Publication Date


Document Type


Committee Members

Abinash Agrawal (Advisor), Amy Burgin (Committee Member), Chad Hammerschmidt (Committee Member)

Degree Name

Master of Science (MS)


Dimethylmercury (DMHg) has been examined almost exclusively in marine environments to date, plays an uncertain role in the global cycling of Hg, and is produced by a currently unknown mechanism in natural systems. We examined DMHg production in microcosms containing 100 cm3 of freshwater sediment sampled from 3 wetlands and a lake near Dayton, Ohio. DMHg was produced from all sediments analyzed, and found that production is increased significantly by the addition of inorganic Hg from ~0.1pM to ~10pM, its production is unaffected by autoclaving the sediment, and organic carbon additions had no discernible effect on production. Its total concentrations are most likely the result of an interaction between methylating and demethylating processes. These results suggest that DMHg production may be pervasive among freshwater sediments.

Page Count


Department or Program

Department of Earth and Environmental Sciences

Year Degree Awarded