Expert on mercury contamination in the environment, particularly in the Great Lakes, northern Wisconsin lakes and the Everglades.
- Climate change
- Great Lakes and coastal ecosystems
- Groundwater flow, contamination and quantity
- Mercury as a pollutant.
- Observer, 2010 United Nations Framework Convention on Climate Change in Cancun, Mexico.
- Co-organizer, 2006 8th International Conference on Mercury as a Global Pollutant.
- Member, U.S. Environmental Protection Agency Science Advisory Board, which developed a risk assessment for U.S. mercury emissions.