Toxicities of dinitrotoluenes and trinitrobenzene freshly amended or weathered and aged in a sandy loam soil to <i>enchytraeus crypticus</i>

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The authors investigated individual toxicities of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to the potworm Enchytraeus crypticus using the enchytraeid reproduction test. Studies were designed to generate ecotoxicological benchmarks that can be used for developing ecological soil-screening levels for ecological risk assessments of contaminated soils and to identify and characterize the predominant soil physicochemical parameters that can affect the toxicities of TNT and RDX to E. crypticus. Soils, which had a wide range of physicochemical parameters, included Teller sandy loam, Sassafras sandy loam, Richfield clay loam, Kirkland clay loam, and Webster clay loam. Analyses of quantitative relationships between the toxicological benchmarks for TNT and soil property measurements identified soil organic matter content as the dominant property mitigating TNT toxicity for juvenile production by E. crypticus in freshly amended soil. Both the clay and organic matter contents of the soil modulated reproduction toxicity of TNT that was weathered and aged in soil for 3 mo. Toxicity of RDX for E. crypticus was greater in the coarse-textured sandy loam soils compared with the fine-textured clay loam soils. The present studies revealed alterations in toxicity to E. crypticus after weathering and aging TNT in soil, and these alterations were soil- and endpoint-specific.

Section: Discussionsupporting

confidence: 77%

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 Enchytraeus crypticus

Kuperman

Checkai

Simini

et al. 2013

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“…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%

“…These procedures allowed us to more accurately approximate the exposure conditions for soil biota in the field, compared with tests conducted with freshly amended chemicals or tests conducted following a short equilibration period (e.g., 24 h) [22][23][24][25][26]28]. The range-finding tests were conducted to determine Se concentrations for the definitive toxicity testing.…”

Section: Soil Treatmentsmentioning

confidence: 99%

“…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%

“…We have developed procedures that simulate, at least partially, the natural weathering and aging processes for chemicals in soil. These procedures allowed us to more accurately approximate the exposure conditions for soil biota in the field, compared with tests conducted with freshly amended chemicals or tests conducted following a short equilibration period (e.g., 24 h) [22][23][24][25][26]28]. Before definitive toxicity testing was conducted, samples of each freshly amended soil were hydrated with ASTM International type I water to 60% of the water-holding capacity to commence weathering and aging of Se in soil in open, chemically inert containers.…”

Section: Soil Treatmentsmentioning

confidence: 99%

See 2 more Smart Citations

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

Kuperman¹,

Checkai²,

Simini³

et al. 2018

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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.

Inhibition of soil microbial activity by nitrogen‐based energetic materials

Kuperman¹,

Minyard

Checkai³

et al. 2017

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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.