Toluene is a widely used organic solvent, heavily employed in many manufacturing industries. Recently, evidence has begun accumulate on the deleterious effect of toluene exposure on the auditory system. Although little published information exists regarding these effects; the reported findings indicate a need for further investigation. The results of such investigations may dramatically affect occupational hearing conservation practices and legislation. Both human and animal studies will be summarized discussing the effects of toluene alone or in combination with noise. (Auth)
Hearing Loss, Toluene ; Occupational Diseases ; Toxicity

This paper introduced the basic standards of the heart failure in Vietnam and the world such as opinions of Prof. Dang Van Chung, Gleger, Vu Dinh Hai, Tran Do Trinh, world health organization, New York Heart Association... and good points and bad points of each standard. This paper also introduced the new classification of the heart failure.
Hearing Loss, Toluene ; Occupational Diseases ; Toxicity

Acidosis ; etiology ; Humans ; Kidney Diseases ; etiology ; Toluene ; toxicity

OBJECTIVES: Polycyclic aromatic hydrocarbons (PAH) and toluene have been reported to induce reactive oxygen species and oxidative stress. This study was performed to investigate the effects of low level exposure to PAHs or toluene on the lipid peroxidation level in elementary school children and the elderly in a rural area. METHODS: Forty seven elementary school children and 40 elderly people who were living in a rural area and not occupationally exposed to PAH or toluene were the subjects of this study. Information about active or passive smoking and diet was obtained using a self-administered questionnaire. The urinary 1-hydroxypyrene (1-OHP), 2-naphthol, hippuric acid and thiobarbituric acid reactive substance (TBARS) concentrations were measured, and these values were corrected with the urinary creatinine concentration. RESULTS: In school children, the geometric means of the urinary 1-OHP, 2-naphthol, hippuric acid and TBARS levels were 0.02 ymol/mol creatinine, 0.47 micron mol/mol creatinine, 0.14 g/g creatinine and 0.95 micron mol/g creatinine, respectively. Those values for the elderly were 0.07 micron mol/mol creatinine, 1.87 micron mol/mol creatinine, 0.11 g/g creatinine and 1.18 micron mol/g creatinine, respectively. The mean levels of urinary 1-OHP, 2-naphthol and TBARS were significantly higher in the elderly subjects than in the children. The urinary TBARS level was not correlated with the urinary 1-OHP, 2-naphthol and hippuric acid, but they were correlated with the age of the subjects. CONCLSIONS: These results suggest that low level inhalation exposure to PAH or toluene does not markedly increase lipid peroxidation, and age is a significant determinant of lipid peroxidation.
Child ; Environmental Exposure/*adverse effects ; Environmental Pollutants/*toxicity ; Female ; Humans ; Male ; Middle Aged ; Polycyclic Hydrocarbons, Aromatic/*toxicity ; *Rural Population ; Thiobarbituric Acid Reactive Substances/*analysis ; Toluene/*toxicity ; Urinalysis

Animals ; Female ; Injections, Intraventricular ; Male ; Maze Learning ; drug effects ; Memory ; drug effects ; Mice ; Mice, Inbred Strains ; Toluene ; administration & dosage ; toxicity

Benzene and toluene have been widely employed as industrial solvents in Korea. However, they have recently been identified as cytogenetic toxic agents. This study is to observe the cytogenetic toxicities of benzene and toluene singularly and combined. The following concentrations of solvents were administered twice intraperitoneally to Sprague-Dawley rats: low concentration (11mg/Kg benzene and 108.75mg/Kg toluene), middle concentration (220mg/Kg benzene and (217.5mg/Kg toluene), and high concentration (440mg/Kg benzene and 435mg/Kg toluene). A low concentration represents the short term exposure limit of industrial workers. To examine the cytogenetic effects of the above solvents, the micronucleus test and the metaphase analysis were conducted followed by a statistical analysis based on non-parametric methods such as the Kruskal-Wallis multi sample test and the distribution free multiple comparison test A low concentration of benzene did not produce significant changes, however the two higher concentration of benzene showed clear signs of cytogenetic toxicities of bone marrow cells (i.e., the micronucleus occurrence rate and the chromosomal aberration rate were increased and the polychromatic erythrocyte percentage was decreased). While a low concentration of toluene produced no significant changes, the two higher concentrations of toluene showed similar signs of cytogenetic toxicities to bone marrow cells but to a somewhat lesser degree than benzene. When benzene and toluene were administered simultaneously at the two higher concentrations in order to observe their combined effects, all three signs of cytogenetic toxicities of bone marrow cells were decreased to a greater degree than the administration of benzene only. However, there were no significant reduction in the cytogenetic toxicities when benzene and toluene were simultaneously administered at low concentration. The above results showed that higher concentration of benzene and toluene displayed cytogenetic toxicities but showed competitive inhibition when they were administered simultaneously. However, there were no significant changes at low concentrations.
Animal ; Benzene/toxicity* ; Bone Marrow/pathology* ; Chromosome Aberrations/chemically induced* ; Chromosome Disorders ; Injections, Intraperitoneal ; Male ; Rats ; Rats, Inbred Strains ; Toluene/toxicity*

BACKGROUND/AIMS: The current study was designed to determine whether the indoor air pollution in a hemodialysis room (HD) was different from that of other comparable areas in a hospital. METHODS: Five air monitor samplers were hung on the ceiling and placed on the table in both the HD and general ward nursing stations, respectively. In addition, five samplers were placed in the nurse's breathing zone of the HD and the general ward, respectively. Ten air monitor samplers were also placed on the edge of the bed in the HD, which represented the patient's breathing zone. The levels of benzene and toluene were analyzed by GC/MS. RESULTS: In the general ward, the toluene concentration was significantly higher in the nurse breathing zone than that for the ceiling or table samples (p=0.001). The benzene concentration was also significantly higher in the general ward nurse breathing zone than that in the HD (p=0.006). In addition, the benzene concentrations on the table were higher at the general ward as compared to the HD (p=0.028), but there was no significant difference between the ceiling, general ward station and HD. CONCLUSIONS: Both the benzene and toluene concentrations in the HD appear to be more affected by the outdoor atmospheric conditions than by any potential indoor internal sources.
Adult ; Aged ; Air Pollution, Indoor/*analysis ; Benzene/analysis/*toxicity ; *Environmental Monitoring ; Female ; Health Status Indicators ; Humans ; Kidney Failure, Chronic ; Korea ; Male ; Middle Aged ; *Renal Dialysis ; *Safety ; Toluene/analysis/*toxicity ; *Urban Population

The development of a serological marker for early diagnosis of isocyanate-induced occupational asthma (isocyanate-OA) may improve clinical outcome. Our previous proteomic study found that expression of vitamin D-binding protein (VDBP) was upregulated in the patients with isocyanate-OA. In the present study, we evaluated the clinical relevance of VDBP as a serological marker in screening for isocyanate-OA among exposed workers and its role in the pathogenesis of isocyanate-OA. Three study groups including 61 patients with isocyanate-OA (group I), 180 asymptomatic exposed controls (AECs, group II), 58 unexposed healthy controls (NCs, group III) were enrolled in this study. The baseline serum VDBP level was significantly higher in group I compared with groups II and III. The sensitivity and specificity for predicting the phenotype of isocyanate-OA with VDBP were 69% and 81%, respectively. The group I subjects with high VDBP (> or = 311 microg/ml) had significantly lower PC20 methacholine levels than did subjects with low VDBP. The in vitro studies showed that TDI suppressed the uptake of VDBP into RLE-6TN cells, which was mediated by the downregulation of megalin, an endocytic receptor of the 25-hydroxycholecalciferol-VDBP complex. Furthermore, toluene diisocyanate (TDI) increased VEGF production and secretion from this epithelial cells by suppression of 1,25-dihydroxycholecalciferol [1,25(OH)2D3] production. The findings of this study suggest that the serum VDBP level may be used as a serological marker for the detection of isocyanate-OA among workers exposed to isocyanate. The TDI-induced VEGF production/secretion was reversed by 1,25(OH)2D3 treatment, which may provide a potential therapeutic strategy for patients with isocyanate-OA.
Adult ; Animals ; *Asthma/blood/chemically induced/pathology ; Cell Line ; Epithelial Cells ; Female ; Gene Expression/drug effects ; Humans ; Isocyanates/toxicity ; Male ; Middle Aged ; *Occupational Diseases/blood/chemically induced/pathology ; Rats ; Toluene 2,4-Diisocyanate/toxicity ; Vitamin D-Binding Protein/*blood

This investigation was designed to confirm IL-8 production from human bronchial epithelial cells with toluene diisocyanate (TDI) exposure and to examine the effects of pro-inflammatory cytokine and dexamethasone. We cultured Beas-2B, a bronchial epithelial cell line with TDI-HSA conjugate and compared with those without conjugate. IL-8 in the supernatant was measured by ELISA. To evaluate the effect of proinflammatory cytokines, peripheral blood mononuclear cells (PBMC) were collected from TDI- and non-TDI asthma patients, and were added to the epithelial cell culture. Dexamethasone or antibodies to TNF-alpha and IL-1beta were pre-incubated with PBMC supernatant. There was a significant production of IL-8 from bronchial epithelial cells with addition of TDI-HSA conjugate in a dose-dependent manner, which was significantly augmented with addition of PBMC supernatant. Higher production of IL-8 was noted with addition of PBMC supernatant from TDI-asthma patients than in those from non-TDI asthma patients. IL-1beta and IL-1beta/TFNalpha antibodies were able to suppress the IL-8 productions. Pre-treatment of dexamethasone induced dose-dependent inhibition of the IL-8 production. These results suggest that the IL-8 production from bronchial epithelial cells contribute to neutrophil recruitment occurring in TDIinduced airway inflammation. IL-1beta released from PBMC of TDI-induced asthma patients may be one of the pro-inflammatory cytokines to enhance IL-8 production.
Asthma/immunology ; Bronchi/*cytology/metabolism ; Cell Line ; Dexamethasone/pharmacology ; Epithelial Cells/cytology/*drug effects/*metabolism ; Glucocorticoids/pharmacology ; Human ; Interleukin-8/*metabolism ; Leukocytes, Mononuclear/cytology/metabolism ; Support, Non-U.S. Gov't ; Toluene 2,4-Diisocyanate/*toxicity

OBJECTIVES: We established a Wistar rat model of asthma caused by toluene diisocyanate (TDI) exposure, and investigated the relationship between TDI exposure concentrations and respiratory hypersensitivity, airway inflammation, and cytokine secretions in animals, to better understand the mechanism of TDI induced occupational asthma. METHODS: Wistar rats were exposed to two different concentrations of TDI vapor four hours a day for five consecutive days. Bronchoalveolar lavage (BAL) was performed, and differential leucocytes from the BAL fluid were analyzed. Lung histopathological examination was carried out to investigate the inflammatory status in the airways. Production of cytokines interleukin (IL)-4 and IL-5 productions in the BAL fluid in vivo was determined with enzyme-linked immunosorbent assay kits. RESULTS: The TDI-exposed rats exhibited greater airway hypersensitivity symptoms than the control rats. The BAL differential cell count and lung histopathological examination demonstrated that inflammation reactions were present in both the central and peripheral airways, characterized with marked infiltration of eosinophils in the TDI-exposed rats. The cytokine assay showed that IL-4 and IL-5 were predominantly produced in the BAL fluid in vivo. CONCLUSIONS: These findings imply that TDI exposure concentrations may greatly affect the occurrence and extent of inflammatory events and that Th2 type cytokines may play an important role in the immunopathogenesis of TDI-induced occupational respiratory hypersensitivity.
Animals ; Bronchoalveolar Lavage Fluid/chemistry/cytology ; Enzyme-Linked Immunosorbent Assay ; Eosinophils/cytology/immunology ; Female ; Gases/chemistry ; Hypersensitivity/pathology ; Interleukin-4/*analysis ; Interleukin-5/*analysis ; Lung/*drug effects/pathology/secretion ; Rats ; Rats, Wistar ; Toluene 2,4-Diisocyanate/*toxicity