ARB Research Seminar

This page updated July 24, 2013

Atmospheric Perspective on Toxic Metal Deposition to Water Bodies and Water Sheds

James J. Schauer, Ph.D., P.E., Associate Professor, University of Wisconsin-Madison

October 26, 2006
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA



Although atmospheric depositions of toxic metals are believed to be important contributors to the total burden of metal inputs to many water bodies and water sheds, it is often difficult to quantify the total atmospheric deposition of these metals and their sources. Although wet deposition fluxes are relatively easy to measure, it is much harder to identify the sources of the depositing metals. Dry deposition fluxes are much more difficult to quantify and therefore also present challenges for source attribution. Most efforts to link sources of depositing toxic metals seek to directly link the deposition fluxes to sources without measurement of atmospheric concentrations. The advantages of decoupling atmospheric transport and source apportionment from deposition velocity rates allows tools developed in the atmospheric science fields to better quantify sources of deposition than can typically be obtained from a direct measurement of only deposition rates. The atmospheric measurement and analysis tools that can help understand the sources and deposition of metals that impact water bodies will be discussed.

To highlight the importance of understanding the atmospheric source-receptor relationships in quantifying sources of toxic metal deposition, two recent atmospheric studies will be presented. The first study examines the emissions of toxic metals from mobile sources, which provides important inputs to atmospheric transport models to predict toxic metal deposition and provides insight into the speciation of metals emitted from mobile sources. The second study examines the dynamics and sources of atmospheric mercury in LA Basin.

Speaker Biography

James J. Schauer, Ph.D., P.E., is an Associate Professor in the Environmental Chemistry and Technology Program and the Civil and Environmental Engineering Program at the University of Wisconsin-Madison, and serves as the Director of the Water Science and Engineering Laboratory at the University of Wisconsin. He received his Ph.D. in Environmental Engineering Science from the California Institute of Technology, his MS in Environmental Engineering from the University of California at Berkeley and his BS degree in Chemical and Petroleum Refining Engineering from the Colorado School of Mines. Dr. Schauer has previously worked in the chemical and petroleum refining industry as a Chemical Process Engineer and has helped commission and start-up large chemical facilities in Asia, Europe, North America, and Africa. Dr. Schauer currently leads an internationally recognized research team that employs advanced chemical analysis and air pollution sampling techniques to understand the chemical composition of source emissions and atmospheric pollutant concentrations. These methods are being used to understand the origin of impact of air pollutants in the urban atmosphere, human health, the ecosystems, and global climate change. Dr. Schauer has authored and co-authored more than 60 peer reviewed manuscripts in leading environmental science, environmental engineering, and air pollution journals in the past 8 years. Prof. Schauer is the 2002 recipient of the Health Effect Institute Rosenblith Award and the 2006 recipient of the American Association for Aerosol Research Kenneth T. Whitby Award. Dr Schauer is honored as a Guest Professor at Peking University (formerly Beijing University) in Beijing, China.

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