Recent increase in atmospheric deposition of mercury to California aquatic systems inferred from a 300-year geochronological assessment of lake sediments

Journal Article · Tue Jan 08 04:00:00 EST 2008 · Applied Geochemistry, 23(3):399-407

DOI:https://doi.org/10.1016/j.apgeochem.2007.12.021· OSTI ID:1004836

Sanders, Rhea D; Coale, Kenneth H; Gill, Gary A; Andrews, Alen H; Stephenson, Mark

Age-dated sediment cores from 4 remote lakes across California were analyzed for total Hg (HgT) concentration as a function of pre- and post-industrialization. Particle size, magnetic susceptibility and organic C and N, were measured to determine if the Hg concentration in sediment cores could be related to atmospheric deposition and/or watershed processes. Results indicate that (a) for each lake modern (1970–2004) HgT lake sediment concentrations have increased by an average factor of 5 times more than historic (pre-1850) HgT concentrations; (b) the ratio of modern to pre-industrial lake sediment HgT for these lakes are higher than estimated for other locations where atmospheric deposition is presumed to be the main source of Hg; (c) 2 of the 4 studied lakes demonstrated significant relationships between HgT concentrations and percentage organic material (r2 = 0.68 and p < 0.01; r2 = 0.67 and p < 0.01) whereas the other two indicated no significant relationship (r2 = 0.05 and p = 0.51; r2 = 0.12 and p = 0.36).

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1004836
• Report Number(s): PNNL-SA-77275
• Journal Information: Applied Geochemistry, 23(3):399-407, Journal Name: Applied Geochemistry, 23(3):399-407 Journal Issue: 3 Vol. 23; ISSN 0883-2927; ISSN APPGEY
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CALIFORNIA
DEPOSITION
LAKES
MAGNETIC SUSCEPTIBILITY
MERCURY
PARTICLE SIZE
SEDIMENTS
WATERSHEDS