Industrial Organic Solvents Research Articles

Acute and Chronic Exposure of Toluene Induces Genotoxicity in Different Regions of the Brain in Normal and Allergic Mouse Models.

Toluene is a widely used industrial organic solvent and is ubiquitous in our environment. The neurobehavioral and neurotoxic effects of toluene are well recognized; however, its genotoxicity is still under discussion. Toluene biotransformation leads to the generation of reactive oxygen species that cause oxidative stress and DNA damages. Individuals with different immunogenetic backgrounds have different sensitivities to toxic chemical exposure. Previous studies have suggested that allergic stimulation may influence the threshold for toluene sensitivity due to the modulation of neurotrophin-related genes. Therefore, we aimed to investigate toluene-induced genotoxicity in different brain regions following acute and chronic exposure in vivo and to further examine whether allergic stimulation may influence the sensitivity to toluene-induced genotoxicity. In this present study, we found that exposure of toluene induced oxidative DNA damages resulting in genotoxicity in different brain regions including cortex, cerebellum, and hippocampus using comet assay. Higher genotoxicity induced by toluene was observed in the hippocampus of control mice compared to OVA-immunized mice. These results provide evidence that toluene-induced genotoxicity may contribute to its neurotoxicity in different immunogenetic individuals.

A superhydrophobic and elastic melamine sponge for oil/water separation

The leakage of industrial oil and organic solvents can wreak great harm to the environment and ecology.

Synthesis of magnesium sulfate from seawater using alkaline industrial wastes, sulfuric acid, and organic solvents

ABSTRACTIn this study, we used three processes to synthesize magnesium sulfate from seawater. First, alkaline industrial wastes, cement kiln dust and paper sludge ash, were injected to the seawater to precipitate magnesium in the form of magnesium hydroxide (Mg(OH)2). Then, magnesium was eluted with a small amount of H2SO4 to make a high concentration magnesium solution. Finally, an organic solvent was added to precipitate magnesium sulfate (MgSO4). Over 90% of magnesium was recovered through the three processes. It is expected that 11.3 kg of magnesium sulfate (based on MgSO4 · 6H2O) can be synthesized from 1 ton of seawater.

Estimation of safe environmental concentrations of ionic liquids towards bacteria by chemical toxicity distribution method

Ionic Liquids (ILs) are considered as the potential replacement of industrial organic solvents because of their salient physical and chemical properties, for example, ionic nature, low vapor pressure, and good solubility properties. These properties make ILs feasible for potential application. Industrialization of ILs has a potential to adversely affect and pose risk to the ecosystem because of their toxic nature. However, the conventional research on the ILs is mainly carried out by performing acute the toxicity assessment of individual species for individual ILs which is termed as effect assessment. Effect assessment for individual ILs is insufficient for the ecotoxicological risk assessment of ILs. Subsequently, effect assessment of single ILs on one species is not sufficient to evaluate risk. The main objective of the current research was to estimate the safe environmental concentrations (SECs) of ILs towards three bacterial strains V fischeri, E coli and S vacuolatus by Chemical Toxicity Distribution (CTD) method. CTDs provided the SECs for a group Imidazolium NTf2 ILs toward three bacteria. E coli was the most sensitive species amongst three species when exposed to the selected group of ILs with 2.976 × 10−4 mmol/L as SEC.

Influence factors of determining optimal organic solvents for swelling cured brominated epoxy resins to delaminate waste printed circuit boards

In the previous study, organic solvent dimethyl sulfoxide (DMSO) could effectively delaminate waste printed circuit boards (WPCBs) by swelling cured brominated epoxy resins (CBER). To find more organic solvents which can swell CBER, the total and three-dimensional Hansen solubility parameters (3d-HSP) of CBER in WPCBs were calculated by a group contribution method and an equilibrium swelling degree method. During testing equilibrium swelling degree, seventeen industrial common organic solvents were used to swell CBER in WPCBs. The results were that the total solubility parameter of CBER (δt) was 24.6–26.4 (J/cm3)1/2, and 3d-HSP were that dispersion force (δd) was 20.9(J/cm3)1/2, intermolecular dipole interaction force (δp) was 11.1(J/cm3)1/2, and hydrogen-bonding force (δh) was 11.6 (J/cm3)1/2. Then, 3-cresol was chosen to swell CBER in WPCBs according to its total and 3d-HSP. Result indicated that the WPCBs were delaminated completely in 3-cresol solvent. Finally, experimental results and theoretical analysis showed that the glass transition temperature (Tg) and solubility parameter of CBER were two very important factors for choosing organic solvents to delaminate the WPCBs. In addition, interaction forces of molecular functional groups between CBER and organic solvents were also an influence factor.

Characteristics and Source Apportionment of VOCs of High Pollution Process at Chemical Industrial Area in Winter of China

Online GC was adopted to monitor VOCs of high pollution process near a chemical industrial area in winter. PMF model was used to identify the major sources of VOCs and evaluate their contributions. The result showed that the main components during the period of observation were toluene, xylene, C3-C4 hydrocarbon and chloroform, etc. Organic sulfur compounds were the major odor pollutants at the chemical industrial area. The compounds including isobutane, n-butane, propane and acrylonitrile were enriched during two pollution periods. VOCs and NOx had the diurnal features of high concentration in the evening versus lower concentration during daytime, indicating the main influence from chemical industrial sources. While O3 had the diurnal features reflecting the photochemical reaction at chemical industrial area in winter. The PMF result showed that 48.0% of the total VOCs concentrations were attributed to synthetic materials industry, 24.0% to industrial organic sulfur process and wastewater treatment (including three sources), 14.7% to industrial organic solvent usage, and 13.3% to petrochemical process. So the wastewater treatment unit was a major source of odor pollution at chemical industrial area.

2,5-hexanedione induced apoptosis of rat bone marrow mesenchymal stem cells by reactive oxygen species.

n-Hexane, a common industrial organic solvent, causes multiple organ damage, especially neurotoxicity, which is proved to be caused by its metabolite 2,5-hexanedione (2,5-HD). We previously showed that 2,5-HD induced apoptosis of rat bone marrow mesenchymal stem cells (BMSCs). In the current study, we explored the mechanism of 2,5-HD-induced apoptosis, especially the role played by reactive oxygen species (ROS). Intracellular ROS levels after 2,5-HD treatment were measured by the dichloro-dihydro-fluorescein diacetate (DCFH-DA) method, and the antioxidant N-acetyl cysteine (NAC) was used to scavenge ROS. Apoptosis, mitochondrial membrane potential (MMP), and caspase-3 activity were measured after 2,5-HD exposure with or without NAC pretreatment. In rat BMSCs, 20 mM 2,5-HD significantly increased ROS levels and apoptosis. In addition, MMP activity was decreased and caspase-3 activity was increased. With NAC pretreatment, ROS increases were prevented, cells were rescued from apoptosis, and both MMP and caspase-3 activity returned to normal levels. Western blotting analysis of malondialdehyde-modified proteins and superoxide dismutase (SOD) 1 showed that after 2,5-HD exposure, BMSCs had oxidative damage and abnormal SOD1 expression. These returned to normal when cells were pretreated with NAC in addition to 20 mM 2,5-HD. Furthermore, the expressions of NF-κB p65/RelA and phospho-NF-κB p65/RelA (Ser536) were suppressed after 2,5-HD exposure and restored by NAC pretreatment. 2,5-HD-induced apoptosis in rat BMSCs is potentially mediated by excessive ROS production.

Disulfiram inhibition of cyanide formation after acetonitrile poisoning

Context Cyanide poisoning may be caused by acetonitrile, a common industrial organic solvent and laboratory agent. Objective To describe the potential use of disulfiram in treating acetonitrile poisoning in a human clinical case and to further study its effect in human liver microsomes in vitro. Case details A 30-year-old man initially presented with a cholinergic toxic syndrome following ingestion of aldicarb. Toxicological analysis revealed coingestion of ethanol. He subsequently developed severe metabolic acidosis caused by the cyanogenic compound acetonitrile which was erroneously interpreted as acetone in the chromatogram. After three treatments with hydroxocobalamin (5 g i.v.) and sodium thiosulfate (12.5 g i.v.) on days 2, 3, and 5, he had transient improvement but recurrent lactic acidosis. Treatment with disulfiram was associated on day 7 with resolution of metabolic acidosis and slowing of the decrease in acetonitrile concentration. He recovered from acetonitrile toxicity completely. The time course of acetonitrile, thiocyanate, and cyanide concentrations suggested that disulfiram inhibited cyanide formation. Results In vitro experiments with human liver microsomes showed the cyanide concentration was significantly lower after incubation with acetonitrile and disulfiram than acetonitrile alone (a mean 60% reduction in cyanide level). Discussion Although disulfiram was given late in the course of the poisoning it is possible that it contributed to the recovery.

Enhanced horizontal transfer of antibiotic resistance genes in freshwater microcosms induced by an ionic liquid.

The spread and propagation of antibiotic resistance genes (ARGs) is a worldwide public health concern. Ionic liquids (ILs), considered as “environmentally friendly” replacements for industrial organic solvents, have been widely applied in modern industry. However, few data have been collected regarding the potential ecological and environmental risks of ILs, which are important for preparing for their potential discharge into the environment. In this paper, the IL 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6]) (0.001-5.0 g/L) was tested for its effects on facilitating ARGs horizontal transfer mediated by plasmid RP4 in freshwater microcosms. In the horizontal transfer microcosms, the transfer frequency of plasmid RP4 was significantly enhanced (60-fold higher than untreated groups) by the IL [BMIm][PF6] (1.0 g/L). Meanwhile, two strains of opportunistic pathogen Acinetobacter spp. and Salmonella spp. were isolated among the transconjugants, illustrating plasmid RP4 mediated horizontal transfer of ARGs occurred in pathogen. This could increase the risk of ARGs dissemination to human pathogens and pose great threat to public health. The cause that [BMIm[PF6] enhanced the transfer frequency of plasmid RP4 was proposed by suppressed cell membrane barrier and enhanced cell membrane permeability, which was evidenced by flow cytometry (FCM). This is the first report that some ILs facilitate horizontal transfer of plasmid RP4 which is widely distributed in the environment and thus add the adverse effects of the environmental risk of ILs.

1,2-Dichloroethane-induced toxic encephalopathy: A case series with morphological investigations

1,2-Dichloroethane (DCE) is commonly used as an industrial organic solvent and causes occupational diseases. Toxic encephalopathy is the most common and serious disorder resulting from DCE intoxication. Five patients who worked in shoemaking, pipemaking or a paint factory were identified as suffering from severe encephalopathy due to DCE intoxication. DCE-induced toxic encephalopathy manifests as various neurological deficits, with changes observable by neuroimaging. The main clinical manifestation is headache accompanied by intracranial hypertension. The typical cranial CT/MR scan of DCE toxic encephalopathy shows extensive brain edema and diffuse, symmetric, abnormal signal intensities in the cerebellar dentate nucleus, basal ganglia, and white matter in the bilateral cerebral hemispheres. The diagnosis of DCE toxic encephalopathy can be confirmed by the typical clinical and neuroimaging characteristics together with a history of exposure to substances contaminated with DCE. Dehydrating agents and glucocorticoids are the primary treatments. With early diagnosis and prompt treatment, promising results and recovery can be achieved. Effective prevention is expected to reduce the incidence of DCE toxic encephalopathy.

An Ionic Liquid Facilitates the Proliferation of Antibiotic Resistance Genes Mediated by Class I Integrons

Ionic liquids (ILs), as “environmentally friendly” replacements for industrial volatile organic solvents, have been widely and recently applied in the chemical industry. However, few data have been collected regarding the toxicity and potential environmental effects of ILs, which are fairly important for preparing for their potential release into the environment. In this study, the IL 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6]) was tested for its ability to promote the proliferation and dissemination of antibiotic resistance genes (ARGs) in environmental bacteria. In freshwater microcosms, [BMIm][PF6] (0.5 g/L) significantly enhanced the abundance of the sulI gene (500-fold greater than in untreated controls). Meanwhile, [BMIm][PF6] significantly increased the abundance of class I integrons, which play a key role in ARG dissemination. A positive correlation (p < 0.01) between the intI and sulI genes suggested that [BMIm][PF6]-facilitated sulI propagation was mediated by class I integrons. This idea was supported by sequencing, which showed the sulI locus in the 3′ region of class I integrons. Class I integron transfer experiments between different indigenous strains of Alcaligenes sp. (SMXR) and Acinetobacter sp. (StrR) were conducted to show that the horizontal transfer frequency of class I integrons was up to 88-fold higher in the presence of an IL. An IL increased cell membrane permeability as evidenced by flow cytometry, thereby assisting sulI gene transfer mediated by class I integrons. This is the first report that ILs facilitate the proliferation of ARGs in environmental bacteria and thus increase risks to public health.

The Test of Organic Solvents Vapours Based on Commercial Tin Dioxide Gas Sensors

This article describes the experiments carried out with the system of three tin dioxide gas sensors MQR 1003, TGS 822 and TGS 813, as well as the achieved results. Vapours of five industrial organic solvents were tested. The measurement values were processed by a cluster analysis. The programmes STATGRAPHIC 5.0 Plus and MATLAB 7.11 were used for data processing. The achieved results show, that the used commercial sensors are able to successfuly distinguish chosen industrial solvents and the results can be used for discrimination of organic solvents vapours in air.

Synthesis and characterization of solubility enhanced metal-free phthalocyanines for liquid crystal display black matrix of low dielectric constant

For the liquid crystal display (LCD) black matrix (BM) with a low dielectric constant and high light absorption property, it is advantageous to employ dyes instead of carbon black or pigments. For this purpose, the dyes should have high solubility in industrial organic solvents. For improved solubility in industrial solvents, three metal-free phthalocyanines (PC), peripherally substituted with bulky groups, were synthesized and dye-based BMs were fabricated. The solubility as well as the spectral and thermal properties of the dyes were examined, and the optical, thermal and dielectric properties of a dye-based black matrix were tested. The greenish phthalocyanine dyes with high molar extinction coefficients and high thermal stability showed enhanced solubility in industrial solvents as a result of the greater steric hindrance among the dye molecules and higher affinity between the dye molecules and solvents. The dye-based BMs had low dielectric constants and exhibited superior optical properties and satisfactory thermal stability.

Toluene exposure during brain growth spurt and adolescence produces differential effects on N-methyl- d-aspartate receptor-mediated currents in rat hippocampus

Toluene, an industrial organic solvent, is voluntarily inhaled as drug of abuse. Because inhibition of N-methyl- d-aspartate (NMDA) receptors is one of the possible mechanisms underlying developmental neurotoxicity of toluene, the purpose of the present study was to examine the effects of toluene exposure during two major neurodevelopmental stages, brain growth spurt and adolescence, on NMDA receptor-mediated current. Rats were administered with toluene (500 mg/kg, i.p.) or corn oil daily over postnatal days (PN) 4–9 (brain growth spurt) or PN 21–26 (early adolescence). Intracellular electrophysiological recordings employing in CA1 pyramidal neurons in the hippocampal slices were performed during PN 30–38. Toluene exposure during brain growth spurt enhanced NMDA receptor-mediated excitatory postsynaptic currents (EPSCs) by electrical stimulation, but impaired the paired-pulse facilitation and NMDA response by exogenous application of NMDA. Toluene exposure during adolescence resulted in an increase in NMDA receptor-mediated EPSCs and a decrease in exogenous NMDA-induced currents, while lack of any effect on paired-pulse facilitation. These findings suggest that toluene exposure during brain growth spurt and adolescence might result in an increase in synaptic NMDA receptor responsiveness and a decrease in extrasynaptic NMDA receptor responsiveness, while only toluene exposure during brain growth spurt can produce presynaptic modulation in CA1 pyramidal neurons. The functional changes in NMDA receptor-mediated transmission underlying developmental toluene exposure may lead to the neurobehavioral disturbances.

N-Methyl-2-Pyrrolidone Is a Biologically Active Thalidomide Subunit with In Vivoanti-Myeloma Properties

AbstractAbstract 4082N-methyl-2-pyrrolidone (NMP) is considered an inert drug delivery vehicle that is widely used as an industrial organic solvent. NMP is found in a range of pharmaceutical preparations and bio-prosthetic cements. In particular, NMP is used to solubilize kinase inhibitors for pre-clinical testing in experimental mice.The Vk*MYC transgenic mouse is a model of multiple myeloma (MM) that recapitulates the human disease. We have adapted Vk*MYC MM using a syngeneic transplant approach to shorten latency and facilitate testing of novel therapeutics. In this model, we noted delayed disease progression and improved survival in NMP treated mice compared to alternative vehicle controls. To confirm this observation, matched cohorts of mice bearing monoclonal kappa-secreting MM were treated with 20% NMP/80% polyethylene glycol (PEG) (n = 13), PEG alone (n = 10) or PBS (n = 7) at 100uL per 20g mouse daily p.o. Mice were monitored by serial serum protein electrophoresis and quantitative kappa immunoglobulin (IgK) estimation. At the commencement of therapy, cohorts were well matched for disease burden; mean M-spikes 12%, 14% and 14% of total serum protein for NMP, PBS and PEG respectively (p=0.58 NMP vs. PBS, p=0.68 NMP vs. PEG). After 28d treatment, NMP-treated mice had lower paraproteinemia compared to PBS and PEG controls (mean M-spike NMP 31%, PBS 42% and PEG 40%; p < 0.05 NMP vs. PBS or PEG), with concordant suppression of IgK (NMP 18g/L vs. PBS 39g/L, p<0.05). Survival in NMP-treated mice was also significantly longer than that in PBS-treated controls (median survival 50d and 40d respectively; p<0.05 log rank). Survival of PEG-only treated mice did not differ from PBS controls (median survival 39.5d; p=0.49).We compared the structure of NMP to known MM therapeutics, revealing that NMP is a subunit of thalidomide and its analogues. We next tested NMP for cytotoxicity and immune-modulatory drug (IMiD) activity in vitro. NMP (1uM – 10mM) was not directly cytotoxic to healthy donor peripheral blood mononuclear cells (PBMCs) or the U266 myeloma cell line. However, treatment of PBMC with 10uM NMP significantly enhanced NK cell cytotoxicity against the NK cell-sensitive target cell line K562 from 26% to 42% (p < 0.05). Further, NMP favored a Th-1 cytokine profile without directly altering the frequency of CD4, CD8, NK or regulatory T cell subsets in vitro. As compared to the IMiD lenalidomide, NMP inhibited TNF-a production from LPS stimulated monocytes. Given the IMiD-like effects of NMP, we assessed its ability to alter the expression of NK cell ligands on myeloma targets. NMP upregulated both NKG2D and DNAM-1 ligands (MIC-A, MIC-B, ULBP-1, ULBP-2 and CD155) on U266 cells, thereby enhancing the NK cell mediated lysis of the U266 cell line.Our results demonstrate the in vivo anti-myeloma activity and IMiD-like properties of NMP, indicating that it is a putative active thalidomide subunit. The detection of IMiD-like activity was facilitated by a sensitive, immune competent MM model. NMP should no longer be considered inert for the purposes of drug delivery. These findings mandate re-evaluation of drug efficacy data where NMP has been used as the drug delivery vehicle, particularly in immune-competent cancer models. Our findings with NMP may allow the development of new IMiDs. Finally, occupational or iatrogenic exposure to NMP should be further assessed as a potential risk for immunologically mediated adverse effects. Disclosures:No relevant conflicts of interest to declare.

Catalytic oxidation of industrial organic solvent vapors

In the present study the catalytic oxidation of an industrial organic solvent consisting predominantly of C-9 to C-10 paraffins and napthtenics and derived from low aromatic white spirit on CuO and Pt catalysts was investigated at ambient pressure and temperatures between 330 and 770 K. Catalysts were prepared in the laboratory and compared to commercial ones. Characterization was based on x-ray diffraction (XRD) analysis, x-ray fluorescence (XRF) analysis, scanning electron microscope (SEM) analysis and nitrogen adsorption data. The commercial platinum catalyst was proved highly efficient in the oxidation of the commercial solvent, necessitating lower temperatures for total oxidation. Catalyst loading in active component is clearly not of primordial importance, since its dispersion and crystallinity as well as the presence of other metallic compounds influence also the catalytic activity. In the case of copper catalysts studied, the different support (alumina) characteristics also would contribute to the difference in catalytic activity. Finally, the power law kinetics may successfully be used in order to explain the catalytic oxidation data of the organic solvent, where its constituents are modeled as a single carbon-containing compound.

Skin penetration and kinetics of pristine fullerenes (C 60) topically exposed in industrial organic solvents

Pristine fullerenes (C 60) in different solvents will be used in many industrial and pharmaceutical manufacturing and derivatizing processes. This report explores the impact of solvents on skin penetration of C 60 from different types of industrial solvents (toluene, cyclohexane, chloroform and mineral oil). Yorkshire weanling pigs ( n = 3) were topically dosed with 500 μL of 200 μg/mL C 60 in a given solvent for 24 h and re-dosed daily for 4 days to simulate the worst scenario in occupational exposures. The dose sites were tape-stripped and skin biopsies were taken after 26 tape-strips for quantitative analysis. When dosed in toluene, cyclohexane or chloroform, pristine fullerenes penetrated deeply into the stratum corneum, the primary barrier of skin. More C 60 was detected in the stratum corneum when dosed in chloroform compared to toluene or cyclohexane. Fullerenes were not detected in the skin when dosed in mineral oil. This is the first direct evidence of solvent effects on the skin penetration of pristine fullerenes. The penetration of C 60 into the stratum corneum was verified using isolated stratum corneum in vitro; the solvent effects on the stratum corneum absorption of C 60 were consistent with those observed in vivo. In vitro flow-through diffusion cell experiments were conducted in pig skin and fullerenes were not detected in the receptor solutions by 24 h. The limit of detection was 0.001 μg/mL of fullerenes in 2 mL of the receptor solutions.

Trichloroethylene liver toxicity in mouse and rat: microarray analysis reveals species differences in gene expression

Trichloroethylene (TCE), an industrial organic solvent found in the environment, is a known carcinogen in laboratory animals and is believed to be carcinogenic in humans. Its carcinogenicity is subject to species-specific differences in biological activity, causing hepatocellular carcinoma in mouse and renal-cell carcinoma in rat. We have sought to better understand TCE's mode of action (MOA) by studying the alterations in gene expression profiles of liver in mice and rats that were administrated TCE by oral gavage either once or daily for 14 days. Microarray analysis revealed distinct transcriptional profiles and differences in biological pathways not only species-specific, but also pulse-dose effects within each species. For example, inhibition of the TGF-beta pathway and activation of MAPK signaling were specific to mice repeatedly exposed to TCE. A better understanding of the MOA in mice and rats will lead to better hypotheses of TCE's affect on humans.

Morphology and physiology of anaerobic granular sludge exposed to an organic solvent

The use of quantitative image analysis techniques, together with physiological information might be used to monitor and detect operational problems in advance to reactor performance failure. Industrial organic solvents, such as White Spirit, are potentially harmful to granular sludge. In preliminary batch assays, 33 mg L(-1) of solvent caused 50% relative biomass activity loss. In an expanded granular sludge blanket reactor fed with 40 mg L(-1) of solvent, during 222h, the reactor performance seemed to be unaffected, presenting COD removal efficiency consistently >95%. However, in the last days of exposure, the biogas production and the methane content were inhibited. Afterwards, already during recovery phase, the COD removal efficiency decreased to 33%, probably because the reactor was underloaded and the biomass became saturated in solvent only at this stage. In the first hours of exposure the specific acetoclastic and the specific hydrogenotrophic methanogenic activities decreased 29% and 21%, respectively. The % of aggregates projected area with equivalent diameter (D(eq))>1mm decreased from 81% to 53%. The mean D(eq) of the aggregates > or =0.2mm decreased, as well as the settling velocity, showing that the granules experienced fragmentation phenomenon caused by the solvent shock load. The ratio between total filaments length and total aggregates projected area (LfA) increased 2 days before effluent volatile suspended solids, suggesting that LfA could be an early-warning indicator of washout events.

Audiological findings in individuals exposed to organic solvents: Case studies

Millions of people around the world are exposed to industrial organic solvents such as toluene and xylene in the manufacturing sectors. Solvents are neurotoxic substances that are detrimental to the functioning of the nervous system, including the central auditory nervous system (CANS). This study investigated hearing and auditory processing in seven individuals with a history of exposure to industrial solvents. A battery of audiological tests was administered to all subjects: pure tone, speech, and impedance audiometry, otoacoustic emissions tests, auditory brainstem responses, middle latency responses, as well as the SCAN-A and R-SPIN tests with low predictability sentence lists. All individuals in this study exhibited findings consistent with retrocochlear and/or central abnormality. Two of the seven subjects in this study had normal pure tone thresholds at all frequencies bilaterally, yet showed abnormal retrocochlear/central results on one or more tests. The auditory test battery approach used in this study appears to be valuable in evaluating the pathological conditions of the CANS in solvent-exposed individuals.