Soil properties affect the toxicities of 2,4,6‐trinitrotoluene (TNT) and hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX) to the enchytraeid worm <i>Enchytraeus crypticus</i>

An initiative within the US military is targeting the replacement of traditional munitions constituents with insensitive munitions to reduce the risk of accidental detonation. The bioavailability and bioaccumulative potential of the insensitive munitions compound 2,4-dinitroanisole (DNAN) to Eisenia fetida was assessed in soils with different geochemical characteristics. Prior to exposure, soils were chemically spiked with DNAN and aged for 1 wk or 29 wk. Transformation products 2- and 4-amino-nitroanisole (2A-4NAN and 4A-2NAN) occurred in aged soils and their porewater but never at concentrations higher than the residual DNAN. The sum of DNAN, 2A-4NAN, and 4A-2NAN (sumDNAN) in soil decreased with aging, likely by irreversible binding. Both clay and organic matter contents of the soil appeared to affect the bioavailability of DNAN. The sumDNAN body residues of earthworms approached apparent steady state after 1 d and remained relatively constant through to day 7. Higher concentrations of 2A-4NAN and 4A-2NAN measured in worm tissues relative to those in soil suggest reductive transformation of DNAN in the tissues. Mean bioaccumulation factors (ratio of tissue to soil concentrations) varied from 1.2 to 4.3, whereas mean bioconcentration factors (ratio of tissue to porewater concentrations) ranged from 1.4 to 3.2. Porewater seems to play a significant role in the accumulation of DNAN in earthworms, consistent with equilibrium partitioning theory. The concentration of DNAN in soil porewater could serve as an indicator of bioavailability as well as a predictor of the concentration of that compound in earthworms. Environ Toxicol Chem 2016;35:1835-1842. Publlished 2015 SETAC. This article is a US Government work, and as such, is in the public domain in the United States of America.

Section: Resultssupporting

confidence: 62%

Accumulation of 2,4‐dinitroanisole in the earthwormEisenia fetidafrom chemically spiked and aged natural soils

Lotufo

Coleman

Harmon

et al. 2016

“…Juvenile production was the more sensitive measurement endpoint for assessing Se toxicity to E. crypticus compared with adult survival, which comports with results of our previous studies [21][22][23][25][26][27]. Adult survival was significantly (p < 0.0001) decreased at the 11.35 mg/kg (bounded LOEC) treatment compared with the negative control.…”

Section: Se Toxicity To Soil Invertebratessupporting

confidence: 85%

“…Natural soil, Sassafras sandy loam (fine-loamy, siliceous, mesic Typic Hapludults) [20], was collected from an open grassland field in the coastal plain on the property of the US Army Aberdeen Proving Ground (Harford County, MD, USA). This soil was selected for developing ecotoxicological values protective of soil organisms because 1) it was previously used to establish ecotoxicological benchmarks for organic and inorganic chemicals in standardized soil invertebrate toxicity tests [21][22][23][24][25][26][27][28], and 2) it has physical and chemical characteristics that support qualitatively "high" relative bioavailability for metals in natural soils [18]. The pH of this slightly acidic soil was adjusted to represent conditions of an alkaline aerobic upland soil, to promote the formation of water-soluble forms of Se [29], thus increasing the relative bioavailability of Se [18] in toxicity tests.…”

Section: Soil Collection and Characterizationmentioning

confidence: 99%

Selenium toxicity to survival and reproduction of Collembola and Enchytraeids in a sandy loam soil

Kuperman¹,

Checkai²,

Simini³

et al. 2018

Self Cite

We investigated the toxicity of selenium (Se) to the soil invertebrates Folsomia candida (Collembola) and Enchytraeus crypticus (potworm). Studies were designed to generate ecotoxicological benchmarks for developing ecological soil screening levels (Eco-SSLs) for risk assessments of contaminated soils. For the present studies, we selected Sassafras sandy loam, an aerobic upland soil with soil characteristics (low levels of clay and organic matter, soil pH adjusted from 5.2 to 7.1) that support high relative bioavailability of the anionic Se species that is typically found in aerobic soil. The Se was amended into soil as sodium selenate, subjected to weathering and aging using 21 d of alternating cycles of air-drying/rehydration to 60% of the water-holding capacity of the Sassafras sandy loam soil, under ambient greenhouse conditions. Effective concentrations at 20 and 50% (EC20 and EC50) levels for production of juveniles (reproduction) were 4.7 and 10.9 mg of Se/kg of soil (dry mass basis), respectively, for Collembola, and 4.4 and 6.2 mg/kg, respectively, for the potworms. The data enabled the derivation of toxicity benchmarks, contributing to the development of a soil invertebrate-based Eco-SSL of 4.1 mg/kg for Se. Environ Toxicol Chem 2018;37:846-853. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

“…Also, these results clearly demonstrate that toxicity benchmarks for EMs and the corresponding activity‐based soil screening concentrations and ecological soil cleanup values can be reliably established for soil biological processes, and comply with stipulations and requirements developed for Eco‐SSL values . The toxicity benchmarks for 2,4‐DNT, 2‐ADNT, 4‐ADNT, and NG developed in the present study for the soil microbial activity endpoints can complement and expand on the ecotoxicological significance of data from the standardized single‐species toxicity tests with soil invertebrates and terrestrial plants developed in other studies .…”

Section: Discussionmentioning

confidence: 90%

Inhibition of soil microbial activity by nitrogen‐based energetic materials

Kuperman¹,

Minyard

Checkai³

et al. 2017

Self Cite

We investigated individual toxicities of the nitrogen-based energetic materials (EMs) 2,4-dinitrotoluene (2,4-DNT); 2-amino-4,6-dinitrotoluene (2-ADNT); 4-amino-2,6-dinitrotoluene (4-ADNT); and nitroglycerin (NG) on microbial activity in Sassafras sandy loam (SSL) soil, which has physicochemical characteristics that support very high qualitative relative bioavailability for organic chemicals. Batches of SSL soil for basal respiration (BR) and substrate-induced respiration (SIR) assays were separately amended with individual EMs or acetone carrier control. Total microbial biomass carbon (biomass C) was determined from CO production increases after addition of 2500 mg/kg of glucose-water slurry to the soil. Exposure concentrations of each EM in soil were determined using US Environmental Protection Agency method 8330A. Basal respiration was the most sensitive endpoint for assessing the effects of nitroaromatic EMs on microbial activity in SSL, whereas SIR and biomass C were more sensitive endpoints for assessing the effects of NG in soil. The orders of toxicity (from greatest to least) were 4-ADNT > 2,4-DNT = 2-ADNT > NG for BR; but for SIR and biomass C, the order of toxicity was NG > 2,4-DNT > 2-ADNT = 4-ADNT. No inhibition of SIR was found up to and including the greatest concentration of each ADNT tested in SSL. These ecotoxicological data will be helpful in identifying concentrations of contaminant EMs in soil that present acceptable ecological risks for biologically mediated processes in soil. Environ Toxicol Chem 2017;36:2981-2990. Published 2017 Wiley Periodicals Inc. on behalf of SETAC.This article is a US government work and, as such, is in the public domain in the United States of America.