T8 AM Ecological Fate and Effects of Explosives and Related Compounds
Tuesday, 15 November 2005: 8:00 AM - 11:40 AM in 337-338

(CON-1117-762533) Fate and Toxicity of Explosives in Sediments.

Conder, J¹, Lotufo, G², ¹ ENVIRON International Corporation, Irvine, CA, USA² U.S. Army Corps of Engineers, Vicksburg, MS, USA

ABSTRACT- Contamination of sediment and surface water with explosives (e.g., TNT, TNB, RDX, HMX, picric acid, and tetryl) is associated with military activities at ammunition production sites and military training facilities. We present an overview of the fate and toxicity of sediment-associated explosives and related compounds, including a review of the adverse biological effects of explosive compounds and their transformation products to benthic invertebrates exposed to spiked sediments and corresponding pore waters. The assessment of the fate and effects of explosives that undergo rapid transformation when added to sediment in laboratory toxicity experiments has been challenging, complicating development of accurate reference and screening values for use in ecological risk assessment. Extrapolating ecological risks at contaminated sites from laboratory-based toxicity benchmark values to field situations is burdened with high uncertainty due to the unknown fate and toxicity of aged explosives in field sediments. Although there are reports of high levels of sediment contamination by explosives, lack of information on spatial distribution, bioavailability, and toxicity of sediment-associated explosives in historically-contaminated military and active training sites precludes an accurate evaluation of the local and global environmental significance of the presence of explosives in aquatic systems. Future studies should be designed to characterize the temporal nature of the dose-response relationship in spike-sediment studies with explosives, establish experimental data that enables comparisons of the bioaccumulation and toxicity of explosive compounds to benthic invertebrates belonging to different functional groups, and provide data that allows comparisons of the toxicity of explosives in spiked and field-collected sediments. The use of biomimetic devices (e.g., solid phase microextraction fibers) as tools in meeting many of these challenges will be discussed.

Key words: sediment, transformation, explosives, toxicity testing