scholarly journals Factors Affecting Urinary tt-Muconic Acid Detection among Benzene Exposed Workers at Gasoline Stations

Author(s):  
Sunisa Chaiklieng ◽  
Pornnapa Suggaravetsiri ◽  
Norbert Kaminski ◽  
Herman Autrup

Trans, trans-muconic acid (tt-MA) is a metabolite that is widely used as a biomarker to identify low exposure to benzene, a human carcinogen. This study aimed to investigate occupational factors related to the urinary tt-MA detection of benzene exposed workers in gasoline stations. Spot urine samples were collected and analyzed for tt-MA using a high performance liquid chromatography. Additional data were collected via subject interviews using a structured questionnaire. The personal benzene concentration was measured and analyzed by gas chromatography with a flame ionization detector. Results showed that, among the 170 workers, tt-MA was detected in 24.7% of workers and the concentration ranged from 23.0 to 1127.8 µg/g creatinine. Over 25% of those detections possessing tt-MA exceeding the recommended 500 µg/g creatinine was safe. A multiple logistic regression analysis identified that factors significantly associated with the detectable tt-MA were having no other part-time jobs (ORadj = 4.2), personal benzene concentrations of 0.05 ppm or higher (ORadj = 10.3), close to fuel nozzle during refuelling (ORadj = 93.7), and no job training (ORadj = 2.74). Safety training is recommended for those tt-MA detected workers or under a reference benzene concentration of 0.05 ppm or higher. The proposed reference of occupational action level to benzene exposure is 0.05 ppm and compliance could be assessed tt-MA for biomonitoring of those benzene exposed workers.

2018 ◽  
Vol 37 (11) ◽  
pp. 1180-1186 ◽  
Author(s):  
MM Youssef ◽  
EMS El-Din ◽  
MM AbuShady ◽  
NR El-Baroudy ◽  
TA Abd el hamid ◽  
...  

Background: Bronchial asthma is one of the top disabling diseases in pediatrics. Limited research has been studied the association of the widely used plastic monomer bisphenol A (BPA) with childhood asthma. Objective: To compare the levels of urinary BPA in asthmatic and control children and to investigate the implication of BPA among other risk factors for the development of asthma. Subjects and methods: This case–control study included 97 children (45 asthmatic and 52 healthy controls) aged 3–8 years. Asthmatic children were diagnosed according to Global initiative for asthma (GINA) guidelines. Sociodemographic factors were assessed and urinary levels of BPA were determined in spot urine samples using high-performance liquid chromatography. The contribution of BPA among predictors for developing asthma was studied in asthmatic children. Results: Median total urinary BPA levels were significantly higher in asthmatic children than in control group (1.56 ng/mL in asthmatic children compared to 0.790 ng/mL in control group, p = 0.001). Children who had total urinary BPA levels >1.3 ng/mL were more likely to be asthmatic (odds ratio: 2.84, 95% confidence interval 1.22–6.59, p = 0.015). Multiple logistic regression analysis for predictors of asthma showed the importance of higher levels of BPA (>1.3 ng/mL) as a more significant predictor than passive smoking ( p = 0.006 for BPA categories vs. p = 0.049 for passive smoking). Conclusion: Association of higher levels of urinary BPA with the diagnosis of asthma in children may indicate the potential risk of BPA exposure in the precipitation of bronchial asthma. Further clinical and biochemical research are needed to clarify the proper mechanism explaining this association.


Author(s):  
Marta Oliveira ◽  
Sílvia Capelas ◽  
Cristina Delerue-Matos ◽  
Simone Morais

Grilling activities release large amounts of hazardous pollutants, but information on restaurant grill workers’ exposure to polycyclic aromatic hydrocarbons (PAHs) is almost inexistent. This study assessed the impact of grilling emissions on total workers’ exposure to PAHs by evaluating the concentrations of six urinary biomarkers of exposure (OHPAHs): naphthalene, acenaphthene, fluorene, phenanthrene, pyrene, and benzo(a)pyrene. Individual levels and excretion profiles of urinary OHPAHs were determined during working and nonworking periods. Urinary OHPAHs were quantified by high-performance liquid-chromatography with fluorescence detection. Levels of total OHPAHs (∑OHPAHs) were significantly increased (about nine times; p ≤ 0.001) during working comparatively with nonworking days. Urinary 1-hydroxynaphthalene + 1-hydroxyacenapthene and 2-hydroxyfluorene presented the highest increments (ca. 23- and 6-fold increase, respectively), followed by 1-hydroxyphenanthrene (ca. 2.3 times) and 1-hydroxypyrene (ca. 1.8 times). Additionally, 1-hydroxypyrene levels were higher than the benchmark, 0.5 µmol/mol creatinine, in 5% of exposed workers. Moreover, 3-hydroxybenzo(a)pyrene, biomarker of exposure to carcinogenic PAHs, was detected in 13% of exposed workers. Individual excretion profiles showed a cumulative increase in ∑OHPAHs during consecutive working days. A principal component analysis model partially discriminated workers’ exposure during working and nonworking periods showing the impact of grilling activities. Urinary OHPAHs were increased in grill workers during working days.


2021 ◽  
Vol 865 ◽  
pp. 158573
Author(s):  
Jingshi Wang ◽  
Zhigang Shen ◽  
Min Yi ◽  
Xiaojing Zhang

1995 ◽  
Vol 58 (1) ◽  
pp. 91-94 ◽  
Author(s):  
J. E. LINE ◽  
R. E. BRACKETT

This study was conducted to investigate several factors affecting the removal of aflatoxin B1 by Flavobacterium aurantiacum NRRL B-184. A simple spectrophotometric procedure was evaluated and compared to an established high-performance liquid chromatography (HPLC) method and found to be useful for determining aflatoxin concentration in test solutions of phosphate buffer. Using the spectrophotometric method, 72-h cultures of F. aurantiacum were observed to remove more toxin from solution than 24-h cultures. Likewise, populations of 1010cells removed aflatoxin at a faster rate than did 109 cells, although the total amount removed did not differ. Transferring F. aurantiacum cultures in tryptic soy broth every 3 days for over 3 days for over 8 months had no apparent effect on their ability to remove measurable amounts of aflatoxin B1 from solution. Populations of 1 × 109 CFU/ml or less heat-inactivated F. aurantiacum were unable to remove aflatoxin B1 from phosphate buffer.


2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Suying Ma ◽  
Haixia Lv ◽  
Xiaojun Shang

A high performance liquid chromatographic (HPLC) method with UV detector for the determination of dyclonine hydrochloride and a gas chromatography (GC) method with flame ionization detector (FID) for the determination of camphor and menthol in lotion were developed. The developed HPLC method involved using a SinoChoom ODS-BP C18reversed-phase column (5 μm, 4.6 mm × 200 mm) and mobile phase consisting of acetonitrile : water : triethylamine in a ratio of 45 : 55 : 1.0; pH was adjusted to 3.5 with glacial acetic acid. The developed GC method for determination of camphor and menthol involved using an Agilent 19091J-413 capillary chromatographic column (30 m × 320 μm × 0.25 μm). The two methods were validated according to official compendia guidelines. The calibration of dyclonine hydrochloride for HPLC method was linear over the range of 20–200 μg/mL. The retention time was found at 6.0 min for dyclonine hydrochloride. The calibration of camphor and menthol of GC method was linear over the range of 10–2000 μg/mL. The retention time was found at 2.9 min for camphor and 3.05 min for menthol. The proposed HPLC and GC methods were proved to be suitable for the determination of dyclonine hydrochloride, camphor, and menthol in lotion.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Bin Zhou ◽  
ShuDao Zhang ◽  
Ying Zhang ◽  
JiaHao Tan

In order to achieve energy saving and reduce the total cost of ownership, green storage has become the first priority for data center. Detecting and deleting the redundant data are the key factors to the reduction of the energy consumption of CPU, while high performance stable chunking strategy provides the groundwork for detecting redundant data. The existing chunking algorithm greatly reduces the system performance when confronted with big data and it wastes a lot of energy. Factors affecting the chunking performance are analyzed and discussed in the paper and a new fingerprint signature calculation is implemented. Furthermore, a Bit String Content Aware Chunking Strategy (BCCS) is put forward. This strategy reduces the cost of signature computation in chunking process to improve the system performance and cuts down the energy consumption of the cloud storage data center. On the basis of relevant test scenarios and test data of this paper, the advantages of the chunking strategy are verified.


2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Katarzyna Jagodzińska ◽  
Michał Czerep ◽  
Edyta Kudlek ◽  
Mateusz Wnukowski ◽  
Marek Pronobis ◽  
...  

Abstract To date, few studies on the potential utilization of agricultural residue torrefaction products have been performed. Thus, torrefaction product characterization aimed at its potential utilization was performed. Wheat–barley straw pellets and wheat–rye chaff were used in the study. The impact of the torrefaction temperature (280–320 °C) on polycyclic aromatic hydrocarbons (PAHs) content in the biochar and noncondensable gas (noncondensables) composition was investigated. The impact of the torrefaction time (30–75 min) on the composition of the condensable volatiles (condensables) and their toxicity were also studied. The torrefaction process was performed in a batch-scale reactor. The PAH contents were measured using high-performance liquid chromatography (HPLC), and the noncondensables composition was measured online using a gas analyzer and then gas chromatograph with flame ionization detector (GC-FID). The condensables composition and main compound quantification were determined and quantified using gas chromatography–mass spectrometry (GC/MS). Three toxicity tests, for saltwater bacteria (Microtox® bioassay), freshwater crustaceans (Daphtoxkit F magna®), and vascular plants (Lemna sp. growth inhibition test), were performed for the condensables. The PAHs content in the biochar, regardless of the torrefaction temperature, allows them to be used in agriculture. The produced torgas shall be co-combusted with full-caloric fuel because of its low calorific value. Toxic compounds (furans and phenols) were identified in the condensable samples, and regardless of the processing time, the condensables were classified as highly toxic. Therefore, they can be used either as pesticides or as an anaerobic digestion substrate after their detoxification.


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