Environmental toxicity testing and chemical analyses of soil were performed as part of an ecological risk assessment at the Joliet Army Ammunition Plant (JAAP), Joliet, Illinois Soils were collected from an area where munitions were loaded, assembled, and packed (area L7, group I), and from an area where waste explosives were burned on unprotected soil (area L2) Control samples were collected from an adjacent field Soil toxicity was determined using early seedling growth and vigor tests, earthworm survival and growth tests, and Microtox@ assays Relative toxicity of soils was determined within each area based on statistical significance ( p = 0 05) of plant and earthworm growth and survival, and the effective concentration at which lu minescence of the bacterium Photobacterium phosphoreum was reduced by 50% (EC50) in the Microtox assay Samples were designated as having high, moderate, or no significant toxicity Soil that had significant toxicity according to at least one test, and representative samples showing no toxicity, were analyzed for munitions via HPLC Chemical residues found in soils were 2,4,6 trinitrotoluene (TNT), 1,3,5 trinitrobenzene (TNB), 2,4 dinitrotoluene (2,4-DNT), 2,6 dinitrotoluene, 2 amino-4,6-DNT, 4-amino-2,6 DNT, 1,3,5 trinitro 1,3,5 triazine (RDX), and octahydro-1,3,5,7 tetranitro-1,3,5,7-tetrazocine (HMX) All soils with no significant toxicity were void of these chemicals However, some soils void of munitions still showed toxicity that may have been caused by elevated levels of heavy metals Linear regressions of toxicity test results vs chemical concentrations showed that TNT and TNB accounted for most of the soil toxicity Lowest observable-effect concentrations (LOEC) of TNT were de termined from these data This study presents a simple, relatively inexpensive methodology for assessing toxicity of soils con taining TNT, RDX, and other contaminants related to munitions production Keywords -Ecological risk assessment ExplosivesTNT RDX

A microcosm technique is presented that uses community and trophic‐level analysis of soil nematodes and microarthropods to determine the effects of chemicals on soil systems. Forest soil was treated with either copper (0, 100, 200, 400, and 600 m̈g g−1), p‐nitrophenol (0, 20, 40, 80, and 160 m̈g g−1), or trinitrotoluene (0, 25, 50, 100, and 200 m̈g g−1). Nematodes were sorted into bacterivore, fungivore, herbivore, and omnivore‐predator trophic groups, and a hatchling category. Microarthropods were sorted to the acarine suborders Prostigmata, Mesostigmata, and Oribatida; the insectan order Collembola; and a miscellaneous group. Omnivore‐predator nematodes and mesostigmatid and oribatid mites were the groups most sensitive to copper and were significantly reduced at levels as low as 100 m̈g g−1 copper. Total nematode and microarthropod numbers declined above 200 m̈g g−1 copper. Trophic structure analysis suggested that high sensitivity of nematode predators to intermediate levels of copper reduced predation on herbivore nematodes and resulted in greater numbers of nematodes compared to controls. p‐Nitrophenol was very toxic to the nematode community, and all trophic groups were significantly reduced above 20 m̈g g−1. However, there was no effect of p‐nitrophenol on microarthropods. Trinitrotoluene had no significant negative effect on total abundance of either group of soil fauna, but oribatids were significantly reduced at 200 m̈g g−1. Our results demonstrated that soil nematodes and microarthropods were sensitive indicators of environmental contaminants and that trophic‐structure and community analysis has the potential to detect more subtle indirect effects of chemicals on soil food‐web structure. We conclude that microcosms with field communities of soil microfauna offer high resolution of the ecotoxicological effects of chemicals in complex soil systems.

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Energetic materials are employed in a wide range of commercial and military activities and often are released into the environment. Scientifically based ecological soil-screening levels (Eco-SSLs) are needed to identify contaminant explosive levels in soil that present an acceptable ecological risk. Insufficient information for 2,4,6-trinitrotoluene (TNT) to generate Eco-SSLs for soil invertebrates necessitated toxicity testing. We adapted the standardized Enchytraeid Reproduction Test and selected Enchytraeus crypticus for these studies. Tests were conducted in Sassafras sandy loam soil, which supports relatively high bioavailability of TNT. Weathering and aging procedures for TNT amended to test soil were incorporated into the study design to produce toxicity data that better reflect the soil exposure conditions in the field compared with toxicity in freshly amended soils. This included exposing hydrated TNT-amended soils in open glass containers in the greenhouse to alternating wetting and drying cycles. Definitive tests showed that toxicity for E. crypticus adult survival and juvenile production was increased significantly in weathered and aged soil treatments compared with toxicity in freshly amended soil based on 95% confidence intervals. The median effect concentration and 20% effective concentration for reproduction were 98 and 77 mg/kg, respectively, for TNT freshly amended into soil and 48 and 37 mg/kg, respectively, for weathered and aged TNT soil treatments. These findings of increased toxicity to E. crypticus in weathered and aged TNT soil treatments compared with exposures in freshly amended soils show that future investigations should include a weathering and aging component to generate toxicity data that provide more complete information on ecotoxicological effects of energetic contaminants in soil.