Slicing a core of lake sediment

Sediment cores from lakes and reservoirs can be used to reconstruct contaminant histories in watersheds. Sediment-core analyses indicate that concentrations of PAHs in many U.S. urban lakes are increasing, and multiple lines of evidence indicate that the source of the PAHs in coal-tar-based pavement sealants. Learn more about coal-tar sealants and PAHs here.