Average Benzene Concentrations Research Articles

In-situ treatment of gaseous benzene in fixed-bed biofilter with polyurethane foam: Functional population response and benzene transformation pathway

Volatile organic compounds emitted from landfills posed adverse effect on health. In this study, gaseous benzene was biologically treated using an in-situ biofilter without air pump. Its performance was investigated and the removal efficiency of benzene reached over 90 %. The decrease in the average benzene concentration was consistent with first-order reaction kinetics. Mycolicibacterium dominated the bacterial consortium (41–57 %) throughout the degradation. Annotation of genes by metagenomic analysis helped to deduce the degradation pathways (benzene degradation, catechol ortho-cleavage and meta-cleavage) and to reveal the contribution of different species to the degradation process. In total, 21 kinds of key genes and 13 enzymes were involved in the three modules of benzene transformation. Mycolicibacter icosiumassiliensis and Sphingobium sp. SCG-1 carried multiple functional genes critically involved in benzene biodegradation. These findings provide technical and theoretical support for the in-situ bioremediation of benzene-contaminated soil and waste gas reduction in landfills.

Reducing inter-unit pollutant transfer through multifamily unit compartmentalization

Compartmentalization, which refers to air sealing each unit within a building from the exterior and other interior spaces, has been proposed as a strategy to improve indoor air quality and energy efficiency in multifamily buildings. This study collected field data on air tightness and pollutant transfer in three new-construction multifamily buildings in California, which was used to develop a model in CONTAM that simulated the impact of leakage levels, ventilation strategies, and climate zones on inter-unit pollutant transfer in multifamily buildings. Air leakage testing found an average total unit leakage of 0.8 L/s50/m2, almost twice as tight as California’s current compartmentalization requirement (1.5 L/s50/m2). Two buildings designed with balanced ventilation systems were measured to have imbalanced continuous unit ventilation flows, which were further imbalanced by intermittent exhaust fan operation. Tracer gas testing in two buildings indicated that only about 1–3% of the total air entering a unit came from each neighbouring unit. Furthermore, all particles were apparently removed along the way, as there was no observable particle matter transfer at the tested air tightness levels (0.6–0.9 L/s50/m2). Modelling results indicated that leakier units led to greater dilution of pollutants generated within the unit but increased gaseous pollutant transfer from neighbouring units. The average concentration of benzene, a proxy gas for cigarette smoke, transferred into non-smoking units from neighbours who did smoke almost doubled, surpassing acceptable exposure levels, in the leaky simulation (2.3 L/s50/m2) compared to the tight simulation (0.8 L/s50/m2). Overall, this study suggests that stricter compartmentalization requirements should be adopted in multifamily building code updates, as tighter requirements appear to be manageable for builders and beneficial for indoor air quality when combined with mechanical ventilation.

Long-Term Exposure to Low Concentrations of Ambient Benzene and Mortality in a National English Cohort.

Background: Benzene affects human health through environmental exposure in addition to occupational contact. However, few studies have examined the associations between long-term exposure to low concentrations of ambient benzene and mortality risks in nonoccupational settings.Methods: This prospective cohort study consists of 393,042 participants without stroke, myocardial infarction, or cancer at baseline from the UK Biobank. Annual average concentrations of benzene for each year during follow-up were measured using air dispersion models. The main outcomes were all-cause mortality and mortality from specific causes. Cox proportional-hazards models with time-varying exposure measurements were used to estimate the hazard ratios and 95% confidence intervals (CIs) for mortality risks. Restricted cubic spline models were used to estimate exposure-response relationships.Measurements and Main Results: With each interquartile range increase in the average annual concentration of benzene, the adjusted hazard ratios of mortality risk from all causes, cardiovascular disease, cancer, and respiratory disease were 1.26 (95% CI, 1.24-1.27), 1.24 (95% CI, 1.21-1.28), 1.27 (95% CI, 1.25-1.29), and 1.25 (95% CI, 1.20-1.30), respectively. The monotonically increasing exposure-response curves showed no threshold and plateau within the observed concentration range. Furthermore, the effect of benzene exposure on mortality persisted across different subgroups and was somewhat stronger in younger and White people (P for interaction < 0.05).Conclusions: Long-term exposure to low concentrations of ambient benzene significantly increases mortality risk in the general population. Ambient benzene represents a potential threat to public health, and further investigations are needed to support timely pollution regulation and health protection.

Seasonal and diurnal measurement of ambient benzene at a high traffic inflation site in Delhi: Health risk assessment and its possible role in ozone formation pathways.

Benzene is the most toxic and hazardous pollutant among volatile organic compounds (VOCs), as it comes under group 1 carcinogens recognized by the International Agency for Research on Cancer (IARC). It also plays a significant role in forming secondary pollutants like ozone. The benzene concentration was measured using a charcoal sorbent tube by active sampling at a traffic junction and analysis was done using GC-FID. The maximum average concentration of benzene in ambient air was found to be 33 μg/m3. A diurnal study of benzene measurement shows higher benzene concentrations in the evening compared to the morning. Seasonal variation of benzene is found to be winter > spring > summer > autumn > monsoon and OFP was found to be 21, 19, 14, 13, and 10 respectively. Cancer (ILCR) and non-cancer (HQ) health risk assessment was done to determine the impact of ambient benzene on the residents of urban areas. The yearly average value of ILCR was found to be 2×10-6 ± 1×10-6 which ranges from acceptable value to three times the WHO acceptable value i.e 1×10-6. The correlation of ozone and its precursor, benzene with meteorological parameters is also evaluated. The correlation of benzene and ozone with solar radiation shows the influence of photochemical reactions on the levels of benzene and ozone at the study site, although it is low.

Air Pollutant Patterns and Human Health Risk following the East Palestine, Ohio, Train Derailment.

On February 3, 2023, a train carrying numerous hazardous chemicals derailed in East Palestine, OH, spurring temporary evacuation of residents and a controlled burn of some of the hazardous cargo. Residents reported health symptoms, including headaches and respiratory, skin, and eye irritation. Initial data from U.S. Environmental Protection Agency (EPA) stationary air monitors indicated levels of potential concern for air toxics based on hazard quotient calculations. To provide complementary data, we conducted mobile air quality sampling on February 20 and 21 using proton transfer reaction-mass spectrometry. Measurements were taken at 1 s intervals along routes designed to sample both close to and farther from the derailment. Mobile air monitoring indicated that average concentrations of benzene, toluene, xylenes, and vinyl chloride were below minimal risk levels for intermediate and chronic exposures, similar to EPA stationary monitoring data. Levels of acrolein were high relative to those of other volatile organic compounds, with spatial analyses showing levels in East Palestine up to 6 times higher than the local rural background. Nontargeted analyses identified levels of additional unique compounds above background levels, some displaying spatiotemporal patterns similar to that of acrolein and others exhibiting distinct hot spots. These initial findings warrant follow-up mobile air quality monitoring to characterize longitudinal exposure and risk levels.

Assessment of health risk and burden of disease induced by exposure to benzene, toluene, ethylbenzene, and xylene in the outdoor air in Tehran, Iran.

The health risk and burden of disease induced by exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) in the outdoor air in Tehran, 2019 were assessed based on the data of five fixed stations with weekly BTEX measurements. The non-carcinogenic risk, carcinogenic risk, and disease burden from exposure to BTEX compounds were determined by hazard index (HI), incremental lifetime cancer risk (ILCR), and disability-adjusted life year (DALY), respectively. The average annual concentrations of benzene, toluene, ethylbenzene, and xylene in the outdoor air in Tehran were 6.59, 21.62, 4.68, and 20.88 μg/m3, respectively. The lowest seasonal BTEX concentrations were observed in spring and the highest ones occurred in summer. The HI values of BTEX in the outdoor air in Tehran by district ranged from 0.34 to 0.58 (less than one). The average ILCR values of benzene and ethylbenzene were 5.37 × 10-5 and 1.23 × 10-5, respectively (in the range of probable increased cancer risk). The DALYs, death, DALY rate (per 100,000 people) and death rate (per 100,000 people) induced by BTEX exposure in the outdoor air in Tehran were determined to be 180.21, 3.51, 2.07, and 0.04, respectively. The five highest attributable DALY rates in Tehran by district were observed in the districts 10 (2.60), 11 (2.43), 17 (2.41), 20 (2.32), and 9 (2.32), respectively. The corrective measures such as controlling road traffic and improving the quality of vehicles and gasoline in Tehran could reduce the burden of disease from BTEX along with the health effects of other outdoor air pollutants.

Identify Primary Air Pollution Sources of BTEX by Using Positive Matrix Factorization (PMF): A Case Study of Ho Chi Minh City, Vietnam.

Ho Chi Minh City (HCMC) is one of the main socioeconomic and financial centers of Vietnam. The city also faces serious air pollution. However, the city polluted with benzene, toluene, ethylbenzene, and xylene (BTEX) has rarely been studied. We used positive matrix factorization (PMF) to analyze BTEX concentrations measured at two sampling locations to identify the main sources of BTEX in HCMC. The locations represented residential area (i.e., To Hien Thanh) and industrial area (i.e., Tan Binh Industrial Park). At the To Hien Thanh location, the average concentrations of benzene, ethylbenzene, toluene, and xylene were 6.9, 14.4, 4.9, and 12.7µg/m3, respectively. At the Tan Binh location, the average concentrations of benzene, ethylbenzene, toluene, and xylene were 9.8, 22.6, 2.4, and 9.2µg/m3, respectively. The results showed that PMF was a reliable model for source apportionment in HCMC. Traffic activities were the main sources of BTEX. Besides, industrial activities also contributed to BTEX emissions, especially the location near the industrial park. The majority of BTEXs at the To Hien Thanh sampling site come from traffic sources accounting for 56.2%. Activities from traffic and photochemical reactions (42.7%) and industrial sources (40.5%) were the main sources affecting BTEX emissions at the sampling site of Tan Binh Industrial Park. This study can be used as a reference for mitigation solutions to reduce the BTEX emission in HCMC.

Evaluating the feasibility of air environment management system for VOCs through ‘VOCs specification’ of petroleum refining industry

The chemical industry releases various types of volatile organic compounds (VOCs) into the atmosphere, and the concentration of VOCs emitted from chimneys is regulated worldwide. However, some VOCs such as benzene are highly carcinogenic, while others such as ethylene and propylene may cause secondary air pollution, owing to their high ozone-generating ability. Accordingly, the US EPA(United State, Environment Protect Agency) introduced a fenceline monitoring system that regulates the concentration of VOCs at the boundary of a facility, away from the chimney source. This system was first introduced in the petroleum refining industry, which simultaneously emits benzene, affecting the local community because of its high carcinogenicity, and ethylene, propylene, xylene, and toluene, which have a high photochemical ozone creation potential (POCP). These emissions contribute to air pollution. In Korea, the concentration at the chimney is regulated; however, the concentration at the plant boundary is not considered. In accordance with the EPA regulations, Korea’s petroleum refining industries were identified and the limitations of the Clean Air Conservation Act were studied. The average concentration of benzene at the research facility examined in this study was 8.53 µg/m3, which complied with the benzene action level of 9 µg/m3. However, this value was exceeded at some points along the fenceline, in proximity to the benzene-toluene-xylene (BTX) manufacturing process. The composition ratios of toluene and xylene were 27% and 16%, respectively, which were higher than those of ethylene or propylene. These results suggest that reduction measures in the BTX manufacturing process are necessary. This study shows that legal regulations should enforce reduction measures through continuous monitoring at the fenceline of petroleum refineries in Korea.

Prioritization of VOCs Emitted from Co-Processing Cement Kiln Using a Fuzzy Analytic Hierarchy Process Method

The violate organic compounds (VOCs) emission from co-processing cement kiln has not been comprehensively investigated and evaluated. In this study, we sampled and determined the VOCs emitted from a typical co-processing cement kiln in Beijing, China. VOCs characteristics, ozone formation potential (OFP), and main odor components for the emitted gas were analyzed. Additionally, a Fuzzy Analytic Hierarchy Process (F-AHP) was innovatively applied to estimate the priority VOCs. The study shows that aromatic (36.6%) and oxygen contained VOCs (O-VOCs) (30.3%) were the most abundant VOCs, with a high average concentration of benzene (1622.0 μg/m3) and acrolein (1105.5 μg/m3). Acrolein, propene, benzene, 1-butane, and 1,3-butadiene were the dominate OFP compounds, with the corresponding average OFP concentration of 8325.6, 3768.2, 1167.9, 1065.9, and 1027.2 μg/m3, respectively. Acrolein was also found to be the dominate main odor component. Eleven VOCs, including one O-VOC, one halohydrocarbon, and nine alkenes, were screened out by F-AHP. Alkene was the priority VOCs category and acrolein was the most important VOC in the stack gas. The results of this study are helpful to systematically understand the VOCs’ characteristics, OFP, main odor components, and priority compounds of VOCs in the stack gas of co-processing cement kiln, and provide a new method for the screening of priority VOCs compounds.

Assessing the effect of BTEX on blood and spirometry parameters staff in a petroleum refinery.

This study aimed to investigate the impact of BTEX compound on blood and spirometry parameters of staff in the Abadan petroleum refinery (Iran). In 80 staff was examined in terms of BTEX exposure (40 exposed and 40 non-exposed). In this study, the air sampling was carried out according to the NIOSH 1,501 method and an automated hematology analyzer was used to analyze all blood samples to evaluate blood parameters and using a Micro Direct automated computerized spirometer. Spss20 software was used to interpret the performance. According to the obtained results, total BTEX concentrations with the recommended standard level showed that, toluene, ethylbenzene, and xylenes, concentrations in Abadan Oil Refining Company Workers' breathing zone were lower than the TLV-TWA recommended by ACGIH. However, the average concentration of benzene was higher than the allowable limit. Therefore, in this study the effect of benzene on the blood and respiratory parameters of the workers was evaluated, the comparison of the blood and respiratory parameters between the groups of exposed and unexposed workers did not reveal any statistical difference between the groups (p > 0.001). The results showed no statistically significant connection between mean blood and spirometry parameters and benzene exposure. Also, based on results the effect of benzene problems needs to be prevented in employees with adequate engineering and management controls and periodic inspection.

Association between BTEX (benzene, toluene, ethylbenzene and xylene) concentration in ambient air with hematological and spirometric indices: a population-based study

The study aimed to evaluated the relationship between BTEX (benzene, toluene, ethyl benzene and xylene) concentrations in the ambient air with human biomarkers in Assaluyeh city, Iran. According to the results, the average benzene concentration in the high pollution city was measured at 30.05 µg/m3, which is higher than the value recommended (0.03 mg/m3) by the U.S. Environmental Protection Agency (U.S. EPA). The mean spirometric parameters of the resident population in two high and low pollution areas were forced vital capacity (FVC) (high = 4.52; low = 4.78 L), forced expiratory volume in 1 second (FEV1) (high = 3.52; low = 3.88 L), FEV1/FVC (high = 77.9; low = 82.08%), peak expiratory flow (PEF) (high = 9.76; low = 27.85 L/min), and forced inspiratory flow 25–75% (FEF25-75) (high = 3.17; low = 3.95 L/s). Besides, no statistically significant difference was observed between the two groups by comparison of blood tests and the mean concentration of BTEX. BTEX concentration was measured at zero in low pollution areas due to lack of traffic and industries, but it was higher than the respiratory air standard and in the high-pollution area due to the being close to gas and petrochemical stations and industries in the surrounding. As a result, prolonged exposure to higher concentrations of BTEX increases the risks of respiratory dysfunction.

Relationship between the Safe Benzene Concentration with Blood Profile of Printing X Surabaya Workers

Introduction : Benzene is a volatile compound and widely uses as a solvent. In its work process, printingindustry used materials containing benzene. One of the target organs of benzene exposure is bone marrow.Therefore, the effect of benzene exposure is damage to the blood formation system.Methods : This research was an observational study with a quantitative approach and cross-sectional design.Subjects used 11 workers population of printing X Surabaya. All variables were analyzed by using rankspearman correlation.Result: The test results showed that most of the levels of benzene exposure exceeded the determined LimitValue. A total of 6 (64%) workers worked ≥ 10 years. The test results revealed significant benzene exposurewith changes in HCT and MCHC values. The average safe concentration of benzene is 0.01868. The resultsof safe C testing with blood profile showed that significant for safe C Benzene with red blood cells RBC andHCT (p&lt;0,05).Conclussion : The results of the calculation of safe C benzene and blood profile of workers showed asignificant relationship between safe C and RBC and HCT. There was no significant relationship in WBC,HGB, MCV, MCH, MCHC.

Measurement of BTEX (benzene, toluene, ethylbenzene and xylene) concentration at gas stations

Background: 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. Methods: 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. Results: 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. Conclusion: 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.

Screening-level assessment of cancer risk associated with ambient air exposure in Aamjiwnaang First Nation

BACKGROUND AND AIM: The manuscript reports findings from a screening-level assessment of cancer risk from outdoor air in and around Aamjiwnaang First Nation. Aamjiwnaang is situated in the Sarnia-Lambton area, which is known for its industrial and petrochemical industry. The area is also known for poor air quality, chemical spills and other environmental events. Residents are concerned about the health impacts of these exposures. Ambient air pollution can contribute to cardiovascular, respiratory diseases, and certain types of cancer. Some communities may be at higher risk to these negative health impacts due to their geographical proximity to pollution sources. METHODS: Outdoor air concentrations were collected from four monitoring stations in the Aamjiwnaang region for known carcinogens benzene and 1,3-butadiene. Air quality data from both current (2015-2016) and historical (1995-1996, 2005-2006) records were examined. Air concentrations were mapped with geographic information systems to assess spatial variations. Outdoor air concentrations were compiled and the Lifetime Excess Cancer Risks (LECR) associated with long-term exposure to known carcinogens were estimated. RESULTS:LECR results for both benzene and 1,3-butadiene were above one per million. The LECR for benzene was 6.4 per million when the Health Canada slope factor was applied and 12.0 when using the US EPA. For 1,3-butadiene the LECR estimate was 8.8 per million. While air quality has improved over time, in 2015-2016 benzene and 1,3 butadiene levels were higher in Aamjiwnaang than provincial averages. Furthermore, benzene levels were above the Ambient Air Quality Criteria target. CONCLUSIONS:We found that ambient air in and around Aamjiwnaang contains a higher annual average concentration of benzene than recommended and may be related to higher cancer risks. This work provides a better understanding of environmental exposures and potential associated cancer risks for residents in the Aamjiwnaang community. This study highlights the need for further air monitoring and a more detailed risk assessment. KEYWORDS: Cancer and cancer-precursors, Risk assessment, Air pollution

The influence of benzene air pollution on leukemia incidence and mortality rates

Abstract The following study identifies areas where adverse conditions related to benzene pollution are concurrent with leukaemia incidence and mortality (C91–C95). Moreover, it determines the similarities between benzene and leukaemia levels, as well and rules defining their co-occurrence. The analysis covered the period of 2015–2017. Data were obtained from Dane.gov.pl (number of leukaemia cases), the Polish National Cancer Registry website (number of deaths), the Local Data Bank of the Central Statistical Office (population data) and the Chief Inspectorate of Environmental Protection and the Air Quality Portal (data on air quality). Based on the conducted analysis, it was concluded that the following poviat towns have an unfavourable epidemic situation related to leukaemia: Kielce (incidence), Rzeszów (incidence), Elbląg (mortality); meanwhile, high leukaemia incidence and mortality co-occurred with high average benzene concentration in 2015–2017 in the following poviat towns: Kielce, Rybnik, Płock and Rzeszów. It was found that leukaemias belonging to the three-character ICD-10 categories C94, C95 and C92 show the highest rate of co-occurrence with benzene concentration. In addition, two main rules for the co-occurrence of benzene pollution and leukaemia were identified. It was also noted that it is necessary to continue the research for a longer time period, especially in the poviat towns of Kielce and Rzeszów.

Assessment of BTEX exposure and carcinogenic risks for mail carriers in Tehran, Iran

This study investigated personal exposure of mail carriers to atmospheric benzene, toluene, ethylbenzene, and xylenes (BTEX) and estimated their carcinogenic and non-carcinogenic risks due to their exposure to these compounds. A total of 36 mail carriers and 24 post office employees as the control group working in Tehran were included in this study. Spot urine samples were also collected before and after shifts. Monte Carlo simulations were used to estimate the distributions of carcinogenic and non-carcinogenic risks from BTEX exposures. Mail carriers were exposed to 10.4 (± 6.2), 35.3 (± 15.5), 5.5 (± 2.3), and 23.1 (± 10.4) μg/m3 as the average (±SD) concentrations of benzene, toluene, ethylbenzene, and xylenes, respectively. The urinary concentrations of these compounds were 124.0 (±61.2), 242.5 (±96.9), 140.7 (±74.2), and 444.3 (±147.0) ng/L, respectively. These values were significantly higher than those observed for control group. For mail carriers, after-shift urinary concentrations of BTEX were statistically higher than before-shifts concentrations. Carcinogenic risks of mail carriers were higher than those for control group with a mean of 5.82×10−6 exceeding the US EPA limits. Sensitivity analyses showed that concentration had the highest effect on the estimated risks, followed by exposure frequency and exposure time. This study showed that mail carriers are exposed to BTEX at levels that increase their risk to develop cancer. Therefore, programs to reduce the cancer risk among mail carriers should be designed to reduce exposures, possibly by changing shift hours, working days per year, and total years of occupation.

Benzene Monitoring and S-Phenylmercapturic Acid Determination of Workers at Oil Sites in Congo-Brazzaville

The toxicity of benzene is well known, and its leukemia effect has established. It is a natural constituent of crude oil and the diseases related to its exposure are recognized as occupational diseases. Objective: To assess occupational exposure of benzene to workers in an oil and gas production company. Materials and Methods: Firstly, it was a descriptive, cross-sectional study which consisted of benzene atmospheric quantification in a sample individual measurement of a homogeneous exposure group of workers. Secondly, urinary assays of S-phenylmercapturic acid have been performed at the end of the shift in the selected workers. Results: The study has included 79 (47.88%) workers, 17 atmospheric samples were usable and 79 urinary assays at the end of the shift were performed. The average benzene concentration for all sites was 10 times lower than the regulatory average exposure value (1 ppm = 3.2 mg/m3): average: 0.122 pp, median: 0.053 ppm and range: 0.019 - 1.448 ppm. All 79 urinary assays of S-phenylmercapturic acid with a biological exposure index of less than 25 μg/g creatinine: mean: 0.70 μg/g creatinine, median: 0.52 μg/g creatinine and extends: 0.23 to 6.7 μg/g creatinine. Conclusion: Exposure was below to the limit value for benzene in both atmospheric metrology and biometrology. Therefore it is an occupational group with low exposure to benzene. Thus, the medical supervision will be adapted according to the potentially exposing tasks.

Assessment of Indoor Benzene and Its Alkyl Derivatives Concentrations in Offices Belonging to University of Technology (Poland)

Indoor air contamination in office rooms is regarded as one of the most important issues in the protection of workers’ health, because contaminants, even those occurring at low concentrations, can cause health problems for the office staff in view of the long exposure time. This paper presents the results of measurements of benzene and its alkyl derivatives (toluene, ethylbenzene, xylenes, styrene, and 1,3,5-trimethylbenzene)—known indicators of human exposure to volatile organic compounds (VOCs) in the air in newly renovated offices at University of Technology (Upper Silesia, Poland). Monthly samples of indoor and outdoor air were collected during the years 2018–2019 by passive methods and analyzed by thermal desorption-gas chromatography with flame ionization detector (TD-GC/FID). In the first month of measurements average concentrations of the sum of five VOCs under consideration was 127.7 µg/m3, then in subsequent months between 15.1 µg/m3 to 87.3 µg/m3. The average concentration of carcinogenic benzene was below 1.5 μg/m3. Toluene had the highest concentration among studied VOCs, accounting for as high as 60% and 84% of the total indoor and outdoor VOCs, respectively. High indoor-to-outdoor (I/O) ratios for ethylbenzene (7.1), m,p-xylene (9.8), and styrene (12.5) indicate the dominant role of indoor sources.

Exposure levels of volatile organic compounds and potential health risks for passengers and workers at an intercity bus terminal

This work focuses on the concentration and health effects of volatile organic compounds (VOCs) at an intercity bus terminal in Taipei City, Taiwan. In this study, 36 VOCs were detected in the bus terminal, including 19 hazardous air pollutants. The measurement results indicate that ethanol, acetone, toluene, and methyl tert-butyl ether (MTBE) were the main VOCs dominating this bus terminal. Moreover, the average concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds was 106.0 μg/m3 inside the bus terminal, contributing to approximately 70% of the hazardous air pollutants. The measurement results suggest that traffic emissions, especially from diesel buses, were the major pollution sources in the bus terminal. The cancer risk for 1,3-butadiene, benzene, ethylbenzene, and naphthalene exceeded the suggested value by the U.S. EPA. In addition, the individual chronic hazard quotient of benzene was higher than the recommended level. The findings of this work imply that bus terminal workers face a potential health risk, which is a matter of concern.

Cancer Risk Assessment for Workers Exposed to Pollution Source, a Petrochemical Company, Iran.

Background:Air pollution have led to severe problem of adverse health effect in the world. This study aimed to conduct the health risk assessment, cancer risk analysis, and non-cancer risk for exposure to volatile organic compounds (VOCs) and hydrogen sulfide (H 2 S) in petrochemical industry.Methods:In this cross-sectional research, 123 samples were collected in the ambient air in Iran during winter 2016. For sampling and analysis of VOCs and H 2 S, 3 methods (numbers 1500, 1501, and 6013) presented by the National Institute of Occupational Safety and Health (NIOSH) were used. For determination of risk assessment of chemical pollutants, semi-quantitative method presented by the Occupational Safety and Health Division, Singapore was used. Finally, for calculation of cancer risk analysis, Chronic Daily Intake (CDI) and calculation of non-cancer risk, Exposure Concentration (EC) were used.Results:Average concentration of benzene (2.12±0.95) in breathing zone of workers were higher than the Threshold Limit Values-Time Weighted Average (TLV-TWA) (P<0.05). Among chemical substance, benzene had very high rank of risk in petrochemical industry. Rank of risk for H 2 S, toluene, and xylene present in the breathing zone of workers was low. The mean cancer risk for workers exposed to benzene was estimated 8.78×10−3, in other words, 8.7 cancer per 1000 i.e. higher than the acceptable standard of 10−6. In our study, non-cancer risk for BTX was higher than the acceptable standard of 1.Conclusion:In particular, overall cancer and toxic risk can be associated with long term exposure to benzene.