Toxicity of Selenium, Weathered and Aged in Soil, to the Collembolan Folsomia candida
Final rept. Jul 2002-May 2006
ARMY EDGEWOOD CHEMICAL BIOLOGICAL CENTER APG MD RESEARCH AND TECHNOLOGY DIR
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We investigated the toxicity of selenium Se to the soil invertebrate Folsomia candida using the Folsomia Reproduction Test ISO 112671999. Studies were designed to generate ecotoxicological benchmarks for developing the ecological soil screening levels Eco-SSLs for risk assessments of contaminated soils. For this study, we selected aerobic upland soil, Sassafras sandy loam SSL, with soil characteristics low levels of clay and organic matter, soil pH adjusted high that support high relative bioavailability of the anionic Se species that is typically found in aerobic soil. Se was amended into soil as sodium selenate, subjected to weathering-and-aging using 21 days of alternating cycles of air-dryingrehydration to 60 75 of the water-holding capacity of the SSL soil, under ambient greenhouse conditions. Effective concentration at 20 and 50 EC20 and EC50 levels were 4.7 and 10.9 mg of Sekg of soil, respectively, as determined on the basis of production of juveniles reproduction by F. candida exposed to Se weathered-and-aged in SSL soil. Toxicity benchmarks established in this study were submitted to the U.S. Environmental Protection Agency Eco-SSL Workgroup, and the EC20 value was used in developing soil invertebrate-based Eco-SSL for Se.
- Inorganic Chemistry
- Geology, Geochemistry and Mineralogy