Benzene ; analysis ; chemistry ; Benzene Derivatives ; blood ; urine ; Humans

Benzene ; Benzene Derivatives ; Bile ; Chromatography, Gas ; Gallbladder ; Gas Chromatography-Mass Spectrometry ; Humans ; Toluene

Objective: To establish a purge and trap-gas chromatography-mass spectrometry method based on soil analysis model for the determination of six benzene homologues (benzene, toluene, ethylbenzene, m-xylene, p-xylene and o-xylene) in human blood. Methods: From September 2020 to May 2021, diatomite was used as a dispersant to add 2.0 ml blood sample and fully mixed. The sample was directly injected into the purging and collecting bottle after purging. The gas chromatography column was used for separation. The retention time locking was used for qualitative analysis and the selected ion scanning mode (SIM) was used for detection. The detection limit and recovery rate of the method were analyzed. Results: The linear range of the method for the determination of six benzene homologues in human blood was 0.02-10.00 ng/ml, the correlation coefficient was 0.9927-0.9968, the detection limit was 0.006-0.016 ng/ml, the recovery rate of sample spiking was 84.39%-102.41%, and the precision of the method was 3.06%-6.90%. Conclusion: Purge and trap-gas chromatography-mass spectrometry can simultaneously determine the contents of six benzene homologues in human blood. The pretreatment method is simple, time-saving, and the method has low detection limit, which provides a scientific basis for the detection of benzene homologues in human body.
Humans ; Benzene/analysis* ; Gas Chromatography-Mass Spectrometry/methods* ; Xylenes/analysis* ; Benzene Derivatives/analysis* ; Toluene/analysis*

OBJECTIVETo establish the biological exposure limit values of urinary S-phenylmercapturic acid (SPMA) for assessing occupational exposure to benzene.

METHODSStudy participants were selected from 55 workers of benzene exposures below 32.5 mg/m(3). The concentration of personal exposure to benzene was measured by gas chromatography and sampled with personal sampler. The urine samples were collected at the end of work shift and individual internal exposure level was evaluated by determination of SPMA in urine by HPLC/MS method. Comparison of external and internal exposure was assessed by the relative internal exposure (RIE) index.

RESULTSThe benzene exposure level ranged from 0.71 to 32.17 mg/m(3) (geometric mean 6.98 mg/m(3), median 7.50 mg/m(3)). The urinary SPMA at the end of the work shift were significantly correlated with benzene exposure, (microg/g Cr) = -8.625 + 18.367X (mg/m(3)), r = 0.8035, (P < 0.01). According to the occupational exposure limit for benzene in China and calculation of regression equation, the expected value of urinary SPMA was 101.58 microg/g Cr. Mean level of biotransformation of per mg/m(3) benzene to urinary SPMA was 18.23 microg/g Cr and the metabolic efficiencies of benzene transformation to urinary SPMA decreased with benzene exposure increased.

CONCLUSIONBased on abroad documents and data, biological limit value for occupational exposure to benzene in China is recommended as follows: 100 microg/g Cr (47 micromol/mol Cr) for SPMA in the urine at the end of shift.

Acetylcysteine ; analogs & derivatives ; urine ; Adult ; Benzene ; adverse effects ; analysis ; Benzene Derivatives ; urine ; China ; Humans ; Middle Aged ; Occupational Exposure ; adverse effects ; analysis ; Threshold Limit Values ; Young Adult

In this study, we characterize the hemodynamic changes in the main olfactory bulb of anesthetized Sprague-Dawley (SD) rats with near-infrared spectroscopy (NIRS, ISS Imagent) during presentation of two different odorants. Odorants were presented for 10 seconds with clean air via an automatic odor stimulator. Odorants are: (i) plain air as a reference (Blank), (ii) 2-Heptanone (HEP), (iii) Isopropylbenzene (IB). Our results indicated that a plain air did not cause any change in the concentrations of oxygenated (Delta[HbO2]) and deoxygenated hemoglobin (Delta[Hbr]), but HEP and IB induced strong changes. Furthermore, these odor-specific changes had regional differences within the MOB. Our results suggest that NIRS technology might be a useful tool to identify of various odorants in a non-invasive manner using animals which has a superb olfactory system.
Animals ; Benzene Derivatives ; Hemodynamics ; Hemoglobins ; Ketones ; Odors ; Olfactory Bulb ; Oxygen ; Rats ; Spectroscopy, Near-Infrared

Benzene ; poisoning ; DNA Damage ; DNA Repair ; genetics ; Deoxyguanosine ; analogs & derivatives ; genetics ; Humans ; Mutagens ; poisoning ; Poisoning ; genetics

OBJECTIVETo establish a method for the determination of N-butylbenzene in the workplace atmosphere by gas chromatography.

METHODSN-butylbenzene in the workplace atmosphere was collected by activated charcoal tube, desorbed using carbon disulfide, and determined by capillary column gas chromatography.

RESULTSThe method showed a linear relationship within the range of 0∼100 µg/ml. The regression equation was y = 0.870x-0.014, with the correlation coefficient r being 0.999 9. The limit of detection was 0.32 µg/ml. The minimum detectable concentration was 0.21 mg/m³ (with sampled air volume of 1.5 L). The average spike recovery rate was 97.8%∼102.6%. The within-run precision was 3.06% and the between-run precision was 3.64%. The rate of average desorption was 99.6%. The breakthrough volume was 6.34 mg. The sampling efficiency was 100%. The samples could be stored for at least 7 days at room temperature.

CONCLUSIONAll parameters of the method meet the requirements of GBZ/T 210.4-2008 "Guide for establishing occupational health standards-Part 4 Determination methods of air chemicals in workplace" and can be applied for the determination of N-butylbenzene in workplace atmosphere.

Air ; analysis ; Air Pollutants, Occupational ; analysis ; Benzene Derivatives ; analysis ; Chromatography, Gas ; methods ; Linear Models ; Workplace

Combined with conventional methods, developments in both geochemical (delineation of redox processes) and molecular microbial methods (analysis of 16S rDNA genes and functional genes) have allowed us to study in details microorganisms and genes involved in the anaerobic degradation of benzene, toluene, ethylbenzene and xylene (BTEX) under specific redox conditions. This review summarizes recent research in this field. The potential for anaerobic BTEX degradation is widely spread. Specific groups of microorganisms appear to be involved in degradation under different redox conditions. Members of the Azoarcus/Thauera cluster perform BTEX degradation under denitrifying conditions, Geobacteraceae under Fe (III) reducing conditions and Desulfobacteriaceae under sulfate reducing conditions. The information so far obtained on biochemistry and molecular genetics of BTEX degradation indicates that each BTEX compound is funneled into the central benzyol-CoA pathway by a different peripheral pathway. The peripheral pathways of per BTEX compound show similarities among different physiological groups of microorganisms. We also describe how knowledge obtained on the microbial aspects of BTEX degradation can be used to enhance and monitor anaerobic BTEX degradation.
Bacteria, Anaerobic ; chemistry ; genetics ; Benzene ; chemistry ; Benzene Derivatives ; chemistry ; Biodegradation, Environmental ; Electron Transport ; Genes, Bacterial ; Oxidation-Reduction ; Toluene ; chemistry ; Water Microbiology ; Water Pollutants, Chemical ; Xylenes ; chemistry

OBJECTIVES: The purpose of the present study was to investigate the effects of volatile organic compounds, and formaldehyde on heart rate variability among elderly people who are vulnerable to ambient pollution. METHODS: From May to August of 2009, 57 subjects older than 60 years were recruited in this study. Indoor air pollutants (volatile organic compounds and formaldehyde) were measured by a personal passive sampler. Heart rate variability (HRV) was measured in the sitting position for five minutes and assessed by time-domain and frequency-domain. RESULTS: Multiple linear regression analysis showed significantly less low-frequency (LF) and high-frequency (HF) associated with elevated benzene levels. Exposure to toluene was associated with decreases in the Standard deviation of the NN intervals (SDNN) and LF. SDNN and LF were negatively associated with the increment of ethylbenzene levels. CONCLUSIONS: An adverse effect on cardiovascular function caused by volatile organic compounds was observed among the elderly people of Seoul even though indoor air pollutant levels were lower than the yearly average guideline for indoor air quality in Korea.
Aged ; Air Pollutants ; Air Pollution, Indoor ; Benzene ; Benzene Derivatives ; Formaldehyde ; Heart ; Heart Rate ; Humans ; Korea ; Linear Models ; Toluene ; Volatile Organic Compounds

PURPOSE: The aim of this study is to identify effects of emotional labor, job stress and personal resources on job satisfaction in home healthcare nurses. METHODS: The subjects were 149 home healthcare nurses working for home healthcare centers at 61 hospitals. Data were collected using a structured questionnaire from November 22, 2010 to February 28, 2011 and analyzed with descriptive statistics, t-test, ANOVA, Pearson's correlation, Hierarchical multiple linear regression analysis. RESULTS: The mean score of emotional labor level was 4.23+/-0.95, that of job stress level 3.39+/-0.57, that of personal resources 3.38+/-0.36, and that of job satisfaction 3.31+/-0.40. There were positive correlations among emotional labor, job stress, personal resources and job satisfaction. After age, educational level, job position, and work period in home health care, and traffic accident were controlled, the variables, emotional labor (beta=-.198, p = .034) and personal resources (beta=.236, p = .005) turned out to account for 13.3% of the job satisfaction. But job stress was not a statistically significant predictor. CONCLUSION: Home healthcare nurses were needed to minimize emotional labor and revitalize personal resources in order to maintain a comparatively high level of job satisfaction. Furthermore, it is necessary to carry out systematic education and an organizational management scheme into practice.
Accidents, Traffic ; Amides ; Benzene Derivatives ; Delivery of Health Care ; Home Care Services ; Humans ; Job Satisfaction ; Linear Models ; Surveys and Questionnaires