Atmospheric lead deposition to Okefenokee Swamp, Georgia, USA.
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.
Jackson
Brian P
BP
Advanced Analytical Center for Environmental Sciences, Savannah River Ecology Laboratory, University of Georgia PO Drawer E, Aiken, SC 29802, USA. jackson@srel.edu
Winger
Parley V
PV
Lasier
Peter J
PJ
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*
D000393:Air Pollutants; D003031:Coal; D012987:Soil; D001335:Vehicle Emissions; D014874:Water Pollutants, Chemical; D007854:Lead