Historical atmospheric lead and other trace elements deposition records in an ombrotrophic peat pocosin: A new record from North Carolina.

摘要

Human activities introduce pollutant elements into the atmosphere, from which they enter sedimentary environments via precipitation and dry deposition. In this study, pocosin peat in eastern North Carolina was used to track the sources of atmospherically deposited trace elements. Peat chronology was based on 210Pb and fallout 137Cs. Concentrations, accumulation rates and enrichment factors for twenty-five elements, along with Sr and Pb isotopic compositions, were obtained. The results show that local leaded gasoline usage dominated the lead source. However, other anthropogenic sources such as coal combustion, mining, and agricultural development may have also introduced Pb and other trace elements through windblown dust. Sr isotopes require sources more radiogenic than seawater Sr; twentieth century Pb isotopes are consistent with predominant input from gasoline lead and coal combustion. The pocosin record of lead is similar to published records from the eastern United States and Western Europe, but contrasts with those from Asia.