Spatial and temporal patterns of mercury accumulation in lacustrine sediments across the Laurentian Great Lakes region

A high resolution study of spatial and temporal variability of natural and anthropogenic compounds in offshore Lake Superior sediments

“…Relatively high THg ARs in several cores were observed in the 1960-90 period (Fig. 8C), which is consistent with dates of peak accumulation in observations across the entire Great Lakes region (Drevnick et al, 2011;Engstrom and Swain, 1997). THg AR dropped by an average of 25% in five of eight cores after their peak until 2000, after which they were static or perhaps even slightly increasing.…”

Lead isotopes as particulate contaminant tracers and chronostratigraphic markers in lake sediments in northeastern North America

“…Gaseous elemental mercury exists in the atmosphere significantly longer than particulate Hg, so the source of Hg to Fairbanks Lake could be from a wide geographical range of sources. The Hg flux profile is consistent with fossil fuel and smelter Hg emissions for all of North America (Pirrone et al, 1998) and for this region (Drevnick et al, 2012).…”

Soil mercury and its response to atmospheric mercury deposition across the northeastern United States

“…The historical record obtained from paleolimnological studies suggests that atmospheric Hg deposition has increased steadily (two-to three-fold) since the onset of industrialization until the late 1900s (Swain et al 1992, Fitzgerald et al 1998, Lorey and Driscoll 1999, Schuster et al 2002, Biester et al 2007). Studies have also indicated that regional Hg deposition has decreased in recent decades, which is coincident with efforts to control Hg emissions in North America (Engstrom and Swain 1997, Drevnick et al 2011, Schmeltz et al 2011. Studies suggest that Hg deposition Notes: The deposition before industrialization (,1850) was considered to be steadfast at each of the subregions.…”

“…peaked around the 1890s due to mining, and again in the 1970s largely due to coal combustion (Streets et al 2011, Amos et al 2013, then declined recently (a 25% decrease rate from the 1970s to current flux suggested by Driscoll et al 2007 andDrevnick et al 2011). Hence, we reconstructed historical total Hg deposition in each subregion (Fig.…”