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PROCEDURES FOR DERIVING EQUILIBRIUM PARTITIONING SEDIMENT BENCHMARKS (ESBS) FOR THE PROTECTION OF BENTHIC ORGANISMS: ENDRIN
Citation:
BURGESS, R. M. PROCEDURES FOR DERIVING EQUILIBRIUM PARTITIONING SEDIMENT BENCHMARKS (ESBS) FOR THE PROTECTION OF BENTHIC ORGANISMS: ENDRIN. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-02/009 (NTIS PB2004-1204047), 2002.
Description:
This equilibrium partitioning sediment benchmark (ESB) document describes procedures to derive concentrations of the insecticide endrin in sediment which are protective of the presence of benthic organisms. The equilibrium partitioning (EqP) approach was chosen because it accounts for the varying biological availability of chemicals in different sediments and allows for the incorporation of the appropriate biological effects concentration. This provides for the derivation of benchmarks that are causally linked to the specific chemical, applicable across sediments, and appropriately protective of benthic organisms.
EqP can be used to calculate ESBs for any toxicity endpoint for which there are water-only toxicity data; it is not limited to any single effect endpoint. For the purposes of this document, the Final Chronic Value (FCV) from the Water Quality Criterion (WQC) for endrin was used as the toxicity benchmark. This value is intended to be the concentration of a chemical in water that is protective of the presence of aquatic life. The ESBWQC is derived by multiplying the FCV by the chemical's KOC, yielding the concentration in sediment (normalized to organic carbon) that should provide the same level of protection in sediment that the FCV provides in water. For endrin, this concentration is 5.4 g endrin/gOC for freshwater sediments and 0.99 g/gOC for saltwater sediments. Confidence limits of 2.4 to 12 g/gOC for freshwater sediments and 0.44 to 2.2 g/gOC for saltwater sediments were calculated using the uncertainty associated with the degree to which toxicity could be predicted by multiplying the KOC and the water-only effects concentration. The ESBWQCs should be interpreted as chemical concentrations below which adverse effects are not expected. At concentrations above the ESBWQCs, effects may occur with increasing severity as the degree of exceedance increases. These benchmarks do not protect against additive, synergistic, or antagonistic effects of contaminants or bioaccumulative effects to aquatic life, wildlife, or human health.