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1.
Environ Sci Pollut Res Int ; 31(21): 31443-31454, 2024 May.
Article in English | MEDLINE | ID: mdl-38630400

ABSTRACT

Benzene, toluene, ethylbenzene, and xylene (BTEX) are ubiquitous in the environment, and all of them can cause neurotoxicity. However, the association between BTEX exposure and dyslexia, a disorder with language network-related regions in left hemisphere affected, remains unclear. We aimed to assess the relationship between BTEX exposure and dyslexic odds among school-aged children. A case-control study, including 355 dyslexics and 390 controls from three cities in China, was conducted. Six BTEX metabolites were measured in their urine samples. Logistic regression model was used to explore the association between the BTEX metabolites and the dyslexic odds. Urinary trans,trans-muconic acid (MU: a metabolite of benzene) was significantly associated with an increased dyslexic odds [odds ratio (OR) = 1.23, 95% confidence interval (CI): 1.01, 1.50], and the adjusted OR of the dyslexic odds in the third tertile was 1.72 (95% CI: 1.06, 2.77) compared to that in the lowest tertile regarding urinary MU concentration. Furthermore, the association between urinary MU level and the dyslexic odds was more pronounced among children from low-income families based on stratified analyses. Urinary metabolite levels of toluene, ethylbenzene, and xylene were not found to be associated with the dyslexic odds. In summary, elevated MU concentrations may be associated with an increased dyslexic odds. We should take measures to reduce MU related exposure among children, particularly those with low family income.


Subject(s)
Benzene Derivatives , Benzene , Dyslexia , Toluene , Xylenes , Humans , Child , Xylenes/urine , Toluene/urine , Male , Benzene Derivatives/urine , China , Female , Dyslexia/urine , Case-Control Studies , Environmental Exposure , Sorbic Acid/analogs & derivatives , Sorbic Acid/metabolism , Odds Ratio
2.
J Asthma ; 61(8): 801-807, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38198535

ABSTRACT

BACKGROUND: We investigated the correlation between urine VOC metabolites and airway function in children exposed to anthropogenic volatile organic compounds (VOCs), notable pollutants impacting respiratory health. METHODS: Out of 157 respondents, 141 completed skin prick tests, spirometry, IOS, and provided urine samples following the International Study of Asthma and Allergies in Childhood (ISAAC)-related questions. Allergic sensitization was assessed through skin prick tests, and airway functions were evaluated using spirometry and impulse oscillometry (IOS). Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) was recorded and FEV1/FVC ratio was calculated. Airway mechanics parameters including respiratory resistance at 5 Hz (Rrs5) mean respiratory resistance between 5 Hz and 20 Hz (Rrs5-20), were also recorded. Urine concentrations of metabolites of benzene, ethylbenzene, toluene, xylene, styrene, formaldehyde, carbon-disulfide were analyzed by gas chromatography/tandem mass spectroscopy. RESULTS: The median age at study participation was 7.1 (SD 0.3) years. Muconic acid (benzene metabolites) and o-methyl-hippuric acid (xylene metabolites) above medians were associated with a significant increase in Rrs5 (muconic acid: aß = 0.150, p = .002; o-methyl-hippuric acid: aß = 0.143, p = .023) and a decrease in FEV1/FVC (o-methyl-hippuric acid: aß = 0.054, p = .028) compared to those below median. No associations were observed for Rrs5-20 and FEV1 between the groups categorized as above and below the median (all parameter p values > .05). CONCLUSIONS: Elevated levels of benzene and xylene metabolites were associated with a significant increase in Rrs5 and a decrease in FEV1/FVC, related to increased resistance and restrictive lung conditions compared to individuals with concentrations below the median.


Subject(s)
Volatile Organic Compounds , Humans , Child , Volatile Organic Compounds/urine , Male , Female , Vital Capacity , Spirometry , Forced Expiratory Volume , Skin Tests , Sorbic Acid/analogs & derivatives , Sorbic Acid/analysis , Environmental Exposure/adverse effects , Environmental Exposure/analysis , Respiratory Function Tests , Xylenes/urine , Benzene/analysis , Airway Resistance , Benzene Derivatives/urine , Air Pollutants/urine , Air Pollutants/analysis , Air Pollutants/adverse effects , Asthma/urine , Asthma/physiopathology , Hippurates/urine , Oscillometry , Lung
3.
Ecotoxicol Environ Saf ; 241: 113717, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35679732

ABSTRACT

The aim of this study was to compare the concentrations of the benzene, toluene, ethylbenzene, and xylene (BTEX) compounds in the urine of smokers and the control group considering the role of age, weight, job, history of waterpipe and cigarette smoking, and driving time. The chemicals in the urine of 99 smokers and 31 nonsmokers were extracted by liquid-liquid extraction method and their concentrations were measured by liquid injection GC/MS. The mean concentration of benzene, toluene, ethylbenzene, m-xylene, o-xylene, p-xylene, and total BTEX in waterpipe smokers were found to be 471.40, 670.90, 127.91, 167.64, 90.62, 46.04, and 1574.50 ng/g. creatinine, respectively. For the waterpipe&cigarette smokers, the concentration of the compounds were 708.00, 959.00, 146.40, 192.50, 93.30, 53.07, and 2152.00 ng/g.creatinine, respectively. For nonsmokers the concentrations of these compounds were 88.12, 140.40, 36.68, 57.29, 31.53, 26.21, and 380.30 ng/g.creatinine, respectively. Driving time, waterpipe smoking and cigarette smoking were positively associated with BTEX concentration (p < 0.05). Fruity tobacco showed higher concentrations of BTEX compared to the regular tobacco, and athlete persons had les urinary BTEX than the non-athletes. There was not significant correlation between the BTEX and age, height, weight, and BMI. High concentrations of BTEX compounds in the urine of waterpipe and cigarette smokers compared to nonsmokers indicate that waterpipe and cigarette can be an important source of exposure to these compounds and the known adverse effects of these compounds, especially carcinogenicity, threaten the health of smokers.


Subject(s)
Benzene , Water Pipe Smoking , Benzene Derivatives/urine , Creatinine , Humans , Non-Smokers , Smokers , Toluene/urine , Xylenes/urine
4.
Rocz Panstw Zakl Hig ; 73(1): 121-130, 2022.
Article in English | MEDLINE | ID: mdl-35322964

ABSTRACT

Background: Occupational factors have previously been mentioned as contributing to decreased kidney function and the development of chronic kidney disease of unknown cause. Sea salt workers are one of the occupations facing high outdoor temperatures and a highly, intensive workload. Objectives: The purpose of the study was to examine whether the kidney function of sea salt workers at the beginning of the harvest season differs from kidney function at the end of the harvest season and to identify factors that can predict the change of kidney function. Material and methods: Data were collected from salt workers (n=50) who were between 18­60 years of age without hypertension, diabetes, and kidney disease in Samut Sakhon province, Thailand. Urine specific gravity (USG) was used for hydration status and the estimated glomerular filter rate (eGFR) was used to measure kidney function. The mixed model was used to find differences over the harvest season and prediction of factors. Results: On average, the eGFR was estimated to decrease by 15.2 ml/min/1.73 m2 over the harvest season. The decline in eGFR of sea salt workers with moderate and heavy workloads were significantly faster than their light workload counterparts after controlling for other covariates. Similarly, dehydration (USG ≥ 1.030) significantly accelerated the rate of kidney function loss. Conclusion: Our study confirmed exposure to heat over the harvest season leads to decreased eGFR in sea salt workers. The rate of change of eGFR could be predicted by workload and hydration status. Workers with dehydration who performed medium to heavy workloads in farms showed faster kidney function decline than those who performed light workload.


Subject(s)
Occupational Exposure , Humans , Kidney/chemistry , Seasons , Thailand , Xylenes/urine
5.
Mikrochim Acta ; 187(7): 387, 2020 06 14.
Article in English | MEDLINE | ID: mdl-32535659

ABSTRACT

A deep eutectic solvent functionalized graphene oxide composite adsorbent (DFG) was synthesized through reversible-addition fragmentation chain-transfer polymerization. The synthesized DFG had multiple adsorption interactions after covalent modification with a deep eutectic solvent (allyltriethylammonium bromide/ethylene glycol). Adsorption isotherms and kinetics studies of DFG indicate that the adsorption of hippuric acid (HA) and methylhippuric acid (MHA) was monolayer chemical adsorption. The comparison of DFG with commercial adsorbents demonstrates that the adsorption ability of DFG was superior. This was due to the multiple adsorption interactions of DFG for the three analytes (mainly π-interaction, hydrogen bonding, electrostatic adsorption, and hydrophobic interaction). The DFG adsorbent was applied to miniaturized pipette-tip solid-phase extraction (MPT-SPE), followed by high-performance liquid chromatography (HPLC) to determine biomarkers in urine for toluene and xylene exposure. The DFG-MPT-SPE-HPLC method required only 2.00 mg of DFG as adsorbent, 0.50 mL of washing solvent, and 0.40 mL of elution solvent to achieve a wide linear range (0.200-200 µg mL-1), high recoveries (90.9-99.1%), and high precision (RSD ≤ 6.3%). The proposed method was applied to determine HA and MHA in urine samples from occupational workers. Graphical abstract Deep eutectic solvent functionalized graphene oxide composite adsorbent for miniaturized pipette-tip solid-phase extraction of toluene and xylene exposure biomarkers in urine prior to their determination with HPLC-UV.


Subject(s)
Graphite/chemistry , Ionic Liquids/chemistry , Toluene/urine , Xylenes/urine , Adsorption , Biomarkers/chemistry , Biomarkers/urine , Chromatography, High Pressure Liquid , Graphite/chemical synthesis , Humans , Ionic Liquids/chemical synthesis , Quaternary Ammonium Compounds/chemical synthesis , Quaternary Ammonium Compounds/chemistry , Solid Phase Extraction/instrumentation , Solid Phase Extraction/methods , Solvents/chemical synthesis , Solvents/chemistry , Toluene/chemistry , Toluene/isolation & purification , Xylenes/chemistry , Xylenes/isolation & purification
6.
Article in Chinese | MEDLINE | ID: mdl-32306697

ABSTRACT

Objective: To describe for the determination of contents of metabolites of benzene compounds in urine sample by high performance liquid chromatography. Methods: After acidification with hydrochloric acid, metabolites in urine were first extracted by acetonitrile and isopropanol (V∶V, 9∶1) with excessive sodium chloride, then gradient separated on a C18 column and then determined by DAD detector. Results: There were good linear relationship between peak areas and injection quality in range of 2.00-100 mg/L (r>0.999). The detection limit and quantitative limit of this method were 4.15-70.7 µg/L and 13.8-235 µg/L respectively. The precision for the analysis of urine was1.78%-8.23% (n =6). The average recovery of metabolites was 85.4%-105.5% at thee spiked levels in the range of 2.00-100 mg/L. Conclusion: The accuracy and reproducibility obtained make this method useful for the biological monitoring of occupational exposure to toluene, xylene, styrene and ethylbenzene.


Subject(s)
Benzene Derivatives/urine , Benzene/analysis , Styrene/urine , Toluene/urine , Xylenes/urine , Chromatography, High Pressure Liquid , Humans , Occupational Exposure/analysis , Reproducibility of Results
7.
Article in Chinese | MEDLINE | ID: mdl-31177703

ABSTRACT

Objective: To develop a method using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to determine the urinary metabolites of benzene, toluene and xylene. The selected metabolites are S-phenylmercapturic acid (S-PMA) , trans, trans-muconic acid (t, t-MA) , 8-hydroxy-2 deoxyguanosine (8-OHdG) , hippuric acid (HA) , 2-methylhippuric acid (2-MHA) , 3-methylhippuric acid (3-MHA) and 4-methylhippuric acid (4-MHA) . Methods: The urine sample was pretreated using methanol to precipitate the proteins. HSS T3 chromatographic column was used to separate the metabolites. The mass spectrometric acquisition was carried out using multiple reaction monitoring (MRM) after ionization with ESI source. External standard method was used for quantification. Results: All the standard curves showed good linear relation, and r of the seven metabolites was all above 0.999. The detection limits and quantitative limits of the seven metabolites were 0.01-500 ng/ml and 0.02-1 000 ng/ml (based on the actual dilution ratio) , respectively. The average spiked recoveries of four loadings ranged from 85.8% to 109.9%. The intra-day and inter-day precisions were 0.2%-4.5% and 0.6%-9.5%, respectively. The samples can be kept for at least 14 days at both 4 ℃ and -20 ℃. Conclusion: This method is simple, rapid and highly sensitive with low cost, and its accuracy, precision and stability can meet the daily test requirements. It can be applied for the determination of urinary S-PMA, t, t-MA, 8-OHdG, HA, 2-MHA, 3-MHA and 4-MHA for the occupational population exposed to benzene, toluene and xylene.


Subject(s)
Benzene , Chromatography, High Pressure Liquid , Toluene , Xylenes , Benzene/analysis , Mass Spectrometry , Occupational Exposure , Toluene/urine , Xylenes/metabolism , Xylenes/urine
8.
J Pharm Biomed Anal ; 174: 115-122, 2019 Sep 10.
Article in English | MEDLINE | ID: mdl-31163345

ABSTRACT

Benzene (B), toluene (T), ethylbenzene (E), o-, m- and p-xylene (o-, m-, p-X) are ubiquitous and frequently exposed to human throughout the environment. Previously published test methods for phenolic biomarkers are not sensitive enough to be detected in most general population groups and require a lot of labor. A simple and convenient headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry method was described for the simultaneous determination of 15 hydroxyl biomarkers of BTEX in urine. Hydroxyl biomarkers in urine were vaporized and adsorbed onto a selected fiber after enzyme hydrolysis with ß-glucuronidase/arylsulfatase. The optimal HS-SPME conditions were achieved with an 85-µm-carboxen-polydimethylsiloxane fiber, an extraction temperature of 70 °C, a heating time of 30 min, and a pH of 4.0. The desorption was performed for 1 min at 250 °C. Under the established conditions, the lowest limits of detection were from 0.02 to 0.15 µg/L in 5.0 mL of urine, and the intra- and inter-day relative standard deviations were less than 12.7% at 0.5, 2.0, 50, and 200 µg/L. The calibration curve demonstrated good linearity with greater than r2 = 0.99 in synthetic urine. This method is convenient, simple, environmentally friendly, and amenable to automation.


Subject(s)
Benzene Derivatives/urine , Benzene/chemistry , Biomarkers/urine , Toluene/urine , Xylenes/urine , Adolescent , Calibration , Child , Child, Preschool , Gas Chromatography-Mass Spectrometry , Humans , Hydrogen-Ion Concentration , Ions , Limit of Detection , Linear Models , Reproducibility of Results , Solid Phase Microextraction , Temperature , Urinalysis
9.
J Occup Health ; 61(1): 82-90, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30698338

ABSTRACT

OBJECTIVES: The purpose of this study was to develop a simple and accurate gas chromatography-mass spectrometry (GC-MS) method for simultaneous determination of four urinary metabolites from four organic solvents, that is, hippuric acid (HA) from toluene, methylhippuric acid (MHA) from xylene, and mandelic acid (MA) and phenylglyoxylic acid (PGA) from styrene or ethylbenzene for biological monitoring. METHODS: The four metabolites were directly methyl-esterified with 2,2-dimethoxypropane and analyzed using GC-MS. The proposed method was validated according to the US Food and Drug Administration guidance. The accuracy of the proposed method was confirmed by analyzing a ClinChek® -Control for occupational medicine (RECIPE Chemicals +Instruments GmbH). RESULTS: Calibration curves showed linearity in the concentration range of 10-1000 mg/L for each metabolite, with correlation coefficients >0.999. For each metabolite, the limits of detection and quantification were 3 mg/L and 10 mg/L, respectively. The recovery was 93%-117%, intraday accuracy, expressed as the deviation from the nominal value, was 92.7%-103.0%, and intraday precision, expressed as the relative standard deviation (RSD), was 1.3%-4.7%. Interday accuracy and precision were 93.4%-104.0% and 1.2%-9.5%, respectively. The analytical values of ClinChek obtained using the proposed method were sufficiently accurate. CONCLUSIONS: The proposed method is a simple and accurate which is suitable for routine analyses that could be used for biological monitoring of occupational exposure to four organic solvents.


Subject(s)
Environmental Monitoring/methods , Gas Chromatography-Mass Spectrometry/methods , Occupational Exposure/analysis , Benzene Derivatives/urine , Esterification , Humans , Propanols , Reproducibility of Results , Styrene/urine , Toluene/urine , Xylenes/urine
10.
Sci Total Environ ; 656: 540-546, 2019 Mar 15.
Article in English | MEDLINE | ID: mdl-30529957

ABSTRACT

Composting facilities workers are potentially exposed to different volatile organic compounds (VOCs). This study aims to investigate the potential exposure to benzene, toluene, ethylbenzene and xylenes (BTEX) compounds among workers of composting facilities by measuring un-metabolized BTEX in urine and to investigate the effect that several lifestyle factors (i.e. smoking and residential traffic), using personal protective equipment, and religious practices such as Ramadan fasting can have on the urinary BTEX concentrations. We assessed concentrations of BTEX in the urine of a composting facility workers. Samples were collected in May 2018. Overall, 25 workers chosen as the exposed group and 20 inhabitants living close to the composting facility as a control group. The urine samples were collected from studied subjects. Identification and quantification of un-metabolized BTEX was performed using a headspace gas chromatography-mass spectrometry (GC-MS). Detailed information of participants was gathered by a comprehensive questionnaire. The geometric mean levels of urinary benzene, toluene, ethylbenzene, m­p xylene, and o­xylene in the exposed subjects were 1.27, 2.12, 0.54, 1.22 and 1.51 µg/L, respectively; 1.4 to 3.7-time higher than values in control group (p < 0.05). Post-shift levels were significantly higher than pre-shift for all chemicals (p < 0.05). Smoking habits, exposure to environmental tobacco smoke, and Ramadan fasting predicted urinary BTEX levels. Personal protective equipment which included a simple N95 mask did not protected workers from BTEX emissions. Composting facilities represent a significant source BTEX emissions and exposure for staff. More effective protective strategies are required to minimize exposure and related occupational hazards.


Subject(s)
Air Pollutants, Occupational/urine , Composting , Life Style , Occupational Exposure , Volatile Organic Compounds/metabolism , Adult , Benzene/metabolism , Benzene Derivatives/urine , Humans , Iran , Male , Toluene/urine , Xylenes/urine
11.
Sci Total Environ ; 631-632: 857-865, 2018 Aug 01.
Article in English | MEDLINE | ID: mdl-29727996

ABSTRACT

Urinary benzene, toluene, ethylbenzene, and xylenes (BTEX) can be used as a reliable biomarker of exposure to these pollutants. This study was aimed to investigate the urinary BTEX concentration in operators of healthcare waste (HCW) autoclaves. This cross-sectional study was conducted in selected hospitals in Tehran, Iran between April and June 2017. Twenty operators (as the case group) and twenty control subjects were enrolled in the study. Personal urine samples were collected at the beginning and end of the work shift. Urinary BTEX were measured by a headspace gas chromatography-mass spectrometry (GC/MS). A detailed questionnaire was used to gather information from subjects. Results showed that the median of urinary benzene, toluene, ethylbenzene, m-p xylene, and o-xylene levels in the exposed group were 3.26, 3.36, 0.84, 3.94 and 4.48 µg/L, respectively. With the exception of ethylbenzene, subjects in the exposed group had significantly higher urinary BTEX levels than control group (p < 0.05). Urinary BTEX concentrations in the exposed case group were 2.5-fold higher than in the control group. There was a significant relationship between the amount of generated waste per day and the urinary BTEX in the exposed group. Smoking status and type of autoclave used were also identified as predictors of urinary BTEX concentrations. The healthcare waste treatment autoclaves can be considered as a significant BTEX exposure source for operators working with these treatment facilities. The appropriate personal protection equipment and control measures capable in reducing BTEX exposure should be provided to HCW workers to reduce their exposures to BTEX.


Subject(s)
Air Pollutants, Occupational/urine , Medical Waste Disposal/methods , Occupational Exposure/analysis , Adult , Benzene/analysis , Benzene/metabolism , Benzene Derivatives/urine , Biomarkers/urine , Cross-Sectional Studies , Environmental Monitoring/methods , Humans , Iran , Toluene/analysis , Toluene/urine , Xylenes/analysis , Xylenes/urine
12.
Urol Oncol ; 36(5): 243.e21-243.e27, 2018 May.
Article in English | MEDLINE | ID: mdl-29395956

ABSTRACT

BACKGROUND: Prostate cancer (PCa) is the most frequently diagnosed noncutaneous malignant tumor among males in the Western world. Prostate-specific antigen has been considered the most important biomarker for PCa detection; however, it lacks specificity, leading to the search for alternative biomarkers. Volatile organic compounds (VOCs) are released during cell metabolism and can be found in exhaled breath, urine, and other fluids. VOCs have been used in the diagnosis of lung, breast, ovarian, and colorectal cancers, among others. The objective of this study was to identify urinary VOCs that may be sensitive and specific biomarkers for PCa. METHODS: The study included 29 patients with PCa and 21 with benign prostatic hyperplasia. Urine samples were obtained from all participants before and after prostate massage. VOCs were identified by gas chromatography-mass spectrometry. IBM SPSS Statistics v.20 was used for statistical analysis. Sample normality and homogeneity of variances were studied and, according to the distribution normality, ANOVA or the Kruskal-Wallis test was applied to evaluate significant differences between groups. The Pearson test was used to establish correlations. RESULTS: Fifty-seven VOCs were identified. Samples gathered before prostate massage showed significant between-group differences in urinary levels of furan (P≤ 0.001), 2-ethylhexanol (P = 0.032), 3,5-dimethylbenzaldehyde (P = 0.027), santolin triene (P = 0.032), and 2,6-dimethyl-7-octen-2-ol (P = 0.003). Samples gathered after prostate massage showed significant differences in urinary levels of furan (P≤ 0.001), 3- methylphenol (P = 0.014), p-xylene (P = 0.002), phenol (P≤ 0.001), and 2-butanone (P = 0.001). CONCLUSIONS: Significant differences between PCa and BPH patients were found in urinary levels of certain VOCs both before and after prostate massage, supporting the proposal that VOCs may serve as PCa-specific biomarkers.


Subject(s)
Biomarkers, Tumor/urine , Furans/urine , Prostatic Hyperplasia/diagnosis , Prostatic Neoplasms/diagnosis , Volatile Organic Compounds/urine , Xylenes/urine , Aged , Case-Control Studies , Follow-Up Studies , Humans , Male , Middle Aged , Prognosis , Prostatic Hyperplasia/urine , Prostatic Neoplasms/urine
13.
Ecotoxicol Environ Saf ; 149: 19-25, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29145162

ABSTRACT

Elevated emissions of volatile organic compounds, including benzene, toluene, ethylbenzene, and o, p, and m-xylenes (BTEX), are an occupational health concern at oil transfer stations. This exploratory study investigated personal exposure to BTEX through environmental air and urine samples collected from 50 male workers at a major oil distribution company in Iran. Airborne BTEX exposures were evaluated over 8h periods during work-shift by using personal passive samplers. Urinary BTEX levels were determined using solid-phase microextraction with gas chromatography mass spectrometry for separation and detection. Mean exposure to ambient concentrations of benzene differed by workers' job type: tanker loading workers (5390µg/m3), tank-gauging workers (830µg/m3), drivers (81.9µg/m3), firefighters (71.2µg/m3) and office workers (19.8µg/m3). Exposure across job type was similarly stratified across all personal exposures to BTEX measured in air samples with maximum concentrations found for tanker loading workers. Average exposures concentrations of BTEX measured in urine were 11.83 ppb benzene, 1.87 ppb toluene, 0.43 ppb ethylebenzene, and 3.76 ppb xylene. Personal air exposure to benzene was found to be positively associated with benzene concentrations measured in urine; however, a relationship was not observed to the other BTEX compounds. Urinary exposure profiles are a potentially useful, noninvasive, and rapid method for assessing exposure to benzene in a developing and relatively remote production region.


Subject(s)
Air Pollutants, Occupational/urine , Environmental Monitoring/methods , Occupational Exposure/analysis , Petroleum/analysis , Volatile Organic Compounds/urine , Benzene/analysis , Benzene Derivatives/urine , Gas Chromatography-Mass Spectrometry , Humans , Iran , Male , Toluene/urine , Xylenes/urine
14.
Chemosphere ; 173: 261-266, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28110016

ABSTRACT

Benzene, toluene, ethylbenzene, o-, m-, and p-xylenes (BTEX) are ubiquitous outdoor and indoor air pollutants associated with both environmental and health effects. The objective of this exploratory study was to determine the magnitude and variability of urinary BTEX levels among residents of two areas located in the same city (Nicosia, Cyprus). The two areas differed with respect to their proximity to an industrial cluster and an intercity-highway. First morning urine voids were collected during a random campaign from selected households in the two urban areas (n = 48). Urinary BTEX measurements were obtained using headspace solid phase micro extraction coupled with gas chromatography-mass spectrometry. The majority of participants were females (65%) and non-smokers (85%) with a mean age of 49 years. Median urinary BTEX levels were: 118 ng L-1, 124 ng L-1, 9 ng L-1, 29 ng L-1 and 28 ng L-1 for benzene, toluene, ethylbenzene, (p + m)-xylene and o-xylene, respectively. With the exception of benzene, participants from area 2 (closer to the industrial cluster and an intercity road than area 1) had significantly (p < 0.05) higher urinary BTEX levels than those from area 1 (regression analysis). The residence location (in area 2) was the sole significant (p < 0.05) predictor of urinary BTEX levels after adjusting for sex, smoking, age, body mass index, and educational level. This observational study showed differences in BTEX exposures between two urban areas of the same city. This baseline BTEX dataset may prove useful for future activities of natural gas extraction and handling nearby urban settings.


Subject(s)
Air Pollutants/urine , Benzene Derivatives/urine , Benzene/analysis , Toluene/urine , Xylenes/urine , Cross-Sectional Studies , Environmental Monitoring/methods , Female , Gas Chromatography-Mass Spectrometry/methods , Humans , Male , Middle Aged , Solid Phase Extraction
15.
Inhal Toxicol ; 28(6): 260-73, 2016.
Article in English | MEDLINE | ID: mdl-27053005

ABSTRACT

CONTEXT: Urinary biomarkers are widely used among biomonitoring studies because of their ease of collection and nonintrusiveness. Chloroform and TEX (i.e., toluene, ethylbenzene, and m-xylene) are chemicals that are often found together because of common use. Although interactions occurring among TEX are well-known, no information exists on possible kinetic interactions between these chemicals and chloroform at the level of parent compound or urinary biomarkers. OBJECTIVE: The objective of this study was therefore to study the possible interactions between these compounds in human volunteers with special emphasis on the potential impact on urinary biomarkers. MATERIALS AND METHODS: Five male volunteers were exposed by inhalation for 6 h to single, binary, and quaternary mixtures that included chloroform. Exhaled air and blood samples were collected and analyzed for parent compound concentrations. Urinary biomarkers (o-cresol, mandelic, and m-methylhippuric acids) were quantified in urine samples. Published PBPK model for chloroform was used, and a Vmax of 3.4 mg/h/kg was optimized to provide a better fit with blood data. Adapted PBPK models from our previous study were used for parent compounds and urinary biomarkers for TEX. RESULTS: Binary exposures with chloroform resulted in no significant interactions. Experimental data for quaternary mixture exposures were well predicted by PBPK models using published description of competitive inhibition among TEX components. However, no significant interactions were observed at levels used in this study. CONCLUSION: PBPK models for urinary biomarkers proved to be a good tool in quantifying exposure to VOC.


Subject(s)
Chloroform/pharmacokinetics , Chloroform/urine , Environmental Monitoring/methods , Models, Biological , Volatile Organic Compounds/pharmacokinetics , Volatile Organic Compounds/urine , Adolescent , Adult , Benzene Derivatives/pharmacokinetics , Benzene Derivatives/urine , Biomarkers/blood , Biomarkers/urine , Chloroform/administration & dosage , Computer Simulation , Cresols/urine , Hippurates/urine , Humans , Inhalation Exposure , Male , Mandelic Acids/urine , Predictive Value of Tests , Toluene/pharmacokinetics , Toluene/urine , Urinalysis , Volatile Organic Compounds/administration & dosage , Volatile Organic Compounds/blood , Xylenes/pharmacokinetics , Xylenes/urine , Young Adult
16.
J Toxicol Environ Health A ; 78(17): 1133-6, 2015.
Article in English | MEDLINE | ID: mdl-26460693

ABSTRACT

Benzene, toluene, ethylbenzene, and isomeric xylenes (BTEX) are by-products of tobacco smoke and traffic emissions. The aim of this study was to determine the contribution of cigarette smoking to urinary levels of BTEX present in humans. Nicotine and cotinine, biomarkers of exposure to tobacco smoke, as well as BTEX, were measured in urine of smokers (n = 70) and nonsmokers (n = 65) using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). In smokers, a significant correlation was found between urinary BTEX levels and nicotine and cotinine. In addition, significant regression models with nicotine and cotinine as predictors showed that BTEX in smokers' urine was predominantly derived from exposure to tobacco smoke. In nonsmokers a weak correlation between BTEX and nicotine and cotinine was found in urine. Further, there was a lack of significant contribution of BTEX to urinary nicotine and cotinine concentrations in nonsmokers. Thus, it was presumed that vehicle exhaust was the main source of exposure to BTEX in nonsmokers.


Subject(s)
Air Pollutants/urine , Cotinine/urine , Nicotine/urine , Tobacco Smoke Pollution/analysis , Adult , Benzene Derivatives/urine , Biomarkers/urine , Female , Gas Chromatography-Mass Spectrometry , Humans , Male , Smoking/adverse effects , Solid Phase Microextraction , Toluene/urine , Vehicle Emissions , Xylenes/urine
17.
J Sep Sci ; 38(24): 4276-85, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26500147

ABSTRACT

For the first time, electromembrane extraction combined with liquid chromatography and tandem mass spectrometry was applied for the determination of urinary benzene, toluene, ethylbenzene, and xylene metabolites. S-Phenylmercapturic acid, hippuric acid, phenylglyoxylic acid, and methylhippuric acid isomers were extracted from human urine through a supported liquid membrane consisting of 1-octanol into an alkaline acceptor solution filling the inside of a hollow fiber by application of an electric field. Various extraction factors were investigated and optimized using response surface methodology, the statistical method. The optimum conditions were established to be 300 V applied voltage, 15 min extraction time, 1500 rpm stirring speed, and 5 mM ammonium acetate (pH 10.2) acceptor solution. The method was validated with respect to selectivity, linearity, accuracy, precision, limit of detection, limit of quantification, recovery, and reproducibility. The results showed good linearity (r(2) > 0.995), precision, and accuracy. The extract recoveries were 52.8-79.0%. Finally, we applied this method to real samples and successfully measured benzene, toluene, ethylbenzene, and xylene metabolites.


Subject(s)
Benzene Derivatives/urine , Chromatography, Liquid , Tandem Mass Spectrometry , Toluene/urine , Urinalysis/instrumentation , Urinalysis/methods , Xylenes/urine , Humans , Limit of Detection , Molecular Structure , Solid Phase Microextraction
18.
Int J Occup Med Environ Health ; 27(2): 314-25, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24715421

ABSTRACT

OBJECTIVES: The aim of this study was to assess the exposure of patients to organic substances produced and identified in surgical smoke formed in the abdominal cavity during laparoscopic cholecystectomy. MATERIAL AND METHODS: Identification of these substances in surgical smoke was performed by the use of gas chromatography-mass spectrometry (GC-MS) with selective ion monitoring (SIM). The selected biomarkers of exposure to surgical smoke included benzene, toluene, ethylbenzene and xylene. Their concentrations in the urine samples collected from each patient before and after the surgery were determined by SPME-GC/MS. RESULTS: Qualitative analysis of the smoke produced during laparoscopic procedures revealed the presence of a wide variety of potentially toxic chemicals such as benzene, toluene, xylene, dioxins and other substances. The average concentrations of benzene and toluene in the urine of the patients who underwent laparoscopic cholecystectomy, in contrast to the other determined compounds, were significantly higher after the surgery than before it, which indicates that they were absorbed. CONCLUSIONS: The source of the compounds produced in the abdominal cavity during the surgery is tissue pyrolysis in the presence of carbon dioxide atmosphere. All patients undergoing laparoscopic procedures are at risk of absorbing and excreting smoke by-products. Exposure of the patient to emerging chemical compounds is usually a one-time and short-term incident, yet concentrations of benzene and toluene found in the urine were significantly higher after the surgery than before it.


Subject(s)
Cholecystectomy, Laparoscopic , Peritoneal Absorption , Smoke/analysis , Abdominal Cavity/surgery , Adolescent , Adult , Aged , Benzene/analysis , Benzene Derivatives/urine , Electrocoagulation , Electrosurgery , Female , Gas Chromatography-Mass Spectrometry , Humans , Male , Middle Aged , Patient Safety , Risk Assessment , Toluene/urine , Xylenes/urine , Young Adult
19.
Neurotoxicol Teratol ; 37: 39-43, 2013.
Article in English | MEDLINE | ID: mdl-23422509

ABSTRACT

OBJECTIVES: We evaluated color vision impairment in workers exposed to organic solvents, especially xylene. METHODS: Three groups of subjects, comprising 63 workers occupationally exposed to organic solvents, 122 non-exposed workers in the same industry, and 185 subjects from the general population as controls, were evaluated for color vision. Exposure to solvents was indirectly evaluated by measuring the concentration of a urinary metabolite. Color vision was assessed using the Lanthony Desaturated 15-hue (Lanthony D-15) panel. RESULTS: Color confusion index (CCI) values in the exposed group were significantly higher than in the non-exposed workers or the general population, after adjustment for age and education, and significantly correlated with the concentration of methylhippuric acid. Color vision impairments were detected more frequently among the exposed group, and the most common types were type III and complex impairments. The rate of type III impairments was 9.52% in the exposed group, 1.64% in the non-exposed group, and 1.62% in the general population. CONCLUSION: Our results support the hypothesis that acquired color vision impairments could be induced by exposure to xylene. Testing for color vision impairment is a relatively simple, non-invasive and sensitive diagnostic method for relatively low-level exposures to xylene.


Subject(s)
Color Vision Defects/chemically induced , Occupational Diseases/chemically induced , Occupational Exposure/adverse effects , Ships , Solvents/toxicity , Xylenes/toxicity , Adult , Case-Control Studies , Color Vision/drug effects , Color Vision Defects/diagnosis , Color Vision Defects/epidemiology , Humans , Occupational Diseases/diagnosis , Occupational Diseases/epidemiology , Occupational Exposure/analysis , Republic of Korea , Solvents/chemistry , Solvents/pharmacokinetics , Workplace/standards , Xylenes/chemistry , Xylenes/urine
20.
Biomarkers ; 17(4): 343-51, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22458326

ABSTRACT

This cross-sectional study was aimed at reconstructing the exposure to gasoline in 102 petrol station attendants by environmental and biological monitoring of benzene, toluene, ethylbenzene and xylene (BTEX) and biomonitoring of methyl tert-butyl ether (MTBE). Airborne BTEX were higher for manual refuelers than self-service assistants and were highly correlated with each other. Significant relationships were found between airborne BTX and the corresponding urinary solvents (U-BTX) and beween airborne B and urinary MTBE (U-MTBE). Smokers eliminated higher values of U-B, trans,trans-muconic (t,t-MA) and S-phenylmercapturic (S-PMA) acids but not U-MTBE. All these biomarkers were, however, significantly raised during the shift, independently from smoking. Linear regression confirmed that occupational exposure was a main predictor of U-MTBE, U-B and S-PMA values, both the latter confounded by smoking habits. The study supports the usefulness of biomonitoring even at low exposure levels.


Subject(s)
Air Pollutants, Occupational/urine , Benzene Derivatives/urine , Benzene/metabolism , Methyl Ethers/urine , Occupational Exposure , Toluene/urine , Xylenes/urine , Adult , Air/analysis , Biomarkers/urine , Cross-Sectional Studies , Female , Gasoline , Humans , Hydrocarbons, Aromatic/urine , Linear Models , Male , Middle Aged , Smoking/urine , Statistics, Nonparametric
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