Organic Pollutants in Sediment Core Archives

Abstract

A review. Org. contaminant profiles in lake and marine sediment cores are important for understanding the persistence of pollutants in aquatic ecosystems, as well as for evaluating the success of emission restrictions and regulations. Several different classes of org. contaminants can be reconstructed from cores. The earliest studies measured PCBs, DDT, and polycyclic arom. hydrocarbons, but paleolimnol. approaches are now common for a suite of organochlorines and brominated flame retardants, as well as emerging studies on fluorinated persistent org. pollutants and historical sewage indicators (fecal sterols). In order for the history of org. contaminant inputs to be successfully reconstructed from sediment cores, the contaminant must have a high affinity for sedimentary particulates and low water soly., ensuring its rapid delivery and incorporation into the sediment record, and minimal porewater migration once it is deposited. In addn., the compd. must be resistant to microbial degrdn. and post-depositional transformation, so that any changes in compn. and abundance down-core may be confidently attributed to changing contaminant inputs to the aquatic environment. Using several independent lines of evidence, we review the reliability of sediment cores as historical archives for organochlorines, brominated flame retardants, perfluoroalkyl substances, polycyclic arom. hydrocarbons, and fecal sterols. The objective of this chapter is to provide a framework for researchers to critically evaluate the reliability of sediment cores for reflecting historical inputs of legacy and emerging org. contaminants. [on SciFinder(R)]