Preparation of the sediment guideline document entitled: Equilibrium Sediment Guidelines (ESGs) for the Protection of Benthic Organisms: PAH Mixtures.
(U.S. Environmental Protection Agency)

This equilibrium partitioning sediment guideline document recommends an approach for summing the toxicological contributions of mixtures of 34 PAHs in sediments to determine if their concentrations in any specific sediment would be protective of benthic organisms from their direct toxicity. The EPA chose the equilibrium partitioning approach because it takes into account the varying biological availability of chemicals in different sediments and allows incorporation of the appropriate biological effects concentration to predict the concentration of total PAH in sediment that is protective of benthic organisms. GLEC provided support to revise, complete and publish the PAH mixtures ESG document. The work assignment included writing additional subsections, technically reviewing the document, responding to and performing any necessary revisions, and producing a final draft document for external review.