Search Results (405)

Human exposure to persistent organic pollutants such as polychlorinated biphenyls (PCB) and brominated flame retardants (BFR), including both legacy and emerging compounds, remains a concern due to their bioaccumulative nature and potential health effects. Comprehensive analytical methods are necessary to monitor these substances in complex biological matrices, such as human serum. A gas chromatography–mass spectrometry (GC-MS) method was developed for the simultaneous determination of 44 analytes, encompassing PCB and a broad spectrum of BFR with diverse physicochemical properties. The extraction procedure and GC-MS parameters were optimized using a design of experiments approach to maximize performance while minimizing analysis time. The method demonstrated high sensitivity, precision, and accuracy, thereby meeting internationally recognized validation criteria for biomonitoring applications. To further ensure analytical reliability, compound confirmation was achieved using gas chromatography–high-resolution mass spectrometry, providing enhanced selectivity and confidence in identification, particularly for low-level analytes. Key advantages of the method include its applicability to analytes with significantly different chemical behaviors and its capacity to quantify a large number of target compounds simultaneously. This makes it a powerful tool for assessing human exposure to both regulated and emerging halogenated contaminants. Full article

Individuals across their lifespan may experience hearing loss from medications or chemicals, prompting concern about ototoxic environmental exposures. This study applies computational modeling as a screening-level hazard identification and chemical prioritization approach and is not intended to constitute a human health risk assessment or to estimate exposure- or dose-dependent ototoxic risk. We evaluated in silico drug-induced ototoxicity models on 80 environmental chemicals, excluding 4 with known ototoxicity, and analyzed 76 chemicals using fingerprinting, similarity assessment, and machine learning classification. We compared predicted environmental ototoxicants with ototoxic drugs, paired select polychlorinated biphenyls with the antineoplastic drug mitotane, and used PCB 177 as a case study to construct an ototoxicity pathway. A systems biology framework predicted and compared molecular targets of mitotane and PCB 177 to generate a network-level mechanism. The consensus model (accuracy 0.95 test; 0.90 validation) identified 18 of 76 chemicals as potential ototoxicants within acceptable confidence ranges. Mitotane and PCB 177 were both predicted to disrupt thyroid-stimulating hormone receptor signaling, suggesting thyroid-mediated pathways may contribute to auditory harm; additional targets included AhR, transthyretin, and PXR. Findings indicate overlapping mechanisms involving metabolic, cellular, and inflammatory processes. This work shows that integrated computational modeling can support virtual screening and prioritization for chemical and drug ototoxicity risk assessment. Full article

Commercial smooth-hound sharks of the genus Mustelus are commonly landed and consumed in Mediterranean fisheries, raising concerns about potential human exposure to persistent contaminants. This study investigated the occurrence of organochlorine compounds (OCs), including hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) and its metabolites, and polychlorinated biphenyls (PCBs), together with per- and polyfluoroalkyl substances (PFAS), in muscle and liver tissues of Mustelus mustelus and Mustelus punctulatus collected in the waters of the Egadi Archipelago (central Mediterranean Sea). OCs were detected in all analyzed samples, with total PCB concentrations reaching higher values in liver compared to muscle tissues, reflecting tissue-specific accumulation and detoxification processes. PFAS were detected in all analyzed muscle samples (1.10–58.5 ng/g w.w.), with PFOS, PFOA and PFNA generally below current European regulatory thresholds, although isolated exceedances were observed. Stable isotope analysis (δ¹³C and δ¹⁵N) highlighted differences in trophic ecology between the two species and suggested that feeding habitat and trophic position may influence contaminant exposure patterns, particularly in M. punctulatus. The human health risk assessment, conducted as a screening-level evaluation, indicated potential concern associated with PCB concentrations in liver tissue, while risks associated with muscle consumption were generally lower. Overall, the integration of contaminant analysis and stable isotopes provides insights into organismal exposure pathways and supports the use of smooth-hound sharks as sentinels of contaminant presence in Mediterranean coastal ecosystems. Full article

Aquatic environments have been a critical source of nutrition for millennia, with wild fisheries supplying protein and nutrients to populations worldwide. A notable shift has occurred in recent decades with the expansion of aquaculture, now representing a fast-growing sector in food production. Aquaculture plays a key role in mitigating the depletion of wild fish stocks and addressing issues related to overfishing. Despite its potential benefits, the sustainability of both wild and farmed aquatic food systems is challenged by anthropogenic pollution. Contaminants from agricultural runoff, industrial discharges, and domestic effluents enter freshwater systems and eventually reach marine environments, where they may be transported globally through ocean currents. Maintaining water quality is paramount to food safety, environmental integrity, and long-term food security. In addition to conventional seafood products such as fish and shellfish, foods such as those derived from microalgae are gaining attention in Western markets for their high nutritional value and potential functional properties. These organisms have been consumed in Asia for generations and are now being explored as sustainable foods and ingredients as an alternative source of protein. Contaminants in aquatic food products include residues of agrochemicals, persistent organic pollutants (POPs) such as dioxins, polychlorinated biphenyls (PCBs), and per- and polyfluoroalkyl substances (PFASs), as well as brominated flame retardants and heavy metals. Public and scientific attention has intensified around plastic pollution, particularly microplastics and nanoplastics, which are increasingly detected in aquatic organisms and are the subject of ongoing toxicological and ecological risk assessments. While the presence of these hazards necessitates robust risk assessment and regulatory oversight, it is important to balance these concerns against the health benefits of aquatic foods, which are rich in omega-3 fatty acids, high-quality proteins, vitamins, and trace elements. Furthermore, beyond direct human health implications, the environmental impact of pollutant sources must be addressed through integrated management approaches to ensure the long-term sustainability of aquatic ecosystems and the food systems they support. This review covers regulatory frameworks, risk assessments, and management issues relating to aquatic environments, including the impact of climate change. It aims to serve as a comprehensive resource for researchers, policymakers, food businesses who harvest food from aquatic systems and other stakeholders. Full article

Backgrounds: The marine diatom Ditylum brightwellii has been widely used as a model species for ecotoxicological assessments in marine environments. Heat shock proteins (Hsps) function as molecular chaperones that protect cells under diverse stress conditions. Of them, Hsp104 participates in the protein restoration system by reversing protein aggregation. Methods: In the present study, we determined the full-length sequence of DbHsp104 in D. brightwellii using transcriptome sequencing and gene cloning. Results: The open reading frame (ORF) was 2745 bp in length, encoding a protein of 915 amino acids (101.15 kDa). Phylogenetic and domain structural analysis revealed that DbHsp104 possesses conserved features of eukaryotic Hsp104. In addition, transcriptional responses of the gene were evaluated after exposures to thermal stress at 20, 25, and 30 °C, and heavy metals and endocrine-disrupting chemicals (EDCs) for 24 h. Relative gene expression analysis showed that DbHsp104 was significantly up-regulated under thermal stress and copper exposures, peaking at 4.87- and 5.55-fold (p < 0.001) increases, respectively. In contrast, no significant changes were observed in response to nickel, bisphenol A (BPA), polychlorinated biphenyl (PCB), and endosulfan (EDS) treatments. Conclusions: These results suggest that DbHsp104 is specifically responsive to acute stress induced by thermal stress and copper, highlighting its potential as a molecular biomarker in marine environments. Full article

The present ecological study endeavours to evaluate the variability of life expectancy (MLE) and mortality rate (MR) on a micro scale, specifically between populations of neighbouring villages in the Silesia Province. This endeavour is of particular significance due to the chronic exposure to halogenated persistent organic pollutants (POPs) in one of the villages under study. The present study is innovative in comparison with previous research in this field, as it considers the impact of the most toxic dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), and utilises a village-level reference area. A thorough investigation was undertaken to determine the possible consequences of inhalation exposure within the local community to polychlorinated dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs). A robust correlation was evidenced between chronic exposure of case study residents to 2,3,7,8-TCDD and their mortality. Furthermore, an investigation revealed a strong correlation between the concentration of 2,3,7,8-TCDD in the air and actual MLE. An increase in the concentration of 2,3,7,8-TCDD by 10 fg I-TEQ/m³ has the potential to result in a reduction in the mean MLE of the exposed inhabitants of Silesia by 1 year and 9 months. In addition, the results of this study indicate that the female population exhibits a lifespan that is 7 years and 10 months longer than that of the male population. However, given the substantial differences in the mean MLE observed also in low-polluted areas of this region, it is probable that not only environmental factors, including exposure to PCDD/Fs and PCBs, but also various socio-economic factors may be involved. Full article

Marine sediments are a key component of aquatic ecosystems, linking diverse water uses, functions, and services. Chemical contamination of sediments is a global concern, with many jurisdictions striving to prevent future pollution and manage existing contamination. This study evaluates the contamination status of Rovinj’s coastal waters using an integrated approach that combines sediment and biota chemical analyses. Sediments were analyzed to assess long-term contaminant accumulation (D8.C1), while the Mediterranean mussel (Mytilus galloprovincialis) served as a bioindicator of bioavailable contaminants and their cumulative effects on marine habitats (D8.C2). Sediment samples were collected from five sites (S1–S5), and mussels were caged using Mussel Watch installations for approximately 120 days at a control site (Lim Bay) and within Rovinj harbor. Both matrices were analyzed for heavy metals (As, Cd, Cu, Cr, Hg, Ni, Pb, and Zn), polycyclic aromatic hydrocarbons (16 PAHs), and polychlorinated biphenyls (PCBs), following the EU Water Framework Directive. All sampled locations showed a reduction in sediment contamination relative to 2011 data, with most concentrations below ecotoxicological thresholds. Exceptions included elevated ΣPAH and PCB concentrations in the harbor (S1 = 3.18 mg/kg DW; 0.33 mg/kg DW) and marina (S2 = 3.64 mg/kg DW; 0.89 mg/kg DW), as well as Ni levels (S3 = 30 mg/kg DW; S4 = 34 mg/kg DW). Despite higher contaminant loads at some locations, mussel contaminant bioaccumulation remained limited, and their vitality and survival were only moderately affected in the harbor. Although localized increases in some contaminants were detected, all calculated Q_PECm values remained below 1.0, indicating no significant ecological risk. However, a moderate-to-high probability of toxic effects (P) may occur with long-term exposure for biota inhabiting harbor and marina areas. The results of this study demonstrate continued improvement in the environmental quality of Rovinj’s coastal waters compared to the previous decade. Full article

Agricultural pollution, such as contamination from manure storage or leaking livestock buildings, often spreads through the catchment, affecting groundwater and surface water. An effective solution is the construction of permeable organic barriers. This study evaluates the efficiency of an innovative bioactive barrier in removing nitrogen compounds (NO₃⁻ and NH₄⁺) and polychlorinated biphenyls (PCBs). Two types of barriers were tested: a horizontal deposit under a manure storage point and a vertical deposit in the leachate flow path. The bioactivity of the barrier was confirmed by the presence of bacterial genes involved in nitrogen transformation and PCB degradation. Results showed a 70% reduction in NO₃⁻ (368.4 mg·L⁻¹) and 43% reduction in NH₄⁺ (42.4 mg·L⁻¹). Genetic analysis identified bacteria capable of complete denitrification, resembling Pseudomonas stutzeri. The analysis also indicated that higher summer temperatures and pH levels fostered microbial communities capable of nitrogen transformation. Cluster analysis revealed that the vertical deposit zone was crucial for nitrogen removal. Additionally, the vertical barrier achieved a 53% reduction in PCBs, with Pseudomonas aeruginosa-like bacteria identified as PCB degraders. Full article

The intestinal epithelium constitutes a critical barrier that protects the host from luminal toxins. Persistent organic pollutants (POPs), including dioxins and dioxin-like polychlorinated biphenyls, are ubiquitous aryl hydrocarbon receptor (AhR) ligands. However, their effects on intestinal barrier integrity remain poorly understood. We examined representative POPs in vitro (using human Caco-2 monolayers) and in vivo (using a mouse jejunal loop model). Measurements of transepithelial electrical resistance, fluorescein isothiocyanate–dextran permeability, and cytotoxicity revealed that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) impaired barrier function at non-cytotoxic concentrations. This effect was accompanied by increased ethoxyresorufin-O-deethylase activity and subsequently reversed by the AhR antagonist CH223191, indicating AhR dependence. Mechanistically, TCDD suppressed claudin-1, claudin-4, and zonula occludens-1 expression while upregulating the transcription factor Slug, consistent with junctional remodeling. In vivo, TCDD enhanced systemic dextran leakage and reduced claudin-4 expression in jejunal epithelia. These findings identify intestinal barrier disruption as a sensitive toxicological endpoint of POP exposure and provide mechanistic insight into the link between environmental pollutants and gastrointestinal dysfunction. Full article

Breast cancer is one of the most prevalent malignancies affecting women worldwide. Among environmental risk factors, increasing attention has been given to endocrine-disrupting chemicals (EDCs), which can interfere with hormonal signaling pathways. Chronic exposure to these compounds, even at low doses, may lead to molecular changes that initiate carcinogenesis or promote tumor progression. Owing to EDCs’ resistance to degradation and ability to bioaccumulate in organisms and the environment, they pose a growing concern for human health. They can mimic or block natural hormones by binding to receptors, such as estrogen, progesterone, aryl hydrocarbon, or thyroid-stimulating receptors, disrupting hormone synthesis, secretion, and metabolism. They have shown the ability to initiate carcinogenic changes in breast tissue or accelerate cancer progression. This review focuses on the relationship between EDC exposure and breast cancer, examining both their mechanisms of action and long-term health effects. Compounds such as polychlorinated biphenyls, parabens, phenols, 2,3,7,8-tetrachlorodibenzo-p-dioxin, diethylhexyl phthalate, and bisphenol A, which are frequently encountered in everyday products, are discussed in detail. By presenting European Union guidelines and exploring EDCs’ biological activity and pathways of endocrine disruption, we aimed to raise awareness of their potential risks and emphasize the need for further research. Full article

Polychlorinated biphenyls (PCBs) are persistent organic pollutants associated with neurodevelopmental toxicity, yet the effects of exposure during adolescence and adulthood remain underexplored. This scoping review evaluates the neurotoxic outcomes of post-weaning PCB exposure in rodent models. A comprehensive literature search was conducted across PubMed, Embase, and Scopus. Studies were screened according to PRISMA guidelines. Articles were included if they reported neurotoxic or behavioral outcomes in mice or rats exposed to PCBs during post-weaning stages. Thirty-five studies met the inclusion criteria, encompassing a variety of PCB congeners and mixtures administered via oral, inhalation, or intraperitoneal routes. Reported neurotoxic outcomes included histological and morphological brain changes, oxidative stress, disrupted calcium signaling, altered neurotransmitter systems, apoptosis, and gene expression alterations. These outcomes were assessed using diverse methodological approaches, including immunohistochemistry, biochemical assays, and gene expression profiling. Behavioral outcomes affected by PCB exposure included locomotion, anxiety-like behavior, learning and memory, motor coordination, and cognitive flexibility. Effects were often exposure-specific and sex-dependent, with limited female-focused studies and integrative molecular-behavioral assessments. These findings highlight the broad neurotoxic potential of PCBs following adolescent or adult exposure and underscore the need for further mechanistic, sex-specific research to inform health risk assessment and regulatory policy. Full article

The Yamuna River, among India’s most polluted waterways, is burdened by industrial, agricultural, and domestic discharges containing complex organic and inorganic contaminants. This study introduces a novel, integrated approach combining comprehensive pollutant profiling by liquid chromatography–mass spectrometry (LC-MS) with bioremediation using laboratory-validated native algal consortia. Water samples from a severely polluted Delhi stretch revealed alarming levels of heavy metals (e.g., lead: 47.33 mg/L) and over 550 organic pollutants, including polychlorinated biphenyls, dioxins, carcinogens, and neurotoxins. Two consortia, each assembled from indigenous algal strains, were evaluated under controlled conditions against both pollutant-rich water and non-polluted controls. Consortium 1 (Scenedesmus, Chlorococcum, Oocystis) outperformed Consortium 2 (Chlorella, Klebsormidium, Monoraphidium), achieving up to 87.07% reduction in lead and >95% removal of nitrate and phosphate, alongside substantial decreases in chemical and biological oxygen demand. By integrating high-resolution chemical analytics with native microbial remediation, this work provides the first demonstration of simultaneous removal of diverse pollutant classes in Yamuna water. The findings establish native algal consortia as cost-effective, sustainable bioremediation tools and underscore LC-MS as a critical method for holistic aquatic pollution assessment. Full article

Toxicant-associated steatohepatitis (TASH) is caused by environmental toxicants rather than metabolic factors; however, its pathogenic mechanisms remain poorly understood. Polychlorinated biphenyl 138 (PCB138), a persistent lipophilic contaminant that bioaccumulates in adipose tissue, may promote TASH through unclear mechanisms. In this study, we investigated whether PCB138 induces liver injury via hepatic iron dysregulation and adipose-liver inflammatory signaling. Male C57BL/6 mice received intraperitoneal PCB138 (1, 5, 10, or 50 mg/kg, four injections over six weeks). HepG2 hepatocytes were treated with PCB138 with or without ferric ammonium citrate (FAC), and PCB138-exposed 3T3-L1 adipocytes were co-cultured with HepG2 cells using a Transwell system. PCB138 dose-dependently increased serum transaminase and hepatic non-heme iron levels, with Hamp upregulation, macrophage infiltration, and fibrosis. In HepG2 cells, PCB138 synergized with FAC to elevate intracellular Fe²⁺, induced Hamp, suppressed Slc40a1, and upregulated inflammatory/profibrotic genes. In Transwell co-cultures, TNF-α, IL-6, and IL-1β from PCB138-exposed adipocytes amplified hepatic iron dysregulation and fibrotic responses. These findings demonstrated that PCB138 induced TASH through hepatic iron dysregulation and adipose-derived inflammatory signaling, independent of steatosis. These results highlighted the iron–adipose axis as a novel mechanistic link between PCB138 exposure and liver injury, offering potential therapeutic targets. Full article

The Black Sea is a semi-enclosed basin subject to intense anthropogenic pressures and transboundary pollution, making reliable and comparable monitoring data essential for large-scale environmental assessments. However, national practices differ considerably, hindering data integration and coordinated reporting under international frameworks. This study, conducted within the Horizon 2020 project “Advancing Black Sea Research and Innovation to Co-develop Blue Growth within Resilient Ecosystems” (BRIDGE-BS), evaluated pollutant surveillance methodologies with a focus on heavy metals and priority organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides). Standard Operating Procedures (SOPs) were collected from institutions across Black Sea countries and systematically compared for water, sediment, and biota matrices. The analysis revealed shared reliance on internationally recognized techniques but also heterogeneity in sediment fraction selection, digestion and extraction conditions, instrumental approaches, and quality assurance/quality control (QA/QC) documentation. To complement this assessment, an intercalibration (IC) exercise was organized through the QUASIMEME proficiency testing scheme, accompanied by a follow-up structured questionnaire sent to participant institutions. While individual results remain confidential, collective feedback highlighted common challenges in calibration, blank correction, certified reference materials (CRMs) availability, digestion variability, instrument maintenance, and the reporting of uncertainty and detection limits. Together, these findings confirm that harmonization in the Black Sea requires not only improved comparability of laboratory methods but also the future alignment of assessment methodologies, including indicators and thresholds, to support coherent, basin-wide environmental evaluations under regional conventions and EU directives. Full article

While many studies on the health effects of PM_2.5 exist, the risks of PM_2.5 species remain largely unexplored in Middle Eastern and North African countries. This study assesses, for the first time, the carcinogenic and non-carcinogenic health risks for elements, polycyclic aromatic hydrocarbons (PAHs), phthalates, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) bound to PM_2.5 in the Greater Cairo Area. A total of 59 samples were collected from an urban site in Dokki (November 2019–January 2020). Chemical analysis showed higher concentrations of PCDFs (5418 fg/m³) than PCDDs (1469 fg/m³), with DL-PCBs being the most abundant (6577 fg/m³). Health risk assessment for inhalation showed non-carcinogenic risks for all age groups, especially for newborns. Manganese (Mn) and lead (Pb) posed the highest elemental non-carcinogenic risk, while the hazard quotient (HQ) for PAHs exceeded 1 across all ages. PCDDs, PCDFs, and DL-PCBs showed an estimated cancer risk reaching 10⁻⁶ in adults, indicating a significant health concern. Key contributors to cancer risk included arsenic (As), chromium (Cr(VI)), and vanadium (V), which accounted for over 80% of the total elemental cancer risk. Major and trace elements posed the highest lifetime cancer risk, nearly 37 times the acceptable level. Full article