Search Results (1,985)

Heavy metals in lake sediments represent typical persistent contaminants characterized by recalcitrance, bioaccumulation potential, and delayed toxic effects, thereby exerting sustained adverse impacts on lacustrine ecosystem stability and human health. Liuye Lake is a representative small-to-medium urban lake impacted by ambient domestic sewage discharge and agricultural non-point source pollution, with documented nitrogen and phosphorus enrichment. However, the contamination profile of heavy metals in its surface sediments has not been systematically investigated to date. In this work, surface sediment samples were collected from Liuye Lake, and nine heavy metal elements (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn) were determined. An integrated approach incorporating Monte Carlo simulation, the geo-accumulation index (I_geo), and the enrichment factor (EF) method was employed to assess the ecological risk and human health risk imposed by these metals. The results revealed the following: (1) Average concentrations of eight heavy metals exceeded the background values of the Dongting Lake water system, with the exception of As, and Hg displayed potential localized anomalies. (2) Surface sediments were collectively categorized as slightly contaminated, with Hg identified as the primary pollutant, followed by minor contamination of Mn, Cr, and Ni; Monte Carlo simulation further suggested a probable risk that Mn contamination could progress to moderate levels. (3) All heavy metals posed low potential ecological risk, with an overall potential ecological risk index (RI) of 62.71, where Cd, Hg, and As were the dominant contributors. (4) Both non-carcinogenic and carcinogenic risks were generally within acceptable limits, whereas children exhibited higher non-carcinogenic susceptibility relative to adults; As and Mn were the leading contributors to non-carcinogenic risk, while Cr and As dominated carcinogenic risk. This study offers a scientific foundation for the prevention and control of heavy metal pollution and the ecological management of urban lakes. Full article

Mercury (Hg) bioaccumulation in freshwater fish represents a major pathway of human exposure, particularly in cascade reservoir systems where hydrological retention and legacy contamination can enhance methylmercury (MeHg) formation and trophic transfer. This study quantified total mercury (THg) concentrations in seven tissues of seven fish species from the Arda River cascade (Bulgaria). Multi-tissue measurements were integrated with morphometric predictors, multivariate statistical analyses, and combined deterministic and probabilistic human-health risk assessments. Muscle and liver contained the highest THg concentrations, whereas gills and gonads exhibited the lowest levels. Predatory species and larger individuals accumulated significantly more Hg, reflecting trophic magnification and size-dependent exposure. A longitudinal gradient across the cascade reservoirs suggests hydrological retention effects influencing mercury distribution. Species- and tissue-specific size–Hg relationships further indicate heterogeneous bioaccumulation dynamics among taxa. Risk assessment indicated acceptable exposure for adults and pregnant women at average consumption (140 g·week⁻¹), but elevated exposure for children consuming high-Hg predators. Monte Carlo simulations (N = 30,000) revealed upper-tail risks, while Safe Weekly Intake thresholds provided species-specific consumption limits. These findings highlight the value of integrating multi-tissue monitoring with probabilistic risk modelling to support evidence-based fish-consumption advisories in contaminated freshwater systems. Full article

The Black Sea is highly vulnerable to environmental degradation, making the evaluation of contaminant transfer within its food webs essential for ecosystem protection, sustainable resource management, and human health risk assessment. Marine organisms accumulate contaminants through three main processes: bioconcentration (direct uptake from the abiotic environment), biomagnification (trophic transfer through consumption of contaminated prey), and bioaccumulation, which integrates contaminants from all exposure pathways. Despite numerous studies reporting contaminant concentrations in Black Sea waters, sediments, and biota, integrated analyses of trophic transfer within both pelagic and benthic food webs in the Romanian coastal sector remain limited. This study assessed the bioamplification of heavy metals—HMs, persistent organic pollutants—POPs (OCPs, PCBs) and polycyclic aromatic hydrocarbons—PAHs along the main pelagic and benthic food webs in the Romanian coastal sector, based on concentrations measured in representative invertebrate and fish species. The results revealed a compartment-driven contamination pattern, with the benthic food web functioning as an important reservoir and transfer pathway. Heavy metals showed variable and context-dependent trophic transfer, with selective amplification for Cu and Ni in some benthic links, trophic dilution or neutral transfer for Cd and Pb, and more consistent retention for Cr. In contrast, several PCB congeners showed clear biomagnification, particularly in benthic predator–prey relationships. PAHs displayed compound-dependent trophic transfer, with more pronounced amplification in benthic pathways. Overall, biomagnification was stronger for organic pollutants, particularly PCBs, than for heavy metals. The study contributes to two United Nations Sustainable Development Goals (SDGs): SDG 14 (Life Below Water) and SDG 12 (Responsible Consumption and Production). Full article

Cadmium (Cd) contamination of agricultural soils poses a serious threat to crop productivity and food safety due to its high mobility, bioaccumulation potential, and toxicity. This study investigated the effects of increasing Cd levels on growth performance, physiological responses, Cd partitioning, mineral nutrient disruption, and Cd accumulation in four Brassicaceae crops (cress, watercress, broccoli, and white cabbage). Plants were grown in plastic pots filled with 4 kg of soil under controlled greenhouse conditions and exposed to five different Cd concentrations (0, 5, 10, 20, and 50 mg kg⁻¹). Cd exposure significantly affected growth and physiological responses in a species-dependent manner. Compared to the control, shoot dry weight decreased by up to 66.4% in broccoli and 51.7% in cress at the highest Cd level, while white cabbage exhibited comparatively greater tolerance. Oxidative stress indicators showed contrasting patterns, with hydrogen peroxide (H₂O₂) increasing by up to 8.8-fold, whereas proline and membrane permeability (MP) responses varied among species. Photosynthetic pigments declined in cress but increased in broccoli under high Cd conditions, suggesting differential adaptive strategies. Cd accumulated predominantly in roots; however, root retention capacity declined at elevated Cd concentrations (20–50 mg kg⁻¹ soil), leading to greater Cd translocation to shoots. Elevated translocation factors and shoot Cd distribution demonstrated that physiological tolerance did not necessarily limit Cd accumulation in edible tissues. Cd stress also induced notable imbalances in essential mineral nutrients, particularly potassium (K), calcium (Ca), and zinc (Zn), reflecting strong Cd–nutrient interactions at uptake and transport levels. These nutrient disruptions not only exacerbated physiological stress responses but also reduced the nutritional quality of plant tissues. Notably, species maintaining relatively stable growth under moderate Cd exposure still accumulated substantial Cd concentrations in shoots, highlighting a critical disconnect between agronomic performance and food safety. In conclusion, the findings demonstrate that Brassicaceae crops exhibit contrasting strategies in response to Cd stress, with significant implications for Cd entry into the food chain. The study emphasizes the importance of integrating physiological assessment with metal partitioning and nutrient balance analyses when evaluating crop suitability for cultivation in Cd-contaminated soils and for mitigating potential risks to human health. Full article

Lubricating oil (LO) is manufactured in various formulations for different applications. The inappropriate disposal of petroleum hydrocarbons can increase soil contamination, promoting deleterious environmental and human health impacts. More specifically, following prolonged exposure, LO contaminants are known to have carcinogenic and neurotoxic effects in humans. Bioremediation provides an effective and attractive strategy to expedite the clean-up processes of LO contaminants. We isolated and identified environmentally adapted strains of Pseudomonas aeruginosa, Pseudomonas putida, and Proteus vulgaris from Houston watershed bayou soils. Interestingly, all three exhibited increased resistance, vis-a-vis surrogate strains, to various antibiotic challenges (of chloramphenicol, tetracycline, kanamycin, penicillin, streptomycin, etc.) and increased biofilm formation ranging from 1.6 to 6.7-fold. In fact, all three environmental strains were significantly better at producing enhanced biofilm formation in the presence of spent LO rather than clean LO as well as outproducing biofilm made by the surrogate strains. Finally, the environmental isolates P. aeruginosa, P. putida, and P. vulgaris demonstrated an enhanced ability to sequester clean (2-, 2.5- and 1.14-fold) and spent (1.4-, 1.5, and 1.2-fold) LO when compared to their commercially acquired surrogate reference strains. Our three environmentally isolated organisms from Houston watershed soils appeared to be environmentally adapted to tolerate LO exposures. In the presence of LOs, all three environmentally isolated strains exhibited enhanced growth, enhanced biofilm production, and improved bioaccumulation of LOs relative to commercial reference strains. Taken together, environmentally adapted organisms can promote the bioremediation of contaminants threatening our environment and, potentially, human health. Full article

The global functional food market continues to expand, and edible mushrooms are emerging as high-value ingredients due to their rich nutritional profile, particularly their high protein content, balanced amino acid composition, and dietary fiber. This growing industrial interest is reflected in the registration of more than 322 patents in the past five years according to the Derwent Innovation patent database. Recent advances include the integration of precision mycology (PM) and omics-based approaches, such as CRISPR-Cas9, into solid-state fermentation and submerged fermentation, enabling improvements in natural umami flavor and bioactive composition. Innovative products, including meat analogues with fibrous textures, functional beverages such as kombucha and juices, and fermented dairy products such as yogurts and cheeses, have been formulated to deliver prebiotic, antioxidant, and immunomodulatory properties. Future trends indicate a shift towards the production of high-value nutraceutical peptides and biomass, together with the adoption of artificial intelligence (AI) and the Internet of Things (IoT) to enhance bioreactor automation and scalability. Nevertheless, significant challenges remain, including regulatory constraints, the scarcity of clinical validation in humans, and the need for strict control over the bioaccumulation of heavy metals in mushroom-derived raw materials. Addressing these gaps will be critical for advancing regulatory frameworks, improving industrial standardization, and supporting the translational development of mushroom-based functional foods. Full article

Elemental migration and enrichment are important processes influencing tea plant growth and the assembly of rhizosphere bacterial communities within the rock–soil–plant continuum. This study explores how soil parent materials (granite, quartz schist, and sericite schist) are potentially associated with these processes and their observed associations with the elemental composition of tea leaves. Exploratory statistical analyses revealed distinct, lithology-specific biogeochemical patterns that serve as a foundation for hypothesis generation. In granite soils, chlorite correlated with the mobility of Cr, Pb, Cu, Ni, Mg, and Na, coinciding with shifts in the relative abundances of Verrucomicrobia, Armatimonadetes, and Chloroflexi. In quartz schist, kaolinite exhibited notable correlations with the dynamics of Pb, Cr, Ni, Zn, and As, which were statistically linked to Planctomycetes, Proteobacteria, and Acidobacteria. Complex mineral–microbe interactions were observed in sericite schist soils, where clay minerals (e.g., chlorite, illite) were closely associated with the migration of multiple elements (Pb, K, Ca, Cd, As, Al, Fe, Zn), paralleling structural variations in communities of Actinobacteria, Planctomycetes, Chloroflexi, and Proteobacteria. Potassium (K), calcium (Ca), and manganese (Mn) showed bioaccumulation tendencies in tea leaves across all lithologies, with an enrichment capacity order of Ca > K > Mn > Mg > Na > Al. Exploratory Classification and Regression Tree (CART) analysis suggested that the migration of K, Ca, Cu, Zn, and Hg corresponded most closely with their soil concentrations. Manganese (Mn) exhibited a mineral-associated trend, with kaolinite content as a potential correlate, while cadmium (Cd) migration was statistically linked to the relative abundance of Armatimonadetes. These findings highlight potential candidate relationships between mineralogy, microbes, and elemental mobility rather than confirming causal mechanisms, emphasizing the need for further validation in larger or experimental datasets. Full article

Uranium mining generates complex multi-element contamination that affects interconnected ecosystem components, posing long-term ecological and sanitary risks; this review places these impacts in a broad environmental context and aims to synthesize current knowledge on the distribution, migration, and accumulation of uranium and associated heavy metals in water, soil, and plants. A structured analysis of international peer-reviewed literature was conducted, focusing on documented pathways of metal release from tailings and waste dumps, geochemical controls on mobility, and biological uptake by vegetation. The reviewed studies consistently show that tailings and disturbed ore-bearing strata act as persistent sources of uranium and heavy metals (e.g., Cd, Pb, Cr, Ni, Zn, Mn, As), which migrate through infiltration, acid mine drainage, and atmospheric dispersion, leading to elevated concentrations in surface and groundwater and long-term accumulation in soils. Soils function as the principal sink controlling metal bioavailability, while vegetation reflects the bioavailable fraction and exhibits pronounced species-specific accumulation patterns. These processes establish an active “soil–water–plant” transfer chain that facilitates entry of contaminants into food webs. The synthesis indicates that combined uranium and heavy metal contamination represents a sustained ecological and public health concern in uranium-mining regions and underscores the need for integrated monitoring of soils, waters, and vegetation, along with quantitative risk assessment and scientifically grounded remediation strategies. Full article

Per- and polyfluoroalkyl substances (PFAS) constitute a large and chemically diverse class of synthetic compounds characterized by one or more fully fluorinated methyl or methylene groups. Many PFAS are toxic, environmentally persistent, bioaccumulative, and highly mobile, resulting in widespread contamination and biological exposure. Across taxa PFAS exhibit affinity for proteins and preferentially accumulates in protein-rich, highly perfused tissues. Protein binding critically influences PFAS distribution, bioaccumulation, toxicity, and elimination. A variety of different approaches for determining bind affinity have existed for decades; however, depending on experimental conditions, calculated affinities can vary over multiple orders of magnitude which limits comparison of protein–PFAS binding affinities across studies and across PFAS chemical space. Addressing this limitation requires robust and standardized experimental platforms capable of rapidly generating quantitative binding data. Among the most important targets is serum albumin—the principal transport protein in vertebrate blood—which plays a central role in governing PFAS toxicokinetics. This review summarizes current methodologies for measuring protein–PFAS binding affinities, evaluates the strengths and limitations of each approach, synthesizes the existing literature on serum albumin–PFAS interactions, and highlights differential scanning fluorimetry as a rapid, reproducible, and sensitive technique for in vitro assessment of relative protein–PFAS binding. Full article

Boron is a chemically distinctive bioelement whose electron-deficient structure enables reversible coordination with oxygen-rich functional groups such as diols and hydroxyls. This property allows boron to modulate molecular stability, conformation, and biological reactivity, giving rise to both beneficial pharmacological effects and toxicological outcomes. This review examines the dual biological role of boron through the framework of bioactive boron-containing natural products and natural compounds capable of forming reversible boron complexes. Particular attention is given to naturally occurring boron-containing antibiotics, including the polyketide macrodiolides boromycin, aplasmomycin, tartrolons, and hyaboron, where boron plays a direct structural and functional role in antimicrobial activity. These compounds demonstrate how boron coordination can influence ion transport, membrane interactions, and molecular assembly, contributing to potent antibacterial properties. Beyond intrinsically boron-containing metabolites, many natural antibiotics and toxins possess oxygen-rich architectures capable of forming transient borate complexes through vicinal 1,2-diol motifs. Examples include polyene macrolide antibiotics such as amphotericin B, fungichromin, and nystatin, as well as tetracyclines, rifamycins, and macrolides such as sorangicin A, where boron coordination may affect solubility, aggregation, ionophoric behavior, and biological selectivity. Similar chemistry is observed in marine neurotoxins and polyether toxins—including tetrodotoxin, saxitoxin derivatives, azaspiracids, pectenotoxins, ciguatoxins, and gambierones—whose hydroxyl-rich frameworks enable reversible interactions with boron species present in seawater. Such complexation may enhance aqueous stability and contribute to trophic transfer and bioaccumulation within marine ecosystems. By framing boron as a molecular “double edge,” this review integrates chemical, biological, and environmental perspectives to highlight how boron coordination can simultaneously enhance antimicrobial activity while influencing toxicity and ecological persistence. Recognizing the role of boron in shaping the activity of natural products provides new insight into antibiotic function, toxin behavior, and the broader impact of boron chemistry in biological systems. Full article

Organochlorine pesticides (OCPs), a broad class of highly stable and lipophilic chemicals, have been widely used to control pests and disease vectors in agriculture, households, and the public health sector. Due to their lipophilic nature and resistance to degradation, OCPs accumulate in the fatty tissues of fish and shellfish, positioning these foods as critical vectors for human exposure. This review synthesizes current global research on the presence of OCPs in fish and shellfish, with an emphasis on geographical variation, species-specific accumulation patterns, and temporal trends. This study discusses the sources and pathways which bring OCPs to the aquatic environment to highlight regional disparities in pollutant levels, influenced by industrial activities, agricultural practices, and waste management systems. It also explores the mechanisms of bioaccumulation and biomagnification that contribute to the elevated levels of OCPs in fish and shellfish, underscoring the complexities of food chain dynamics in contaminant transfer. This paper also highlights the diverse adverse effects of OCPs on consumer health, including chronic and carcinogenic diseases such as endocrine and respiratory malfunctions, neurotoxicity, kidney and liver damage, reproductive disorders, and skin or eye injuries, while suggesting mitigation strategies to promote an OCP-free and healthy aquatic environment. Full article

We compared fish assemblage structure and total mercury (THg) bioaccumulation between a natural floodplain lake and a constructed irrigation canal in central Brazil. A total of 473 individuals representing 34 species were recorded, and dorsal muscle samples from 62 specimens representing shared species or species occupying comparable trophic positions were analyzed for THg (Curimatella immaculata, Hemiodus microlepis, Astyanax aff. bimaculatus, Triportheus albus, Geophagus sveni, Pimelodus blochii, Pygocentrus nattereri, Lycengraulis batesii, and Cichla kelberi). The floodplain lake exhibited higher species richness, diversity, and evenness, whereas the irrigation canal supported a simplified assemblage dominated by fewer species. Total Hg concentrations were significantly higher in the lake than in the irrigation canal; however, this pattern was observed only for the carnivorous guild (t = 5.384, p < 0.0001) and the detritivorous guild (t = 4.183, p = 0.0001). THg increased significantly with trophic level in both systems, from detritivores to carnivores (F₂,₄ = 15.127, p = 0.009), yielding comparable trophic magnification slopes (lake: 1.46, 95% CI: 1.11–1.81; canal: 1.36, 95% CI: 0.94–1.77). Despite lower diversity and THg concentrations in the irrigation canal, Hg transfer efficiency across trophic levels was conserved between systems. Full article

Per- and polyfluoroalkyl substances (PFAS) continue to be one of the most persistent global contaminants and are increasingly recognized as leading metabolic- and hepatic-dysfunction mediators. Despite extensive investigation of PFAS toxicity, a critical gap in the identification and integration of toxicokinetic drivers of hepatic bioaccumulation with mechanistic pathways driving mitochondrial and nuclear receptor-related injury, more specifically, with respect to alternative PFAS strategies, still remains. Legacy PFAS, including PFOA and PFOS, accumulate in the liver and disturb mitochondrial homeostasis as they disrupt β-oxidation, induce oxidative stress, and alter lipid and bile acid metabolism. Meanwhile, the next-generation PFAS variants (including short-chain and polymeric substitutes) are rapidly increasing in environmental concentrations, but remain insufficiently characterized and poorly regulated, raising concerns that substitution-based strategies may maintain their toxicological risk. We summarize the evidence of the association between PFAS bioaccumulation and mitochondrial dysfunction, metabolic reprogramming, and inflammatory signaling, and illustrate mechanistic convergence across legacy and emerging PFAS. We also review insights from recent experimental models, such as 3D hepatocyte systems and human-relevant receptor platforms that more closely mimic chronic exposure states. This review emphasizes mechanistic convergence across legacy and emerging PFAS, highlighting shared pathways that may persist despite chemical substitution. Thus, we discuss key gaps in monitoring, toxicity assessment, and policy, including the requirement of regulatory paradigms that treat PFAS as a class rather than individual compounds. Full article

This study provides a comprehensive assessment of 12 metal(loid)s in the muscle tissue of the commercially vital shrimp, Penaeus semisulcatus, from four stations (Bozyazi, Silifke, Karatas, and Iskenderun) along the Northeastern Mediterranean. Metal concentrations were evaluated separately for males and females, utilizing Estimated Weekly Intake (EWI), Target Hazard Quotient (THQ), Carcinogenic Risk (CR), and Selenium Health Benefit Value (HBV_Se) indices. While the species is generally safe for consumption across the region, a striking, localized bioaccumulation of Chromium (Cr) was identified specifically in Iskenderun Bay, where male shrimps exhibited concentrations (1.209 mg/kg wet weight) approximately 10-fold higher than females, highlighting a sex-specific sensitivity likely linked to metabolic and physiological differences. By adopting a precautionary risk assessment framework—considering the region’s intense industrial profile—this localized spike resulted in a Total Carcinogenic Risk (∑CR = 5.15 × 10⁻⁴) for this group, exceeding the priority threshold. Furthermore, widespread Lead (Pb) contamination was detected across all stations, with several samples surpassing EU maximum levels (0.50 mg/kg). Regarding Arsenic (As), while high total concentrations led to THQ values > 1 across the regional gradient, this was characterized as a conservative modeling artifact rather than a physiological threat, as Arsenic in crustaceans is predominantly in the non-toxic organic form. Conversely, any potential risk from Mercury (Hg) was conclusively mitigated by an overwhelming molar excess of Selenium (Se) at all locations, confirmed by consistently positive HBV_Se values (0.312–0.658). In conclusion, our findings demonstrate that seafood safety is conditional and region-specific. The study underscores that localized contamination “hotspots” can be easily masked by non-sex-specific sampling and emphasizes the necessity of moving beyond simplistic risk models by incorporating selenium-mercury antagonism and precautionary risk assumptions for industrial pollutants. Full article

Urban and peri-urban river systems subjected to intensive agriculture are vulnerable to diffuse metal(loid) inputs, yet the integration of hydrological compartments, bioindicators, and human health risk remains poorly explored. This study investigated the seasonal dynamics, bioaccumulation patterns, and potential human health risks associated with metal(loid)s in the Santa Virgem River (Brazil–Paraguay border), using water from backwater zones and three plant groups (Apiaceae angiosperms, mosses, and the liverwort Dumortiera sp.). Water and plant samples were collected during five seasonal campaigns (2019–2020) and analyzed by ICP OES. Multivariate analysis (PCA) was applied, and biological accumulation coefficients (BAC) and chronic daily intake (CDI) were estimated for adults and children under different ingestion scenarios. Results showed that Mg, Fe, K, S, and P dominated water chemistry, while As, Cd, Cr, Cu, Pb, and Se were mostly below detection limits. PCA explained 77.6% of total variance, distinguishing agricultural and hydrological phases. Bryophytes exhibited markedly higher BAC values, particularly for Mn (up to 2.3 × 10⁵) and Fe, compared with Apiaceae. CDI and hazard assessment indicated negligible non-carcinogenic risk for most elements (HQ < 1), except phosphorus, which dominated the Hazard Index due to its low reference dose. Overall, the results demonstrate that hydrodynamic conditions and plant functional traits jointly control metal(loid) dynamics, highlighting the value of multispecies biomonitoring in peri-urban river systems. Full article