High Concentrations Of Benzene Research Articles

A novel diurnal and seasonal variation analysis of BTEX in Bengaluru urban area

In the urban atmosphere of Bengaluru, various volatile organic compounds (VOCs), particularly Benzene, Toluene, Ethylbenzene, and Xylene (BTEX), have shown an increasing trend in concentration. The present research was conducted during summer and monsoon seasons, focusing on Kadubeesanahalli, a high-traffic area within the Bengaluru Metropolitan City. Hourly sample data was collected using a BTEX analyzer (Model GC955-600) and subsequently transformed into daily, monthly, and seasonal values. The study revealed distinct patterns in benzene concentrations. Benzene levels were lowest during the early morning hours, specifically from 1:00 a.m. to 7:00 a.m.. Concentrations then increased from 7:00 a.m. to 9:00 a.m. and again from 4:00 p.m. to 11:00 p.m., corresponding to the morning and evening peak traffic hours. However, between 10:00 a.m. and 4:00 p.m., the concentration decreased due to reduced traffic levels. These diurnal variations in benzene concentration are influenced by meteorological parameters. Comparing the two seasons, higher concentrations of Benzene, Ethyl-Benzene, and MP-xylene were observed during the summer season. This increase is attributed to the elevated temperatures during summer, which promote the vaporization of BTEX compounds. Conversely, lower BTEX concentrations were recorded during the monsoon season due to the wet deposition process. The observed positive correlation (r > 0.5) among BTEX parameters strongly suggests a common source, most likely originating from vehicular emissions.

Indoor Levels of Volatile Organic Compounds at Households in Ulaanbaatar City

Objectives: VOCs, or Volatile Organic Compounds, are a group of organic chemicals that can easily evaporate into the air at room temperature. They are called “volatile” because they have high vapor pressure and can readily form vapors or gases at normal atmospheric conditions. To address this knowledge gap, we aimed to assess VOC exposure and its associated health risks.Method: Samples were collected through the adsorbent tube, followed by detachment from the solvent by organic solvents solvent or methanol, and analyzed by gas chromatographic equipment attached with a flame ionization detector (FID). We selected 150 households from the Chingeltei and Bayangol districts in Ulaanbaatar city, specifically sections 4, 5, 6, and 12, to examine the levels of indoor VOCs in this study. We used the nonparametric Mann-Whitney U test to compare medians of VOC levels for two independent groups. Kruskal-Wallis test was carried out to determine if there was any significant difference between medians of VOC levels for more than two independent groups, including the type of paint used, wooden furniture used, and construction year.Results: We found no significant difference in benzene concentration among different types of households (p<0.8112). The highest benzene concentration (0.181 µg/m3) was measured in apartments and houses. Although there was no statistically significant difference between household room types, the kitchen had a higher benzene concentration than other rooms (p<0.8156). Factors such as household total volume, building construction year, and materials used for floors and walls did not significantly affect indoor benzene concentration. Most of the day, the benzene levels exceeded the standards set by the Indoor Air Quality Act of South Korea and the recommended levels by the Health Minister and Construction and Urban Development Minister of Mongolia. In 133 households in Ulaanbaatar city, indoor VOCs, specifically benzene concentration, exceeded the recommended level stated in Order No. A105/08 by the Health Minister and Construction and Urban Development Minister in 2017.Conclusion: Indoor benzene concentration did not vary significantly based on household type, room type, household volume, building construction year, construction wall material, construction floor material, whether new furniture was purchased or the dwelling was repaired and painted within the last two months, proximity to major roads, or indoor smoking status.

Kinetic Aspects of Benzene Degradation over TiO2-N and Composite Fe/Bi2WO6/TiO2-N Photocatalysts under Irradiation with Visible Light

In this study, composite materials based on nanocrystalline anatase TiO2 doped with nitrogen and bismuth tungstate are synthesized using a hydrothermal method. All samples are tested in the oxidation of volatile organic compounds under visible light to find the correlations between their physicochemical characteristics and photocatalytic activity. The kinetic aspects are studied both in batch and continuous-flow reactors, using ethanol and benzene as test compounds. The Bi2WO6/TiO2-N heterostructure enhanced with Fe species efficiently utilizes visible light in the blue region and exhibits much higher activity in the degradation of ethanol vapor than pristine TiO2-N. However, an increased activity of Fe/Bi2WO6/TiO2-N can have an adverse effect in the degradation of benzene vapor. A temporary deactivation of the photocatalyst can occur at a high concentration of benzene due to the fast accumulation of non-volatile intermediates on its surface. The formed intermediates suppress the adsorption of the initial benzene and substantially increase the time required for its complete removal from the gas phase. An increase in temperature up to 140 °C makes it possible to increase the rate of the overall oxidation process, and the use of the Fe/Bi2WO6/TiO2-N composite improves the selectivity of oxidation compared to pristine TiO2-N.

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.

Effect of calcium hydroxide on the characteristics of volatile organic compounds emission during sewage sludge incineration

AbstractEmission of volatile organic compounds (VOCs) during sludge incineration was explored after the addition of calcium hydroxide (Ca [OH]2), and the effects of incineration temperature, sludge particle size, and moisture content were investigated in a lab‐scale tubular furnace. Further, the contribution of the emission of VOCs in ozone formation potential (OFP) without Ca (OH)2 was calculated. The results indicated that incineration temperature in the range of 550–950°C can inhibit the emission of VOCs, with concentrations of the emissions varying from 3076.91 to 1277.11 μg/m3. Ca (OH)2 content had pronounced effects on the emission of VOCs during sludge incineration. The emission concentration of the VOCs decreased from 2421.16 to 1226.68 μg/m3 with Ca (OH)2 content increasing from 0 to 0.8 g. Sludge particle size and moisture content had little effects on the total amount of emitted VOCs during sludge incineration. Meanwhile, the contribution of the components of VOCs from sludge incineration in OFP was analyzed, which exhibited a decreasing trend: aromatic compounds > other substances > alkanes and olefins > chlorinated organic compounds. Aromatic compounds displayed the highest contribution rate at 92.72% because of the high concentration of benzene (1033.43 μg/m3). Our study provided theoretical data and a strong evidence of reduction in the emission of VOCs, OFP, and environmental regulation during sludge incineration.

Living proximity to petrochemical industries and the risk of attention-deficit/hyperactivity disorder in children

Evidence regarding the negative neurodevelopmental effects of compound exposure to petrochemicals remains limited. We aimed to evaluate the association between exposure to petrochemical facilities and generated emissions during early life and the risk of attention-deficit/hyperactivity disorder (ADHD) development in children. We conducted a population-based birth cohort study using the 2004 to 2014 Taiwanese Birth Certificate Database and verified diagnoses of ADHD using the National Health Insurance Database. The level of petrochemical exposure in each participant's residential township was evaluated using the following 3 measurements: distance to the nearest petrochemical industrial plant (PIP), petrochemical exposure probability (accounting for monthly prevailing wind measurements), and monthly benzene concentrations estimated using kriging-based land-use regression models. We applied Cox proportional hazard models to evaluate the association. During the study period, 48,854 out of 1,863,963 children were diagnosed as having ADHD. The results revealed that residents of townships in close proximity to PIPs (hazard ratio [HR] = 1.20, 95% confidence interval [CI]: 1.16–1.23, <3 vs. ≥10 km), highly affected by petrochemical-containing prevailing winds (HR = 1.12, 95% CI: 1.08–1.16, ≥40% vs. <10%), and with high benzene concentrations (HR = 1.26, 95% CI: 1.23–1.29, ≥0.75 vs. <0.55 ppb) were consistently associated with the increased risk of ADHD development in children. The findings of the sensitivity analysis remained robust, particularly for the 2004 to 2009 birth cohort and for models accounting for a longer duration of postnatal exposure. This work provided clear evidence that living near petrochemical plants increases the risk of ADHD development in children. Further studies are warranted to confirm our findings.

Organic Chemical Contaminants in Water System Infrastructure Following Wildfire.

Wildfires have destroyed multiple residential communities in California in recent years. After fires in 2017 and 2018, high concentrations of benzene and other volatile organic compounds (VOCs) were found in public drinking water systems in fire-affected areas. The sources of the contamination and appropriate remediation have been urgent matters for investigation. This study characterizes target and non-target VOCs and semi volatile organic compounds (SVOCs) in water from a highly contaminated service line after the 2018 Camp Fire (Paradise, CA). Ninety-five organic compounds were identified or tentatively identified in the service line. Laboratory combustion experiments with drinking water pipes made of polyvinyl chloride (PVC), cross-linked polyethylene (PEX) and high-density polyethylene (HDPE) and a review of the literature were used to evaluate potential sources of the detected chemicals. Among the service line contaminants were thirty-two compounds associated with PVC pyrolysis and twenty-eight organic compounds also associated with the pyrolysis of polyethylene. The service line sample also contained fifty-five compounds associated with uncontrolled burning of biomass and waste materials. The findings support hypotheses that wildfires can contaminate drinking water systems both by thermal damage to plastic pipes and intrusion of smoke. Residual chlorine disinfectant in the water system modifies the contaminant distribution observed.

Investigation of the Presence Volatile Organic Compounds (BTEX) in the Ambient Air and Biogases Produced by a Shiraz Landfill in Southern Iran

The generation and emission of volatile organic compounds (VOCs) affects the environment and air quality, playing an important role in global warming, depletion of atmospheric ozone and emission of unpleasant odors, but also directly affect human health. This study investigated the health risks of benzene, toluene, ethylbenzene, xylene (BTEX) compounds and biogas released in and around the municipal landfill. Sampling of the VOCs was carried out by the 1501NIOSH method from 8 points over 5 months. The samples were analyzed for BTEX in the ambient air of the landfill, resulting in 0.03–18.09 ppm concentrations, while for biogases a 0.08–25.2 ppm range was found. Assessment of definite health and potential risks showed that the lifetime cancer risk (LCR) for benzene and hazard quotient (HQ) for the BTEX components in all studied sampling sites are higher than the acceptable standard. The high concentration of benzene measured in ambient air indicated that petroleum compounds containing benzene and its derivatives have the highest value in the category of BTEX compounds among all emissions. Therefore, high concentrations of volatile compounds derived from VOCs, especially benzene, should be reduced at the site with control engineering measures.

Hollow ZSM-5 zeolite encapsulating Pt nanoparticles: Cage-confinement effects for the enhanced catalytic oxidation of benzene

A zeolitic cage was introduced and rationally fabricated by encapsulating Pt nanoparticles (NPs) in hollow ZSM-5, a nanomaterial with a cavity and porous shell, for efficient catalytic oxidation of benzene. The structure and formation of the zeolitic cage were systematically investigated and characterized using transmission electron microscopy, nitrogen sorption investigations, X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy, and X-ray diffraction. The obtained hollow 0.2 Pt@ZSM-5 exhibited a comparable low-temperature catalytic activity with 0.5Pt/ZSM-5 with T90 value of 178 °C. Various characterization techniques combined with adsorption experiments uncover the tremendous role of the zeolitic cage in the catalytic activity toward benzene oxidation. The porous shell prevented benzene dilution and the acidity originating from the hollow interior of ZSM-5 promoted the storage of benzene, thereby forming a high local concentration of benzene around Pt NPs, resulting in excellent catalytic performance. These findings provide valuable insights into the rational design of efficient catalysts for the catalytic oxidation of volatile organic compounds.

Living near petrochemical industries and risks of attention-deficit/hyperactivity disorder

BACKGROUND AND AIM: Growing evidence has revealed that air pollution would increase the risk of attention-deficit/hyperactivity disorder (ADHD); however, little is known about the effect of petrochemicals on neurodevelopment in children. We aim to evaluate the association between petrochemical exposure during pregnancy and early life and risks of ADHD in children. METHODS: We conducted a population-based birth cohort study using the 2004–2016 Taiwanese Birth Certificate Database, and verified the diagnosis of ADHD using the National Health Insurance Research Database. The petrochemical exposure in each subject’s residential township was evaluated using three approaches: distance to the nearest petrochemical industrial plants (PIPs), petrochemical exposure probability which accounts for monthly prevailing wind direction, and monthly benzene concentrations estimated by using Kriging-based land use regression models. We applied Cox proportional hazard models to evaluate the associations. RESULTS:During the study period, 49771 out of 1863963 children have been diagnosed as having ADHD. For prenatal exposure, we found that living in townships near PIPs (hazard ratio [HR] = 1.14–1.19, reference: ≥40 km) or with high benzene concentrations (HR = 1.04–1.19, reference: 0.5 ppb) during pregnancy would increase the risks of ADHD. Similar detrimental effects were also observed for petrochemical exposure during postnatal period. Furthermore, those children with high postnatal petrochemical exposure probability were also found to have increased risks for developing ADHD (HR = 1.06–1.10, reference: 10 %). CONCLUSIONS:The present work revealed that living near petrochemical industries would increase the risks of ADHD, and further studies are warranted to confirm our findings. KEYWORDS: Air pollution, Neurodevelopmental outcomes, Children's environmental health, Big data

Study on the method of detection of benzene exposure biomarkers by solid phase extraction-gas chromatography-tandem mass spectrometry

Objective: A gas chromatography-tandem mass spectrometry detection method for benzene and its metabolites was established to provide methodological support and theoretical basis for the study of benzene toxicity mechanism. Methods: In August 2019 to March 2020, the animal model of containing high concentration of benzene by inhalation of poison through the respiratory tract of mice was established, taken the blood of mice after dyeing the poison, and the HLB solid phase extraction method was used to extract and purify the samples. The gas chromatography-tandem mass spectrometry detection method was used to qualitative and quantitative analysis of the target substances. After separated by HP-17MS capillary chromatographic column, the compounds were ionized with EI ion source, mass spectrometry detection was carried out by selective ion scanning method (SIM) , and quantification was carried out by external standard curve method. Results: Benzene and its metabolites (phenol, catechol, hydroquinone and m-trihydroxybenzene) in blood could be effectively separated and quasi deterministic and quantitative by this method. The regression equations and correlation coefficients of this method for detecting benzene and its metabolites were: benzene: y=3252.1x+1540, r=0.9993; phenol: y=2046.5x+1423, r=0.9991; catechol: y=1853.9x+945, r=0.9993; hydroquinone: y=1891.5x+840, r=0.9992; m-trihydroxybenzene: y=1052.4x+655, r=0.9991. The detection limits for benzene, phenol, catechol, hydroquinone and m-trihydroxybenzene were 0.03, 0.03, 0.05, 0.05 and 0.10 μg/g, respectively. And the lower limits of quantification were 0.10, 0.10, 0.15, 0.15 and 0.30 μg/g, respectively. The intra-assay precision interval was 2.64%-10.06%, the inter-assay precision interval was 1.37%-10.17%, and the spike recovery rate was 89.8%-102.3%. This method could be used to quantitatively detect benzene, phenol, catechol, hydroquinone and m-trihydroxybenzene in the blood of benzene-infected mice. Conclusion: Solid phase extraction-gas chromatography-mass spectrometry can be used for qualitative and quantitative detection of benzene and its metabolites (phenol, catechol, hydroquinone and m-trihydroxybenzene) accurately.

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.

Prevalence and Risk Factors of Respiratory Syncytial Virus in Children under 5 Years of Age in the WHO European Region: A Systematic Review and Meta-Analysis.

A respiratory syncytial virus (RSV) is the major cause of respiratory tract infection in children under 5 years. However, RSV infection in the European Region of the World Health Organization has not been systematically reviewed. The aim was to determine the prevalence and factors associated with RSV in children under 5 years of age in European regions. A systematic review and meta-analysis was performed. CINAHL, Medline, LILACS, ProQuest, SciELO, and Scopus databases were consulted for studies published in the last 5 years, following Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The search equation was “respiratory syncytial virus AND (newborn OR infant OR child) AND (prevalence OR risk factors)”. Studies reporting the prevalence of RSV were eligible for inclusion in the meta-analysis. A total of 20 articles were included. The meta-analytic prevalence estimation of RSV, with a sample of n = 16,115 children, was 46% (95% CI 34–59%). The main risk factors were age, male gender, winter season, and environmental factors such as cold temperatures, higher relative humidity, high concentrations of benzene, exposure to tobacco, and living in urban areas. Robust age-specific estimates of RSV infection in healthy children should be promoted in order to determine the optimal age for immunization. In addition, it is necessary to analyse in greater depth the potentially predictive factors of RSV infection, to be included in prevention strategies.

Prevalence and Risk Factors of Respiratory Syncytial Virus in Children Under 5 Years: A Systematic Review and Meta-Analysis

Background: Respiratory syncytial virus (RSV) is the major cause of respiratory tract infection in children under 5 years. However, RSV infection in the European region of the World Health Organization has not been systematically reviewed. Aim: To determine the prevalence and factors associated with RSV in children under 5 years of age in European regions. Methods: A systematic review and meta-analysis was performed. CINAHL, Medline, LILACS, ProQuest, SciELO and Scopus databases were consulted for studies publisehd in the last 5 years, following Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The search equation was “respiratory syncytial virus AND (newborn OR infant OR child) AND (prevalence OR risk factors). Studies reporting the prevalence of RSV were eligible for inclusion in the meta-analysis. Findings: A total of 21 articles were included with a total sample of n = 24,465 children. The meta-analytic prevalence estimation of RSV, with a sample of n = 16,115 children, was 46% (95% CI 34–59%). The main risk factors were age, male gender, winter season and environmental factors such as cold temperatures, higher relative humidity, high concentrations of benzene and ozone, exposure to tobacco and living in urban areas. Interpretation: Robust age-specific estimates of RSV infection in healthy children should be promoted in order to determine the optimal age for immunization. In addition, it is necessary to analyze in greater depth the potentially predictive factors of RSV infection, to be included in prevention strategies. Funding Statement: None. Declaration of Interests: We declare no competing interests.

Research on emissions controlling of coal-made Fischer–Tropsch process diesel/methanol unconventional pollutants

ABSTRACT Thirty unconventional gaseous substances in Fischer–Tropsch process diesel/methanol-mixed fuel with different methanol blending ratios were measured and classified for diesel engine pollutant discharge. The measurement results showed high concentrations of several unconventional pollutants, including propylene, 1,3 butadiene, acrolein, benzene, toluene, ethylbenzene, and xylene, accounting for approximately 83% of the total concentration. The methanol blending ratio was increased from 0 to 15%, the amounts of unconventional pollutants such as olefins, alkanes, and aromatic hydrocarbons were decreased by 38.4%, 27.7%, and 23.7%, respectively, and the amounts of aldehydes and ketones were increased by 31.2%. The amounts of unconventional pollutants such as 1,3 butadiene, n-hexane, and benzene were decreased by 36.6%, 28.8%, and 29.2%, and the amount of acrolein was increased by 28.7%. At maximum torque, aromatic hydrocarbon emissions were reduced by 23.8%, aldehyde and ketone emissions were reduced by 44.8%, olefin emissions were increased by 142.8%, and alkane emissions were reduced by 14.5%; compared to maximum torque conditions, olefins under calibration category emissions were increased by 41.2%, alkane emissions were increased by 8.8%, aromatic hydrocarbon emissions were increased by 9.5%, and aldehyde and ketone emissions were increased by 25%.

Surface functionalization methodologies on activated carbons and their benzene adsorption

The present work reports the effect of different functionalization methodologies on surface modification of porous carbon and its efficacy for benzene adsorption. The virgin and surface-modified adsorbents were characterized by FTIR, N2 sorption analysis, SEM, and Boehm titration. The adsorption isotherms were measured at different temperatures using a highly sensitive magnetic suspension microbalance. At lower benzene concentration, the virgin carbon was found to possess reasonable adsorption capacity, while at higher benzene concentration, the surface-modified carbon tends to perform better. The maximum benzene adsorption capacity at 25 ??C and vapor pressure of 90 mbar is as follows: 467 mg/g (NORIT-AC), 227 mg/g (AC-APS (1 M)), 388 mg/g (Norit-AC-HT), 492 mg/g (AC-HNO3), and 531 mg/g (AC-H2SO4).

Characteristics, sources and regional inter-transport of ambient volatile organic compounds in a city located downwind of several large coke production bases in China

Abstract Volatile organic compounds (VOCs) are important precursors of atmospheric ozone (O3) and particulate matter (PM). Taiyuan, located downwind of several large coke production bases, is a heavily polluted city in China, with high concentrations of PM and increasing concentrations of ground-level O3. In this study, 116 air samples were collected in four seasons of 2015 and analyzed for non-methane hydrocarbon and halocarbon species. The annual average concentration of the total VOCs (TVOCs) in Taiyuan was observed to be higher and slightly lower than that in Beijing and Shenzhen, respectively. High concentrations of benzene and a high benzene to toluene (B/T) ratio were the most evident features. TVOCs levels showed significant seasonal variations, increasing from spring (31.08 ppbv) to winter (67.33 ppbv). Although the concentrations of many air pollutants declined to a minimum, TVOCs continued to show high levels during the summer. Six sources were resolved using positive matrix factorization (PMF), and results indicated that coking processes was the largest contributor (32.56%) to ambient VOCs in Taiyuan, followed by coal and biomass combustion (23.25%). In winter, the contributions of combustion sources and liquefied petroleum gas/natural gas/coalbed methane (LPG/NG/CBM) usage significantly increased compared with those in other seasons. The coking bases located upwind of Taiyuan in the southwestern and western directions were the major potential source regions of coking related VOCs, as indicated using the potential source contribution function (PSCF) analysis. More than 70%, 40% and 80% of the air masses were transported from Taiyuan to the Beijing-Tianjin-Hebei (BTH) region during spring, autumn and winter, respectively. This study indicated that the coke production bases in Shanxi should be listed as the key regions to address the air pollution problems throughout north China. In addition, the combustion source in Taiyuan was associated with high local emissions, while Hebei province located in the northeastern direction, Shaanxi and Inner Mongolia located in the northwestern direction were the potential sources of solvent and LPG/NG/CBM usage, respectively.

Monitoring of volatile organic compounds in ambient air of Taldykorgan, Kazakhstan

The pollution of ambient air is one of the main sources of risk to human health in the world. There is a direct relationship between the level of air pollution and risk of the development of cancer, cardiovascular, respiratory and other diseases. Benzene, toluene, ethylbenzene and o-xylene (BTEX) are one of the most toxic volatile organic compounds. The aim of this study was to quantify BTEX in air of Taldykorgan, Kazakhstan using solid-phase microextraction followed by gas chromatography with mass-spectrometric detection. In different sampling seasons, average concentrations of four BTEX analytes varied from 7.5 to 27 µg/m3, from 15 to 250 µg/m3, from 2.4 to 12.8 µg/m3 and from 2.6 to 21 µg/m3, respectively. The highest concentrations of TEX were detected in autumn, while the highest concentrations of benzene were observed in winter. Toluene-to-benzene ratios in almost all measurements were above 1 indicating that the traffic emissions are the main source of air pollution with BTEX.

An integrated approach for produced water treatment using microemulsions modified activated carbon

In this study, the physical and chemical characterization of produced water was done followed by treatment through sand filtration coupled with activated carbon microemulsion modified activated carbon techniques. The results of characterization showed that the produced water had high chemical oxygen demand (COD), and total organic carbon (TOC) values i.e. 10,496 and 2405 mg/l respectively as well as high concentration of benzene, toluene, ethylbenzene and xylene (BTEX) and various metals. After the sand filtration, considerable reduction in TSS and COD was achieved. Furthermore, BTEX as volatile organic compounds were also removed by more than 93% except for toluene. However, sand filtration was not enough to remove most of the metals and ions. Therefore, further treatment was done through activated carbon and modified activated carbon and their treatment efficiency was compared. Both techniques were able to achieve higher removal efficiencies for BTEX, metals and ions. Thus, the treated water was free from all major pollutants of produced water and can be considered suitable for reuse at industrial or domestic level. This study aims to promote the reuse of produced water to reduce reliance on limited clean water resources.

Determination of Safe Benzene concentration at Kebon Jeruk Toll Gate Keeper Jakarta indonesia

Benzene is a liquid aromatic hydrocarbon compound that is clear, colorless, flammable, and volatile. High concentrations of benzene in the body through inhalation can cause health problems. The purpose of this study is to determine the safe concentration of benzene exposure (C6H6) in Jakarta Kebon Jeruk toll gate keeper. Toll gate keepers are vulnerable to exposure to benzene compounds in the air. 20 toll gate keeper who are divided into toll gate 1 and toll gate 2 were population in the study. The sample technique used total population sampling. The present study used quantitative data analysis manually calculated through the calculation of safe concentration in the environmental toxicology concept. Safe concentration data on Jakarta Kebon Jeruk toll gate keeper were based on data from rat experimental animals, experimental body surface, workers� characteristics of body weight, body height, body surface area, breathing rate and working duration. In addition, data on benzene concentration, animal km, human km, NOAEL and safe limits for toxin doses were also used. The average measurement results of benzene concentration in the air entering the body of workers through inhalation was 0.00167 mg/m3 (0.0052 ppm). This value is lower than benzene threshold according to the Minister of Manpower Regulation Number 5 of 2018 of 0.5 ppm.6 The safe concentration of benzene calculated was 0.0875 mg/m3 (0.0273 ppm). Based on the calculation of safe concentration, the concentration of benzene in the environment of the Kebon Jeruk toll gate keeper indicated safe. © 2019, Indian Journal of Public Health Research and Development. All rights reserved.