Polychlorinated biphenyl contamination trends in Lake Hartwell, South Carolina (USA): Sediment recovery profiles spanning two decades

Department of Environmental Engineering and Science, Clemson University, 342 Computer Court, Anderson, SC 29625, USA.
Chemosphere (Impact Factor: 3.34). 02/2007; 66(10):1821-8. DOI: 10.1016/j.chemosphere.2006.09.013
Source: PubMed

ABSTRACT To assess the ca. 20-year polychlorinated biphenyl (PCB) contamination trends in Lake Hartwell, SC, sediment cores from the Twelve Mile Creek arm were collected in July 2004 at two sites (G30 and G33) first sampled in the mid-1980s. Congener-specific PCB data as a function of depth from the sediment-water interface for the 2004 sediment samples were compared to data obtained from 1987 and 1998 samples taken from the same locations. Despite modest decreases in total PCB levels near the G30 sediment-water interface, historical increases in average degrees of chlorination may elevate the overall toxic risk at this site. Unlike G30, the more rapid recovery in the near-surface sediment of G33 suggests that the effectiveness of the U.S. EPA natural attenuation record of decision is site-specific and is unlikely to result in uniform surface sediment recovery throughout the most contaminated regions of Lake Hartwell.

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    • "Biodegradation half-lives of PCBs in sediments and soils vary from several years to decades (Shelton and Tiedje, 1984; Brown and Wagner, 1990; Lake et al., 1992; Beurskens et al., 1995). Heavy congeners are more persistent in soil due to lower volatility; light congeners degrade more rapidly and migrate faster (Notarianni et al., 1998); dominance of light congeners may be a sign of degradation of heavy congeners (Sivey and Lee, 2007). PCBs may persist at toxic levels in sediments, despite dredging, particularly in downstream reaches of a contaminated river system (Cieniawski and Collier, 2003) and dredging may, increase exposure to PCBs (Martinez et al., 2010). "
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    Chemosphere 11/2014; 114:93–100. DOI:10.1016/j.chemosphere.2014.03.092 · 3.34 Impact Factor
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