Modern and historic atmospheric mercury fluxes in northern Alaska: Global sources and Arctic depletion.
We reconstruct from lake-sediment archives atmospheric Hg deposition to Arctic Alaska over the last several centuries and constrain a contemporary lake/watershed mass-balance with real-time measurement of Hg fluxes in rainfall, runoff, and evasion. Results indicate that (a) anthropogenic Hg impact in the Arctic is of similar magnitude to that at temperate latitudes; (b) whole-lake Hg sedimentation determined from 55 210Pb-dated cores from the five small lakes demonstrates a 3-fold increase in atmospheric Hg deposition since the advent of the Industrial Revolution; (c) because of high soil Hg concentrations and relatively low atmospheric deposition fluxes, erosional inputs to these lakes are more significant than in similar temperate systems; (d) volatilization accounts for about 20% of the Hg losses (evasion and sedimentation); and (e) another source term is needed to balance the evasional and sedimentation sinks. This additional flux (1.21+/-0.74 microg m(-2) yr(-1)) is comparable to direct atmospheric Hg deposition and may be due to some combination of springtime Arctic depletion and more generalized deposition of reactive gaseous Hg species.
Fitzgerald
William F
WF
Department of Marine Sciences, University of Connecticut, Groton, Connecticut 06340, USA. wfitzger@uconnvm.uconn.edu
Engstrom
Daniel R
DR
Lamborg
Carl H
CH
Tseng
Chun-Mao
CM
Balcom
Prentiss H
PH
Hammerschmidt
Chad R
CR
D000413:Alaska; D001110:Arctic Regions; D001272:Atmosphere; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D049672:History, 19th Century; D049673:History, 20th Century; D008628:Mercury / Q000032:analysis* / Q000266:history*; D014873:Water Pollutants / Q000032:analysis* / Q000266:history*; D014881:Water Supply
D014873:Water Pollutants; D008628:Mercury