Rates of mercury methylation and methylmercury demethylation in wetlands near Hamilton Army Airfield on San Francisco Bay

摘要

Rates of mercury methylation and demethylation were measured in a coastal wetland using stable isotopes of mercury and methylmercury. After incubation intact cores for a period of 5 hours, measured methylation rates varied from 0.05 to 1.5 percent of the injected 199Hg(II) isotope. While ambient levels of total mercury averaged 350 ng/g and were quite consistent between 0 and 10 cm depth, levels of ambient methylmercury varied quite dramatically from 0.2 to 3.8 ng/g.