UC Merced Geochemist, Dr. Peggy O'Day, to focus on arsenicin California's environment

MERCED, CA — It seeps into our groundwater supply. It has accumulated in agricultural soils through its use as a pesticide. Few people could say what it is exactly, but the mere name sounds dangerous and lethal - arsenic.

How arsenic and other dangerous heavy metals travel through the environment and are sometimes concentrated in certain areas of the soil and groundwater will be a focus of teaching and research for Peggy O'Day, Ph.D. She was recently named Associate Professor in the Division of Natural Sciences at the University of California, Merced - the newest campus of the UC system and the first major research university to be built in the 21st century.

O'Day says subsurface rocks and groundwater filter elements such as arsenic, selenium and mercury on the micro- and macroscopic levels. While these elements are often naturally occurring, some of the more dense occurrences are due to human activity.

"Arsenic had many uses prior to the 20th century and was a common ingredient in paints, cosmetics and curatives," says O'Day. "What's worrisome is that an element such as arsenic does not break down into something else with time - it may change its chemical form, but the element is still there."

In some areas of California's fertile Central Valley, arsenic-laced pesticides and herbicides were used beginning in the early 1900s until the mid-1980s, resulting in some dangerous concentrations of the element in groundwater and soils. Although arsenic's use in pesticides in the United States has been discontinued, it is still widely used as a wood preservative in the form of chromium copper arsenate. In addition, arsenical pesticides are still used liberally in many countries worldwide.

In coming to UC Merced, O'Day will continue her research on arsenic remobilization from sediments, which is currently funded by an environmental engineering research grant from the National Science Foundation. She is currently studying arsenic behavior in the environment at two sites in California - in East Palo Alto at the edge of the San Francisco Bay and in a reservoir in the Owens Valley that is part of the Los Angeles Aqueduct System.

O'Day says that more research on metal cycling in the environment should be done in California - in both the Sierra Nevada foothills and the Central Valley. "Mercury was commonly used during the Gold Rush era, and continues to be present throughout the foothills of California. Selenium is another topic that calls for much more research due to the toxic levels found throughout California's Central Valley," she says.

As a distinguished geochemist and a leading researcher in geochemical processes, O'Day comes to UC Merced from Arizona State University, where she has taught and conducted research for the past nine years in the Departments of Geological Sciences and Chemistry & Biochemistry. She obtained a doctorate in applied earth sciences at Stanford University in 1992, a master's degree in geological sciences at Cornell University, and a bachelor's of science degree with honors in geology at the University of California, Davis.

"Dr. O'Day's research is supported by a number of federal agencies because she brings outstanding leadership and innovation to diagnose problems and to develop solutions," says Dean of Natural Sciences Maria Pallavicini. "Together with other faculty, she will create a stellar program in molecular-level environmental science at UC Merced."

Fellow scientist and geochemist, Susan Carroll, Ph.D., of the Lawrence Livermore Lab, has worked with O'Day on a multitude of projects during the past 10 years, in settings that vary from well-controlled laboratories to extensive fieldwork.

"Peggy constantly comes up with new ideas to solve scientific problems," says Carroll. "She is an innovative pioneer in the application of sophisticated x-ray absorption spectroscopy to understand the behavior of metals at mineral surfaces."

Adds Director of UC Merced's Sierra Nevada Research Institute Sam Traina, "As a world-class geochemist, Dr. O'Day will bring critical knowledge and skills to UC Merced. Her research will be critical to our understanding of the cycles and transformations of nutrients and pollutants in natural and disturbed ecosystems."

In joining the founding faculty at UC Merced, O'Day says she sees tremendous potential to develop a unique, cross-disciplinary educational setting for students and faculty. "Helping students understand the connections between chemistry and math, for example, will be very exciting for me as a teacher."

O'Day's other research interests include: the study of the behavior of strontium and cesium in subsurface sediments related to their release as radionuclides at Department of Energy sites (such as in Hanford); applications of spectroscopic and microscopic methods to understanding the chemical behavior and cycling of elements in the environment as contaminants and nutrients; health and ecological impacts of metals in the environment; and biogeochemical interactions between mineral surfaces, fluids, and microorganisms in seafloor hydrothermal systems.

UC Merced will welcome its first 1,000 students in fall of 2004, with an eventual student capacity of 25,000. Initial undergraduate degree programs will include computer science and engineering,

environmental engineering, biological sciences, earth systems sciences, world cultures and history, and social and behavioral sciences. Masters and doctoral degrees will be offered in computer and information systems, environmental systems, systems biology, world cultures, and social and behavioral sciences.

UC Merced, the 10th campus of the University of California system, is the first major research university to be built in the United States in the 21st century. Over the coming decades, the campus is expected to grow to a student population of 25,000. UC Merced will serve students in three ways that complement the changing needs of today's society: 1) a residential campus serving 25,000 students when complete; 2) educational centers throughout the San Joaquin Valley; and 3) cooperative agreements with the California Community College system.

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