P. V. Winger P. J. Lasier B. P. Jackson 2004 <p><span>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 ⁰⁶Pb/²⁰⁷Pb ratios in gasoline is consistent with an increased input of Pb from leaded gasoline emissions remain a major source of Pb to the Okefenokee.</span></p> application/pdf 10.1016/j.envpol.2003.12.019 en Elsevier Atmospheric lead deposition to Okefenokee Swamp, Georgia, USA article