جستجوی مقالات مرتبط با کلیدواژه « btex » در نشریات گروه « پزشکی »

The present research addressed the spatiotemporal variations in such pollutants as benzene, toluene, ethylbenzene, and xylene (BTEX) in the atmosphere of Arak, a city in central Iran. Also, the health risk evaluation and ozone formation potential (OFP) were assessed.

The air samples were collected and evaluated through gas chromatography-mass spectrometry (GC-MS) over a one-year period.

The overall BTEX levels ranged between 2.7-256 µgr/m3. The seasonal levels showed considerable variations among benzene, toluene, ethylbenzene, and xylene, and the levels of total BTEX. Comparison of the air samples between morning and evening for the concentrations of BTEX components revealed that the values were higher in the evening; however, there were no significant differences observed among them. The spatial map indicated that the maximal concentration of BTEX components occurred in high-traffic zones of the city. The maximal and minimal OFP levels were recorded in the summer (254.8 µgr/m3) and autumn (64.9 µgr/m3), respectively. The average toluene/benzene (T/B) ratio found to be 4.3, indicating the fuel combustion was the major source of atmospheric BTEX from vehicles.

The measured cancer risk value for benzene (6.68×10-5) was higher than those recommended by the WHO and U.S. Environmental Protection Agency. Therefore, exposure to atmospheric benzene had a carcinogenic risk for Arak inhabitants.  This needs further investigation in future studies. The acceptable hazard quotients (<1) for all BTEX species posed minimal risks of non-cancer diseases for the population.

 This article evaluates the health risk of occupational exposure to BTEX compounds, cancer risk, and noncancer risk analysis among gas station workers. 

 This cross-sectional research evaluates pollutants rank of risk released at Ahvaz stations in Iran. We have collected 96 samples of workers exposed to BTEX and eight samples for control in the ambient air. The National Institute for Occupational Safety and Health (NIOSH) recommended BTEX method numbers 1500 and 1501 for sampling and analysis. To evaluate the risk assessment of pollutants, we utilized a semi-quantitative method offered by Singapore's Occupational Safety and Health Division. 

 The average benzene concentration in the operators' breathing zone (1.202 0.83 ppm) was greater than the threshold limit values-time weighted average (TLVs-TWA) (P < 0.05). Other contaminants had concentrations that were lower than the ACGIH's TLV-TWA (P < 0.05). In gas stations, benzene has a very high danger ranking among chemical compounds. Toluene, ethyl benzene, and xylene in the employees' breathing zone posed a modest risk. The average cancer risk for benzene-exposed operators, head shift workers, and supervisors was calculated to be 4.46 × 10−3, 2.90 × 10−3, and 2.08 × 10−3, respectively. The risk of cancer is projected to be higher than the tolerable level of 10-6. 

 In unique, long-term exposure to benzene has been linked to an increased risk of cancer and toxic effects, and a health-risk assessment can provide useful information about current workplace contaminants.

 Electrosurgical units produce the highest level of surgical smoke. Therefore, the present study aimed to determine concentration of surgical smoke compounds produced in orthopedic surgeries.

 The present study was performed on 20 patients in the operating room units of 5 Azar Hospital in Gorgan, Iran. Twenty smoke specimens were collected from electrosurgical units during orthopedic surgeries. The concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) was determined using an air-sampling pump and SKC charcoal sorbent tubes. The collected data were analyzed using frequency distribution as well as generalized linear and ranked logistic regression tests in SPSS software (version 17).

 Most patients had a body mass index (BMI) level of >24 kg/m2. The mean age of patients was 25.28 years. The average concentrations of benzene, toluene, ethylbenzene, and xylene were 540 µg/m3, 430 µg/m3, and 340µg/m3, and 390µg/m3, respectively. The concentration of particles with an aerodynamic diameter of 2.5 μm or less (PM2.5) was 22.75 µg/m3. Benzene values were higher than the National Institute for Occupational Safety and Health limit. The PM2.5 values were unhealthy for sensitive groups according to the Air Quality Index. Moreover, BMI had a significant association with the amount of benzene produced intraoperatively (p=0.016). The findings also showed that the surgery duration had a significant association with toluene production (p=0.049).

 The concentration of BTEX compounds was low, but the PM2.5 values are high in the studied operating rooms. Long-term exposure to BTEX compounds can be considered as a health risk for operating room personnel.

Fuel stations are one of the major sources of air pollution with volatile organic compounds, especially the four main petrol compounds benzene, toluene, ethylbenzene, and xylene (BTEX). BTEX in gasoline enters the air of gas stations due to high evaporation of gasoline. Therefore, determining the concentration of these compounds in gas stations in crowded and busy cities is one of the important priorities of environmental health, which is doubly important in terms of its negative effects on health.

In this descriptive cross-sectional study, a total of 39 samples were collected from 13 gas stations. Sampling was performed in autumn 2018 in three working shifts (morning, noon, and night). The method NIOSH-1501 (i.e., using charcoal sorbent tubes and SKC pump with a flow rate of 0.2 L/min) was used for sampling the BTEX compounds. The mean difference and correlation of BTEX compounds based on meteorological parameters and the number of nozzles in gas stations were assessed using one-way ANOVA and correlation tests.

The mean and standard deviation of benzene, toluene, ethylbenzene, and xylene concentrations in the air of fuel stations were 2.784 ± 1.461, 3.495 ± 1.390, 2.091 ± 0.811, and 1.140 ± 0.419 mg/m3, respectively. The relationship between BTEX compounds and meteorological parameters such as humidity and exposure time is very important. There is a strong correlation between the concentrations of BTEX compounds. The highest correlation was observed between benzene and toluene and the lowest one was observed between benzene and xylene. In this study, no significant relationship was
observed between air temperature and concentration of BTEX compounds, but there was a relationship between relative humidity and the concentration of BTEX compounds.

The average benzene concentration in the air at the fuel stations was about 5.5 times the standard limit. Authorities should improve fuel quality and reduce its evaporation through engineering measures to overcome the issue.

Specific improvements in the risk assessment of chemicals have been recently considered by many national and international expert groups. This study aimed to identify the highest occupational exposure levels in  Abadan Oil Refining Company, Iran, to benzene, toluene, ethylbenzene, and xylene (BTEX) in 2020.

This is a cross-sectional, descriptive and analytical study carried out in several units (ten units) in Abadan Oil Refining Company. Air sampling and BTEX analysis were conducted according to NIOSH method number 1501. To determine the risk of exposure to BTEX pollutants, we used the method proposed by the Department of Occupational Safety and Health of Malaysia. Then, the hazard rate, exposure rate, and health risk level caused by exposure to chemicals were determined. Spss20 software was used to analyze the data.

The results showed the employees studied in this research were exposed to the pollutants of BTEX during their work. Comparing total BTEX concentrations with the recommended standard level showed that BTEX concentrations in Abadan Oil Refining Company Workers’ breathing zone were lower than the TLV-TWA recommended by ACGIH; also, the findings of this risk assessment study showed benzene had the highest risk ranking in seven operating units and a low risk ranking in three other units. Moreover, toluene, ethylbenzene, and xylene had a very low risk in all operating units.

Corrective and preventive measures should be taken to eliminate or minimize the exposure rate due to the significant effects of benzene exposure.

The present study aimed to evaluate the health risk of heavy metals (iron, zinc, cadmium, arsenic, nickel, lead, and mercury), benzene, toluene, ethylbenzene and xylene (BTEX), and polycyclic aromatic hydrocarbons (PAHs) in the workplace in a secondary oil re-refining factory. In this descriptive, cross-sectional study, samples were collected and analyzed using the NIOSH 1501 method at eight sampling points with determined concentrations of BTEX, 16Ʃ PAHs, and heavy metals. The concentration of each pollutant was evaluated based on the type of workers (packaging/filtration). The risk assessment of the contaminants was carried out using the RAIS software, and the risk of non-carcinogenic compounds was estimated based on the reference respiratory concentration (mg/m3). The results showed that the lifetime cancer risk index (LCR) cumulative risk of the heavy metals was within the definitive risk range at all the sampling points. The highest carcinogenic risk of LCR belonged to arsenic at sampling point H (filtration chamber), and the highest cumulative carcinogenic risk of the total contaminants in the environmental sampling points belonged to sampling point H. At all the sampling points, the LCR carcinogenic risk accumulation for the hydrocarbon compounds was within the definitive range. The maximum cumulative lifetime cancer risk for the hydrocarbon compounds was evaluated in filtration (point B), and the most hazardous carcinogens were arsenic, benzo(a)pyrene, and naphthalene. The proposed risk assessment method was observed to be comprehensive, and its results could be used for corrective and controlling measures and the prioritization of risk reduction resources.