Toluene In Ambient Air Research Articles

The Effects of Toluene Plus Noise on Hearing Thresholds: An Evaluation Based on Repeated Measurements in the German Printing Industry

The ototoxicity of occupational exposure to toluene plus noise was investigated in a longitudinal study in rotogravure printing and existing findings in the literature were evaluated. The study comprised four repeated examinations during 5 years and started with 333 male workers. Lifetime weighted average exposures (LWAE) to toluene and noise were determined from individual work histories and historic recordings; recent individual exposures were measured 10 times during the study (toluene, active sampling; noise, stationary measurements). Auditory thresholds were measured with pure tone audiometry at 0.125, 0.25, 0.5, 0.75, 1, 2, 3, 4, 6, 8, 12 kHz. Mean LWAE exposures to toluene and noise were 45+/-17 ppm plus 82+/-7 dB(A) for high toluene exposed and 10+/-7 ppm plus 82+/-4 dB(A) for low toluene exposed subjects, mean current exposures were 26+/-20 ppm plus 81+/-4 dB(A) and 3+/-3 ppm plus 82+/-4 dB(A). Mean exposure duration was 21.3+/-6.5 years for long exposed and 5.9+/-2.2 years for short exposed subjects. Repeated measurement analyses of variance did not reveal effects of toluene intensity, exposure duration and interactions between toluene intensity and noise intensity. Noise intensity [79+/-3 dB(A) vs. 84+/-1 dB(A)] was significant for auditory thresholds. A case concept utilising developments of individual auditory thresholds did not reveal significant toluene effects. Logistic models including age, exposure duration, toluene in ambient air, current noise and either hippuric acid or ortho-cresol (o-cresol) found only age to be significant for elevated OR of high frequency hearing loss. Due to missing toluene effects, it was concluded that the threshold level for developing hearing loss as a result of occupational exposure to toluene plus noise might be above the current limit of 50 ppm toluene.

Psychomotor performance and subjective symptoms at low level toluene exposure

Objectives: Possible effects of long term occupational exposure to toluene below the level of 100 ppm on psychomotor performance and subjective symptoms were investigated in a cross sectional approach. Methods:...

Sources and photodecomposition of formaldehyde and acetaldehyde in Rome ambient air

Atmospheric levels of formaldehyde and acetaldehyde as well as their diurnal and seasonal variations were investigated from 1994 to 1997 in downtown Rome during sunny and wind calm days. Hourly concentrations of formaldehyde ranged from 8 to 28 ppbV in summer and 7 to 17 ppbv in winter; acetaldehyde concentrations varied correspondingly within the 3–18 and 2–7 ppbv intervals. Percentages of both aldehydes photochemically produced were estimated through a simple relationship based upon the comparison of individual ratios of formaldehyde and acetaldehyde to toluene in ambient air and automobile emission. Photochemical production was found to weigh upon atmospheric levels for 80–90% in summer days. It dropped below 35% in the winter period, when direct emission from traffic largely predominated. Photochemical summer source was more efficient for acetaldehyde than for formaldehyde, especially in the early morning. The importance of formaldehyde as the major source of hydroxyl radicals in Rome was also assessed.

Measurements of benzene and toluene in ambient air using proton-transfer-reaction mass spectrometry: calibration, humidity dependence, and field intercomparison

PTR-MS (proton transfer reaction–mass spectrometry) is a chemical ionization mass spectrometry technique that uses proton transfer reactions with H 3O + ions for on-line measurements of organic trace gases in air. The instrument is calibrated for benzene and toluene, and the humidity dependence is investigated. The observed humidity dependence is explained using a simple model that calculates the distribution of H 3O + · (H 2O) n ( n=0, 1, 2, 3) cluster ions in the reactor. These findings were verified in a field intercomparison by comparing PTR-MS measurements of benzene and toluene with GC (gas chromatograph) analyses of gas samples. Isoprene, acetone, acetonitrile, methanol, dimethyl sulfide, and acetaldehyde were also investigated, and no humidity dependence was found, except for isoprene, when larger clusters were used as primary ions.

Qualitative color vision impairment in toluene-exposed workers.

The aim of this study was to evaluate whether toluene, like many other organic solvents and solvent mixtures, could impair color vision. We investigated color vision impairment in three groups of workers, two groups occupationally exposed to toluene and a nonexposed group. The first exposed group, group E1, comprised 41 workers (median value of toluene in air 35.00 ppm, range 11.3-49.3 ppm) and the second exposed group, group E2, comprised 32 subjects (median value of toluene in air 156.00 ppm, range 66.0-250.0 ppm). The nonexposed group, group NE, comprised 83 subjects. Color vision was evaluated by the Lanthony D-15 desaturated test according to Verriest's classification: type I, loss in the red-green range; type II, loss in the blue-yellow and red-green ranges, and type III, loss in the blue-yellow range. Subjects were classified as dyschromates if specific acquired loss was determined in at least one eye. In both exposed groups, exposure was evaluated by measurement of the concentration of toluene in the ambient air and in the blood. In group E2, level of hippuric acid and orthocresol in urine after the work shift were also determined. The Mann-Whitney U-test, t-test, chi 2-test, and Spearman's rank correlation and multiple regression analysis were used for statistical analysis. Type III dyschromatopsia was detected in all groups examined: 26.6% of the workers in group NE, 31.7% of those in group E1, and 50% of those in group E2. As many as 15.6% of the workers in group E2, 4.8% of those in group E1, and only 1.2% of those in group NE had type II dyschromatopsia. A statistically significant difference in the prevalence of total dyschromatopsia (type III + type II) was established among the three examined groups together (chi 2 = 14.13; df = 2; P < 0.01), between group E2 and group E1 (chi 2 = 4.96; P < 0.05), and between group E2 and group NE (chi 2 = 12.50; P < 0.005), whereas no significant difference was found between groups E1 and NE. Type III dyschromatopsia was significantly correlated with age in group NE (P < 0.01) and in group E1 (P < 0.005). In group E2, both type II (P < 0.05) and type III dyschromatopsia correlated with toluene in ambient air and with the duration of exposure to toluene (both P < 0.005). In group E2, total dyschromatopsia correlated significantly with toluene in ambient air and in blood (both P < 0.05) as well as with hippuric acid in urine after the work shift (P < 0.001). This study suggests that toluene can impair color vision.

Assessment of colour vision impairment in male workers exposed to toluene generally above occupational exposure limits.

We investigated colour vision impairment in 45 male workers occupationally exposed to toluene (mean value of toluene concentration in ambient air = 119.96 ppm) and in 53 controls. Colour vision was evaluated by Lanthony-D-15 desaturated test and expressed as Age and Alcohol Intake Adjusted Colour Confusion Score (AACDS) or types of dyschromatopsia. Exposure was evaluated by measurement of toluene concentration in ambient air and blood, and hippuric acid and orthocresol determined in urine after the workshift. A statistically significant higher AACDS value was established in the exposed subjects compared to the controls (p < 0.0001). There was no significant difference between AACDS values on Wednesday morning compared to Monday morning. In the exposed group AACDS significantly correlated with the concentration of toluene in ambient air, concentration of toluene in blood and the concentration of hippuric acid in urine after the workshift (all p < 0.0001). Dyschromatopsias were detected in both groups, although no significant difference between groups was established. In the exposed group concentration of toluene in ambient air, alcohol intake and age explained 35.1%, concentration of toluene in blood, age and alcohol intake explained 19.9%, and concentration of hippuric acid in urine and age explained 19.2% of the variation in type III dyschromatopsia. Concentration of toluene in ambient air and age explained 28.3% of the variation in total dyschromatopsia, and concentration of hippuric acid and age explained 13.8%. In the control group, age and alcohol intake explained 19.6% of the variation in type III dyschromatopsia. In exposed workers a significant difference was found in the AACDS value compared to controls. However, no significant difference was found in the prevalence of colour vision loss in the yellow-blue and/or red-green axis. Based on the results of this study the authors conclude that the effect of toluene on colour vision can be chronic and that the possible reparation period in colour vision impairment is longer than 64 hours.

S-p-toluylmercapturic acid in the urine of workers exposed to toluene: a new biomarker for toluene exposure.

A mercapturic acid attached to the aromatic ring of toluene was for the first time detected in human urine as a metabolite of toluene. Since the metabolism of toluene is usually considered to take place at the side-chain, this gives, besides the biosynthesis of cresols, a further hint of a metabolic conversion of the aromatic system. We examined a group of 33 workers occupationally exposed to toluene, determining the concentrations of toluene in ambient air and in whole blood, o-cresol and hippuric acid in urine and p-toluylmercapturic acid (p-TMA) in urine. All blood and urine samples were collected post-shift. The renal excretion of S-p-toluylmercapturic acid showed highly significant correlations with established parameters of a biological monitoring of toluene. The median ambient air concentration was 63 ppm, ranging from 13 to 151 ppm, the median concentration of toluene in whole blood was 804 microg/l, corresponding to median urinary concentrations for o-cresol of 2.3 mg/l, hippuric acid of 2.3 g/l and p-TMA of 20.4 microg/l. p-TMA was not detectable in urine samples of a control group of 10 non-exposed persons. Both the German Biological Tolerance Values (BAT-values) for toluene in blood (1000 microg/l) and o-cresol in urine (3 mg/l) correspond to a mean p-TMA elimination of approximately 50 microg/l, and thus are in agreement with each other. According to our results p-TMA reflects internal toluene exposure diagnostically sensitive and specifical. With the developed analytical procedure we determined a median benzylmercapturic acid (BMA) concentration of 190 microg/l in the urine samples of the toluene exposed persons. We also determined a median BMA concentration of 30 microg/l in the control samples of non-exposed persons. However, these results are preliminary and require further confirmation as the reliability of the method was determined only for p-TMA.

Occupational chronic exposure to organic solvents. XVI. Ambient and biological monitoring of workers exposed to toluene.

Ambient air and biological monitoring of an occupational toluene exposure was carried out on a group of 33 workers. The biological monitoring of the workers was based on determination of the concentration of toluene in blood and on quantification of the urinary metabolites o-cresol and hippuric acid. All blood and urine samples were collected post-shift. The average toluene concentration in the workplace air was 65 ppm, ranging from 13 to 151 ppm. AN average concentration of toluene in the blood of 911 microns/1 was found, corresponding to an average urinary concentration of 2.9 mg/1 (2.3 mg/g creatinine) o-cresol and 2.4 g/l (1.9 g/g creatinine) hippuric acid. Both urinary metabolites can be correlated with the concentration of toluene in ambient air and blood, respectively. The results of our study indicate that the determination of the urinary o-cresol excretion represents a diagnostically specific and sensitive parameter for the estimation of an individual toluene uptake. In contrast, monitoring of the concentration of hippuric acid in urine cannot be recommended for assessment of individual exposure. To set up a biological tolerance value (BAT) for o-cresol, a urinary concentration of 3 mg/l o-cresol should be in accordance with the current MAK value of 50 ppm toluene.

Quantification of toxic hydrocarbon target compounds in engine exhaust and air by aluminum oxide porous-layer open-tubular capillary gas chromatography-mass spectrometry using isotopically labeled internal standards

Abstract A method for the determination of 1,3-butadiene, benzene and toluene in ambient air and engine exhaust is described. Air was sampled with a canister and then analysed by Al 2 O 3 -coated porous-layer open-tubular (PLOT) capillary gas chromatography-mass spectrometry. The PLOT column provides better resolution for light hydrocarbons and also alleviates the need of using a sub-ambient oven temperature. While the retention times might change owing to the adsorption of moisture, the use of mass spectrometry for detection and isotopically labeled analytes as the internal standards greatly improved the confidence of identification. The heating of solid deuterated butadiene sulfone provides a convenient method for the preparation of deuterated butadiene standard gas. To couple a wide-bore PLOT column with a bench-top mass spectrometer, a pressure gradient and open split interface were used in order to maintain the chromatographic resolution and limit the running time within a reasonable range.

Continuous detection of toluene in ambient air with a coated piezoelectric crystal

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTContinuous detection of toluene in ambient air with a coated piezoelectric crystalMat H. Ho, George G. Guilbault, and Bernd. RietzCite this: Anal. Chem. 1980, 52, 9, 1489–1492Publication Date (Print):August 1, 1980Publication History Published online1 May 2002Published inissue 1 August 1980https://doi.org/10.1021/ac50059a024RIGHTS & PERMISSIONSArticle Views78Altmetric-Citations53LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (508 KB) Get e-Alerts Get e-Alerts