern Sinagua of the Verde Valley, Arizona, was featured in the March, 2005 issues of Chemical and and Engineering News (http://pubs.acs.org/cen/news/83/i11/8311arsenic.html).