MERCURY INCREASES IN LAKE TANGANYIKA SINCE ~1880

A series of sediment cores were collected in Lake Tanganyika, Africa, and were analyzed for mercury concentrations. A general trend is observed in each of the three cores that were studied. A decrease in mercury levels was observed from the 1600’s (appx. 20 ng/g) until concentrations reached a minimum during the mid-1800’s (appx. 10 ng/g). This decrease is likely driven, at least in part, by dilution with carbonate phases, which increase over this time period. The mid-1800’s marks a change from the decreasing mercury levels to an increase over the following century. The most recent results (circa 2006) show a rise in concentration to over 70 ng/g. The rise in mercury concentrations coincides with the beginning of the Industrial Revolution, which began in the mid to late 18^th century. Close correlations between δ¹³C values in carbonates and Hg concentrations suggest that the mercury levels in this system are likely dominated by fossil fuel combustion rather than other anthropogenic impacts.