Acute Toxicity of 2,4,6-Trinitrotoluene in Earthworm (Eisenia andrei) (original) (raw)
Related papers
Chemosphere, 2004
Soils contaminated with 2,4,6-trinitrotoluene (TNT) and TNT primary reduction products have been found to be toxic to certain soil invertebrates, such as earthworms. The mechanism of toxicity of TNT and of its by-products is still not known. To ascertain if one of the TNT reduction products underlies TNT toxicity, we tested the toxicity and bioaccumulation of TNT reduction products. 2-Amino-4,6-dinitrotoluene (2-ADNT), 4-amino-2,6-dinitrotoluene (4-ADNT), 2,4-diamino-6-nitrotoluene (2,4-DANT) and 2,6-diamino-4-nitrotoluene (2,6-DANT) were tested separately in adult earthworms (Eisenia andrei) following a 14-d exposure to amended sandy loam forest soil. TNT, 4-ADNT, and 2-ADNT were lethal to earthworms (14-d LC 50 were: 580, 531 and 1088 lmol kg À1 , or 132, 105 and 215 mg kg À1 dry soil, respectively) and gave the following order of toxicity: 4-ADNT > TNT > 2-ADNT. Exposure to 2,4-DANT and to 2,6-DANT caused no mortality at 600 lmol kg À1 or 100 mg kg À1 dry soil. We found that all four TNT reduction products accumulated in earthworm tissues and 2-ADNT reached the highest levels at 3.0 ± 0.3 lmol g À1 tissue. The 14d bioaccumulation factors were 5.1, 6.4, 5.1 and 3.2 for 2-ADNT, 4-ADNT, 2,4-DANT and 2,6-DANT, respectively. Results also suggest that some TNT metabolites are at least as toxic as TNT and should be considered when evaluating the overall toxicity of TNT-contaminated soil to earthworms. Crown
Environmental Science and Pollution Research, 1999
The effect of ammunition-like compounds and armament waste on the mortality and reproduction of terrestrial invertebrates was assayed by using two biotests: the enchytraeid-biotest with Enchytraeus crypticus and the collembolabiotest with Folsomia candida. Toxicity was investigated by using standard soil (Lufa 2.2) spiked with 2,4,6-trinitrotoluene (TNT), hexahydro-l,3,5-trinitro-l,3,5-triazine (hexogen, RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (octogen, HMX) and 2,4,6~triaminotoluene (TAT). Ecotoxicity was investigated with ammunition-contaminated soil material from the former ammunition plant "Tanne" at Clausthal-Zellerfeld (CTNTla) and the Brandplatz (incineration site) in Torgau-Elsnig (TETNTla), Germany. TNT increased mortality and reduced reproduction of both test organisms corresponding to the concentrations used, whereas hexogen, octogen and TAT had no effect in the tested concentrations (1000-2000 mg/kg). From the two soil materials, TETNTla was much more toxic than CTNTla. The LC50(7d) in the enchytraeid-biotest was 570 mg TNT/kg and the ECS0(28d) 369 mg TNT/kg soil material (dw). In the collembolabiotest the LCS0(7d) was 185 mg TNT/kg and the EC50(28d) 110 mg TNT/kg soil matter (dw).
Archives of Environmental Contamination and Toxicology, 2004
Polynitro-organic compounds such as 2,4,6-trinitrotoluene (TNT) can be released into the environment from production and processing facilities and military firing ranges as well as through field use and disposal practices. Based on laboratory toxicity data, TNT has lethal (at ‡260 mg TNT/kg dry soil) and sublethal effects (at ‡59 mg TNT/kg dry soil) to the earthworm. However, field studies are needed to relate exposure of organisms to explosives in mixed-contaminated soil under field conditions and to define effects-based ecotoxicologic benchmarks for TNT-contaminated soil. In the present study, the lethal and sublethal effects of a 10-day in situ exposure at a TNT-contaminated field site using mesh-bag mesocosms were assessed. In addition to the survival end point, the biomarkers of earthworm exposure and effect-including tissue residues, lysosomal neutral red retention time (NRRT), and total immune activity (TIA)-were measured. Concentrations of TNT in soil mesocosms ranged from 25 to 17,063 mg/kg. Experiments indicated a trend toward decreasing survival of caged Aporrectodea rosea and Eisenia andrei as the concentration of TNT and total nitroaromatic compounds increased. E. andrei tolerated higher concentrations of TNT (up to 4050 mg/kg dry soil) in mesocosms than did indigenous earthworms, who survived only at £1146 mg TNT/kg. Earthworms E. andrei and A. rose survived in 67% and 75% of TNT-contaminated mesocosms, respectively, compared with references groups. NRRT was significantly decreased in surviving earthworms from the contaminated areas compared with those from the reference site. TIA was not affected by field exposure to TNT. Earthworm tissue concentrations of TNT metabolites 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene were not correlated with TNT soil concentrations. In addition, higher tissue concentrations of TNT metabolites were observed at concentrations ranging from 116 to 130 mg TNT/kg soil. The results showed that earthworm exposure in TNT-contaminated soil produced both lethal and sublethal effects in the field. The results of study indicated that mesocosm experiments would be useful to assess the toxicity of a site and to characterize the overall effects of contaminants. However, mesocosm experiments present special considerations (e.g., abiotic factors, exposure period) when used at heterogenous sites, and data must be interpreted with caution.
Archives of …, 2003
Toxicity of 2,4,6-trinitrotoluene (TNT) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) using two terrestrial plant species, lettuce (Lactuca sativa) and barley (Hordeum vugare), was assessed in artificial soil (silica) and forest soil. Lettuce emergence was significantly decreased after 5 days of exposure to TNT nominal spiked concentrations Ն 1,040 mg/kg dry soil in silica. Barley emergence was significantly reduced after 14 days of exposure at initial (t ϭ 0) TNT concentrations Ն 55.9 Ϯ 4.5 mg/kg dry soil in silica and at Ն 291.9 Ϯ 42.8 mg/kg dry forest soil. Biomasses of shoot and roots of barley seeds were significantly reduced after 14 days of exposure at TNT initial exposure concentrations Ն 55.9 Ϯ 4.5 (LOEC) mg/kg dry soil in silica. Results were similar with the forest soil (LOEC ϭ 91.4 Ϯ 7.9 mg TNT/kg dry soil) using the root growth parameter, but the shoot biomass was reduced only at concentrations Ն 291.9 Ϯ 42.8 mg TNT/kg dry soil. Plants were not affected by an HMX exposure up to 3,320 Ϯ 1,019 mg/kg dry soil using silica or 1,866 Ϯ 438 mg/kg dry soil using a forest soil. During the 14-day experiments, TNT was partially transformed in the spiked soil samples, as indicated by the presence of its amino metabolites (2-ADNT and 4-ADNT). Higher quantities of metabolites were detected in forest soils having higher initial TNT concentrations (Յ 1,849.4 Ϯ 228.2 mg/kg) compared to silica (Յ 239.3 Ϯ 88.0 mg TNT/kg). After 14 days, TNT concentrations in spiked silica and forest soil were reduced up to 80.5% at 55.9 Ϯ 4.5 mg/kg initial concentration and 94.4% at 91.4 Ϯ 7.9 mg/kg initial concentration, respectively. Data indicate that TNT is the probable phytotoxicant because it decreased plant emergence and growth in the presence and absence of the ADNT metabolites.
Archives of Environmental Contamination and Toxicology, 2002
Sublethal and chronic toxicities of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) on earthworm Eisenia andrei in a sandy forest soil were assessed. Various reproduction parameters of fecundity (total and hatched number of cocoons, number of juveniles, and their biomass) were significantly decreased by TNT (≥ 58.8 ± 5.1 mg/kg dry soil), RDX (≥ 46.7 ± 2.6 mg/kg), and HMX (≥ 15.6 ± 4.6 mg/kg). These effects occurred at much lower concentrations than those reported earlier using artificial soil preparations. Growth of adults was significantly decreased in the TNT-spiked natural soils at 136.2 ± 25.6 mg/kg dry soil, the highest concentration having no significant mortality. In contrast, survival and growth were not significantly reduced at relatively high measured concentrations of RDX (167.3 mg/kg) and HMX (711.0 mg/kg). Although TNT, RDX, and HMX share a common life-cycle response (i.e., decreased juvenile counts), a number of differences related to other reproduction parameters (e.g., productivity of cocoons) was observed. These results indicate that the tested explosives do not support a common mechanism of toxicity, at least in the earthworm, probably due to differences in their physical-chemical properties as well as metabolites formed during exposure.
RECOMMENDATIONS FOR THE ASSESSMENT OF TNT TOXICITY IN SEDIMENT
Environmental Toxicology and Chemistry, 2004
Previous investigations of the ecotoxicity of TNT in spiked sediments noted the rapid degradation and disappearance of the toxicant, yet little is understood regarding the effects of this process on toxicity and subsequent derivation of toxicity reference values. We conducted environmental fate studies and 28-d sediment toxicity tests with benthic oligochaete worms (Tubifex tubifex) with sediments spiked at three different TNT concentrations (440, 1,409, and 4,403 nmol/g dry wt) aged for 1, 8, and 29 d. Because of rapid degradation of TNT, disappearance of degradation products, and partitioning to overlying water, only 25 to 40% of the added nitroaromatic mass balance was associated with sediment immediately after spiking. Lethal toxicity decreased with aging time and was best described by measured sediment nitroaromatic concentrations (sum of TNT and degradation products) at the beginning of exposure, with a median lethal concentration of nitroaromatic compounds of 184 nmol/g dry weight. To accurately describe the ephemeral exposure doses of TNT and its degradation products during toxicity tests with spiked sediments, we suggest that sediments should be aged at least 8 to 14 d after spiking, exposure should be based on measured sediment concentrations or chemical measures of availability, exchange of overlying water should be avoided or minimized, and short-term toxicity tests should be considered.
Environmental Toxicology and Chemistry, 2005
Energetic materials are employed in a wide range of commercial and military activities and often are released into the environment. Scientifically based ecological soil-screening levels (Eco-SSLs) are needed to identify contaminant explosive levels in soil that present an acceptable ecological risk. Insufficient information for 2,4,6-trinitrotoluene (TNT) to generate Eco-SSLs for soil invertebrates necessitated toxicity testing. We adapted the standardized Enchytraeid Reproduction Test and selected Enchytraeus crypticus for these studies. Tests were conducted in Sassafras sandy loam soil, which supports relatively high bioavailability of TNT. Weathering and aging procedures for TNT amended to test soil were incorporated into the study design to produce toxicity data that better reflect the soil exposure conditions in the field compared with toxicity in freshly amended soils. This included exposing hydrated TNT-amended soils in open glass containers in the greenhouse to alternating wetting and drying cycles. Definitive tests showed that toxicity for E. crypticus adult survival and juvenile production was increased significantly in weathered and aged soil treatments compared with toxicity in freshly amended soil based on 95% confidence intervals. The median effect concentration and 20% effective concentration for reproduction were 98 and 77 mg/kg, respectively, for TNT freshly amended into soil and 48 and 37 mg/kg, respectively, for weathered and aged TNT soil treatments. These findings of increased toxicity to E. crypticus in weathered and aged TNT soil treatments compared with exposures in freshly amended soils show that future investigations should include a weathering and aging component to generate toxicity data that provide more complete information on ecotoxicological effects of energetic contaminants in soil.
Coelomocyte biomarkers in the earthworm Eisenia fetida exposed to 2,4,6-trinitrotoluene (TNT
Environmental Monitoring and Assessment, 2011
Contamination by 2,4,6-trinitrotoluene (TNT) is a global environmental problem at sites of former explosive production, handling, or storage, and could have deleterious consequences for human and ecological health. We investigated its sublethal effects to Eisenia fetida, using two nonspecific biomarkers. In coelomocytes of earthworms exposed 24, 48, or 72 h, we evaluated DNA damage (comet assay) and neutral red retention time (NRRT), using the filter paper contact test. Both percentage of damage (D%) and calculated damage index showed significant DNA damage at almost all concentrations, at all time points assayed. Along exposure time, two different patterns were observed. At the lower TNT concentrations (0.25–0.5 μg/cm2) an increased DNA migration at 48 h, with a decrease close to initial levels after 72 h exposure, was observed. This decrease could be attributed to activation of the DNA repair system. At higher concentrations (1.0–2.0 μg/cm2), the high DNA damage observed remained constant during the 72 h exposure, suggesting that the rate of DNA repair was not enough to compensate such damage. Analysis of NRRT results showed a significant interaction between time and treatment. After 48 h, a significant decrease was observed at 4.0 μg/cm2. After 72 h, NRRT presented a concentration-dependent decrease, significantly different with respect to control at 0.5, 1.0, 2.0, and 4.0 μg/cm2. The two assayed methods, performed on the same sample, showed clear responses to sublethal TNT exposure in E. fetida, providing sensitive unspecific biomarkers of cell injury and DNA damage.
Soil-based phytotoxicity of 2, 4, 6-trinitrotoluene (TNT) to terrestrial higher plants
Archives of environmental …, 1999
Seed germination and early stage seedling growth tests were conducted to determine the ecotoxicological threshold of 2,4,6-trinitrotoluene (TNT) in two soils of different properties. Soils were amended up to 1,600 mg TNT kg Ϫ1 soil and four representative species of higher plants, two dicotyledons (Lepidium sativum L., common name: cress; and Brassica rapa Metzg., turnip) and two monocotyledons (Acena sativa L., oat; and Triticum aestivum L., wheat), were assessed. Cumulative seed germination and fresh shoot biomass were measured as evaluation endpoints. Phytotoxicity of TNT was observed to be affected by soil properties and varied between plant species. Cress and turnip showed higher sensitivity to TNT than did oat and wheat. The lowest observable adverse effect concentration (LOAEC) of TNT derived from this study was 50 mg kg Ϫ1 soil. In contrast to high TNT concentrations, low levels of TNT, i.e., 5-25 mg kg Ϫ1 soil for cress and turnip and 25-50 mg kg Ϫ1 for oat and wheat, stimulated seedling growth. Oat was capable of tolerating as much as 1,600 mg TNT kg Ϫ1 and demonstrated a potential ability of TNT detoxification in one of the soils tested, suggesting that this plant might be useful in the bioremediation of TNT contaminated soils.