117 5 Fate and Toxicity of Explosives in Sediments Guilherme R. Lotufo, Marion Nipper, R. Scott Carr, and Jason M. Conder 5.1 INTRODUCTION Contamination of soils, sediment, groundwater, and surface water with explosives is associated with military activities at ammunition production sites and military train- ing facilities. At ammunition plants, this contamination occurs mainly as a result of contaminated runoff, efluent from the facilities, liquid waste lagoons, and spills [1]. Major explosive contaminants such as 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitroben- zene (TNB), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetra- nitro-1,3,5,7-tetrazocine (HMX), and 2,4,6-trinitrophenylmethylnitramine (tetryl) and their transformation products have been detected in freshwater sediment samples collected from military installations at concentrations ranging from low (e.g., less than 6.7 mg kg –1 ) to exceedingly high (up to 711,000 mg kg –1 ) [1]. Those extremely high concentrations (“hot spots”) are indicative of large amounts of nondissolved and nonsorbed explosives in some contaminated sites. Low concentrations (<3.5 mg kg –1 ) of 2,6-dinitrotoluene (2,6-DNT), tetryl, and 2,4,6-trinitrophenol (picric acid) were detected in marine sediments near a naval facility in Ostrich Bay, Puget Sound, Washington [2]. CONTENTS 5.1 Introduction .................................................................................................. 117 5.2 Methodology for Amending Explosives to Sediments ................................. 118 5.3 Fate and Lethal Toxicity of Explosives in Sediment Exposures .................. 119 5.3.1 Trinitrotoluene and Related Compounds .......................................... 119 5.3.2 2,6-Dinitrotoluene (2,6-DNT) .......................................................... 125 5.3.3 2,4,6-Trinitrophenol (Picric Acid) .................................................... 126 5.3.4 2,4,6-Trinitrophenylmethylnitramine (Tetryl) .................................. 127 5.3.5 Cyclic Nitramines ............................................................................. 127 5.4 Effects of Explosives on Reproduction and Growth of Invertebrates .......... 128 5.5 Toxicity of Porewater Extracted from Sediments Spiked with Explosives ..................................................................................................... 128 5.6 The Use of Biomimetic Devices to Assess Explosives Bioavailability ........ 129 5.7 Conclusions and Research Recommendations ............................................. 131 References .............................................................................................................. 133 © 2009 by Taylor and Francis Group, LLC