Hsu-Kim Receives DOE Award

By Richard Merritt

Heileen Hsu-Kim believes that before scientists can solve the big-picture issue of protecting people and the environment from the harmful effects of mercury, they need to see the small picture.

The very small picture.

She would like to like know exactly what happens when naturally-occurring or man-made mercury first reaches the sediments on the bottom of oceans or lakes and then gets taken in by a microbe. For her, this is the key step in a process that ultimately finds the microbe being eaten by a larger organism, and then another, all the way up the food chain – with the mercury accumulating each step of way.

“We all know that certain forms of mercury are toxic and what they can do living things,” said Hsu-Kim, assistant professor of civil and environmental engineering. “But we don’t totally understand the processes within the sediments that create dangerous forms of mercury. Before we can develop effective remediation strategies for mercury, we really need to see what happening at the nano-scale.”

Her approach to gaining insights into this crucial first-step is now being supported by a five-year, $760,000 Early Career Research Award from the Department of Energy (DOE). Out of the pool of about 1,150 university- and national laboratory-based applicants, 65 were selected this year for funding.

Hsu-Kim plans to spend the next five years teasing out all the subtle biochemical reactions and microbial influences that occur within the sediments to cause the formation of methymercury, a form that is readily taken in by living things.

“This information will ultimately be used to establish a new geochemical framework for predicting mercury methylation potential in contaminated sediments,” she said, ushering in a new field she terms nano-geochemistry.

Her award comes from the Office of Biological and Environmental Research, one of the six offices supporting young investigators who focus on research areas that are a high priority for the DOE. She will also be working with researchers in Duke’s Center for the Environmental Implications of NanoTechnology (CEINT) on this project.

Hsu-Kim has been on the Duke faculty since 2005, after completing a postdoctoral fellowship at the University of Delaware and graduate degrees from the University of California, Berkley.