Determination Of Urinary Concentrations Of Organic Oxygenates In Urban Workers (original) (raw)
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Science of The Total Environment, 2001
. Ž. Workers who work near volatile organic compounds VOCs source s , motor vehicle exhausts andror gasoline vapor emissions, are suspected to be exposed to highly-elevated VOC levels during their work-time. This study confirmed this suspicion and evaluated the work-time exposure VOCs for traffic police officers, parking garage attendants, service station attendants, roadside storekeepers and underground storekeepers, by measuring the concentrations of six aromatic VOCs in workplace air, or personal air and breath samples. For nearly all target VOCs, the post-work breath concentrations of the workers were slightly or significantly higher than the pre-work breath concentrations, depending on the compound and occupation. Furthermore, both the pre-and post-work breath concentrations of the workers showed elevated levels compared with a control group of college students. The post-work breath concentrations were significantly correlated with the personal air concentrations, while the pre-work breath concentrations were not. Smoking workers were not always exposed to higher aromatic VOC levels than non-smoking workers. The breath and personal air concentrations for all the target compounds were both higher for underground parking garage attendants than for ground-level parking attendants. For all the target compounds except toluene, storekeepers exhibited similar levels of exposure for all store types. Print shopkeepers recorded the highest toluene exposure. ᮊ
Thammasat Medical Journal, 2010
The aim of this study was to assess the levels of urine Tertiary Butyl Alcohol (TBA) as an index of biological monitoring for exposure to Methyl Tertiary Butyl Ether (MTBE) among road toll station workers in Bangkok metropolitan area. The subjects of this study consisted of 35 road toll station workers as study group. The Airborne MTBE was measured throughout the work with a VOCs diffusive sampling device (VOC-SD) attached on the breathing zone of each subject. The urine samples were collected after work. The Airborne MTBE was analyzed by gas chromatography equipped with MS and the urine samples were done by one with headspace GC-FID. The geometric mean of Airborne MTBE was 21.9 ppb for road toll station workers. The geometric mean of urine TBA level, a metabolite of MTBE, was 232.7 µg/l for road toll station workers. The correlation between MTBE exposure and urine TBA levels was 0.233 (p=0.033). From these results, TBA in urine may be used as biological exposure marker for occupationally exposed workers to MTBE in Bangkok. However, a bigger sample size in future study may provide stronger significant findings.
Annals of Occupational Hygiene, 2015
To assess exposure to benzene (BEN) and other aromatic compounds (toluene, ethylbenzene, m+p-xylene, o-xylene) (BTEX), methyl tert-butyl ether (MTBE), and ethyl tert-butyl ether (ETBE) in petrol station workers using air sampling and biological monitoring and to propose biological equivalents to occupational limit values. Methods: Eighty-nine petrol station workers and 90 control subjects were investigated. Personal exposure to airborne BTEX and ethers was assessed during a midweek shift; urine samples were collected at the beginning of the work week, prior to and at the end of air sampling. Results: Petrol station workers had median airborne exposures to benzene and MTBE of 59 and 408 µg m −3 , respectively, with urinary benzene (BEN-U) and MTBE (MTBE-U) of 339 and 780 ng l −1 , respectively. Concentrations in petrol station workers were higher than in control subjects. There were significant positive correlations between airborne exposure and the corresponding biological marker, with Pearson's correlation coefficient (r) values of 0.437 and 0.865 for benzene and MTBE, respectively. There was also a strong correlation between airborne benzene and urinary MTBE (r = 0.835). Multiple linear regression analysis showed that the urinary levels of benzene were influenced by personal airborne exposure, urinary creatinine, and tobacco smoking [determination coefficient (R 2) 0.572], while MTBE-U was influenced only by personal exposure (R 2 = 0.741). Conclusions: BEN-U and MTBE-U are sensitive and specific biomarkers of low occupational exposures. We propose using BEN-U as biomarker of exposure to benzene in nonsmokers and suggest 1457 ng l −1 in end shift urine samples as biological exposure equivalent to the EU occupational limit value of 1 p.p.m.; for both smokers and nonsmokers, MTBE-U may be proposed as a surrogate biomarker of benzene exposure, with a biological exposure equivalent of 22 µg l −1 in end shift samples. For MTBE exposure, we suggest the use of MTBE-U with a biological exposure equivalent of 22 µg l −1 corresponding to the occupational limit value of 50 p.p.m.
Environmental Health Perspectives, 2000
The 1990 Clean Air Act mandated oxygenation of gasoline in regions where carbon monoxide standards were not met. To achieve this standard, methyl tertiary butyl ether (MTBE) was increased to 15% by volume during winter months in many locations. Subsequent to the increase of MTBE in gasoline, commuters reported increases in symptoms such as headache, nausea, and eye, nose, and throat irritation. The present study compared 12 individuals selected based on selfreport of symptoms (self-reported sensitives; SRSs) associated with MTBE to 19 controls without self-reported sensitivities. In a double-blind, repeated measures, controlled exposure, subjects were exposed for 15 min to dean air, gasoline, gasoline with 11% MTBE, and gasoline with 15% MTBE. Symptoms, odor ratings, neurobehavioral performance on a task of driving simulation, and psychophysiologic responses (heart and respiration rate, end-tidal CO2, finger pulse volume, electromyograph, finger temperature) were measured before, during, and immediately after exposure. Relative to controls, SRSs reported significantly more total symptoms when exposed to gasoline with 15% MTBE than when exposed to gasoline with 11% MTBE or to dean air.
Assessment of exposure of gas station attendants in Sri Lanka to benzene, toluene and xylenes
Environmental Research, 2019
Exposure to benzene, toluene and p-, m-, o-xylene (BTX) was studied in 29 gas station attendants and 16 office workers in Sri Lanka. The aim of this study was to assess the exposure level and identify potential exposure mitigating measures. Pre-and post-shift samples of end-exhaled air were collected and analysed for BTX on a thermal desorption gas chromatography mass spectrometry system (TD-GC-MS). Urine was collected at the same timepoints and analysed for a metabolite of benzene, S-phenyl mercapturic acid (SPMA), using liquid chromatography-mass spectrometry (LC-MS). Environmental exposure was measured by personal air sampling and analysed by gas chromatography flame ionization detection (GC-FID). Median (range) breathing zone air concentrations were 609 (65.1-1960) μg/m 3 for benzene and 746 (< 5.0-2770) μg/m 3 for toluene. Taking into account long working hours, 28% of the measured exposures exceeded the ACGIH threshold limit value (TLV) for an 8-h time-weighted average of 1.6 mg/m 3 for benzene. Xylene isomers were not detected. End-exhaled air concentrations were significantly increased for gas station attendants compared to office workers (p < 0.005). The difference was 1-3-fold in pre-shift and 2-5-fold in post-shift samples. The increase from pre-to post-shift amounted to 5-15-fold (p < 0.005). Pre-shift BTX concentrations in end-exhaled air were higher in smokers compared to non-smokers (p < 0.01). Exposure due to self-reported fuel spills was related to enhanced exhaled BTX (p < 0.05). The same was found for sleeping at the location of the gas station between two work-shifts. Benzene in end-exhaled air was moderately associated with benzene in the breathing zone (r = 0.422; p < 0.001). Median creatinine-corrected S-phenyl mercapturic acid (SPMA) was similar in pre-and post-shift (2.40 and 3.02 μg/g) in gas station attendants but increased in office workers (from 0.55 to 1.07 μg/g). In conclusion, working as a gas station attendant leads to inhalation exposure and occasional skin exposure to BTX. Smoking was identified as the most important co-exposure. Besides taking preventive measure to reduce exposure, the reduction of working hours to 40 h per week is expected to decrease benzene levels below the current TLV.
Chemosphere, 2001
An exposure risk assessment of workers in a re®nery production unit was undertaken. Gasoline and its main components were investigated through environmental and biological monitoring. Measured variables were environmental benzene, toluene, pentane and hexane; benzene and toluene in blood and urine; tt-MA (metabolite of benzene) in urine. Multivariate statistical analysis of the data showed that worker's exposure to the above substances fell within the limits speci®ed by organisations such as ACGIH. Also, biological values complied with reference values (RV) for non-occupationally-exposed population. Dierent values of biological variables were determined by separating smokers from non-smokers: smokers had hematic and urinary benzene values signi®cantly higher than non-smokers. During a 3-yr sampling, it was possible to identify a signi®cant decrease of benzene in the workplace air and of hematic benzene for non-smokers. The most exposed department, one in which tank-lorries were loaded, needs further investigation and extended monitoring.
Journal of Exposure Analysis and Environmental Epidemiology, 2001
The objective of this study was to compare the driving habits and vehicle maintenance patterns of individuals who report symptoms when exposed to methyl tertiary-butyl ether (MTBE) and those who are asymptomatic when exposed to the oxygenate. Participants were healthy volunteers (CON) and selfreported MTBE-sensitive individuals (SRS) who participated in a controlled exposure study of MTBE in gasoline. A questionnaire was developed to gather information about each participant's automobile usage, engine maintenance habits and fueling and driving patterns. Results showed that the individuals who had self-reported heightened sensitivity to the oxygenate drove their vehicles more often and fueled their vehicles more frequently than asymptomatic individuals. In addition, the self-reported symptomatic individuals in this study were shown to be more likely to drive vehicles with some form of body damage and carbureted engines.
Analytica Chimica Acta, 2007
Methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are oxygenated compounds added to gasoline to enhance octane rating and to improve combustion. They may be found as pollutants of living and working environments. In this work a robotized method for the quantification of low level MTBE, ETBE and TAME in human urine was developed and validated. The analytes were sampled in the headspace of urine by SPME in the presence of MTBE-d12 as internal standard. Different fibers were compared for their linearity and extraction efficiency: carboxen/polydimethylsiloxane, polydimethylsiloxane/divinylbenzene, and polydimethylsiloxane. The first, although highly efficient, was discarded due to deviation of linearity for competitive displacement, and the polydimethylsiloxane/divinylbenzene fiber was chosen instead. The analysis was performed by GC/MS operating in the electron impact mode. The method is very specific, with range of linearity 30-4600 ng L −1 , within-and between-run precision, as coefficient of variation, <22 and <16%, accuracy within 20% the theoretical level, and limit of detection of 6 ng L −1 for all the analytes. The influence of the matrix on the quantification of these ethers was evaluated analysing the specimens of seven traffic policemen exposed to autovehicular emissions: using the calibration curve and the method of standard additions comparable levels of MTBE (68-528 ng L −1 ), ETBE (<6 ng L −1 ), and TAME (<6 ng L −1 ) were obtained.
2019
Background: Gasoline workers are continuously exposed to many kinds of harmful fumes at their working places. These fumes contain terribly dangerous pollutants which can seriously alter the urinary and hematological profiles. This could be pathological in many conditions. Aim and Objective: The aim of this study was to determine the effects (if any) of the exposure of gasoline station workers to the gasoline with special focus on CBC parameters and urinary pattern. Results: In hematological examinations of group-I, WBC Counts, EO, BA, and platelets with indices PCT and MPV were significantly increased (p<0.05). In Group-II, WBC counts, LY, EO, BA and platelets with indices PCT and MPV were significantly increased, whereas RBCs and HGB with their indices HCT, MCV and were significantly decreased. Significant changes in specific gravity, PH-values, Nitrate, Protein, Ketone, UGB and Bilirubin were also investigated. Significant weak negative correlations were found among RBC (r=-0.3...