Benzo[a]pyrene Research Articles

Mediation of FOXA2/IL-6/IL-6R/STAT3 signaling pathway mediates benzo[a]pyrene-induced airway epithelial mesenchymal transformation in asthma

Benzo [a]pyrene (BaP), a toxic pollutant, increases the incidence and severity of asthma. However, the molecular mechanisms underlying the effects of BaP in asthma remain unclear. In terms of research methods, we used BaP to intervene in the animal model of asthma and the human bronchial epithelial (16HBE) cells, and the involved mechanisms were found from the injury, inflammation, and airway epithelial to mesenchymal transition (EMT) in asthma. We also constructed small interfering RNAs and overexpression plasmids to knockdown/overexpress IL-6R and FOXA2 in 16HBE cells and a serotype 9 adeno-associated viral vector for lung tissue overexpression of FOXA2 in mice to determine the mechanism of action of BaP-exacerbated asthma airway EMT. We observed that BaP aggravated inflammatory cell infiltration into the lungs, reduced the Penh value, increased collagen fibres in the lung tissue, and increased serum IgE levels in asthmatic mice. After BaP intervention, the expression of FOXA2 in the lung tissue of asthmatic mice decreased, the production and secretion of IL-6 were stimulated, and STAT3 phosphorylation and nuclear translocation increased, leading to changes in EMT markers. However, EMT decreased after increasing FOXA2 expression and decreasing that of IL-6R and was further enhanced after low FOXA2 expression. Our results revealed that BaP exacerbated airway epithelial cell injury and interfered with FOXA2, activating the IL-6/IL-6R/STAT3 signaling pathway to promote airway EMT in asthma. These findings provide toxicological evidence for the mechanism underlying the contribution of BaP to the increased incidence of asthma and its exacerbations.

Vitamin C-reduced graphene oxide/Fe3O4 composite for simultaneous removal of aflatoxin B1 and benzo(a)pyrene in vegetable oils

Vegetable oils are essential constituent of the daily dietary intake. Nevertheless, they often contain aflatoxin B1 (AFB1) and benzo(a)pyrene (BAP). Physical adsorption is the most commonly used detoxification method in the vegetable oils industry. Regrettably, the previously reported adsorbents have exhibited limited efficacy, rendering them inadequate for meeting the requirements of large-scale production of edible oils. In this work, a superparamagnetic Fe3O4/reduced graphene oxide (rGO) composite was synthesized by a one-step hydrothermal method using vitamin C (VC), and systematically characterized. The Vitamin C-reduced graphene oxide/Fe3O4 composite (VC-rGO/Fe3O4) could serve as an efficient adsorbent in edible vegetable oils for the simultaneous removal of AFB1 and BAP. The results of the batch adsorption studies indicated that the pseudo-second order model and Sips model, respectively, were the best fit kinetic model and adsorption isotherm model. The adsorption of AFB1 and BAP on VC-rGO/Fe3O4 was spontaneous, which included both physical and chemical adsorption processes. The removal efficiencies of VC-rGO/Fe3O4 in 13 vegetable oils were evaluated, revealing a wide range of practical applications. Moreover, the quality and safety of detoxified vegetable oils is acceptable. Therefore, VC-rGO/Fe3O4 have been tested as promising candidates for the simultaneous removal of AFB1 and BAP in edible vegetable oils.

Residues of atrazine and diuron in rice straw, soils, and air post herbicide-contaminated straw biomass burning

This study investigates the environmental impact of burning herbicide-contaminated biomass, focusing on atrazine (ATZ) and diuron (DIU) sprayed on rice straw prior to burning. Samples of soil, biomass residues, total suspended particulate (TSP), particulate matter with an aerodynamic diameter ≤ 10 µm (PM10), and aerosols were collected and analyzed. Soil analysis before and after burning contaminated biomass showed significant changes, with 2,4-dichlorophenoxyacetic acid (2,4-D) initially constituting 79.2% and decreasing by 3.3 times post-burning. Atrazine-desethyl, sebuthylazine, and terbuthylazine were detected post-burning. In raw rice straw biomass, terbuthylazine dominated at 80.0%, but burning ATZ-contaminated biomass led to the detection of atrazine-desethyl and notable increases in sebuthylazine and terbuthylazine. Conversely, burning DIU-contaminated biomass resulted in a shift to 2,4-D dominance. Analysis of atmospheric components showed changes in TSP, PM10, and aerosol samples. Linuron in ambient TSP decreased by 1.6 times after burning ATZ-contaminated biomass, while atrazine increased by 2.9 times. Carcinogenic polycyclic aromatic hydrocarbons (PAHs), including benzo[a]anthracene (BaA), benzo[a]pyrene (BaP), and benzo[b]fluoranthene (BbF), increased by approximately 9.9 to 13.9 times after burning ATZ-contaminated biomass. In PM10, BaA and BaP concentrations increased by approximately 11.4 and 19.0 times, respectively, after burning ATZ-contaminated biomass. This study sheds light on the environmental risks posed by burning herbicide-contaminated biomass, emphasizing the need for sustainable agricultural practices and effective waste management. The findings underscore the importance of regulatory measures to mitigate environmental contamination and protect human health.

The Concentration of Benzo[a]pyrene in Food Cooked by Air Fryer and Oven: A Comparison Study.

The air fryer utilizes heated air rather than hot oil to achieve frying, eliminating the need for cooking oil, rendering it a healthier cooking method than traditional frying and baking. However, there is limited evidence supporting that the air fryer could effectively reduce the level of food-derived carcinogen. In this study, we compared the concentration of Benzo[a]pyrene (BaP), a typical carcinogen, in beef patties cooked using an air fryer and an oven, under different cooking conditions, including temperatures (140 °C, 160 °C, 180 °C, and 200 °C), times (9, 14, and 19 min), and oil added or not. The adjusted linear regression analysis revealed that the BaP concentration in beef cooked in the air fryer was 22.667 (95% CI: 15.984, 29.349) ng/kg lower than that in beef cooked in the oven. Regarding the air fryer, the BaP concentration in beef cooked without oil brushing was below the detection limit, and it was significantly lower than in beef cooked with oil brushing (p < 0.001). Therefore, cooking beef in the air fryer can effectively reduce BaP concentration, particularly due to the advantage of oil-free cooking, suggesting that the air fryer represents a superior option for individuals preparing meat at high temperatures.

Determination of Polycyclic Aromatic Hydrocarbons (PAHs) Concentration in Borehole Water from Orhuworhun Town, Delta State, Nigeria.

The quest for quality water and its importance have made it necessary to assess the potability of the water supply. This investigation was carried out to evaluate the concentration of PAHs in borehole water obtained from Orhuwhorun town in Delta State, Nigeria. The water sample was collected from a resident borehole and stored in a sterile bottle to avoid contamination. The water sample was analyzed for PAHs with the use of a gas chromatography mass spectrometer (GC-MC). The total concentration of PAH in water (?16 EPA PAHs), which are 16, includes chrysene (Chry), benzo[b]fluoranthene (BbF), acenaphthene (Ace), benz[a]anthracene (BaA), acenaphthylene (AcPy), anthracene (Ant), benzo[k]fluoranthene (BkF), benzo[ghi]perylene (BghiP), benzo[a]pyrene (BaP), Indeno[1,2,3- cd]pyrene (IndP), fluoranthene (Flu), dibenz[a,h]anthracene (DahA), naphthalene (Nap), pyrene (Pyr), phenanthrene (Phe), and fluorene (Flu). The mean concentration in this study ranges from 22.729 to 102.109 mg/L. The concentration of dibenz[a,h]anthracene (DahA) was observed to be the highest, while the concentration of Chry was found to be the lowest amongst all Ó16 PAH congeners detected. The result of this study was compared with the U.S. EPA Standard Limit, and all PAH congeners were found to exceed the standard limit, which shows that the sample is not fit for drinking. This significant concentration of PAH in the water can be attributed to various anthropogenic activities and untreated waste containing PAH. Therefore, there is an urgent need for regulatory agencies to make sure that industries check for environmental compliance.

Exploring the role of air pollution on the development of atherosclerosis disorder in human endothelial cells

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): QU - NSPP Introduction Atherosclerosis, the main cause of cardiovascular and cerebrovascular diseases, is a global health threat. Rising cardiovascular disease prevalence, unexplained by traditional risk factors, prompts exploration of the impact of occupational exposure to environmental toxins as a risk factor. benzo[a]pyrene (BaP) is a polyaromatic compound that mediate its toxicity through activation of the Aryl hydrocarbon receptor (AhR). The molecular mechanisms of involvement of environmental toxins and the role of AhR/CYP1A pathway in atherosclerosis development remain not fully investigated. Purpose The current study explores the AhR pathway activation in endothelial cells upon exposure to environmental toxins in order to elucidate the molecular mechanisms of atherosclerotic cardiovascular diseases and plaque formation through investigating pro-inflammatory (CYP1A1, CYP1B1, TNF-a) and pro-apoptotic markers (BCL-2, Caspase-3). Methods EA. hy926 cell line underwent treatment with increasing concentrations of BaP (0-20 microM), as well as 10nm of TCDD, to confirm the results. DSMO was used as a control. Total RNA and protein were isolated to investigate mRNA expression and protein expression of AhR, CYP1A1, CYP1B1, as well as caspase-3, Bcl-2, and TNF-α using RT-PCR and Western Blot analysis. Statistical analysis was done using one-way ANOVA. Results The results showed that BaP induce significant dose-dependent upregulation of AhR and target genes (CYP1A1, CYP1B1). At 20uM, expression of AhR (3-fold), CYP1A1 (2.5-fold) and CYP1B1 (2-fold) was significantly high as compared to their respective controls and low doses. As for apoptotic markers, Bcl-2 was significantly downregulated at the highest concentrations 10uM and 20uM (0.7- and 0.6-fold, respectively). Caspase-3 showed no significant change but exhibited upregulation across all doses. TCDD 10nM significantly upregulated AhR (2.0-fold), CYP1A1 (1.5-fold), CYP1B1 (1.7-fold). Bcl-2 downregulated (0.6-fold), TNF-α significantly upregulated (1.8-fold) at 10nM. Caspase-3 increased 2-folds but was not statistically significant. Conclusion This study illustrated that AhR inducers, such as BaP, can accelerate the pathological progress of atherosclerosis by evoking oxidative stress and inflammation response molecules in human endothelial cells, demonstrated by the reduced expression of anti-apoptotic markers and the increased expression of inflammatory markers.

Polyaromatic Hydrocarbon Inclusion Complexes with 2-Hydroxylpropyl-β/γ-Cyclodextrin: Molecular Dynamic Simulation and Spectroscopic Studies.

In aqueous and solid media, 2-HP-β/γ-CD inclusion complexes with poly aromatic hydrocarbon (PAH) Phenanthrene (PHN), Anthracene (ANT), Benz(a)pyrene (BaP), and Fluoranthene (FLT) were investigated for the first time. The inclusion complexes were characterized and investigated using fluorescence and 1HNMR spectroscopy. The most prevalent complexes consisting of both guests and hosts were those with a 1:1 guest-to-host ratio. The stability constants for the complexes of PHN with 2-HP-β-CD and 2-HP-γ-CD were 85 ± 12 M-1 and 49 ± 29 M-1, respectively. Moreover, the stability constants were found to be 502 ± 46 M-1 and 289 ± 44 M-1 for the complexes of ANT with both hosts. The stability constants for the complexes of BaP with 2-HP-β-CD and 2-HP-γ-CD were (1.5 ± 0.02) × 103 M-1 and (9.41 ± 0.03) × 103 M-1, respectively. The stability constant for the complexes of FLT with 2-HP-β-CD was (1.06 ± 0.06) × 103 M-1. However, FLT was observed to form a weak complex with 2-HP-γ-CD. Molecular dynamic (MD) simulations were used to investigate the mechanism and mode of inclusion processes, and to monitor the atomic-level stability of these complexes. The analysis of MD trajectories demonstrated that all guests formed stable inclusion complexes with both hosts throughout the duration of the simulation time, confirming the experimental findings. However, the flexible Hydroxypropyl arms prevented the PAHs from being encapsulated within the cavity; however, a stable exclusion complex was observed. The main forces that influenced the complexation included van der Waals interactions, hydrophobic forces, and C-H⋯π interaction, which contribute to the stability of these complexes.

One year of active moss biomonitoring in the identification of PAHs in an urbanized area—prospects and implications

Classical monitoring of air pollution provides information on environmental quality but involves high costs. An alternative to this method is the use of bioindicators. The purpose of our work was to evaluate atmospheric aerosol pollution by selected polycyclic aromatic hydrocarbons conducted as part of annual active biomonitoring (“moss-bag” technique) with the use of three moss species: Pleurozium schreberi, Sphagnum fallax, and Dicranum polysetum. The gas chromatography-mass spectrometry (GC–MS) was utilized to determine certain 13 polycyclic aromatic hydrocarbons (PAHs). Three seasonal variations in PAH concentrations have been observed as a result of the study. A fire on the toilet paper plant caused an increase of five new compounds: benzo(k)fluoranthene (BkF), benzo(a)pyrene (BaP), indeno(1.2.3)-cd_pyrene (IP), dibenzo(a.h)anthracene (Dah), and benzo(g.h.i)perylene (Bghi) in proximity after 8 months of exposure compared to previous months. The effect of meteorological conditions on the deposition of PAHs (mainly wind direction) in mosses was confirmed by principal component analysis (PCA). Dicranum polysetum moss accumulated on average 26.5% more PAHs than the other species, which allows considering its broader use in active biomonitoring. The “moss-bag” technique demonstrates its feasibility in assessing the source of PAH air pollution in a long-term study. It is recommended to use this biological method as a valuable tool in air quality monitoring.

Environmental significance of PAH photoproduct formation: TiO2 nanoparticle influence, altered bioavailability, and potential photochemical mechanisms

Interactions between polycyclic aromatic hydrocarbons (PAHs) and titanium dioxide (TiO2) nanoparticles (NPs) can produce unforeseen photoproducts in the aqueous phase. Both PAHs and TiO2-NPs are well-studied and highly persistent environmental pollutants, but the consequences of PAH-TiO2-NP interactions are rarely explored. We investigated PAH photoproduct formation over time for benzo[a]pyrene (BaP), fluoranthene (FLT), and pyrene (PYR) in the presence of ultraviolet A (UVA) using a combination of analytical and computational methods including, identification of PAH photoproducts, assessment of expression profiles for gene indicators of PAH metabolism, and computational evaluation of the reaction mechanisms through which certain photoproducts might be formed. Chemical analyses identified diverse photoproducts, but all PAHs shared a primary photoproduct, 9,10-phenanthraquinone (9,10-PQ), regardless of TiO2-NP presence. The computed reaction mechanisms revealed the roles photodissociation and singlet oxygen chemistry likely play in PAH mediated photochemical processes that result in the congruent production of 9,10-PQ within this study. Our investigation of PAH photoproduct formation has provided substantial evidence of the many, diverse and congruent, photoproducts formed from physicochemically distinct PAHs and how TiO2-NPs influence bioavailability and time-related formation of PAH photoproducts.

Polycyclic aromatic hydrocarbon (PAH) accumulation in selected medicinal plants: a mini review.

The use of plant-based products in healthcare systems has experienced a tremendous rise leading to a substantial increase in global demand. However, the quality and effectiveness of such plant-based treatments are often affected due to contamination of various pollutants including polycyclic aromatic hydrocarbons (PAHs). Like other plants, medicinal plants also uptake and accumulate PAHs when exposed to a contaminated environment. The consumption of such medicinal plants and/or plant-based products causes negative effects on health rather than providing any therapeutic advantages. Unfortunately, research focusing on PAH accumulation in medicinal plants has received very limited attention. This review discusses a sizable number of literature regarding the concentration of sixteen priority PAH pollutants as recognised by the US Environmental Protection Agency (USEPA) in different medicinal plants. The review also highlights the risk assessment of cancer associated with some medicinal plants in terms of benzo[a]pyrene (BaP) equivalent concentrations.

Обеспечение канцерогенной безопасности копченой рыбной продукции

The purpose of the study is to develop recommendations for rational smoke generation parameters that ensure the quality and environmental safety of smoked fish products. Objectives: to establish the influence of smoke generation parameters on the assessment of the carcinogenicity of smoked products; to evaluate the quality and safety of smoked products produced under optimal smoke generation parameters; to develop recommendations to ensure the quality and safety of smoked fish products. Research was carried out at the department of Management of Technical Systems at the Federal State Budgetary Educational Institution of Higher Education Dalrybvtuz (Vladivostok, Primorsky Region). The object of the study is the process of smoke generation. Analytical, physical and chemical methods, and mathematical modeling methods were used. To prepare smoke-drying smoke samples, 10 kg of alder sawdust with a moisture content of 30–35 % was prepared. Hot smoked smelt samples were obtained under optimal smoke generation conditions. The overall organoleptic index was 5. The content of individual polyaromatic hydrocarbons was: chrysene – 71 ng/kg; benz(a)anthracene – 70 ng/kg; benz(b)fluoranthene – 602 ng/kg; benz(a)pyrene – 64 ng/kg; benz(e)pyrene – 667 ng/kg; dibenz(a,c)anthracene – 57 ng/kg; dibenz(a,h)anthracene – 69 ng/kg, which corresponds to a generalized quality index of 0.99 (very good). During the study, the influence of smoke generation parameters on the assessment of the carcinogenicity of smoked fish products was established, and the dependence of the content of individual polyaromatic hydrocarbons on the excess air coefficient in the smoke generation zone was confirmed. Optimal smoke generation modes: smoke generation temperature 475 °C, excess air coefficient – 0.4. Rational smoke generation parameters: smoke generation temperature 450–500 °C, excess air coefficient – 0.3–0.6.

Aortic Injury Induced by Benzo(a)pyrene and Atherogenic Diet Increased Hepatic FGF21 Expression in C57BL/6J Mice.

Benzo(a)pyrene (BaP), an environmental toxicant and endocrine disruptor, has been shown to exacerbate atherosclerosis when combined with a high-fat diet. Fibroblast Growth Factor-21 (FGF21), a novel hormone with anti-atherosclerotic properties, is associated with the presence of atherosclerosis and reduces plaque formation in experimental animals. The present study aimed to investigate the chronic effect of BaP injection on hepatic FGF21 expression, as an anti-atherosclerotic hormone, in mice fed with or without an atherogenic diet (AtD). Eighteen C57BL/6J male mice (6 weeks) were randomly divided into six groups based on the dosage and diet. Blood samples were collected, and serum cholesterol, triglyceride, HDL-C, LDL-C, and glucose levels were measured. FGF21 expression was assessed by quantitative real-time PCR. Atherosclerotic lesions in mice were studied with Oil Red O (ORO) staining. Benzo(a)pyrene causes a significant increase in liver FGF21 expression in a dose-dependent manner, and BaP co-exposure with AtD leads to a further increase in FGF21 expression. Additionally, the addition of BaP to AtD significantly increased the serum glucose, cholesterol, and LDL-C levels and accelerated the formation of atherosclerotic lesions. Besides, our findings showed that there is a significant positive correlation between FGF21 expression and glucose, cholesterol, LDL-C, and ORO-positive areas. Our findings revealed that BaP increases the expression of endogenous FGF21 in treated animals as a compensatory response to protect the heart from atherosclerosis induced by BaP and AtD.

The detoxification ability of sex-role reversed seahorses determines the sexual dimorphism in immune responses to benzo[a]pyrene exposure

Sexual dimorphism in immune responses is an essential factor in environmental adaptation. However, the mechanisms involved remain obscure owing to the scarcity of data from sex-role-reversed species in stressed conditions. Benzo[a]pyrene (BaP) is one of the most pervasive and carcinogenic organic pollutants in coastal environments. In this study, we evaluated the potential effects on renal immunotoxicity of the sex-role-reversed lined seahorse (Hippocampus erectus) toward environmental concentrations BaP exposure. Our results discovered the presence of different energy-immunity trade-off strategies adopted by female and male seahorses during BaP exposure. BaP induced more severe renal damage in female seahorses in a concentration-dependent manner. BaP biotransformation and detoxification in seahorses resemble those in mammals. Benzo[a]pyrene-7,8-dihydrodiol-9,10-oxide (BPDE) and 9-hydroxybenzo[a]pyrene (9-OH-BaP) formed DNA adducts and disrupted Ca2+ homeostasis may together attribute the renal immunotoxicity. Sexual dimorphisms in detoxification of both BPDE and 9-OH-BaP, and in regulation of Ca2+, autophagy and inflammation, mainly determined the extent of renal damage. Moreover, the mechanism of sex hormones regulated sexual dimorphism in immune responses needs to be further elucidated. Collectively, these findings contribute to the understanding of sexual dimorphism in the immunotoxicity induced by BaP exposure in seahorses, which may attribute to the dramatic decline in the biodiversity of the genus.

Effects of soil colloids on adsorption and migration of benzo(a)pyrene on contaminated sites under runoff infiltration processes

In the environment, soil colloids are widespread and possess a significant adsorption capacity. This makes them capable of transporting different pollutants, presenting a potential risk to human and ecological well-being. This study aimed to examine the adsorption and co-migration characteristics of benzo(a)pyrene (BaP) and soil colloids in areas contaminated with organic substances, utilizing both static and dynamic batch experiments. In the static adsorption experiments, it was observed that the adsorption of BaP onto soil colloids followed the pseudo-second-order kinetic model (R2 = 0.966), and the adsorption isotherm conformed to the Langmuir model (R2 = 0.995). The BaP and soil colloids primarily formed bonds through π-π interactions and hydrogen bonds. The dynamic experimental outcomes revealed that elevating colloids concentration contributed to increased BaP mobility. Specifically, when the concentration of soil colloids in influent was 500 mg L−1, the mobility of BaP was 23.2 % compared to that without colloids of 13.4 %. Meanwhile, the lowering influent pH value contributed to increased BaP mobility. Specifically, when the influent pH value was 4.0, the mobility of BaP was 30.1 %. The BaP's mobility gradually declined as the initial concentration of BaP in polluted soil increased. Specifically, when the initial concentration of BaP in polluted soil was 5.27 mg kg−1, the mobility of BaP was 39.1 %. This study provides a support for controlling BaP pollution in soil and groundwater.

Effects of different precursors on the structure of lignin-based biochar and its ability to adsorb benzopyrene from sesame oil

Agricultural by-products of sesame are promising bioresources in food processing. This study extracted lignin from the by-products of sesame oil production, namely, the capsules and straw of black and white sesame. Using acid, alkali, and ethanol methods, 12 distinct lignins were obtained to prepare biochar, aiming to investigate both the structural characteristics of lignin-based biochar (LBB) and its ability to remove benzo[a]pyrene (BaP) from sesame oil. The results showed that white sesame straw was the most suitable raw material for preparing biochar. In terms of the preparation method, acid-extracted lignin biochar was more effective in removing BaP than alkaline or ethanol methods. Notably, WS-1LB (white sesame straw acid-extracted lignin biochar) exhibited the highest BaP adsorption efficiency (91.44 %) and the maximum specific surface area (1065.8187 m2/g), characterized by porous structures. The pseudo 2nd and Freundlich models were found to be the best fit for the adsorption kinetics and isotherms of BaP on LBB, respectively, suggesting that a multilayer adsorption process was dominant. The high adsorption of LBB mainly resulted from pore filling. This study provides an economical and highly efficient biochar adsorbent for the removal of BaP in oil.

Benzo[a]pyrene evokes epithelial-mesenchymal transition and pulmonary fibrosis through AhR-mediated Nrf2-p62 signaling

Benzo[a]pyrene (BaP) and its metabolic end product benzo(a)pyren-7,8-dihydrodiol-9,10-epoxide (BPDE), are known toxic environmental pollutants. This study aimed to analyze whether sub-chronic BPDE exposure initiated pulmonary fibrosis and the potential mechanisms. In this work, male C57BL6/J mice were exposed to BPDE by dynamic inhalation exposure for 8 weeks. Our results indicated that sub-chronic BPDE exposure evoked pulmonary fibrosis and epithelial-mesenchymal transition (EMT) in mice. Both in vivo and in vitro, BPDE exposure promoted nuclear translocation of Snail. Further experiments indicated that nuclear factor erythroid 2-related factor 2 (Nrf2) and p62 were upregulated in BPDE-exposed alveolar epithelial cells. Moreover, Nrf2 siRNA transfection evidently attenuated BPDE-induced p62 upregulation. Besides, p62 shRNA inhibited BPDE-incurred Snail nuclear translocation and EMT. Mechanically, BPDE facilitated physical interaction between p62 and Snail in the nucleus, then repressed Snail protein degradation by p62-dependent autophagy-lysosome pathway, and finally upregulated transcriptional activity of Snail. Additionally, aryl hydrocarbon receptor (AhR) was activated in BPDE-treated alveolar epithelial cells. Dual-luciferase assay indicated activating AhR could bind to Nrf2 gene promoter. Moreover, pretreatment with CH223191 or α-naphthoflavone (α-NF), AhR antagonists, inhibited BPDE-activated Nrf2-p62 signaling, and alleviated BPDE-induced EMT and pulmonary fibrosis in mice. Taken together, AhR-mediated Nrf2-p62 signaling contributes to BaP-induced EMT and pulmonary fibrosis.

Emissions of Benzо(a)pyrene and Carbon Monoxide from Forest Fires as a Source of Atmospheric Pollution in Cities of the Irkutsk Region

An assessment is made of the release of benz(a)pyrene (B(a)P) and accompanying toxic products of incomplete combustion – carbon monoxide and soot – from forest fires as a source of atmospheric air pollution in cities in the Irkutsk region. Mass gross emissions, t/year, averaged for 2014–2020. of the studied substances in all 33 districts of the Irkutsk region were calculated. The dependences of gross emissions B(a)P are establishedDepends on the indicators of forest fires: the amount, area, mass of burnt plant materials, gross emissions of carbon monoxide and soot. The conclusion is made about the pollution of the atmospheric air of cities with carcinogenic B(a)P and toxic carbon monoxide from forest fire emissions.

A multigenerational study can detect the evolutionary response to BaP exposure in the non-biting freshwater midge Chironomus riparius

The release of polycyclic aromatic hydrocarbons (PAHs) into the environment is posing a threat to ecosystems and human health. Benzo(a)pyrene (BaP) is considered a biomarker of PAH exposure and is classified as a Group 1 carcinogen. However, it was not known whether BaP is mutagenic, i.e. induces inherited germline mutations. In this study, we used a recently established method, which combines short-term mutation accumulation lines (MAL) with whole genome sequencing (WGS) to assess mutagenicity in the non-biting midge Chironomus riparius. The mutagenicity analysis was supplemented by an evaluation of the development of population fitness in three successive generations in the case of chronic exposure to BaP at a high concentration (100 μg/L). In addition, the level of ROS-induced oxidative stress was examined in vivo. Exposure to the higher BaP concentration led to an increase in germline mutations relative to the control, while the lower concentration showed no mentionable effect. Against expectations, BaP exposure decreased ROS-level compared to the control and is thus probably not responsible for the increased mutation rate. Likewise, the higher BaP concentration decreased fitness measured as population growth rate per day (PGR) significantly over all generations, without signs of rapid evolutionary adaptations. Our results thus highlighted that high BaP exposure may influence the evolutionary trajectory of organisms.

Environmental BaP/BPDE suppressed trophoblast cell invasion/migration and induced miscarriage by down-regulating lnc-HZ01/MEST/VIM axis

Environmental benzo(a)pyrene (BaP) and itsmetabolite benzo(a)pyrene-7, 8-dihydrodiol-9, 10-epoxide (BPDE), classic endocrine disrupting chemical and persistent organic pollutant, could cause miscarriage. However, the detailed mechanisms are still largely unclear and should be further explored. In this study, we discovered that exposure of trophoblast cells with BPDE could suppressed cell invasion/migration by inhibiting MEST/VIM (Vimentin) pathway. Moreover, BPDE exposure also increased lnc-HZ01 expression level, which further inhibited MEST/VIM pathway and then suppressed invasion/migration. Knockdown of lnc-HZ01 or overexpression of MEST could efficiently rescue invasion/migration of BPDE-exposed Swan 71 cells. Furthermore, lnc-HZ01 was highly expressed and MEST/VIM were lowly expressed in recurrent miscarriage (RM) villous tissues compared with healthy control (HC) group. Finally, we also found that BaP exposure inhibited murine Mest/Vim pathway in placental tissues and induced miscarriage in BaP-exposed mice. Therefore, the regulatory mechanisms were similar in BPDE-exposed human trophoblast cells, RM villous tissues, and placental tissues of BaP-exposed mice with miscarriage, building a bridge to connect BaP/BPDE exposure, invasion/migration, and miscarriage. This study provided novel insights in the toxicological effects and molecular mechanisms of BaP/BPDE-induced miscarriage, which is helpful for better elucidating the toxicological risks of BaP/BPDE on female reproduction.

Investigation of 200 anthropogenic activities in a representative alpine peatland in the Altay Mountains, northwestern China

Peatlands records can be used to reconstruct and understand the history of environmental evolution, as well as a more accurate reflection of human activities. The black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) are ideal natural archives of anthropogenic activities. To identify the information of anthropogenic activities recorded by peatlands in the middle and high latitudes of the alpine mountains in the arid and semi-arid regions of China. this study analyzed the concentrations of BC, δ13C ratios of BC, PAHs, and molecular diagnostic ratios of PHAs (including Benzo(a) anthracene (BaA), Chrysene (Chr), fluoranthene (Flt), anthracene (Ant), phenanthrene (Phe), Benzo(a) pyrene (BaP), and pyrene (Pyr) in a 30-cm peat profile from the Altay Mountain, northwestern China. Our results revealed concentrations of BC from 11.71 to 67.5 mg·g−1, and PAHs from 168.09 to 263.53 ng·g−1. The δ13CBC value ranged from − 31.37 to − 26.27‰, with an average of − 29.54‰, indicating that the BC mainly comes from biomass combustion. The ratios of BaA/(BaA + Chr), Flt/(Flt + Pyr), and Ant/(Ant + Phe) exceeded 0.35, 0.5, and 0.1, respectively, revealing that the PAHs pollutants mainly originated from the combustion of biomass and fossil fuel burning. Furthermore, based on these findings and our knowledge of social development in Altay, industrial transport and tourism have influenced the emission, transport, and deposition of BC and PAH in peatlands in the Altay mountains since the 1980s. After 1980, pollutant concentrations decreased with the implementation of environmental policies. The results not only reveal the influence of anthropogenic activities on the sedimentary characteristics of peatlands in the Altay Mountains, but also provide an important theoretical basis for the conservation of fragile mountain peatlands.