Munition constituents: Preliminary sediment screening criteria for the protection of marine benthic invertebrates.

Sediment screening criteria for many munition constituents (MC) are not available in sources typically used in regulatory-driven ecological risk assessments for contaminated sediment sites. Preliminary sediment quality benchmarks (SQBs) for MC were developed for screening potential risks to marine benthic invertebrates at a munitions contaminated sediment site in Puget Sound, WA, USA. SQBs were developed for 2,4,6-trinitrotoluene (TNT) and 13 breakdown products; six other explosive nitroaromatic compounds and nitramines (e.g., RDX, HMX); and five propellants, plasticizers, and stabilizers. The SQBs were developed using freshwater and limited marine aquatic toxicity values (and hence are considered preliminary) and equilibrium partitioning theory to relate water concentrations of the compounds to sediment concentrations. The SQBs are derived from the lowest available aquatic toxicity values for aquatic invertebrates from published reviews, original studies, and database sources; ranges of logK(ow) and K(oc) values from published reviews and database sources, and some K(oc) values calculated from logK(ow). SQBs are presented for 25 MC as organic carbon-normalized values and as ranges of dry weight values for various levels of organic carbon content of sediments. Comparison of the preliminary SQBs with method detection limits and sample detection limits achieved at the contaminated sediment site demonstrates their utility in risk screening of benthic invertebrates.