Atmospheric lead deposition to Okefenokee Swamp, Georgia, USA
Brian P. Jacksona, Parley V. Wingerb, Peter J. Lasierb
aAdvanced Analytical Center for Environmental Sciences, Savannah
River Ecology Laboratory, University of Georgia, PO Drawer E, Aiken, SC
29802, USA
bUS Geological Survey, Patuxent Wildlife Research Center, Warnell
School of Forest Resources, University of Georgia, Athens, GA 30602, USA
Received 29 April 2003; accepted 19 December 2003
" Capsule": Coal combustion emissions appear
to be a major source of Pb in the Okefenokee wetland.
Abstract
Contamination of the environment from atmospheric deposition during the
twentieth century is pervasive even in areas ostensibly considered pristine
or remote from point sources. In this study, Pb concentrations in a 210Pb-dated
peat core collected from the Okefenokee Swamp, GA were used to assess
historical contaminant input via atmospheric deposition. Lead isotope
ratios were determined by dynamic reaction cell ICP-MS (DRC-ICP-MS). Increases
in Pb concentration occurred in the late nineteenth century and a marked
rise in Pb concentrations pre-dated the widespread use of leaded gasoline
within the US. The 206Pb/207Pb ratios of 1.19 during
this period were consistent with coal combustion emissions. A later increase
in Pb concentration, concurrent with a trend toward more radiogenic 206Pb/207Pb
ratios in gasoline is consistent with an increased input of Pb from leaded
gasoline emissions. However, it appears that coal combustion emissions
remain a major source of Pb to the Okefenokee.
SREL Reprint #2773
Jackson, B. P., P. V. Winger and P. J. Lasier. 2004. Atmospheric lead deposition to Okefenokee Swamp, Georgia, USA. Environmental Pollution 130:445-451.
