title: Atmospheric lead deposition to Okefenokee Swamp, Georgia, USA.
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.
authors.affiliation: Advanced Analytical Center for Environmental Sciences, Savannah River Ecology Laboratory, University of Georgia PO Drawer E, Aiken, SC 29802, USA. jackson@srel.edu
authors.forename: Brian P
authors.initials: BP
authors.lastname: Jackson
authors.forename: Parley V
authors.initials: PV
authors.lastname: Winger
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Lasier
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000266:history*; D003031:Coal / Q000266:history; D004784:Environmental Monitoring / Q000379:methods; D019015:Geologic Sediments / Q000032:analysis; D005845:Georgia; D049673:History, 20th Century; D007854:Lead / Q000032:analysis*; D012987:Soil / Q000032:analysis*; D001335:Vehicle Emissions; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D003031:Coal; D012987:Soil; D001335:Vehicle Emissions; D014874:Water Pollutants, Chemical; D007854:Lead