Search Results (1,200)

Understanding how atmospheric pollutants interact with soil pollution is essential for assessing long-term environmental and human health risks. This study compares concentrations of polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) in PM₁₀ and surface soil near air quality monitoring stations in Zagreb, Croatia. While previous work identified primary emission sources affecting PM₁₀ composition in the area, this study extends the analysis to investigate potential pollutant transfer and accumulation in soils. Multivariate statistical tools, including correlation analysis and principal component analysis (PCA), were employed to gain a deeper understanding of the sources and behavior of pollutants. Results reveal significant correlations between air and soil concentrations for several PTEs and PAHs, particularly when air pollutant data are averaged over extended periods (up to 6 months), indicating cumulative deposition effects. Σ11PAH concentrations in soils ranged from 1.2 to 524 µg/g, while mean BaP in PM₁₀ was 2.2 ng/m³ at traffic-affected stations. Strong positive air–soil correlations were found for Pb and Cu, whereas PAH associations strengthened at longer averaging windows (3–6 months), especially at 10 cm depth. Seasonal variations were observed, with stronger associations in autumn, reflecting intensified emissions and atmospheric conditions that facilitate pollutant transfer. PCA identified similar pollutant groupings in both air and soil matrices, suggesting familiar sources such as traffic emissions, industrial activities, and residential heating. The integrated PCA approach, which jointly analyzed air and soil pollutants, showed coherent behaviour for heavier PAHs and several PTEs (e.g., Pb, Cu), as well as divergence in more volatile or mobile species (e.g., Flu, Zn). Spatial differences among monitoring sites show localized influences on pollutant accumulation. Furthermore, this work demonstrates the value of coordinated air–soil monitoring in urban environments and provides an understanding of pollutant distributions across different components of the environment. Full article

In the Alberta Oil Sands Region (AOSR), environmental stressors linked to oil sands industrial activity may have significant and species-specific impacts on local wildlife. This study evaluated the kynurenine–tryptophan ratio (KTR) as a potential biomarker for environmental exposure in longnose suckers (Catostomus catostomus) and white suckers (Catostomus commersonii) collected from various locations within the AOSR. The relationship between KTR and CYP1 enzyme activity (ethoxyresorufin-O-deethylase; EROD) was assessed alongside biometric indices, including gonadosomatic index (GSI), hepatic somatic index (HSI), and fat content. Both species exhibited increased EROD activity when exposed to oil sands natural deposits and potential industrial activity, indicating significant polycyclic aromatic compound (PAC) exposure. However, KTR changes were species-dependent: longnose suckers showed an inversely proportional relationship between KTR and EROD, while white suckers displayed a directly proportional correlation. Longnose suckers downstream of both municipal waste and industrial activity exhibited significant increases in GSI and fat content, with KTR varying more consistently by location rather than sex, suggesting that KTR may be a more reliable marker for location-based exposure. Species-specific differences in KTR and EROD relationships may be influenced by the distinct environmental requirements of each species, and their differing sensitivities to environmental conditions, including temperature, turbidity and flow conditions, during sampling periods. These findings illustrate the complexity of interpreting environmental biomarkers in wildlife and emphasize the need to consider ecological requirements and environmental conditions. Further research is necessary to validate this biomarker across different years and conditions and enhance its application in environmental monitoring and conservation efforts. Full article

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants with significant ecological and public health implications, particularly in urban wetlands exposed to chronic anthropogenic stress. This study evaluates the occurrence, spatial distribution, seasonal variability, and ecological risk of three low molecular weight PAHs—naphthalene (NAP), phenanthrene (PHEN), and anthracene (ANT)—in surface waters of Caño La Malaria, the main freshwater source of Cucharillas Marsh, Puerto Rico’s largest urban wetland. Surface water samples were collected at four locations during both wet- and dry-season campaigns. Samples were extracted and quantified by GC-MS. NAP was the dominant compound, Σ3PAHs concentrations ranging from 7.4 to 2198.8 ng/L, with higher wet-season levels (mean = 745.79 ng/L) than dry-season levels (mean = 186.71 ng/L); most wet-season samples fell within the mild-to-moderate contamination category. Compositional shifts indicated increased levels of PHEN and ANT during the wet season. No significant spatial differences were found (p = 0.753), and high correlations between sites (r = 0.96) suggest uniform input sources. Diagnostic ratios, inter-species correlations, and principal component analysis (PCA) consistently indicated a predominant pyrogenic origin, with robust PHEN–ANT correlation (r = 0.824) confirming shared combustion-related sources. PCA revealed a clear separation between dry- and wet-season samples, with the latter showing greater variability and stronger associations with NAP and ANT. Ecological risk assessment using hazard quotients (HQ_water) indicated negligible acute toxicity risk across all sites and seasons (<0.01); the highest HQ_water (0.0095), observed upstream during the wet season, remained within this range. However, benchmark exceedances by PHEN and ANT suggest potential chronic risks not captured by the acute ERA framework. These findings support integrated watershed management practices to mitigate PAH pollution and strengthen long-term ecological health in tropical urban wetlands. Full article

The fluorescence of aqueous solutions of the aromatic amino acids tryptophan, tyrosine, and phenylalanine, an albumin solution, and a mixture of water-soluble animal and plant proteins is investigated after treatment with hydroxyl and hydroperoxyl radicals and continuous UV-C radiation at λ = 253.7 nm. The use of independent sources of active species allows for the study of activation and the development of free radical processes in model objects. The analysis is based on Stern–Volmer coefficients for the quenching of the fluorescence of the initial substrates and the ignition of the fluorescence of newly formed products. In the reaction with hydroxyl radicals, the hydrogen atom could be abstracted from any position in the target molecule. Under continuous UV-C radiation, the protein molecule as a whole was excited. Full article

High-molecular-weight polycyclic aromatic hydrocarbons (PAHs), such as pyrene, are persistent environmental pollutants that threaten soil health and agricultural productivity due to their resistance to degradation. This study evaluated the efficacy of domesticated bacteria isolated from contaminated farmland soil and activated sludge, used alone and in combination with corn (Zea mays L.), to remove pyrene from soil, enhance plant growth, improve tolerance, and ensure crop safety. Six bacterial strains were isolated: three from polluted farmland soil (WB1, WB2, and WF2) and three from activated sludge (WNB, WNC, and WH2). High-throughput 16S rRNA amplicon sequencing profiled bacterial communities after 30 days of treatment. Analytical tools, including LEfSe, random forest, and ZiPi analyses, identified biomarkers and core bacteria associated with pyrene degradation, assessing their correlations with plant growth, tolerance, and pyrene accumulation in corn straw. Bacteria from activated sludge (WNB, WNC, and WH2) outperformed farmland soil-derived strains and the inoculant strain ETN19, with WH2 and WNC achieving 65.06% and 87.69% pyrene degradation by days 15 and 30, respectively. The corn–bacteria consortium achieved up to 97% degradation. Activated sewage sludge (ASS)-derived bacteria were more effective at degrading pyrene and enhancing microbial activity, while soil-derived bacteria better promoted plant growth and reduced pyrene accumulation in straw. Microbial communities, dominated by Proteobacteria, exhibited high species richness and resilience, contributing to xenobiotic degradation. The corn-domesticated bacteria consortia effectively degraded pyrene, promoted plant growth, and minimized pollutant accumulation in crops. This remediation technology offers a promising strategy for rapid and sustainable bioremediation of agricultural soils contaminated with organic compounds such as PAHs or other complex pollutants, while promoting the development of efficient bacterial communities that enhance crop growth. Full article

Investigating atmospheric volatile organic compounds (VOCs) is critical for understanding their sources, chemical reactivity, and impacts on air quality, climate, and human health, especially in remote regions like the Tibetan Plateau where baseline data remains scarce. In this study, ambient VOCs species were simultaneously measured at four remote background sites on the Tibetan Plateau (Nyingchi, Namtso, Ngari, and Mount Everest) from 2012 to 2014 to investigate their concentration, composition, sources, and chemical reactivity. Weekly integrated samples were collected and analyzed using a Gas Chromatograph-Mass Spectrometer/Flame Ionization Detector (GC-MS/FID) system. The total VOC mixing ratios exhibited site-dependent variability, with the highest levels observed in Nyingchi, followed by Mount Everest, Ngari and Namtso. The VOC composition in those remote sites was dominated by alkanes (25.7–48.5%) and aromatics (11.4–34.7%), followed by halocarbons (19.1–28.1%) and alkenes (11.5–18.5%). A distinct seasonal trend was observed, with higher VOC concentrations in summer and lower levels in spring and autumn. Source analysis based on correlations between specific VOC species suggests that combustion emissions (e.g., biomass burning or residential heating) were a major contributor during winter and spring, while traffic-related emissions influenced summer VOC levels. In addition, long-range transport of pollutants from South Asia also significantly impacted VOC concentrations across the plateau. Furthermore, reactivity assessments indicated that alkenes were the dominant contributors to OH radical loss rates, whereas aromatics were the largest drivers of ozone formation potential (OFP). These findings highlight the complex interplay of local emissions and regional transport in shaping VOC chemistry in this high-altitude background environment, with implications for atmospheric oxidation capacity and secondary pollutant formation. Full article

The genus Lavandula represents one of the most valuable aromatic and medicinal plants, holding significant economic importance in the pharmaceutical, food, perfumery, and cosmetics industries. Among them, L. multifida is a traditionally used medicinal plant in the Mediterranean region. This work provides a comprehensive review of L. multifida, focusing on its traditional uses, phytochemistry, and pharmacological properties. Unlike conventional lavenders, its essential oil is dominated by phenolic monoterpenes, principally carvacrol, alongside significant concentrations of β-bisabolene, 1,8-cineole, and camphor. This distinct phytochemical profile is further complemented by a rich range of non-volatile constituents, including flavonoids, phenolic acids, and triterpenoids. Pharmacological investigations have validated its broad-spectrum antimicrobial activity, demonstrating efficacy against multidrug-resistant bacterial strains and fungal pathogens through mechanisms such as membrane disruption, metabolic interference, and quorum sensing inhibition. Furthermore, the species exhibits significant antioxidant and anti-inflammatory properties, mediated primarily through radical scavenging, cyclooxygenase inhibition, and cytokine modulation. Owing to its distinct chemistry, specific traditional uses for respiratory and digestive ailments, limited endemic habitat, and underexplored status, L. multifida presents a promising candidate for future research with high potential for novel drug discovery, particularly in antiparasitic and respiratory therapies. This review concludes by identifying key research priorities for L. multifida, including a detailed analysis of its non-volatile compounds, mechanistic elucidation, toxicological assessments, and standardization of extracts. Addressing these gaps is essential to validate its traditional applications and advance its development into evidence-based phytomedicines, adjuvant therapies, and natural agrochemicals. Full article

Previously unobserved (carbamoyl)disulfanyl chlorides were prepared by (i) addition of limiting aromatic secondary amine to (chlorocarbonyl)disulfanyl chloride; (ii) Harris reactions of sulfur dichloride with appropriate O-alkyl N-methyl-N-arylthiocarbamates; and (iii) regiospecific chlorolysis of bis(N-methyl-N-arylcarbamoyl)disulfanes. The newly synthesized unstable species were observed in situ by ¹H NMR and were trapped with alkenes, thiocarbamates, and thiols using methods precedented by the chemistry of analogous (carbamoyl)sulfenyl chlorides. Furthermore, each of the trapped products was synthesized by an alternate route, reinforcing conclusions about their structures. While (N-methyl-N-phenylcarbamoyl)disulfanyl chloride was unstable and decomposed quickly or cyclized intramolecularly, introduction of the N,2,6-trimethylphenyl moiety led to significantly improved stability. As part of this study, an interesting, unexpectedly stable 1,2,4-dithiazinone was discovered and its structure was established by X-ray crystallography. The new heterocycle, with its twisted out-of-plane disulfide bond in a six-membered ring, readily donated a sulfur atom to triphenylphosphine; this reaction resulted in the formation of triphenylphosphine sulfide, along with the corresponding highly stable heterocycle in which the single sulfur that remains is part of a planar five-membered ring, fused to a co-planar aryl moiety. Full article

Micromeria croatica (Pers.) Schott is a Balkan endemic of the Lamiaceae family, valued for its aromatic and medicinal properties, but it is threatened by its limited natural distribution. Micropropagation offers a sustainable method for securing biomass and provides material for chemical studies. In this work, we present the first LC-HRMS profiling of extracts (in methanol, ethyl acetate, and hexane) obtained from both native and micropropagated plants. A total of 29 metabolites were identified. A diverse spectrum of secondary metabolites was identified, including phenolic acids (gallic acid monohydrate, vanillic acid, trans-cinnamic acid), flavonoids (luteolin-7-O-rutinoside, diosmetin-7-O-glucoside, kaempferol-O-rutinoside, eriocitrin), and terpenoids (ursolic acid, tanshinone I, riligustilide). The analysis revealed that all compounds detected in native plants were also present in micropropagated material, demonstrating the preservation of the characteristic phytochemical profile in vitro. Moreover, several compounds, such as apigenin, apigenin-7-O-glucuronide, isomaltopaeoniflorin, and methoxylated flavones, were found exclusively in micropropagated samples, indicating that tissue culture may enhance the chemical diversity of the species. Ethyl acetate extracts showed the highest degree of overlap between native and in vitro plants, whereas methanol and hexane extracts contained a greater number of unique metabolites in micropropagated material. This first comprehensive phytochemical report on M. croatica highlights the importance of micropropagation as a sustainable strategy for conserving rare species while ensuring a reliable source of bioactive metabolites. Full article

Tamoxifen is a well-established selective estrogen receptor modulator (SERM) widely used in breast cancer treatment, yet its efficacy varies across tumor types. To enhance its antitumor potential, we previously synthesized and investigated novel ferrocene-linked (T5, T15) derivatives. This publication is a close continuation of this work, introducing a new indene-based (T6) derivative. Objectives: The main aim of this study was to further broaden our knowledge of the mechanism behind the increased antitumor effect of the ferrocene-linked drugs (T5 and T15) and compare it with a new, indene-based tamoxifen derivative, T6. The indene moiety was selected as a rigid, hydrophobic aromatic unit to probe pharmacological effects independent of ferrocene’s redox activity. Methods: The compounds were tested on MCF7, MDA-MB231 and PANC1 cells. Cell viability was assessed with the AlamarBlue assay and the xCELLigence SP system. Reactive oxygen species (ROS) production was measured with the ROS Glo assay. Flow cytometry and RT-qPCR experiments were conducted to assess apoptosis and ROS regulation as well. Results: The modified compounds demonstrated an increased cell-viability-decreasing effect in breast (MCF7, MDA-MB-231) and pancreatic (PANC1) cancer cell lines, influencing both estrogen-receptor-dependent and -independent pathways. T6 led to G2/M phase arrest in PANC1 cells. Beyond cell cycle disruption, these derivatives significantly elevated ROS levels, contributing to apoptosis. Conclusions: Our findings suggest that these structural modifications retain tamoxifen’s pharmacophore properties while expanding its mechanism of action, particularly through universal interactions independent of the ER status of tumor cells. The enhanced antitumor effects highlight the potential of these derivatives as promising candidates for improved cancer therapies. Full article

The thermal processing of walnut shells was investigated through pyrolysis within the range of 100–650 °C, highlighting the influence of thermal engineering parameters on biomass conversion. The resulting biochar was subjected to chemical activation with phosphoric acid, and its physicochemical properties were evaluated to determine how thermal processing enhances its performance as a cathode material for lithium–sulfur (Li–S) batteries. This approach underscores the role of thermal engineering in bridging biomass valorization with energy storage technologies. In parallel, the gaseous fraction generated during walnut shell fast pyrolysis was collected, and for the first time, volatile organic compounds (VOCs) under atmospheric conditions were identified using solid-phase microextraction (SPME) coupled with gas chromatography–mass spectrometry (GC–MS). The composition of the VOCs was characterized, quantifying aromatic compounds, hydrocarbons, furans, and oxygenated species. This study further linked the thermal decomposition pathways of these compounds to their atmospheric implications by estimating tropospheric lifetimes and evaluating their potential contributions to air quality degradation at the local, regional, and global scales. Full article

Aromatics and their key oxidation intermediate such as formaldehyde and dicarbonyl compounds (glyoxal and methyglyoxal) are crucial precursors for ozone (O₃) and secondary organic aerosols (SOA). However, the spatial–temporal variation in aromatics’ contribution to these intermediate species and O₃/SOA over Eastern China during the past decades remains insufficiently quantified. This study combines satellite observations of formaldehyde and glyoxal column densities (2008–2014) with an innovative tracer method implemented in the Community Multiscale Air Quality (CMAQ) modeling system to quantify aromatic-driven dicarbonyl chemistry. Simulations of summer and autumn in 2010, 2012, 2014, and 2016 are conducted to demonstrate the change in aromatics and its impact through the years. Estimated primary and intermediate VOCs show good consistency with measurements at a supersite; and the simulated vertical column density of formaldehyde and glyoxal agree with satellite observations in spatial distributions. The contribution of aromatic hydrocarbons to the columnar concentration of glyoxal has seen a significant increase since 2010, which can, to some extent, explain the interannual trend of glyoxal column concentrations in key regions of Beijing–Tianjin–Heibei (BTH), Yangtze River Delta (YRD), and Pearl River Delta (PRD). A cross-comparison reveals a good consistency between the observed glyoxal columnar concentrations to formaldehyde columnar concentration ratio (R_GF) from satellite measurements and the high contribution areas of aromatics to glyoxal: pronounced values are observed in the above three key regions in Eastern China. Additionally, the applicability of R_GF and its indicative nature in Eastern China was discussed, revealing notable seasonal and regional variations in R_GF. Revised R_GF thresholds ([0.015–0.03] for models vs. [0.04–0.06] for satellites) improve summer precursor classification, while a threshold of >0.04 could distinguish the areas with high anthropogenic impacts during autumn. These findings advance understanding of VOC oxidation pathways in polluted regions, providing critical insights for ozone and secondary organic aerosol mitigation strategies. The integrated satellite model approach demonstrates the growing atmospheric influence of aromatics amid changing emission patterns in Eastern China. Full article

Phase instability that develops during thermal conversion of heavy oils and bitumen limits the extent of conversion in processes such as visbreaking. It was postulated that aromatic species with conjugated unsaturated systems extending beyond the aromatic rings likely contributed to reactions leading to phase instability, fouling, and coking. Many fluorophores have such conjugated π-electron systems. Three case studies were presented where products from thermal conversion were analyzed by fluorescence spectroscopy: (i) Cold Lake bitumen converted at 150–300 °C; (ii) asphaltenes depleted and enriched Athabasca bitumen converted at 380 °C; and (iii) Athabasca bitumen converted at 400 °C and 0.5–4.0 MPa. It was found that the fluorescence intensity of bitumen increased on thermal conversion. Fluorescence intensity increased in relation to reaction time for conversion at 150–300 °C, but it had a weak relationship with temperature. At 380 and 400 °C, this monotonic relationship was no longer apparent. There was no relationship with refractive index. Despite some overlap in fluorescence intensity values, 400 °C converted products obtained at 2.5–4.0 MPa had lower fluorescence intensity than products obtained at 0.5–2.0 MPa. Tentative explanations were offered for these observations. The change in fluorescence intensity with operating conditions and nature of the feed was consistent with the expected free radical concentration associated with the operating conditions and extent of hydrogen transfer. Although the study did not provide proof for the relationship between the fluorescence intensity and the concentration of aromatic species with conjugated unsaturated systems, the experimental observations were congruent with it. Full article

This review explores the potential of essential oils (EOs) as natural feed additives in aquaculture, highlighting their antimicrobial, antioxidant, and immunostimulatory properties, which contribute to disease prevention and improved fish resilience. EOs, derived from aromatic plants, offer a sustainable alternative to synthetic chemicals, promoting benefits such as enhanced growth rates, feed efficiency, immune function, and reduced pathogen susceptibility. However, several challenges must be addressed to fully unravel their potential, including the optimization of dosages, effective delivery methods, and cost-efficiency. Techniques such as microencapsulation are emerging as promising solutions to improve EO stability and controlled release in aquatic feeds, though further research is needed to refine these approaches and evaluate their scalability. Additionally, there is a need for more research into the mechanisms through which EOs influence fish health, the interactions between active compounds, potential synergistic effects of EO mixtures, and their impact on the aquatic environment and microbiome. Addressing these challenges will ensure the effective and sustainable application of EOs in aquaculture, reducing reliance on synthetic chemicals while fostering a more resilient and eco-friendly industry. A key feature of this review is the systematic presentation of detailed, species-specific tables summarizing the current literature on the application of EOs and plant extracts in fish health management. Full article

This study investigated the bioaccumulation patterns of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and per- and polyfluoroalkyl substances (PFASs) in the liver and muscle tissues of wild boars (n = 39) and domestic pigs (n = 38) from Northern Italy. This research addressed a critical gap in our understanding of how different ecologies and diets influence the uptake of persistent organic contaminants in two closely related species, one domestic and one wild. Significant differences in contaminant profiles were observed, largely attributable to distinct exposure routes and feeding behaviors. Wild boars displayed different quantities and families of environmental contaminants, with higher PCB levels in muscle and PFASs in liver. Conversely, domestic pigs exhibited markedly higher PAH concentrations, primarily linked to contaminated feed in controlled agricultural settings. The liver consistently demonstrated a central role in toxicant retention across both species. Notably, concentrations of several regulated PFAS compounds in both wild and farmed animals exceeded EU maximum levels (sum of PFOS, PFOA, PFNA, and PFHxS: 1.3 µg/kg), raising significant food safety concerns. These findings underscore the critical need for continuous environmental biomonitoring, stricter control of contaminant sources in agriculture, and updated risk assessments for both wild and domestic meat products to protect animal welfare and human health. Full article