Toxicity of Nitro-Heterocyclic and Nitroaromatic Energetic Materials to Terrestrial Plants in a Natural Sandy Loam Soil

摘要

The United States Environmental Protection Agency is developing ecological soil screening level (Eco-SSL) values for ecological risk assessment of contaminants at Superfund sites. Insufficient information for RDX, HMX, 2,4- DNT, 2,6-DNT, and TNB to generate Eco-SSLs for terrestrial plants necessitated toxicity testing to fill the data gaps. Standardized toxicity tests were selected and used, on the basis of their ability to measure chemical toxicity to ecologically relevant test species, and their inclusion of growth component among the measurement endpoints. Tests were conducted in Sassafras sandy loam soil, which supports relatively high bioavailability of the energetic materials. Weathering/aging of amended treatment soil was incorporated in the study to better reflect the exposure conditions in the field soils. Definitive toxicity tests conducted with freshly amended and weathered/aged amended soils generated eco-toxicological benchmarks, including EC20 values for growth that can be used for Eco-SSL development. These study results will be provided to the Eco-SSL workgroup for review and for developing ecological soil screening levels (Eco-SSLs) for RDX, HMX, 2,4-DNT, 2,6-DNT, and TNB.