Search Results (105)

Vehicle exhaust gases remain one of the key sources of atmospheric air pollution and pose a serious threat to ecosystems and public health. This study presents an experimental investigation into reducing the toxicity of gasoline internal combustion engine exhaust using ultrasonic waves and infrared (IR) laser exposure. An original hybrid system integrating an ultrasonic emitter and an IR laser module was developed. Four operating modes were examined: no treatment, ultrasound only, laser only, and combined ultrasound–laser treatment. The concentrations of CH, CO, CO₂, and O₂, as well as exhaust gas temperature, were measured at idle and under operating engine speeds. The experimental results show that ultrasound provides a substantial reduction in CO concentration (up to 40%), while IR laser exposure effectively decreases unburned hydrocarbons CH (by 35–40%). The combined treatment produces a synergistic effect, reducing CH and CO by 38% and 43%, respectively, while increasing the CO₂ fraction and decreasing O₂ content, indicating more complete post-oxidation of combustion products. The underlying physical mechanisms responsible for the purification were identified as acoustic coagulation of particulates, oxidation, and photodissociation of harmful molecules. The findings support the hypothesis that combined ultrasonic and laser treatment can enhance real-time exhaust gas purification efficiency. It is demonstrated that physical treatment of the gas phase not only lowers the persistence of by-products but also promotes more complete oxidation processes within the flow. Full article

Low-concentration trichloroethylene (TCE) and tetrachloroethylene (PCE) indoors pose a significant threat to human health due to their potent carcinogenic properties. However, existing research has predominantly focused on high-concentration scenarios in industrial settings, offering limited guidance for indoor air purification. This study investigated the adsorption mechanisms and performance regulation of coconut shell activated carbon for TCE/PCE through experimental analysis, molecular simulations, and dynamic modeling. Experimental results demonstrated that PCE, characterized by its non-polar nature and high boiling point, exhibited a substantially higher adsorption capacity than TCE. Increased humidity induced competitive adsorption between water molecules and pollutants, reducing the adsorption capacity of PCE by approximately 30%. Molecular simulations validated that water molecules occupied the active sites of oxygen-containing functional groups and pores, impeding the diffusion of TCE/PCE, while the non-polar surface of activated carbon preferentially adsorbs PCE. A dynamic prediction model developed in this study accurately forecasted breakthrough curves under varying pollutant concentrations, temperatures, humidities, and air velocities and quantified the service life of activated carbon. Response surface methodology revealed that controlling inlet concentrations (TCE < 7 ppb, PCE < 30 ppb), air velocity (<1 m/s), humidity (<50%), and temperature (<25 °C) can extend the service life of activated carbon to 3–5 months. Full article

Achieving sustainable air quality improvements in rapidly industrializing regions requires a clear understanding of the emission sources that drive the formation of PM_2.5 pollution. This study identified the sources of PM_2.5 and its organic carbon (OC) in Zibo, a typical industrial city in Northern China Plain, using the Positive Matrix Factorization (PMF) model during five pollution episodes (P1–P5) from 26 November 2022 to 9 February 2023. A high-temporal-resolution online observation of 61 organic molecular tracers was conducted using an Aerodyne TAG stand-alone system combined with a gas chromatograph–mass spectrometer (TAG-GC/MS) system. The results indicate that during pollution episodes, PM_2.5 was contributed by 32.4% from coal combustion and 27.1% from inorganic secondary sources. Moreover, fireworks contributed 13.1% of PM_2.5, primarily due to the extensive fireworks during the Gregorian and Lunar New Year celebrations. Similarly, coal combustion was the largest contributor to OC, followed by mobile sources and secondary organic aerosol (SOA) sources, accounting for 16.2% and 15.3%, respectively. Although fireworks contributed significantly to PM_2.5 concentrations (31.6% in P4 of 20–24 January 2023), their impact on OC was negligible. Overall, a combination of local and regional industrial combustion emissions, mobile sources, extensive residential heating during cold weather, and unfavorable meteorological conditions led to elevated secondary aerosol concentrations and the occurrence of this haze episode. The high-temporal-resolution measurements obtained using the TAG-GC/MS system, which provided more information on source-indicating organic molecules (tracers), significantly enhanced the source apportionment capability of PM_2.5 and OC. The findings provide science-based evidence for designing more sustainable emission control strategies, highlighting that the coordinated management of coal combustion, mobile emissions, and wintertime heating is essential for long-term air quality and public health benefits. Full article

Helminth parasites infect mammalian hosts through complex life cycles, mostly triggering T helper type 2 (Th2) immune responses characterized by interleukin-4 (IL4), interleukin-5 (IL5), and interleukin-13 (IL13) production. Environmental chemical exposures may modulate these immune pathways, potentially affecting infection outcomes. Using The Comparative Toxicogenomics Database (CTD), we analyzed chemical–gene interactions affecting IL4, IL5, and IL13 genes to identify chemicals capable of modulating Th2 immunity and their associated expression profiles. Accordingly, a total of 818 chemicals can interact with IL4, IL5 and/or IL13, with 145 chemicals showing the potential of affecting all three genes. These 145 chemicals include air pollutants (8.3%), allergens (2.7%), bioactive molecules (8.3%), industry-related chemicals (14.5%), medicinal drugs (21.4%), metal and metal-containing chemicals (8.3%), pesticides (3.4%), plant compounds (12.4%), and others (20.7%). We observed a greater number of chemicals associated with increased (n = 95) gene expression compared to decreased (n = 14) gene expression, suggesting a Th2 pathway hyperactivation caused by chemicals capable of affecting IL4, IL5 and IL13. Eight classes of parasitic diseases were observed among chemical-associated conditions. Environmental chemicals extensively modulate Th2 immune responses through diverse molecular mechanisms. The trend concerning upregulation of Th2 pathways may enhance antiparasitic protection but, on the other hand, could predispose individuals to allergic diseases, among other Th2-related conditions. These exploratory findings suggest that chemical pollution may influence the susceptibility and pathogenesis of helminth infections and highlight the need for the incorporation of exposome-based approaches in parasitology research. Full article

The exponential increase in environmental pollutants due to industrialization, urbanization, and agricultural intensification has underscored the urgent need for sensitive, selective, and real-time monitoring technologies. Among emerging analytical tools, organic fluorescent sensors have demonstrated exceptional potential for detecting a wide range of pollutants in water, air, and soil, with a limit of detection (LOD) in the pM–µM range. This review critically examines recent advances in organic fluorescent sensors, focusing on their photophysical properties, molecular structures, sensing mechanisms, and environmental applications. Key categories of organic sensors, including small molecules, polymeric materials, and nanoparticle-based systems, are discussed, highlighting their advantages, such as biocompatibility, tunability, and cost-effectiveness. Comparative insights into inorganic fluorescent sensors, including quantum dots, are also provided, emphasizing their superior photostability and wide operating range (in some cases from pg/mL up to mg/mL) but limited biodegradability and higher toxicity. The integration of nanomaterials and microfluidic systems is presented as a promising route for developing portable, on-site sensing platforms. Finally, the review outlines current challenges and future perspectives, suggesting that fluorescent sensors, particularly organic ones, represent a crucial strategy toward sustainable environmental monitoring and pollutant management. Full article

Lung cancer remains a leading cause of mortality worldwide, driven by increased tobacco use, industrialization, and air pollution. Despite advancements in diagnostics and treatments, effective therapies are still lacking. Reactive oxygen species (ROS) play a dual role in cancer development, regulating key signaling pathways and activating cell death pathways, making them a promising target for new drugs. Research shows that wild-type NRF2/KEAP1 lung tumors, which account for about 60% of lung malignancies, are sensitive to ROS induction, and mutated EGFR1 lung tumors exhibit high ROS levels. Proteolysis-targeting chimeras (PROTACs) have emerged as a promising alternative to small molecule inhibitors (SMIs) for cancer treatment, addressing limitations like undruggability and drug resistance. However, these face challenges such as limited cell penetration and potential toxic side effects. Nanotechnology has introduced “nano-PROTACs,” enhancing tissue accumulation, membrane permeability, and controlled release. In this review, the keystones of ROS in lung cancer will be summarized. Also, a potential therapy for tumors with wild-type NRF2 involving the delivery of ROS inductor nano-PROTAC will be designed. This potential therapy could suppose a potential therapeutic strategy for lung cancer patients with these genetic characteristics. Full article

The human C-C chemokine receptor type 5 (CCR5) is a molecule primarily expressed on the surface of inflammatory cells, acting as the main HIV co-receptor. In order to penetrate host cells, HIV interacts with both CCR5 and the CD4 molecule during the infectious process. Emerging evidence suggests that pollution by metals, such as aluminum, lead, and manganese, triggers CCR5-mediated inflammation, which may have important implications for the risk of HIV infection. Specifically, we hypothesize that exposure to pollution by metals causes inflammation and elevated CCR5 expression on the surface of CD4+ cells, resulting in an increased risk of HIV infection. Our hypothesis is supported by toxicogenomic data, which shows that both air pollutants and some metals (e.g., arsenic, cadmium, nickel) induce CCR5 expression. Finally, approaches to evaluate the hypothesis are suggested. If confirmed, our hypothesis introduces environmental pollution to the set of biological factors influencing the risk of HIV infection. Full article

Benzene, toluene, ethylbenzene, and xylene (BTEX) are widespread volatile organic compounds commonly present in fuels and various industrial materials. Their release into the atmosphere significantly contributes to air pollution, prompting strict regulatory concentration limits in ambient air. In this work, we introduce Multiphoton Electron Extraction Spectroscopy (MEES) as an innovative technique for the sensitive, selective, and online detection and quantitation of BTEX compounds under ambient conditions. MEES employs tunable UV laser pulses to induce the resonant ionization of target molecules under a high electrical field, with subsequent measurement of the generated photocurrent. We now demonstrate the method’s ability to detect BTEX in ambient air, at part-per-trillion (ppt) concentration range, providing distinct spectral signatures for each compound, including individual xylene isomers. The technique represents a significant advancement in BTEX monitoring, with potential applications in environmental sensing and industrial air quality control. Full article

Volatile Organic Compounds (VOCs) are pervasive environmental pollutants with significant implications for air quality and human health. The development of effective technologies for VOC degradation is essential to mitigate their adverse effects. Microwave plasma technology has emerged as a promising solution for VOC abatement due to its ability to generate highly reactive species at ambient conditions, enabling efficient decomposition of VOCs into harmless byproducts. Concurrently, Density Functional Theory (DFT) has become a critical tool for understanding the molecular-level mechanisms of VOC degradation, providing insights into reaction pathways and energy dynamics. This study explores the integration of microwave plasma experiments with DFT simulations to investigate the degradation mechanisms of VOCs under plasma conditions. DFT calculations of microwave plasma degradation for toluene are performed. The results show that on the one hand, toluene can undergo ring-opening. Then, these active molecules or groups react with active free radicals and are ultimately oxidized into CO₂ and H₂O. On the other hand, VOC gas molecules react with active free radicals (O, OH) generated by background gas (O₂ and H₂O) through oxidation reactions, generating organic intermediates such as benzene, benzyl alcohol, and benzoic acid, respectively, which are finally oxidized into CO₂ and H₂O. Our theoretical research results are expected to provide profound insights into the degradation mechanisms of these aromatic hydrocarbon VOCs through microwave plasma and also contribute to a better understanding of the further degradation mechanisms of air pollutants at the molecular level. Full article

Hydrogen chloride (HCl) is one of the most hazardous air pollutants and can cause significant damage to human health and the environment. Therefore, the continuous quantitative monitoring of HCl is of great practical importance. In this work, a novel triphenylamine derivative, named TPTc-DBD, with a Schiff base structure was synthesized. The molecular structure of TPTc-DBD was determined by NMR analysis, FTIR analysis and single crystal diffraction analysis. On this basis, a porous polyvinylidene fluoride (PVDF) film containing TPTc-DBD was then prepared by a spin-coating method, and its sensitivity to HCl was evaluated by naked eye and ultraviolet-visible absorption spectrum, respectively. The detection limit of the composite porous film for HCl molecules was determined to be 5.8 mg/m³. Interestingly, the composite films absorbing HCl can be reactivated by NH₃, which provides a cycle detection ability for HCl. After five testing cycles, the detection error remained below 1%. Furthermore, the microstructure of the film remained unchanged, highlighting its exceptional detection performance for HCl. Full article

In this study, the heterogeneous reaction of oleic acid droplets with gas-phase ozone was studied by an ATR-FTIR flow reactor. The effects of droplet size, relative humidity, and ozone concentration on the reaction kinetics were carefully investigated. Specifically, the pseudo-first-order rate constant k_app and the uptake coefficient γ displayed a size dependence, with k_app decreasing from ~4.5 × 10⁻³ to ~3.2 × 10⁻³ and γ linearly increasing from ~4.4 × 10⁻⁵ to ~3.2 × 10⁻⁴ as the suspended droplet diameter increased from 0.1 to 1.0 μm. It is believed that the reaction kinetics were the major contributor to the reactive uptake in the reaction between the oleic acid droplets and gas-phase ozone observed in this study. In addition, RH showed no obvious influence on the heterogeneous reaction kinetics, in agreement with findings from previous studies. Furthermore, the k_app was found to display a Langmuir–Hinshelwood dependence on the gas-phase ozone concentration with K_O3 = (3.29 ± 0.46) × 10⁻¹⁵ molecules cm⁻³ and k[S] = 0.153 ± 0.007 s⁻¹, which is consistent with observations of the ozonolysis of unsaturated organic materials in the literature. Kinetics data related to the heterogeneous reaction of ozone and oleic acid under different conditions could be used in chemistry transport models and air quality models to better understand air pollutants’ adverse health impacts. Full article

Heavy and transition metal (HTM) ions have significant harmful effects on the physical environment and play crucial roles in biological systems; hence, it is crucial to accurately identify and quantify any trace pollution. Molecular sensors which are based on organic molecules employed as optical probes play a crucial role in sensing and detecting toxic metal ions in water, food, air, and biological environments. When appropriate combinations of conduction and selective recognition are combined, fluorescent and colorimetric chemosensors are appealing instruments that enable the selective, sensitive, affordable, portable, and real-time investigation of the possible presence of heavy and transition metal ions. This feature article aims to provide readers with a more thorough understanding of the different methods of synthesis and how they work. As noted in the literature, we will highlight colorimetric and fluorometric sensors based on their receptors into multiple categories for heavy metal ion detection, such as Hg²⁺, Ag²⁺, Cd^2+, Pb²⁺, and In³⁺, and simultaneous multiple-ion detection. Full article

The cobalt manganese oxides, especially the spinels and related (multiphase) materials described with the formula Co_xMn_3−xO₄ (0 < x < 3), are widely used catalysts in a range of processes in significant industrial and environmental areas. The great diversity in the phase relations, composition, and metal ion valences, together with ion and vacancy site distribution variations, results in great variety and activity as catalysts in various industrially important redox processes such as the removal of CO or volatile organic substances (VOCs) from the air and oxidative destruction of pollutants such as dyes and pharmaceuticals from wastewater using peroxides. These mixed oxides can gain application in the selective oxidation of organic molecules like 5-hydroxyfurfural or aromatic alcohols such as vanillyl alcohol or in the production of fuels and other valuable chemicals (alcohols, esters) with the Fischer–Tropsch method. In this review, we summarize these redox-based reactions in light of the chemical and phase composition of the catalysts with the formula Co_xMn_3−xO₄ with 0 < x < 3. Full article

Fine particulate matter (PM) 2.5 is the main component of air pollution causing pathological responses primarily in the respiratory and cardiovascular systems. Therefore, it is urgent to explore valid strategies to inhibit the adverse reactions induced by PM2.5. In our previous studies, we have revealed that intratracheal instillation of PM2.5 evoked airway remodeling, pulmonary inflammatory, and oxidative stress responses in rat lungs by upregulating VEGFA levels in bronchial epithelial cells and by activating ANGII/AT1R axis activation in vascular endothelial cells. The same results were obtained when human bronchial epithelial cells (Beas−2B) and human umbilical vein endothelial cells (HUVECs) cells were exposed to PM2.5 in vitro. Curcumin is a dietary polyphenol with protective properties, including anti−inflammatory and antioxidant effects. This study aims to determine the potential role of curcumin in protecting against PM2.5−induced adverse responses in the bronchial epithelium and vascular endothelium and the mechanism involved. To this end, we pretreated cells with curcumin (diluted 1000 times in sterile saline) for 2 h and then exposed them to PM2.5. Our results from RT−PCR, a luciferase reporter assay, and ELISA indicated that curcumin pretreatment effectively inhibited PM2.5−induced VEGFA elevation in Beas−2B cells by over 60% via blocking HIF1α accumulation and HIF1 transactivity, Moreover, curcumin also exerted a protective role in suppressing PM2.5−induced ANGII/AT1R axis components expression in HUVEC by over 90% via targeting the transcriptional factors, AP−1 and HIF1. Under the same conditions, curcumin pretreatment also blocked the downstream signaling events following ANGII/AT1R pathway activation, the increase in chemokines and cell adhesion molecules (sICAM−1, VCAM−1, E−Selectin, P−Selectin, IL−8, MCP−1) that drive monocyte−endothelial cell adhesion, as well as the elevated production of oxidative stress mediators (ROS and MDA) in HUVECs according to the data from immunofluorescence and flow cytometric assays. Most importantly, administration of curcumin resulted in an 80% reduction of the HIF1− and AP−1−dependent upregulation of VEGFA and AGT/AT1R axis components and impeding the resultant pro−inflammatory and oxidative responses in the lung of the rats exposed to PM2.5. Taking these data together, we disclosed the important role and mechanism of curcumin in protecting against PM2.5−induced adverse reactions in the bronchial epithelium and vascular endothelium. Curcumin might be used as a feasible and safe dietary agent to reduce the health risk of PM2.5. Full article

Increased levels and detrimental effects of volatile organic compounds (VOCs) on air quality and human health have become an important issue in the environmental field. Benzene is classified as one of the most hazardous air pollutants among non-halogenated aromatic hydrocarbons with toxic, carcinogenic, and mutagenic effects. Various technologies have been applied to decrease harmful emissions from various sources such as petrochemistry, steel manufacturing, organic chemical, paint, adhesive, and pharmaceutical production, vehicle exhausts, etc. Catalytic oxidation to CO₂ and water is an attractive approach to VOC removal due to high efficiency, low energy consumption, and the absence of secondary pollution. However, catalytic oxidation of the benzene molecule is a great challenge because of the extraordinary stability of its six-membered ring structure. Developing highly efficient catalysts is of primary importance for effective elimination of benzene at low temperatures. This review aims to summarize and discuss some recent advances in catalyst composition and preparation strategies. Advantages and disadvantages of using noble metal-based catalysts and transition metal oxide-based catalysts are addressed. Effects of some crucial factors such as catalyst support nature, metal particle size, electronic state of active metal, redox properties, reactivity of lattice oxygen and surface adsorbed oxygen on benzene removal are explored. Thorough elucidation of reaction mechanisms in benzene oxidation is a prerequisite to develop efficient catalysts. Benzene oxidation mechanisms are analyzed based on in situ catalyst characterization, reaction kinetics, and theoretical simulation calculations. Considering the role of oxygen vacancies in improving catalytic performance, attention is given to oxygen defect engineering. Catalyst deactivation due to coexistence of water vapor and other pollutants, e.g., sulfur compounds, is discussed. Future research directions for rational design of catalysts for complete benzene oxidation are provided. Full article