My research interests focus on the transformation and transport of trace elements in the environment. Of particular interest has been the element mercury.
Despite FDA warnings about consumption of seafood due to high mercury concentrations, we know almost nothing about sources of methylmecury to marine fish. The dangers of mercury pollution were first brought to public attention in the 1960s when severe birth defects and neurological disorders were linked to consumption of fish contaminated by mercury waste from an acetaldehyde plant in Minimata, Japan. Since then, scientists have determined that many remote lakes have been contaminated by atmospheric deposition of mercury transported from hundreds of miles away. Globally, much of this atmospheric mercury is emitted by coal-fired power plants and waste incinerators.
My research primarily focuses on identifying and quantifying key chemical and physical transformations of mercury in air and water. This has led me to studies of mercury in dew, fog, aerosols, snow, and even clouds.
Currently my students and I are conducting an EPA funded study of green roofs. We are interested in whether adding living plants to a roof decreases or increases the mercury in the runoff. For more information, visit our green roof page.
Recently, I have become interested in the marine environment, primarily focusing on these questions:
1. What is the primary source of mercury to marine fish?
2. Are marine bacteria capable of methylating mercury, converting it to its most toxic form?
3. How do chemical and physical conversions of mercury in the marine atmosphere affect the deposition of mercury?
4. What are the sources of methylmercury to the atmosphere?
PAST AND CURRENT COLLABORATIONS AND AFFILIATIONS
University of Michigan Air Quality Laboratory
Francois Morel Laboratory, Department of Geosciences, Princeton University
Bess Ward Laboratory, Department of Geosciences, Princeton University
EPA National Exposure Research Laboratory
STUDENT RESEARCH PROJECTS
Adsorption of reactive gaseous mercury onto sea-salt aerosols
Reducing Mercury Contamination with Green Roofs
Effect of Green Roofs on Runoff Water Quality