Search Results (374)

The yellow clam, Amarilladesma mactroides, is an abundant component of the intertidal infauna of the southwestern Atlantic Ocean and an important source of food and income for local communities. In recent years, this species has been increasingly affected by anthropogenic and environmental pressures, contributing to the decline and collapse of several populations. In this study, we characterized the reproductive cycle of A. mactroides in the southernmost region of Brazil using standard approaches, including gonadal histology and biometric parameters, complemented by analyses of proximal composition and fatty acid profiles. Monthly samples of ≥100 clams were collected from October 2021 to September 2022. The results revealed two distinct reproductive peaks: a major peak from October to December (austral spring–summer) and a less pronounced peak from May to July (autumn–winter). Although gonadal histology, particularly oocyte diameter, provided the primary evidence for defining these reproductive peaks, the condition index and concentrations of total lipids and n-3 polyunsaturated fatty acids (n-3 PUFA) also proved useful indicators of reproductive activity. These findings provide new insights into the reproductive dynamics of A. mactroides in southern Brazil and may contribute to the development of strategies for the sustainable management, conservation and aquaculture of this ecologically and socioeconomically important bivalve. Full article

Atmospheric microplastics have emerged as an important environmental contaminant due to their widespread occurrence, persistence, and potential ecological and human health implications. However, information regarding atmospheric microplastic deposition in southeastern Europe remains extremely limited. The present study provides a preliminary moss-based assessment of atmospheric microplastic deposition at selected locations in North Macedonia. Moss samples were collected from sites representing different degrees of anthropogenic influence and analyzed following sample preparation procedures consistent with previous national-scale surveys. Microplastic particles were identified using micro-Fourier Transform Infrared (μ-FTIR) spectroscopy. Microplastics were detected in all investigated moss samples, confirming their widespread atmospheric deposition across the country. The highest concentration was recorded at Vodno–Skopje (16.72 MP g⁻¹ dry weight), followed by Majdan (7.10 MP g⁻¹) and Bojančište (3.29 MP g⁻¹). Pronounced differences in polymer composition were observed among the sampling locations: Vodno–Skopje exhibited the greatest polymer diversity, with polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polylactic acid (PLA), and cellulose acetate (CA) all detected above their respective limits of detection, whereas Majdan was characterized almost exclusively by polyethylene terephthalate (PET) and Bojančište primarily by cellulose acetate (CA) and PLA. The detected microplastic concentrations were within the range of values reported in some European studies, although direct comparisons should be interpreted with caution because of the differences in sampling and analytical methodologies. The findings demonstrate the potential of moss-based biomonitoring as a complementary approach for assessing atmospheric microplastic deposition. However, studies covering a larger number of sampling locations and different temporal periods are required to further evaluate and validate this approach. Full article

The reactive transport of hexavalent chromium (Cr(VI)) in anthropogenically disturbed sites (e.g., mine waste rock dumps, chromium salt industrial sites) is critically influenced by physico-chemical heterogeneity, yet the interplay between physical and chemical heterogeneities remains poorly understood. This study employed a series of experiments and numerical modeling to investigate the transport of Cr(VI), focusing on the implications of physical heterogeneity—represented by preferential flow paths—and chemical heterogeneity—characterized by reductive mineral lenses. Key findings indicate that physical heterogeneity accelerates Cr(VI) breakthrough by 1.4 to 2.1 pore volumes (PV) relative to homogeneous columns. The presence of pyrite lenses delays breakthrough by 0.6–1.2 PV under neutral pH and 1.6–2.0 PV under acidic pH. At a flow rate of 3.0 m/day, the apparent sorption capacity decreases by ~62.5% compared to 0.3 m/day, indicating that physical advection largely suppresses chemical retention under high-flux conditions. The above results demonstrate that physical heterogeneity governs flow paths and advection rates, whereas chemical heterogeneity impedes transport through heterogeneous adsorption and reduction in Cr(VI) to Cr(III) along these pathways. Furthermore, the presence of preferential paths leads to greater spatial variability, which subsequently influences the interaction dynamics between Cr(VI) and reactive minerals in the aqueous environment. The dominance shifts between physical/chemical controls based on flow rates and pH. At higher flow rates, the influence of physical heterogeneity becomes more pronounced, diminishing chemical reactions due to insufficient residence time of Cr(VI). Conversely, a lower pH environment enhances pyrite dissolution, which decouples the dependency on physical heterogeneity by promoting homogeneous reactions. Further evidence was obtained through X-ray photoelectron spectroscopy (XPS) analysis. The experimental observations are complemented by TOUGHREACT-based reactive transport simulations, which further reveal that the apparent dominance shifts arise from competing timescales between advection and surface reaction. The insights gained from the study emphasize the necessity of integrating both physical and chemical spatial variability in risk assessments, transport modeling, and designing targeted remediation strategies. Full article

This study evaluated potentially toxic element (PTEs) contamination (As, Cd, Co, Cr, Cu, Ni, Pb, and Zn) in soil and grapevine leaves across 36 sites in a historical vineyard near Iași, Romania, transitioning toward residential development. Soil samples were analyzed using energy-dispersive X-ray fluorescence (ED-XRF), while leaf tissues collected during the véraison stage (mid-August) underwent microwave-assisted acid digestion followed by inductively coupled plasma mass spectrometry (ICP-MS). Soil analyses revealed that average concentrations of Cr, Ni, and Pb exceeded national normal legal thresholds, while Cu and As surpassed alert permissible limits. Contamination factor ($CF$) and Geoaccumulation Index ($I_{geo}$) metrics confirmed significant anthropogenic Cu enrichment from historical viticultural treatments. Soil-to-leaf transfer factors ($TF$) approached or exceeded 1 for Cu and Zn, though grapevine was not identified as a hyperaccumulator. Spearman correlation modeling demonstrated a statistical decoupling between soil concentrations and foliar tissue levels for Cu ($r_s=-0.21$) and Zn ($r_s=0.075$), confirming that canopy accumulation is governed by historical agrochemical spraying and atmospheric deposition rather than root-driven uptake. Conversely, Pb ($r_s=0.43$) exhibited a moderate direct soil-to-leaf pathway. The potential ecological risk ($PER$) index indicated moderate-to-considerable cumulative risk, primarily driven by Cu ($E_{Cu}=68.64$) and Cd ($E_{Cd}=59.17$). Human health risk assessments established direct ingestion as the primary exposure pathway, with current non-carcinogenic hazards remaining within tolerable limits ($HI<1$). However, the proposed residential conversion increases exposure risks for vulnerable cohorts, underscoring the necessity of systematic soil screening and remediation prior to land redevelopment. Full article

Anthropogenic air pollution represents a significant threat to both environmental and human health, with nitrogen oxides (NO_x) playing a substantial role in the formation of photochemical smog, acid rain, eutrophication, and respiratory diseases. In Bangladesh, NO_x emissions primarily originate from combustion sources such as road transportation, power generation, and industrial activities, while natural sources include lightning, wildfires, and soil emissions. Furthermore, ammonia emissions from fertilizers and livestock exacerbate air quality issues in both urban and rural settings. Despite the acknowledgment of vehicular and industrial contributions, comprehensive and systematic assessments of NO₂ trends across the nation remain scarce. This study presents a complementary, side-by-side assessment of ground-based NO₂ measurements from the Department of Environment (DoE) with atmospheric NO₂ retrieved from the Sentinel-5P TROPOMI Level-3 product via Google Earth Engine (GEE). Spatial distribution patterns of both ground-level and atmospheric NO₂ were analyzed using ArcGIS Pro, along with seasonal and interannual trend assessments from 2018 to 2024. Results indicated pronounced spatial and temporal variability in NO₂ concentrations. The highest levels were consistently recorded over Dhaka and surrounding industrial zones, with moderate accumulation in Chattogram. Winter months (December–February) exhibited hazardous concentrations, with a national maximum of 205.21 µg/m³, while monsoon periods recorded the lowest levels overall, as reflected in its seasonal mean (see below). Seasonal averages indicated the highest concentrations in winter (35.03 µg/m³), followed by pre-monsoon (29.16 µg/m³), with monsoon recording the lowest seasonal mean (19.94 µg/m³). Long-term analysis showed the highest national annual mean NO₂ con-centration in 2018 (44.32 µg/m³), decreasing to 14.81 µg/m³ by 2024, with non-monotonic year-to-year fluctuation in the intervening period (2020–2021 data were unavailable). These findings underscore the necessity for stricter emission regulations and targeted mitigation measures. As a policy recommendation, this may include the implementation of NO_x-selective catalytic reduction (SCR) using NH₃ over metal oxide and zeolite catalysts. This study provides evidence-based insights to support cleaner air initiatives and sustainable environmental management strategies in Bangladesh. Full article

The concentrations of 18 metal(loid)s were measured in five marine invertebrate species (Oxystele tigrine and sinensis, Marthasterias glacialis, Cymbula oculus and granatina, Parechinus angulosus, and Mytilus galloprovincialis) and five macroalgae/seaweed species (Aeodes orbitosa, Gelidium pristoides, Caulerpa filiformis, Ulva sp., and Bifurcaria brassicac formis) collected from eight sites within the marine environment of False Bay, Cape Town, South Africa. To assess the potential human health hazards associated with consumption, samples were acid digestion and analysed using inductively coupled plasma optical emission spectrometry (ICP-OES). The analysed elements included trace metals (Fe, Mn, Zn) toxic metals (Pb, Cd, As), transition metals (Ta, Ti), alkali metals (Li), and metalloid (Se, As). Metal concentration varied widely among species and locations, with values ranging from Zn: not detected (nd)—3836.04 mg/kg dry weight (dw); As: nd—77.98 mg/kg dw; Pb: nd—301.15 mg/kg dw; Li: nd—97.28 mg/kg dw, indicating diverse metal accumulation patterns. Human health risk was evaluated using the target hazard quotient (THQ) and hazard index (HI). Arsenic consistently exceeded the THQ threshold of one across all sites, and all the HI values were greater than one for all edible species, suggesting potential non-carcinogenic health risks associated with the consumption, except for M. glacialis, which is not commonly consumed. The HI metrics demonstrate the adverse impacts of metal concentration in marine biota. The observed spatial and biological variability in metal accumulation highlights the limitations of relying solely on metal concentrations for assessing health risks, food safety or anthropogenic contamination, and therefore more frequent and comprehensive monitoring is recommended. Full article

Electrochemical CO₂ reduction reactions (CO₂RR) offer a viable approach to mitigating anthropogenic CO₂ while simultaneously generating value-added chemicals. Among diverse electrocatalyst classes, metal–organic framework (MOF)-based materials have been extensively explored owing to their excellent tunability of chemical structure, high surface area, and the ability to tailor the coordination/electronic environment of active centers. This state-of-the-art review provides a critical assessment of recent progress in the development of pristine Cu-based MOFs, Cu MOF-derived catalysts, and hybrid Cu@MOFs for the selective production of C₁ products such as CO, CH₄, and formate/formic acid. Theoretical investigations into the roles of the copper center, ligands, pore structures, and interfacial effects reveal that product selectivity is influenced by more than just the oxidation state of Cu sites. Mixed-valence Cu⁺/Cu⁰ junctions, defect-rich surfaces, conductive frameworks, and coordination site tuning constitute fundamental design strategies for steering CO₂ reduction pathways. In addition to electrocatalytic performance, this review emphasizes the importance of life cycle assessment (LCA). Current studies identify electricity demand, separation steps, and operational lifetime as the dominant environmental impact factors in LCA analyses. Combining molecular-level catalyst design with systems-level sustainability considerations, this review highlights key challenges and future prospects for advancing Cu-MOF electrocatalysts toward efficient and sustainable C₁ formation from CO₂. Full article

Urban air pollution poses significant risks to human health, ecosystems, and the environment, highlighting the need for accurate monitoring of atmospheric pollutants. This study investigated the spatial and temporal variability of key tropospheric pollutants, including nitrogen dioxide (NO₂), sulfur dioxide (SO₂), nitrous acid (HONO), formaldehyde (HCHO), and ozone (O₃), in Brighton, UK, using an integrated approach that combined ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS), Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS), and Sentinel-5P TROPOspheric Monitoring Instrument (TROPOMI) observations. Ground-based measurements comprised four MAX-DOAS campaigns conducted between 2021 and 2024 and a long-term LP-DOAS dataset spanning 2017–2023, complemented by coincident TROPOMI observations. The datasets were spatially co-located, temporally aligned, quality-controlled, and analysed using statistical methods, time-series analysis, and polar plot techniques to assess pollutant variability, identify emission sources, and evaluate the agreement between satellite and ground-based observations. The results revealed clear seasonal and diurnal variations in pollutant levels, with elevated NO₂ during winter and enhanced O₃ during summer, reflecting the influence of anthropogenic emissions and photochemical processes. Polar plot analysis further identified distinct wind-dependent pollutant patterns, indicating the importance of local emission sources. Comparisons between ground-based and satellite observations showed that TROPOMI successfully captured the temporal variability of NO₂ measured by means of LP-DOAS, with a moderate positive correlation (r_s = 0.55), but underestimated NO₂ relative to MAX-DOAS observations (r_s = 0.38), reflecting differences in measurement geometry, spatial resolution, and retrieval sensitivity. The overall findings demonstrate that integrating ground-based and satellite observations provides a more comprehensive understanding of urban air quality than either approach alone. This combined monitoring framework improves confidence in satellite-derived atmospheric products and supports more effective air quality assessment and management in Brighton and similar urban environments. Full article

Per- and polyfluoroalkyl substances (PFAS) are an emerging group of anthropogenic environmental pollutants frequently detected in human and animal serum. Although several studies have reported adverse health effects associated with exposure to single PFAS, limited information is available concerning the biological and toxicological impact of PFAS mixtures and their potential interactions with chemotherapeutic agents. This study investigated the effects of acute and chronic exposure to PFAS, including perfluorooctanoic acid (PFOA, 3 nmol/L), perfluorooctane sulfonic acid (PFOS, 5 nmol/L), and their binary mixture containing 3 nmol/L of PFOA plus 5 nmol/L of PFOS, using an in vitro model, mouse ovarian surface epithelial cells (MOSEC), and possible interactions with antineoplastic agents. Results showed increased cell proliferation following acute PFOS exposure; this effect was enhanced in the PFOA-PFOS mixture. In contrast, PFOA exposure showed reduced cell proliferation. Acute exposure to PFOA, PFOS, and their mixture was associated with reduced sensitivity to cabazitaxel and docetaxel, while chronically exposed cells demonstrated increased sensitivity. These findings suggest that PFOA, PFOS, and their mixtures present in human serum and tissues may influence cellular proliferation and alter therapeutic response. These findings further highlight the importance of mixture effects and the exposure duration effect in the toxicological evaluation of PFAS toxicity. Full article

The urgency for sustainable propagation methods is increasing as anthropogenic disturbances threaten global biodiversity and plant productivity. This study focused on the cutting propagation of Campanula pelviformis and Petromarula pinnata, two local endemic species of Crete (Greece) with known multipurpose crop potential. For C. pelviformis, the effects of cutting type and indole-3-butyric acid (IBA) treatments applied with or without the commercially available and environmentally friendly fertilizer Theocopper and population were investigated. For P. pinnata, the effects of cutting type and IBA treatments were examined. Root dry mass was assessed four weeks after propagation onset, while rooting success, root number and length were measured in the third week to evaluate overall rooting performance. Vegetative propagation of P. pinnata was straightforwardly achieved across cutting types (>90% rooting success), and superior root traits were observed in young shoot cuttings. In C. pelviformis, high rooting success (90%) was recorded in four of the six treatments using adventitious shoot cuttings, while the combined application of 1% Theocopper and IBA efficiently enhanced both rooting percentages and root traits in young shoot cuttings and sub-apical stem sections. The results further indicated a population effect on rooting success and traits among cutting types. The data produced may guide conservation purposes and/or sustainable utilization of these neglected species as novel multipurpose crops, especially in landscaping design with native plants. Full article

The Baleysky gold deposit in Eastern Transbaikalia is a classic example of the long-term environmental legacy of gold mining. The cessation of industrial wastewater discharge in 1995 led to the accumulation of more than 3 million m³ of acidic water with high concentrations of heavy metals and metalloids. These waters contain concentrations many times higher than the maximum permissible levels for fishery waters (Mn up to 6594, Al—1473, Zn—486, and Cu—414), posing a significant threat to the ecosystem of the Unda River and the health of the local population. The aim of this study was to evaluate the effectiveness of the artificial geochemical barrier method for treating such waters under laboratory conditions. Column experiments were conducted using local soil and the commercial carbonate sorbent taurite at a sorbent-to-filtrate ratio of 1:5. Taurite demonstrated a significantly higher sorption capacity than soil, substantially reducing the concentrations of As, Cd, Pb, Al, Mn, Fe, Zn, and Cu and raising the pH from 2.90 to 7.96–8.03. Although health risks associated with both carcinogenic (CR) and non-carcinogenic effects (HI) decreased significantly after treatment with taurite, residual risk levels remained unacceptably high (CR ≈ 10⁻³, HI > 1). The results show that engineered geochemical barriers have great potential for reducing anthropogenic contamination at abandoned mining sites, although further optimization of this technology is necessary to achieve compliance with regulatory requirements. Full article

The karst region of Southwest China represents a typical high geological background area characterized by extensive carbonate bedrock and secondary enrichment of heavy metals, particularly cadmium (Cd), in residual soils. Under natural carbonate-buffered conditions, Cd is largely immobilized through mineral associations and surface complexation, resulting in elevated total concentrations but low bioavailability. However, intensified anthropogenic pressures–including acid deposition, mining, excessive fertilization, and improper irrigation—have accelerated soil acidification in paddy fields. Acidification disrupts carbonate geochemical equilibria, weakens buffering capacity, and drives Cd speciation shifts toward more labile forms, thereby enhancing plant uptake and accumulation. These effects are especially pronounced in paddy fields and other systems subject to hydrological and redox fluctuations that further increase Cd mobility. To evaluate these coupled geogenic and anthropogenic controls, we conducted a structured literature synthesis (2016–2026) focusing on peer-reviewed studies of Cd dynamics in Southwestern China’s karst agroecosystems. We critically examine (i) the formation mechanisms and spatial heterogeneity of high-background Cd, (ii) acidification-driven speciation transformation and soil–crop transfer pathways, and (iii) in situ remediation and precision risk assessment strategies. By integrating geological inheritance, geochemical activation, and ecological risk perspectives, this review proposes a conceptual framework to support soil quality standard refinement and adaptive risk management in high-background karst regions. Full article

The mitigation of anthropogenic climate change caused by fossil fuel combustion is a critical global challenge that necessitates a transition to renewable energy systems. Bioethanol represents a major renewable fuel, but first-generation production relies on edible feedstocks, which raises concerns regarding food security. Consequently, research is shifting toward second-generation bioethanol produced from abundant non-edible lignocellulosic biomass sources. This review comprehensively examines the potential of Candida krusei (synonyms: Pichia kudriavzevii, Issatchenkia orientalis) to serve as an alternative biocatalyst for second-generation bioethanol production. Compared with the first-generation bioethanol-producing yeast Saccharomyces cerevisiae, C. krusei exhibits superior physiological traits, such as thermo, acid, and inhibitor tolerances, enabling the utilization of several lignocellulosic feedstocks. This review summarizes the taxonomic and physiological characteristics of C. krusei, describes case studies on bioethanol production, and discusses strategies for reducing production costs. Furthermore, the technical and biosafety challenges associated with the industrial deployment of C. krusei are critically examined, including xylose metabolism limitations, scale-up constraints, and the management of its opportunistic pathogenic nature. A life cycle assessment perspective suggests that the unique physiological properties of C. krusei contribute to reducing greenhouse gas emissions and energy consumption throughout the entire production process, from pretreatment to downstream ethanol recovery. Full article

Florpyrauxifen-benzyl is a newly developed aryl pyridine carboxylic acid ester herbicide for rice paddies, and its effects on microbial communities remain largely unexplored. Rice paddy fields represent the largest source of anthropogenic methane emissions. However, whether the overapplication of florpyrauxifen-benzyl causes changes in methane-metabolizing microorganisms and consequently elevates methane emissions has not been thoroughly investigated. In this study, we investigated the effects of applying florpyrauxifen-benzyl at increasing concentrations on methane-metabolizing microorganisms, using high-throughput sequencing of functional genes involved in methane metabolism. The results were validated via quantitative fluorescence PCR. The application of florpyrauxifen-benzyl at five times the recommended dose significantly increased methane emissions. Co-occurrence network analysis revealed a more complex network structure in the methanogenic community. Furthermore, random forest modeling and LEfSe analysis indicated that Methylocystis, Methylosinus, Methanolobus, Methanosphaera, and Methanococcoides play key roles in maintaining the stability of methane-metabolizing microbial communities. Full article

Per- and polyfluoroalkyl substances (PFASs) include thousands of fluorinated organic compounds of anthropogenic origin. Their extensive use, combined with their high stability, has led to the widespread contamination of water and soil resources. Here, single-step foam fractionation enhanced soil washing was carried out for the remediation of PFAS-contaminated soil. Concentrations of target Perfluoroalkyl Carboxylic Acids (PFCAs) and Perfluoroalkane Sulfonic Acids (PFSAs) were monitored in foam and leachate along the duration of the treatment. Among PFCAs, only long-chain compounds peaked in foam at the beginning of the treatment. This was consistent with the increase in the sorption affinity to the air–water interface with chain length. The same behavior was observed also in PFSAs by comparing PFHXs, PFHpS and PFOS. The fraction of PFCAs still in the leachate after 40 min of treatment was found to decrease with chain length, with PFSAs showing a similar trend. PFAS removal significantly increased with soil particle size, ranging from 48.2 ± 3.2% (fraction < 0.063 µm) to 64.1 ± 1.9% (fraction > 2 mm). Final mass balance analyses detail PFAS distribution among soil, leachate, and foam, providing valuable information for the additional treatment required to destroy the PFAS load extracted from the contaminated soil. Full article