Investigation on the interaction mechanism of phospholipids with polycyclic aromatic hydrocarbons and their derivatives during oil degumming process.

Linking sedimentary PAH occurrence forms to precision lake pollution management: Multidimensional insights via three component analysis.

We investigate two nitrogen-containing isomers of polycyclic aromatic hydrocarbons, quinoline and isoquinoline, of composition C9H7N in collisions with 7keV O+ and 48keV O6+ projectile ions. By employing ion-ion coincidence mass spectrometry, we determine branching ratios for H-loss, C2H2-loss, and HCN-loss dissociation channels of Q2+ and IQ2+. The overall contribution of HCN loss is found to be the dominant decay channel. A comparison with the results of a parallel experiment on naphthalene, the simplest PAH, reveals that HCN loss in both isomers has a higher propensity than the analogous C2H2 loss of naphthalene. The positional identity of the nitrogen atom in the two isomers mainly manifests in many-body fragmentation of their dications. Potential energy surfaces of Q2+ and IQ2+ are further computed to explore complete fragmentation mechanisms. Parent dications (Q2+ and IQ2+) are identified to isomerize via seven-membered ring structures before elimination of C2H2 and HCN. While prompt dissociation is the primary pathway, the dominant channel of each neutral-loss class also exhibits delayed fragmentation.

We report a nickel-catalyzed Satoh-Miura annulation of free benzylamines with alkynes, enabled by a transient directing group (TDG) strategy. The integration of the TDG approach with earth-abundant nickel catalysis provides a straightforward and efficient route for the synthesis of substituted 1-naphthylmethylamines, which exhibits excellent functional group tolerance. Compared with conventional directing group (DG)-directed precious-metal-catalyzed systems for polycyclic aromatic hydrocarbon (PAH) synthesis, this protocol demonstrates advantages in atom- and step-economy, cost effectiveness, and sustainability.

This study investigates the bioaccumulation efficiency and associated health risks of polycyclic aromatic hydrocarbons (PAHs), total petroleum hydrocarbons (TPHs), and heavy metals by Manihot esculenta and Telfairia occidentalis cultivated in K-Dere and Bera, Ogoni using Bioaccumulation factor (BAF) and incremental lifetime cancer risk (ILCR) index. Levels of Heavy metal in the soil were determined using atomic absorption spectrometry, while PAHs and TPHs were analyzed using Fourier Transformed Infrared (FTIR). The results revealed that PAHs were undetected in both study locations, TPHs levels were higher in K-Dere (41.255±3.16 mg/kg) than the Bera (33.484±3.00 mg/kg below the WHO/DPR limit of 50.0 mg/kg, evidencing petroleum contamination. Elevated levels of heavy metals: Fe (26.13±2.12 mg/kg), > WHO limit (22 mg/kg). Cr(0.385±0.001 mg/kg) <WHO standards in K-Dere. PAHs were undetectable in both Manihot esculenta and Telfairia occidentalis, TPHs > US EPA (0.2 mg/kg). BAFs for all metals analyzed were below 1, except for Cr in Telfairia occidentalis from K-Dere (24.5). The ƩILCR showed that combined effects of Pb, Ni, Cr, exposure through Telfairia occidentalis may elicit cancer effect of 1 in every 100 adults (ƩILCR= 5.24 x 10-2). Increased level of heavy metals in leafy vegetables and its corresponding high bioaccumulation indicate high probability of metal-induced cancer effect on the exposed population. Telfairia occidentalis can be explored as a native plant for phytoremediation to remediate heavy metals contaminated soils.

Polycyclic aromatic hydrocarbons (PAH) are prevalent environmental contaminants, which exhibit the mutagenic, carcinogenic, and teratogenic properties. The growing demand for efficient PAH biodegradation (BD), particularly in wastewater treatment. This research investigates hydrocarbon degradation using Vreelandella piezotolerant DM1 across a various pH levels (4, 6, 7, 8, and 10) and its enzymatic capabilities. The study assessed the degradation potential of anthracene and phenanthrene under varying PAH concentrations and pH conditions. Optimal bacterial growth and degradation were observed at 300mg/L of both anthracene and phenanthrene at pH 8. To elucidate the degradation mechanisms, crucial intermediates were identified using gas chromatography mass-spectrometry (GC-MS). The hydrocarbon breakdown intermediates including anthracene-cis-1,2-dihydrodiol, (3Z)-4-[3-hydroxy(2-naphthyl)]-2-oxobut-3-enoic acid, 6,7-benzocoumarin, 1-hydroxy-2-naphthaldehyde, phenanthrene-cis-1,2-dihydrodiol, 1-hydroxy-2-naphthoic acid, and salicylic acid were observed during BD. Both intermediate compounds were conformed the salicylic acid pathway. GC-MS confirms the efficient degradation rates of 62% for anthracene, 82% for phenanthrene, and 83% for mixed hydrocarbons. These observations confirm that optimal conditions are obligatory for the enzymatic activity of the DM1 and a biodegradation pathway was proposed on the identified intermediates. In conculsion, V. piezotolerant DM1 serves as a potential candidate for hydrocarbon degradation in contaminated environment.

In the domain of bottom-up approach, regioselective fusion of aromatic moiety onto an arene templet remains scarcely explored, yet represents a crucial tool for the rapid generation of polycyclic aromatic hydrocarbons (PAHs). An unprecedented bottom-up strategy for the rapid construction of PAHs is developed by employing arene-derived ketones and carbon-rich 1,3-diynes. Many of these synthesized PAHs have tilted π-electronic structure, unique edges and topologies. A range of arene-derived ketones participated in this annulative-π-extension-cyclization cascade under first-row Co(III)-catalysis. Electronic nature of the 1,3-diynes guided the final mode of cyclization leading to the formal fusing of one fluorene moiety via 5-exo-dig cyclization or phenanthrene nucleus through 6-endo-dig cyclization. Intermediate ethynyl-PAHs were also isolated in case of relatively electron-deficient diynes. The contorted π-planes of the synthesized PAHs were elucidated by single-crystal X-ray analysis. Detailed DFT studies reinforce the proposed mechanistic pathway, validating the formation of the major regioisomer of PAHs. Furthermore, less aromatic character of fluorene moiety over phenanthrene nucleus is supported by the NICS(1)zz and ACID calculations.

Polycyclic Aromatic Hydrocarbons (PAHs) are environmental carcinogens that can be continuously exposed to the human body through breathing and other means, causing harm to various organs. The carcinogenic mechanism of PAHs is closely related to CYP1A1. This study reveals the effects of the concentration and duration time of the CYP1A1 inhibitor on human mammary epithelial cells treatment with PAHs, providing a potential target for the prevention and treatment of PAH-related breast cancer. Further verification of its specificity and efficacy through in vivo models is required in the future.

The presence of vanadium compounds in heavy oils poses a significant challenge by poisoning and deactivating refining catalysts, making their removal an essential processing step. However, this process is challenged by the competitive adsorption of abundant polycyclic aromatic hydrocarbons (PAHs) in heavy oils, due to the similar conjugated π-electron structure of PAHs and vanadyl porphyrins. In the presented study, the adsorption behaviors of vanadyl octaethylporphyrin (VOOEP) and 1-methylpyrene (1-MP) on various solid adsorbents were investigated. Among the adsorbents studied, the primary secondary amine adsorbent (PSA) demonstrated superior performance, achieving high VOOEP adsorption capacity and exceptional selectivity, even in the presence of a large excess of 1-MP. The adsorption kinetics, isotherms, and thermodynamics of VOOEP and 1-MP onto PSA were studied. Four common kinetic models (pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion) were used for data fitting. The adsorption isotherms were modeled using Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherms. The adsorption kinetics for both VOOEP and 1-MP on PSA were best described by the pseudo-second-order model, while equilibrium data were well fitted by the Freundlich isotherm. Thermodynamic analysis confirmed that the adsorption of VOOEP and 1-MP on PSA is a spontaneous and exothermic process. The practical applicability of PSA was confirmed with a heavy deasphalted oil (HDAO), where it efficiently removed vanadium with high selectivity, with lower co-adsorption of desirable oil components. The results indicate that PSA is a promising adsorbent for effectively removing vanadium compounds from heavy oils.

Ambient air pollution is a major environmental carcinogen consisting of a complex mixture of particulate matter, gases, and adsorbed toxicants. Fine (PM2.5) and ultrafine (PM0.1) particles are of particular concern due to their capacity to penetrate deep into the lungs and translocate systemically, carrying carcinogens such as heavy metals, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Exposure arises from traffic emissions, industrial activity, biomass combustion, and indoor sources, with inhalation as the primary route. Epidemiologic studies have firmly established associations between air pollution, particularly PM2.5and increased risks of lung, bladder, breast, and hematologic cancers, even at concentrations below regulatory thresholds. Mechanistically, pollutant-induced carcinogenesis is driven by oxidative stress, DNA damage, epigenetic reprogramming, immune dysregulation, and impaired cell cycle control. Air pollution generates reactive oxygen species (ROS), disrupts mitochondrial function, alters DNA repair pathways, and modulates the expression of tumor suppressor genes through methylation and histone modifications. Prolonged inflammation and immune suppression in polluted tissue microenvironments further promote malignant transformation. Recent studies have shown increased interest in microplastics (MPs) as potential environmental carcinogens, given their unique physical properties and poorly characterized toxicological profiles. Preliminary findings indicate that microplastics are detectable in multiple cancer types and may correlate with distinct molecular alterations, suggesting a link to carcinogenesis and highlighting a critical future direction for environmental cancer research.

Abstract Planetary nebulae are sites where ejected stellar material evolves into complex molecules, but the precise physical conditions and chemical routes that govern these processes are unclear. The presence of abundant carbon-rich molecules in O-rich environments poses particular challenges. Here we report the first detection of methyl cation (CH 3 + ) in any planetary nebula, observed in the O-rich nebula NGC 6302 using JWST MIRI/Medium Resolution Spectrometer observations. CH 3 + is a key driver of organic chemistry in UV-irradiated environments. Spatially resolved observations reveal that CH 3 + is colocated with 12 CO, H 2 , H ii , HCO + , and polycyclic aromatic hydrocarbons. LTE modeling of the CH 3 + emission yields excitation temperatures of 500–800 K in the inner bubble and torus, rising to 1000–2000 K in the outer bubble of NGC 6302, with column densities ranging from ∼10 11 to 10 13 cm −2 . This detection suggests that hydrocarbon radical chemistry must be incorporated into planetary nebulae chemical models. Further near-IR observations are crucial to map different chemical networks operating in these environments.

Co-composting of organic waste enhances the degradation of polycyclic aromatic hydrocarbons (PAHs) in the environment. In some cases, however the actual mechanism of the degradation is not very clear. The contribution of starch to the degradation of organic pollutants in co-composting process has not been previously explored, although its effect on the composting process has been studied. Hence, in this study, GC-MS was used to examine the degradation of anthracene in a three (3) weeks co-composting process of starch and green waste compost. The GC-MS analysis was able to identify anthracene and its oxidation product anthraquinone in the compost samples. After three (3) weeks of composting, the 1g/Kg of anthracene added to the compost gave relative abundances of 8x106 and 4.5x106 in the GC-MS chromatogram for the unamended and starch-amended compost respectively. This was an indication that anthracene degradation was more in the starch-amended compost. Despite this observation, ANOVA revealed that amendment with starch was not a significant factor, but rather time (p < 0.05) was. The results from this initial appraisal are interesting. Thus, further investigations with higher starch dosage, longer composting time, as well as the microbial activities of the bioremediation process are currently on to unravel the observed trend and also to propose anthracene degradation kinetics.

Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide and are strongly influenced by both environmental and socioeconomic determinants. Populations engaged in informal and hazardous occupations, such as brickmaking, may experience elevated cardiovascular risk due to chronic exposure to environmental pollutants, including heavy metals (arsenic and lead) and polycyclic aromatic hydrocarbons (PAHs). This study aimed to assess occupational exposure to heavy metals and PAHs and to evaluate atherogenic indices as indicators of cardiovascular risk among brickmakers in the Bajío region of Mexico. A cross-sectional study was conducted among 113 male adults from brickmaking communities in San Luis Potosí (SLP), Guanajuato (GTO), and Querétaro (QRO). Urine and blood samples were analyzed to quantify heavy metals and PAHs, while lipid profiles were used to calculate Castelli's Risk Indices (CRI-I and CRI-II) and the Atherogenic Index of Plasma (AIP). GTO exhibited the highest urinary arsenic concentrations (42.5µg/l), whereas SLP showed the highest blood lead levels (1.52µg/dl). PAH exposure was also highest in GTO (2.25µmol/mol creatinine). Correspondingly, the highest atherogenic index values were observed in GTO: CRI-I (4.28 ± 0.97), CRI-II (2.54 ± 0.64), and AIP (0.145 ± 0.28). A considerable proportion of participants presented moderate to high CVD risk profiles. Significant associations were found between arsenic and lead exposure and elevated CRI-II values, suggesting potential disruption of lipid metabolism. These findings confirm occupational exposure to environmental pollutants in brickmaking populations and indicate that chronic exposure to arsenic and lead may contribute to increased cardiovascular risk, as reflected by higher atherogenic indices.

DNA adducts from benzo(a)pyrene (BaP) and other polycyclic aromatic hydrocarbons (PAH) are related to tumor initiation in many tissues including mammary epithelia. T47D mammary cells are able metabolizers of BaP, forming DNA and cellular protein adducts but also a sizeable amount of extracellular protein adducts. GSH S-transferases (GST) help mitigate adduct formation by glutathione (GSH) conjugation. Here, we varied GSH levels using buthionine sulfoximine (BSO) and BaP pretreatments to deplete or augment GSH, respectively, to study adduct formation and metabolism at 4 µM 3H-BaP over 24–48hr. An inverse relationship was observed between GSH levels and nuclear protein and DNA adducts. Time course experiments showed extracellular protein adducts, identified primarily as bovine serum albumin and α1-AT (α-1-antitrypsin) in culture medium, were 5–10 times greater than cellular protein adducts and comprised 8–9% of total metabolized 3H-BaP. However, specific adduct binding (adducts/mg protein) in cells was much greater than for extracellular protein, likely from their intracellular proximity to CYP-mediated metabolism to BaP reactive metabolites. Proportions of 3H-BaP hydroxylated and conjugated metabolites in BSO and BaP pretreated cells were not greatly altered from DMSO control after 24 hr. Bioinformatic analysis of T47D cell gene expression indicated CYP1B1 and CYP1A1 were primary enzymes for BaP bioactivation. We surmised reactive BaP metabolites that escaped conjugation reactions were sufficiently stable to migrate into the extracellular space. These results suggest BaP reactive metabolites like BPDE (BaP-diol-epoxide) can easily translocate across cell membranes despite robust conjugation systems and ready supplies of essential co-substrates for sulfate or GSH conjugations. The implications in vivo are that BaP reactive metabolites can enter adjacent epithelia and some fraction could result in DNA binding and somatic mutations in cancer susceptibility genes over time. The relationship continues to grow between PAH exposure and pollution, and many malignancies including breast cancers.

This research determined the environmental impacts of contained OBM on the soil and water quality at the drilling area and the environment in and around the drilling area. Field samples from the affected and control sites were analyzed using Atomic Absorption Spectrophotometry (AAS) to assay heavy metals, Gas Chromatography-Mass Spectrometry (GC-MS) to analyze hydrocarbons. Findings bequeathed excellent indications of environmental degradation: Both total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs) in the soil and the water were above the WHO and NESREA standards; heavy metals/ Pb, Cd, Cr, Ni, Zn / were highly enclosed in the drilling regions in contrast to the controls regions; the soil was hydrophobic, low microbial functioning and low fertility; turbidity, oil coats and contaminants in the water samples were high. High correlations exist between soil and water contaminants, indicating the movement of contaminants through the environmental media. The research concludes that the OBM containment systems in Eruemokohwarien are not very efficient and pose a danger to the environment. It suggests the strict implementation of the EGASPIN standards, the adoption of modern remediation technologies, such as thermal desorption and cuttings reinjection, and the implementation of environmental monitoring, including community participation, to ensure sustainable drilling operations and ecological restoration.

The study of cycloaddition mechanisms is central to the fabrication of extended sp2 carbon nanostructures such as graphene nanoribbons and spin chains. Reaction modeling in this context has focused mostly on putative, energetically preferred, exothermic products with limited consideration for symmetry allowed or forbidden mechanistic effects. To classify and optimize allowed reaction mechanisms, modern topological tools can be explored. Here, we introduce a scheme for classifying symmetry-forbidden reaction coordinates in Woodward-Hoffmann correlation diagrams. We show that topological classifiers grant access to the study of reaction pathways and correlation diagrams in the same footing, for the purpose of elucidating mechanisms and products of polycyclic aromatic azomethine ylide (PAMY) cycloadditions of pentacene-yielding polycyclic aromatic hydrocarbons with an isoindole core in the solid-state and on surfaces, as characterized by mass spectrometry and scanning tunneling microscopy, respectively. By means of a tight-binding reaction model and broken-symmetry density functional theory (DFT), we find topologically-allowed pathways for an endothermic reaction mechanism. Our work unveils topological classification as a crucial element of reaction modeling for nanographene engineering, and highlights its fundamental role in the design of cycloadditions in on-surface and solid-state chemical reactions, while underscoring that exothermic pathways can be topologically-forbidden.

Exposure to fine particulate matter (PM2.5) is a leading global health risk factor. Effective mitigation demands a multidimensional understanding that integrates chemical, source and region-level differences in PM2.5 toxicities relevant to human health. We present a standardized in vitro cellular assay dataset characterizing PM2.5 toxic potencies across emission sources, chemical constituents and atmospheric environments. Real-world PM2.5 samples from 23 major anthropogenic sources, covering industrial, transportation and residential sectors, were evaluated for cytotoxicity and oxidative stress potency, identifying key sources driving PM2.5-induced health risks. Toxic potency-adjusted concentrations of bioactive PM2.5 components, including polycyclic aromatic hydrocarbons, elemental carbon, metals, and non-metal species, were quantified to attribute overall PM2.5 toxicity to specific chemicals. Furthermore, the toxic potencies of ambient PM2.5 collected from selected urban and rural areas in China were identified, enabling the development of evaluation metrics for quantifying regional inequalities in PM2.5 health risks. This dataset establishes a universal toxicity benchmark for standardized comparisons of PM2.5 health impacts, providing a valuable resource for exposure assessment, source prioritization, and air quality risk evaluation.

Soil co-contamination with heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) represents a widespread and challenging environmental issue that is difficult to address using conventional remediation methods. This review systematically examines the molecular mechanisms by which plant root exudates mediate the remediation of co-contaminated soils through synergistic interactions with rhizosphere microorganisms. We detail how plants dynamically adjust the composition and secretion of root exudates—such as organic acids, amino acids, sugars, and secondary metabolites—in response to combined HM-PAH stress. These exudates play multifaceted roles in remediation, including chelating HMs, enhancing PAH solubility and bioavailability, and acting as chemoattractants and metabolic substrates for rhizosphere microbes. In return, the recruited microbial communities contribute to pollutant detoxification through various mechanisms, such as biosurfactant production, enzymatic degradation, and improved plant nutrient acquisition. This reciprocal interaction forms a synergistic plant-microbe feedback loop that effectively mitigates combined contamination stress. By integrating evidence from diverse plant–soil systems, this review provides a comprehensive mechanistic framework for understanding root exudate-microbe interactions, offering critical insights for developing enhanced phytoremediation strategies to address complex environmental pollution.

Abstract Multiple ionization and fragmentation of a large polycyclic aromatic hydrocarbon (PAH) molecule, i.e. coronene (C24H12) under the impact of fast(1.5-5.5 MeV/u) O ions are investigated as a function of the perturbation strength (charge state/velocity). The mass spectra from a Wiley-McLaren type time-of-flight mass spectrometer have been measured for different energy and charge state of the
projectile. We have observed a dramatically large enhancement in the ratios (2+/1+) of doubly-to-singly charged parent recoil ion yields and similarly in the 3+/1+ recoil ion ratios which are discussed in the context of highly correlated electrons in the PAH and resulting collective excitations in coronene. These ratios are well-reproduced by a classical over-the-barrier (COB) model. The nearly linear dependence of the measured cross-sections on the projectile charge state is linked to the collective plasmon excitation in the coronene molecule based on a model originally developed for the fullerene. The measured absolute cross sections, obtained using a novel normalization technique, based on complementary electron spectroscopy experiments, are compared with the CTMC-COB (Classical trajectory Monte Carlo calculations including classical over-the-barrier model), as well as with a more sophisticated state-of-the-art quantum-mechanical CDW-EIS(CNDO) (continuum distorted wave eikonal initial state including complete neglect of differential orbitals) model. The absolute partial cross sections for the singly, doubly and triply ionized recoil-ions exhibit an excellent agreement with the CDW-EIS calculations - a step toward the development of quantum mechanical model for such large molecule. The present observation will also have implications towards the study of astrochemistry of the interstellar medium.

Using the Ministry of Environment’s fixed-site air quality monitoring network, we analyzed multiple hazardous air pollutants (HAPs)—including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals—during 2021–2024 and compared their concentrations with internationally reported levels. Pronounced spatial heterogeneity was observed across stations, particularly for VOCs and heavy metals. Stations A, E, and F were dominated by alkanes, whereas stations B, C, and D exhibited higher proportions of oxygenated VOCs (mainly aldehydes and ketones). Across the network, formaldehyde (0.015 μg/m3), dichloromethane (2.60 μg/m3), toluene (2.53 μg/m3), and acetaldehyde (0.004 μg/m3) were identified as the most abundant species. Stations A and E served as VOC hotspots—formaldehyde peaked at station A and toluene at station E—likely due to nearby industrial and port activities. Concentrations of BTEX generally decreased throughout the study period, with a minor rebound at station C in 2022. Regarding heavy metals, elevated concentrations of lead (16.83 ng/m3), nickel (4.71 ng/m3), and arsenic (1.29 ng/m3) were observed at station A, again suggesting influences from industrial or port-related emissions. Overall, formaldehyde, benzene, and 1,2-dichloroethane were identified as key pollutants of concern, with station A representing the most critical hotspot in the monitoring network.