ABSTRACT

Toxicity to Soil Organisms .............................................................................65 3.6 Stimulating Effects of Energetic Materials ....................................................66 3.7 Mechanisms of Toxicity .................................................................................. 67 3.8 Conclusions and Future Outlook .................................................................... 70 References ................................................................................................................ 72

Many sites associated with military operations that involve munitions manufacturing, disposal, testing, and training can contain elevated levels of energetic materials (EMs) and related compounds in soil. Understanding the impacts of EMs and their products on soil quality, fertility, and structure is essential to protecting and sustaining the ecological integrity of terrestrial ecosystems at these sites. Additionally, it is important to understand how soil physical and chemical properties affect the exposure of soil organisms to EM contaminants. Central to achieving these goals is the need to increase our knowledge of the effects of EMs on soil organisms. These compounds can exert their effects directly through toxicity to terrestrial plants, soil invertebrates and microorganisms, or indirectly by altering specic interactions within the soil biota community, or by disrupting the soil food webs. The intensity and duration of the environmental effects of EMs may depend upon those processes that inuence the fate, persistence, and movement of contaminants through the soil and into soil organisms. Ultimately, these effects can interfere with the regulation, ow, and internal cycling of carbon and nutrients in terrestrial ecosystems and undermine the sustainable use of testing and training ranges at defense installations. This chapter reviews the available information on the effects of EM soil contaminants on the three major components of soil ecosystems, including the soil microbial community and soil processes it regulates, the terrestrial plants, and the soil invertebrates. The fate and biotransformation of explosives in soil (reviewed in Chapter 2) and the effects on organisms inhabiting the aqueous phase of soil ecosystems, such as microalgae and protozoans (reviewed in Chapter 4), are only briey discussed in this chapter.