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Benzene is a crucial industrial hydrocarbon, posing significant health risks due to its toxic metabolites like hydroquinone (HQ). This study investigates the role of clusterin (CLU) in benzene toxicity by analyzing its protein and mRNA levels, as well as the expression of Bcl-2 and Bax , to evaluate the feasibility of CLU as a biomarker for chronic benzene poisoning. HL-60 cells were induced to differentiate into neutrophil-like cells using 1% Dimethyl Sulfoxide (DMSO). Enzyme-linked immunosorbent assay (ELISA) and RT-PCR were used to analyze CLU protein and mRNA levels. ELISA was employed to detect sCLU protein content in cell culture supernatants, and western blot was used to assess Bcl-2 and Bax expression. The optimal time for 1% DMSO to induce HL-60 cells into neutrophil-like cells was 48 h. As HQ concentration increased, HL-60 cell viability decreased, CLU protein and sCLU protein levels in the supernatant decreased, CLU mRNA levels decreased, Bcl-2 protein expression decreased, and Bax expression increased. HQ exposure reduces CLU protein concentration and mRNA levels in neutrophil-like cells induced from HL-60 cells, indicating that CLU could be a potential biomarker for chronic benzene poisoning.

this study investigates the health risks and cytotoxicity associated with volatile organic compounds (VOCs) emitted from non-incineration devices used in hospital waste management. The research focuses on the levels of BTEX compounds (benzene, toluene, ethylbenzene, and xylenes) across four hospitals in Tehran, Iran, during the period from October 2022 to March 2023. BTEX concentrations were measured using Gas Chromatography (GC), and cytotoxicity was evaluated through the MTT assay on A549 cells.Results revealed that toluene was the most abundant BTEX compound, with concentrations ranging from 69.30 to 136.68 µg/m 2 , followed by m- and p-xylene. Benzene concentrations were notably lower, ranging from 7.32 to 34.80 µg/m 2 . Hazard quotient (HQ) assessments indicated a lower health risk in hospitals A and D, while hospitals B and C showed HQ values exceeding one, signifying higher potential risks. The study also demonstrated significant cytotoxicity across all hospital waste treatment devices, with the highest cytotoxicity observed in samples from autoclaves equipped with shredders, likely due to the presence of pharmaceutical waste.The findings highlight the necessity for stringent monitoring and regulation of VOC emissions from non-incineration devices to mitigate potential health risks, emphasizing the importance of effective waste management practices in healthcare facilities. This study contributes valuable insights for developing new policies and strategies to reduce the negative environmental and health impacts of hospital waste management.

African American women in the United States have a high risk of adverse pregnancy outcomes. DNA methylation is a potential mechanism by which exposure to BTEX (benzene, toluene, ethylbenzene, and xylenes) may cause adverse pregnancy outcomes. Data are from the Maternal Stress Study, which recruited African American women in the second trimester of pregnancy from February 2009 to June 2010. DNA methylation was measured in archived DNA from venous blood collected in the second trimester. Trimester-specific exposure to airshed BTEX was estimated using maternal self-reported addresses and geospatial models of ambient air pollution developed as part of the Geospatial Determinants of Health Outcomes Consortium. Among the 64 women with exposure and outcome data available, 46 differentially methylated regions (DMRs) were associated with BTEX exposure (FDR adjusted p-value < 0.05) using a DMR-based epigenome-wide association study approach. Overall, 89% of DMRs consistently exhibited hypomethylation with increasing BTEX exposure. Biological pathway analysis identified 11 enriched pathways, with the top 3 involving gamma-aminobutyric acid receptor signaling, oxytocin in brain signaling, and the gustation pathway. These findings highlight the potential impact of BTEX on DNA methylation in pregnant women.

The aim of this study is to investigate the concentration of Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) compounds in the indoor air of residential-commercial complexes and to compare it with other residential buildings (control) as well as to assess the carcinogenicity and non-carcinogenicity risk of these pollutants. BTEX concentration was investigated in the indoor air of 30 ground floor restaurants, 30 upper residential units of the complexes, 20 adjacent residential units (control), and their corridors. The mean BTEX concentration measured in the upper residential units was reported higher than in the control residential units, though they were not significantly different. The lifetime cancer risk (LTCR) value calculated for benzene in the upper residential units was lower than 10−4 and higher than 10−6 across all ages, indicating a carcinogenicity risk. Furthermore, the mean hazard quotient (HQ) for all compounds was obtained lower than 1, suggesting no concern about the non-carcinogenicity risk of these compounds in the studied region. Nevertheless, considering the sources of benzene production in the indoor air as well as the carcinogenicity of these pollutants and the risk they pose in human health, application towards the reduction of the sources and concentration of benzene in the indoor air are necessary.

Tens of millions of individuals go to gasoline stations on a daily basis in the United States. One of the constituents of gasoline is benzene, a Group 1 carcinogen that has been strongly linked to both occupational and non-occupational leukemias. While benzene content in gasoline is federally regulated, there is approximately a thirty-year data gap in United States research on benzene exposures from pumping gasoline. Using a novel self-sampling protocol with whole air canisters, we conducted a gasoline pumping exposure assessment for benzene, toluene, ethylbenzene, and xylene (BTEX) on Baltimore, MD consumers. Geometric mean exposures (geometric standard deviations) were 3.2 (2.7) ppb,9.5 (3.5) ppb, 2.0 (2.8) ppb, and 7.3 (3.0) ppb, respectively, on 32 samples. Using the benzene exposures, we conducted consumer and occupational probabilistic risk assessments and contextualized the risk with ambient benzene exposure risk. We found that the consumer scenarios did not approach the 1:1,000,000 excess risk management threshold and that the occupational scenario did not exceed the 1:10,000 excess risk management threshold. Further, in all Monte Carlo trials, the ambient risk from benzene exposure exceeded that of pumping risk for consumers, but that in approximately 30% of occupational trials, the pumping risk exceeded the ambient risk.

Background: Previous studies have reported positive associations between maternal exposure to air pollutants and several adverse birth outcomes. However, there have been no studies assessing the association between environmental levels of hazardous air pollutants, such as benzene, and neural tube defects (NTDs), a common and serious group of congenital malformations. Objective: Our goal was to conduct a case-control study assessing the association between ambient air levels of benzene, toluene, ethyibenzene, and xylene (BTEX) and the prevalence of NTDs among offspring. Methods: The Texas Birth Defects Registry provided data on NTD cases (spina bifida and anencephaly) delivered between 1999 and 2004. The control group was a random sample of unaffected live births, frequency matched to cases on year of birth. Census tract—level estimates of annual BTEX levels were obtained from the U.S. Environmental Protection Agency 1999 Assessment System for Population Exposure Nationwide. Restricted cubic splines were used in mixed-effects logistic regression models to determine associations between each pollutant and NTD phenotype. Results: Mothers living in census tracts with the highest benzene levels were more likely to have offspring with spina bifida than were women living in census tracts with the lowest levels (odds ratio = 2.30; 95% confidence interval, 1.22-4.33). No significant associations were observed between anencephaly and benzene or between any of the NTD phenotypes and toluene, ethyibenzene, or xylene. Conclusion: In the first study to assess the relationship between environmental levels of BTEX and NTDs, we found an association between benzene and spina bifida. Our results contribute to the growing body of evidence regarding air pollutant exposure and adverse birth outcomes.

OBJECTIVES:The aim of the study was to calculate benchmark dose for chromosomal damage and reduced white blood cell (WBC) associated with exposure to benzene (BZ). METHODS:A group of 317 exposed workers and 102 controls were examined for WBC count and genotoxicity by micronucleus (MN) frequency. The cumulative exposure concentration of BZ was calculated by ambient air BZ concentration at worksites in conjunction with job type and associated service duration. RESULTS:MN frequency (P < 0.01) was higher and WBC count was lower (P < 0.01) in exposed workers on average than in the controls. MN frequency was a more sensitive than WBC; workers older than 30 were more susceptible to abnormal MN frequency and WBC count reduction than those younger than 30. CONCLUSIONS:Benchmark dose estimates indicated that BZ exposure at levels below the current occupational exposure standard can induce genotoxicity and hematotoxicity.

Few studies have examined the effects of environmental concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) on the hematologic system of residents near a petrochemical complex. This study evaluated the potential effects of blood BTEX concentrations on the hematologic parameters of residents in a community near a petrochemical complex (contaminated group) and another community free of known petrochemical pollution (control group). Volunteer residents were randomly recruited. Each participant completed a questionnaire and donated blood samples to evaluate blood BTEX concentrations and hematologic parameters. We found the mean concentrations of blood BTEX of the contaminated group were 1.2 to 6.7 times higher than the control group. Multiple hematologic parameters of participants were significantly different between the two study groups. Inverse associations were found for ln-transformed blood benzene concentrations with mean corpuscular hemoglobin concentration (MCHC) ( β  = − 2.75) and platelet counts ( β  = −8.18). Several weaker associations were also observed between other compounds and multiple hematologic parameters. Our results suggest that the residents living near petrochemical complexes have higher blood BTEX concentrations. Furthermore, the increased blood BTEX levels in residents are associated with the reduction in RBC counts, hemoglobin concentration, hematocrit, MCHC, and platelet counts. This study provided particularly important information for the health risk assessment of residents living near petrochemical complexes.

Background: There is growing evidence that traffic-related air pollution reduces birth weight. Improving exposure assessment is a key issue to advance in this research area. OBJECTIVE: We investigated the effect of prenatal exposure to traffic-related air pollution via geographic information system (GIS) models on birth weight in 570 newborns from the INMA (Environment and Childhood) Sabadell cohort. Methods: We estimated pregnancy and trimester-specific exposures to nitrogen dioxide and aromatic hydrocarbons [benzene, toluene, ethylbenzene, m/p-xylene, and o- xylene (BTEX)] by using temporally adjusted land-use regression (LUR) models. We built models for NO₂ and BTEX using four and three 1-week measurement campaigns, respectively, at 57 locations. We assessed the relationship between prenatal air pollution exposure and birth weight with linear regression models. We performed sensitivity analyses considering time spent at home and time spent in nonresidential outdoor environments during pregnancy. Results: In the overall cohort, neither NO₂ nor BTEX exposure was significantly associated with birth weight in any of the exposure periods. When considering only women who spent < 2 hr/day in nonresidential outdoor environments, the estimated reductions in birth weight associated with an interquartile range increase in BTEX exposure levels were 77 g [95% confidence interval (CI), 7-146 g] and 102 g (95% CI, 28-176 g) for exposures during the whole pregnancy and the second trimester, respectively. The effects of NO₂ exposure were less clear in this subset. Conclusions: The association of BTEX with reduced birth weight underscores the negative role of vehicle exhaust pollutants in reproductive health. Time--activity patterns during pregnancy complement GIS-based models in exposure assessment.

The validation of adsorption treatment based on toxicity assays aims to assess the actual environmental impact caused by effluents after treatment. This study describes the use of rice husk ash as adsorbent and evaluates the efficiency of adsorption treatment to remediate groundwater contaminated with benzene, toluene, ethylbenzene, and xylene (BTEX). The synthetic effluent was prepared with standard benzene, toluene, ethylbenzene, and xylene solutions. Adsorption was assessed at treatment times 0, 60, 120, and 240 min. Compounds were quantified by gas chromatography with flame ionization detector. The treatment was validated based on ecotoxicity assays using Allium cepa as indicator organism. For the treatment times stipulated, samples containing 25, 50, and 100% of BTEX were used. The dilutions were carried out with drinking water according to Fiskesjö ( 1985 ). The relative growth index (RGI), root inhibition index (Ii), and germination index (GI) confirmed the efficiency of the treatment approach tested. The best adsorption time for an initial BTEX concentration of 3.378 mg/L was 60 min. Critical level (EC50) and critical concentration that induced phytotoxic effect on A. cepa germination was observed only for the undiluted effluent.