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At least 19 recordsLinked to original sources

PubMed2006

Photosynthetic parameters as indicators of trinitrotoluene (TNT) inhibitory effect: change in chlorophyll a fluorescence induction upon exposure of lactuca sativa to TNT.

Trinitrotoluene, as a compound of conventional explosive, may cause inhibitory effect on terrestrial plants. When Lactuca sativa was exposed to different concentrations of trinitrotoluene (32-1000 mg/kg), photosynthetic process was investigated by using rapid chlorophyll fluorescence kinetic and pulse modulated fluorometry. The decrease of chlorophyll a variable fluorescence was seen to be caused by the deactivation of photosystem II reaction centers. We found for rapid variable fluorescence to be a useful indicator to evaluate the inhibitory effect of trinitrotoluene on photosystem II primary photochemistry and electron transport. The fluorescence parameters, related to the reduction state of photosystem II and to non-photochemical dissipation of light energy, showed a strong relation between the inhibitory effect of photosystem II activity and concentration of trinitrotoluene. The change of photosynthetic fluorescence parameters induced by trinitrotoluene was a reliable indication of the plant physiological state. We proposed for the reduction state of photosystem II and the non-photochemical energy dissipation to be a useful tool in bioassay toxicity testing of trinitrotoluene polluted soil.

Biomass↗

PubMed2005

Comparative and mixture sediment toxicity of trinitrotoluene and its major transformation products to a freshwater midge.

The explosive trinitrotoluene (TNT) is a prevalent contaminant in many military installations worldwide. Limited knowledge of the comparative toxicity of sediment-associated TNT and related compounds contributes to uncertainty when assessing ecological risks in contaminated sites. Trinitrotoluene undergoes transformation when associated with soils and sediments and typically occurs as a mixture dominated by its reduction products. The objective of this study was to comparatively evaluate the single-compound toxicity of TNT and its major transformation products to the freshwater midge Chironomus tentans in 10-day exposures to sediment spiked with TNT, 2-aminodinitrotoluene (2-ADNT), 2,4-diaminonitrotoluene (2,4-DANT), or trinitrobenzene (TNB). In addition, the nature of the toxicological interactions of the latter compounds in a mixture was evaluated. Upon spiking to sediment, TNT and TNB rapidly degraded to reduced products, and disappearance of extractable compounds suggested irreversible binding to sediment particles. The high degree of transformation and reactivity occurring during 10 days at spiking concentrations as high as 4000 micromol/kg dry weight suggests that TNT and related compounds are unlikely to be encountered in fine-grained sediments at contaminated sites. Similar to previous investigations, the high reactivity of the spiked compound hampered determination of accurate toxic concentrations of TNT and related compounds, and of the nature of toxicological interaction of compounds in a mixture in this study. Sediment concentrations associated with decreased survival were similar for all four compounds, with the 10-d median lethal concentrations (LC50s) determined using initial concentrations ranging from 175 (2-ADNT) to 605 (2,4-DANT) micromol/kg dry weight. Sublethal decrease in growth was not observed for any compound. Results from the mixture experiment suggest additive interaction among TNT and related compounds in sediment exposures.

Animals↗

PubMed1983

Early equatorial cataracts in workers exposed to trinitrotoluene.

Twelve workers (nine men and three women with a mean age of 39.5 +/- 8.9 years) with occupational exposure to trinitrotoluene had a mean duration of exposure of 6.8 +/- 4.7 years. The general physical findings were minimal, but ophthalmologic examinations showed bilateral peripheral cataracts in six of the 12 workers. Cataracts were visible only with maximal mydriasis and were continuous or annular opacities at the equator. The cataracts did not interfere with visual acuity or visual fields. Only one worker with and one without cataracts had increased serum alanine aminotransferase and bilirubin levels, possibly associated with trinitrotoluene exposure.

Adult↗

PubMed1984

Trinitrotoluene-induced effects on rat heme metabolism.

A single injection (100 mg/kg body wt) of trinitrotoluene in rats caused decreased delta-aminolevulinic acid synthase activity in reticulocytes and decreased erythrocyte coproporphyrin concentration 48 hr after the intraperitoneal dosage. For comparison, liver delta-aminolevulinic acid synthase was unaffected while heme synthase activity was below the control range at the same time. Heme oxygenase activity increased simultaneously. These effects are likely to lead to a negative heme balance and may be developed for a biological exposure test to trinitrotoluene in occupational health service.

5-Aminolevulinate Synthetase↗

PubMed2002

Characterization and origin identification of 2,4,6-trinitrotoluene through its by-product isomers by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

The by-products of industrial 2,4,6-trinitrotoluene (TNT), including isomers of trinitrotoluene, dinitrotoluene, trinitrobenzene and dinitrobenzene were investigated using liquid chromatography-mass spectrometry (LC-MS), in order to build a profile for the characterization of TNT samples from various origins. LC-MS with atmospheric pressure chemical ionization, in the negative-ion mode, was found to be the most suitable method for this study. The characterization of TNT by the by-product profile was demonstrated on a variety of TNT samples.

Atmospheric Pressure↗

PubMed1998

[The impact of trinitrotoluene on eyes in miners].

Trinitrotoluene (TNT) effect on the eyes of 250 miners was studied. The length of service of the investigated group varied from one to twenty years. The specific trinitrotoluene cataract of various stages was observed in 54.7% of the examinees. The authors assume that the lens changes depend on the length of service and on the TNT concentrations in the body after predominant skin penetration.

Adult↗

PubMed2026

Formation of environmental persistent free radicals in soil of ammunition demolition site: Roles of 2,4,6-trinitrotoluene and heavy metals.

Environmental Persistent Free Radicals (EPFRs) are a particular type of contaminant present in soil. This study investigated the formation process, environmental behavior, and main influencing variables of EPFRs in soils contaminated with heavy metals and 2,4,6-trinitrotoluene (TNT) from an ammunition demolition site. The results showed that the concentration of total organic carbon (TOC) in the soil was negatively correlated with EPFRs (r = -0.29). In contrast, the content of TNT and copper was significantly positively correlated with EPFRs (r = 0.90 and 0.78, respectively), indicating that TNT acts as a precursor macromolecule in the formation of EPFRs in this type of contaminated soil. Transition metal Cu may be an essential carrier in EPFR production. In order to explore the possible formation mechanism of EPFRs, a simulation experiment was carried out under different temperature and light conditions. The results showed that the photolysis process of TNT was impacted by external energy sources such as heat and light. TNT was firstly adsorbed onto the surface of a transition metal (Cu), and then EPFRs were formed through further electron transfer. This is the first study to detect significant levels of EPFRs in the soil at ammunition demolition sites.

Trinitrotoluene↗

PubMed2001

Transformation of 2,4,6-trinitrotoluene (TNT) by immobilized Phanerochaete chrysosporium under fed-batch and continuous TNT feeding conditions.

The cometabolic transformation of 2,4,6-trinitrotoluene (TNT) by an immobilized Phanerochaete chrysosporium culture was investigated under different TNT and/or glycerol feeding conditions in a 5-L reactor. In the fed-batch feeding mode, as a result of four spiking events at an average feeding rate of 20 mg TNT L(-1) d(-1) and 250 mg glycerol L(-1) d(-1), the initial TNT transformation rate and the glycerol uptake rate of the 7-day-old immobilized cell culture were 2.41 mg L(-1) h(-1) and 16.6 mg L(-1) h(-1), respectively. Thereafter, the TNT fed into the reactor depicted a negative effect on the cell physiology of P. chrysosporium, i.e., both rates decreased constantly. At 32 mg TNT L(-1) d(-1) feeding rate, also in the presence of glycerol (200 mg L(-1) d(-1)), this effect on the fungal cell metabolism was even more significant. When TNT was fed alone at 3.7 mg L(-1) d(-1), it showed an initial 0.75 mg L(-1) h(-1) rate of TNT transformation, i.e., one-third the initial level observed in the presence of glycerol. In contrast, in the continuous feeding mode (dilution rate, D = 0.11 d(-1)), at 5.5 mg TNT L(-1) d(-1) and 220 mg glycerol L(-1) d(-1), the immobilized cell culture exhibited a constant TNT transformation rate for cultivation periods of 50 and 61 days, under uncontrolled and controlled pH conditions, respectively. Thereafter, during the latter experiment, 100% TNT biotransformation was achieved at 1,100 mg L(-1) d(-1) glycerol feeding rate. Immobilized cells (115-day-old), sampled from a continuous TNT feeding experiment, mineralized [(14)C]-TNT to a level of 15.3% following a 41-day incubation period in a microcosm.

Bioreactors↗

PubMed2006

Uptake and biotransformation of 2,4,6-trinitrotoluene (TNT) by microplantlet suspension culture of the marine red macroalga Portieria hornemannii.

Microplantlets of the marine red macroalga Portieria hornemannii efficiently removed the explosive compound 2,4,6-trinitrotoluene (TNT) from seawater. Photosynthetic, axenic microplantlets (1.2 g FW/L) were challenged with enriched seawater medium containing dissolved TNT at concentrations of 1.0, 10, and 50 mg/L. At 22 degrees C and initial TNT concentrations of 10 mg/L or less, TNT removal from seawater was 100% within 72 h, and the first-order rate constant for TNT removal ranged from 0.025 to 0.037 L/gFW h under both illuminated conditions (153 microE/m(2)s, 14:10 LD photoperiod) and dark conditions. Two immediate products of TNT biotransformation, 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dintrotoluene, were identified in the liquid culture medium, with a maximum material balance recovery of 29 mole%. Only trace levels of these products and residual TNT were found within the fresh cell biomass. Removal of TNT by P. hornemannii microplantlets at initial concentrations of 1.0 or 10 mg/L did not affect the respiration rate. At an initial TNT concentration of 10 mg/L, net photosynthesis decreased towards zero, commensurate with the removal of dissolved TNT from seawater, whereas at an initial TNT concentration of 1.0 mg/L, the net photosynthesis rate was not affected.

Biodegradation, Environmental↗

PubMed1986

Metabolic studies of explosives. 5. Detection and analysis of 2,4,6-trinitrotoluene and its metabolites in urine of munition workers by micro liquid chromatography/mass spectrometry.

Metabolites of 2,4,6-trinitrotoluene (TNT) were found in the urine of a group of TNT munition workers. The urine extracts were analysed by micro liquid chromatography/mass spectrometry. The metabolites found included 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, 2,4-diamino-6-nitrotoluene, 2,6-diamino-4-nitrotoluene and untransformed TNT. The detection limit of the metabolites in urine was 0.1 ng/ml for 20 ml urine samples.

Chromatography, High Pressure Liquid↗

PubMed1984

Metabolic studies of explosives. 1--EI and CI mass spectrometry of metabolites of 2,4,6-trinitrotoluene.

A series of metabolites of trinitrotoluene (TNT) have been synthesized and analysed by electron impact (EI) and chemical ionization (CI) mass spectrometry. Identification characteristics of these metabolites by their mass spectra have been determined. Differentiation of isomers is made possible by EI ions which are characteristic of the position of the methyl with regard to the nitro groups.

Aniline Compounds↗

PubMed2004

Multichannel homogeneous immunoassay for detection of 2,4,6-trinitrotoluene (TNT) using a microfabricated capillary array electrophoresis chip.

A high-throughput homogeneous immunoassay for the sensitive detection of 2,4,6-trinitrotoluene (TNT) has been developed using radial capillary array electrophoresis microdevices. Samples consisting of equilibrium mixtures of anti-TNT antibody (Ab), fluorescein-labeled TNT, and various concentrations of unlabeled TNT were electrokinetically injected into 48 channels of a radial capillary array electrophoresis microchannel plate. The rapid electrophoretic separation allows us to analyze the equilibrium ratio formed by the competition between the labeled and the unlabeled TNT for Ab binding. The simultaneous parallel TNT separations facilitate determination of a calibration curve for the TNT assay, which has high sensitivity (LOD, 1 ng/mL) and a wide dynamic range (1-300 ng/mL).

Antibodies↗

PubMed1982

Mutagenicity in Salmonella typhimurium and structure-activity relationships of wastewater components emanating from the manufacture of trinitrotoluene.

The mutagenicity of 36 polynitroaromatic compounds was investigated with five strains of Salmonella typhimurium. Isomeric trinitrotoluenes (TNT), with the exception of 2,4,6-TNT and 2,3,4-TNT, exhibit mutagenicity independently of nitroreductase enzymes, but isomeric aminodinitrotoluenes (ADNT) and isomeric dinitrotoluenes (DNT) need nitroreductase to induce mutation. Within groups of isomeric TNTs, DNTs, and ADNTs, mutagenic response was enhanced by a para orientation of nitro groups. The mutagenic response of isomeric DNTs was found to correlate with the compound's ability to undergo charge-transfer complexation with reductive enzymes, whereas further complexation (such as a Janovsky complex) appears to be required for inducing mutation in dinitrobenzenes. These results indicate that polynitroaromatic compounds in TNT wastewaters possess a significant potential for biologic activity.

Biotransformation↗

PubMed2001

Transcriptional activation of stress genes and cytotoxicity in human liver carcinoma cells (HepG2) exposed to 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, and 2,6-dinitrotoluene.

The CAT-Tox (L) assay has recently been developed and validated for detecting and quantifying the specific molecular mechanisms that underlie toxicity of various xenobotic chemicals. We performed this assay to measure the transcriptional responses associated with 2,4,6-trinitrotoluene (TNT) and 2 of its byproducts [2,4 and 2,6-dinitotoluenes (DNTs)] to 13 different recombinant cell lines generated from human liver carcinoma cells (HepG2) by creating stable transfectants of mammalian promoter chloramphenicol acetyltransferase (CAT) gene fusions. Cytoxicity test with the parental HepG2 cells, using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]-based assay for cell viability, yielded LC50 values of 105 +/- 6 mg/mL for TNT in 1% dimethyl sulfoxide (DMSO), and > 300 mg/mL for DNTs, upon 48 h of exposure. TNT appeared to be more toxic than 2,4-DNT, which also showed a higher toxicity compared to 2,6-DNT. Of the 13 recombinant constructs evaluated, 8 (CYP 1A1, GST Ya, XRE, HMTIIA, c-fos, HSP70, GADD153, and GADD45), 5 (c-fos, HSP70, GADD153, GADD45, and GRP78), and none showed inductions to significant levels (p < 0.05), for TNT, 2,4-DNT, and 2,6-DNT, respectively. For most constructs, the induction of stress genes was concentration-dependent. These results show the potential for TNT and 2,4-DNT to cause protein damage and/or perturbations of protein biosynthesis (HSP70 and GRP78), alterations in DNA sequence or its helical structure (c-fos, GADD153, GADD45), and the potential involvement of TNT in the biotransformation process (CYP 1A1, GST Ya, XRE), and in the toxicokinetics of metal ions (HMTIIA). Within the range of concentrations tested (0-300 mg TNT or DNT/mL in 1% DMSO), no significant inductions (p > 0.05) of NFKBRE, p53RE, CRE, and RARE were found.

Air Pollutants, Occupational↗

PubMed2004

Assessing cytotoxicity of photosensitized transformation products of 2,4,6-trinitrotoluene (TNT) and atrazine with freshwater microbial assemblages.

In this study of riboflavin-sensitized photolysis of 2,4,6-trinitrotoluene (TNT), the final photoproducts were found to include 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, and 3,5-dinitroaniline. After exposure to TNT (10 mg/L) for 90 min, in a river water sample there was inhibition of the viability count of heterotrophic bacterial assemblages by 28.3% and 24.3% and of bacterial heterotrophic mineralization of glucose by 99.5% and 93.6% relative to the light control and dark control groups, respectively. After exposure separately to 10 mg/L 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, or 3,5-dinitroaniline, the viability count of heterotrophic bacterial assemblages was enhanced by 30.0%, 98.2%, and 148.7%, respectively, relative to the TNT group in light and by 12.2%, 40.2%, and 36.5%, respectively, relative to TNT group in dark. After exposure to the same aforementioned test chemicals, heterotrophic activity of bacterial assemblages was inhibited by 75.7%, 72.4%, and 56.0%, respectively, relative to light control group, and there were no significant changes in the dark. A similar study was conducted with atrazine (10 mg/L). The main products of atrazine riboflavin-sensitized phototransformation include desethylatrazine (DEA) and desisopropylatrazine (DIA). It was found that DEA and DIA did not inhibit microbial heterotrophic activity. However, after 72 h the viable count was enhanced by 52.8% and 63.3% in the DEA and DIA exposure groups, respectively, in comparison to the control. These results suggested that photosensitized transformation decreased TNT and atrazine cytotoxicity to microbial assemblages in the natural water. Photoproducts of atrazine--DEA and -DIA, and of TNT could become growth substrates for bacterial assemblages in natural water.

Atrazine↗

PubMed1993

Plasma membrane dependent reduction of 2,4,6-trinitrotoluene by Phanerochaete chrysosporium.

A plasma membrane redox system of Phanerochaete chrysosporium was found to reduce 2,4,6-trinitrotoluene (TNT). Reduction required intact, live mycelia. No reduction was observed with either supplemented (NADPH, NADH or ATP) or unsupplemented extracellular or intracellular fractions, either under aerobic or anaerobic conditions. Reduction was inhibited by potassium ferricyanide, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium, carbonyl cyanide p-trifluoromethoxyphenyl hydrazone, 2,4-dinitrophenol, sodium azide, and tetranitroblue tetrazolium but not by nitroblue tetrazolium, 2,3,5-triphenyl tetrazolium and blue tetrazolium. At higher pH, the rate of reduction as well as proton pumping was enhanced.

Basidiomycota↗

PubMed1994

Phototoxicology. 2. Near-ultraviolet light enhancement of Microtox assays of trinitrotoluene and aminodinitrotoluenes.

Coexposure of 2,4,6-trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2A), or 4-amino-2,6-dinitrotoluene (4A) to near-ultraviolet (nuv) light (lambda max-354 nm) significantly enhanced their toxicity toward Photobacterium phosphoreum (Microtox bioassay) during 30 min but not 15 min. Based on the slopes of the dose-response lines, the nuv coexposure and dark toxic mechanisms of action for TNT, 2A, and 4A appeared to be similar. nuv coexposure of binary mixtures significantly enhanced (supraadditivity) the toxicity of these compounds to P. phosphoreum. Under normal laboratory lighting, the toxicity of TNT + 2A and 2A + 4A mixtures were supraadditive but the toxicity of TNT + 4A mixtures could be explained by simple addition. Supporting these conclusions, the response curves of alpha-terthienyl, a compound known not to require nuv for toxicity, were similar in the dark and with nuv coexposure. In contrast, angelicin and psoralen, compounds known to require nuv coexposure to damage DNA, gave response curves having different slopes in the dark and with nuv coexposure. The nuv coexposure Microtox assay was able to detect and quantify phototoxicity in psoralen, angelicin, alpha-terthienyl, anthracene, TNT, and aminodinitrotoluenes.

Aniline Compounds↗

PubMed1994

Phototoxicology. 3. Comparative toxicity of trinitrotoluene and aminodinitrotoluenes to Daphnia magna, Dugesia dorotocephala, and sheep erythrocytes.

2,4,6-Trinitrotoluene (TNT) and compounds associated with its production are toxic and phototoxic to a wide range of biota. The planarian Dugesia dorotocephala, but not Daphnia magna, metabolized TNT (1 mg/liter) to 4-amino-2,6-dinitrotoluene (4A; 0.4 mg/liter) and 2-amino-4,6-dinitrotoluene (2A; 0.2 mg/liter). Coexposure to near-ultraviolet (nuv) light enhanced the toxicity of 2A more than that of TNT and 4A. The toxicities of TNT, 4A, and 2A to Du. dorotocephala were all decreased by glutathione (GSH) conjugation. This suggests that all had mechanisms of toxic action involving formation of quinone-GSH conjugates. Dark and light mechanisms for TNT and 2A depended on GSH conjugation, but the specific mechanisms may be different for each compound. The dark and light mechanisms of toxic action for 4A appeared to be fundamentally different in that the dark toxic mechanism of action was less dependent on GSH conjugation. Hemolysis studies using sheep erythrocytes showed that the light-enhanced toxic mechanism of action for TNT, 2A, and/or 4A did not involve cellular membrane damage in response to nuv-induced anions.

Abnormalities, Drug-Induced↗