Search Results (102)

Background/Objectives: Polychlorinated biphenyls (PCBs) are persistent environmental contaminants associated with chronic toxicity and neurological dysfunction. PCB 153 is among the most prevalent congeners detected in environmental and dietary matrices. Although transcriptional responses to PCB 153 have been described, its potential association with post-transcriptional regulation remains poorly defined. Here, we performed an exploratory computational RNA-seq splicing analysis of previously generated transcriptomic data from retinoic acid-differentiated SH-SY5Y cells exposed to a sub-cytotoxic concentration of PCB 153. Methods: RNA-seq data were analyzed to identify candidate differentially alternative splicing events (DASEs). Candidate events were further examined for retained intron (RI)-related premature termination codons (PTCs), and potential regulatory interactions, including DASE-RNA-binding protein (RBP) motif enrichment. Results: PCB 153 exposure was associated with differential expression of 32 RNA-binding protein (RBP) encoding genes and with 90 candidate DASEs. Disease enrichment analysis indicates that genes affected by candidate splicing alterations overlapped with gene sets annotated to intellectual disability and related neurodevelopmental phenotypes. Among retained intron events, several were predicted to introduce PTCs, suggesting potential effects on transcript stability or coding potential. Motif enrichment analysis identified positional enrichment of motifs corresponding to CELF2, NUMA1, PRPF8, and RBM22 within DASE-associated regions, nominating these RBPs as putative regulators associated with the observed splicing alterations. Conclusions: This computational study identifies candidate PCB 153-associated splicing alterations and RBP-related regulatory hypotheses in a neuron-like in vitro model, suggesting a potential mechanistic link between PCB 153 and neurodevelopmental dysfunction. Full article

Polychlorinated biphenyls (PCBs) are persistent environmental pollutants associated with neurodevelopmental and neurodegenerative disorders. PCB 118 is one of the most abundant congeners and exerts neurotoxic effects, yet the molecular mechanisms underlying its impact on human neurons remain poorly understood. We investigated the molecular response of retinoic acid-differentiated, neuron-like SH-SY5Y cells exposed to 5 µM PCB 118 for 24 h, a concentration that did not affect cell viability. RNA sequencing identified 1239 differentially expressed genes. Functional enrichment and protein-protein interaction analyses identified upregulation of histone and chromatin structural genes, indicative of substantial chromatin remodeling. In parallel, a significant downregulation of genes involved in ribosome biogenesis and rRNA processing was observed, potentially indicating impairment of the protein synthesis machinery. These transcriptional changes point to a coordinated reprogramming of nuclear architecture and translational machinery, potentially compromising neuronal homeostasis. The modulation of proteostasis-related pathways further supports a mechanistic link between PCB 118 exposure and neuronal dysfunction. Our results provide a comprehensive transcriptional framework connecting PCB 118 to chromatin-mediated gene regulation and suppression of ribosome biogenesis in human neuron-like cells. This study offers mechanistic insights into how environmental PCB exposure may contribute to neurotoxicity and highlights molecular pathways potentially implicated in the development of neurodegenerative disorders. Full article

Persistent organic pollutants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) remain a public health concern due to their persistence, bioaccumulation, and potential health effects. Human breast milk is an important biomonitoring matrix for assessing maternal and infant exposure to lipophilic contaminants. This pilot study aimed to determine concentrations of PCDD/Fs, dioxin-like PCBs (dl-PCBs), and non-dioxin-like PCBs (ndl-PCBs) in breast milk samples collected from five lactating women residing in the Greater Poland Province and to explore potential determinants of exposure. Following participant recruitment, sample collection, and questionnaire-based assessment performed by the authors, breast milk samples were analyzed at the accredited Laboratory of Trace Analysis (Cracow University of Technology, Poland) using isotope dilution gas chromatography coupled with tandem mass spectrometry. Toxic equivalency values (TEQ) were calculated using World Health Organization 2005 toxic equivalency factors (WHO-TEFs). WHO-PCDD/F-TEQ ranged from 0.096 to 0.22 pg/g fresh weight. Median lipid-normalized WHO-PCDD/F-TEQ and total WHO-PCDD/F-PCB-TEQ concentrations were 3.5 and 4.7 pg/g lipid, respectively, remaining below the European Food Safety Authority (EFSA) reference level of 5.9 pg/g lipid; only one sample exceeded this threshold (6.2 pg/g lipid). Lipid-normalized WHO-PCB-TEQ correlated positively with maternal age (ρ = 0.949, p = 0.0389). The observed values were within the lower range reported in recent European studies. The congener patterns suggest a combination of chronic exposure to combustion by-products and long-term bioaccumulation of historical industrial pollutants. Although limited by the small sample size, this exploratory study provides preliminary regional biomonitoring data supporting future environmental exposure research. Full article

Polychlorinated biphenyls (PCBs) persist in the environment as complex mixtures and undergo extensive biotransformation, yet the developmental toxicity of PCB metabolites remains poorly defined. We evaluated developmental, neurobehavioral, and molecular effects of parent PCBs, hydroxylated, methoxylated, and sulfated metabolites, and environmentally relevant mixtures using embryonic zebrafish. This study employed a high-throughput screening approach using nominal exposure concentrations to enable rapid hazard identification and prioritization across a large chemical series. Morphological abnormalities and photomotor behavior were assessed across early development, followed by targeted cyp1a reporter analysis and transcriptomic profiling for a subset of potent exposures. Most chemicals induced morphological effects, with hydroxylated and sulfated metabolites producing effects more frequently and at lower benchmark concentrations than parent congeners. Behavioral alterations were more prevalent in embryonic photomotor response than larval photomotor response and generally co-occurred with morphological effects. Environmental mixtures elicited broad phenotypic profiles comparable to highly active individual compounds. Transcriptomic analyses revealed minimal responses for parent PCBs but robust, exposure-specific gene expression changes for select metabolites, particularly 5-OH-PCB11, and mixtures. Differentially expressed genes were enriched for xenobiotic metabolism, immune signaling, and neuroactive pathways, alongside consistent downregulation of circadian regulators. Together, these results demonstrate contributions of PCB metabolites and mixtures to toxicity. Full article

Quantifying the mixture effects on humans exposed remains challenging because mixture components are correlated and may act bidirectionally by exhibiting nonlinear dose-response relationships, which may contribute to subclinical organ dysfunction. The liver is a vital organ in the body with broad functions, making it vulnerable to injury as it is the first organ exposed to circulating toxicants, which can precipitate hepatic damage. Our study’s objective was to evaluate the combined and component-specific associations of a multi-chemical exposure mixture of heavy metals, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (dioxins), and polychlorinated dibenzofurans (furans), with liver biomarkers, and to compare concentration-based results with the toxic equivalent (TEQ) potency of the weighted results for dioxin-like compounds. In an unweighted analytic sample of U.S. adults from NHANES 2003–2004 with 947 complete cases, we examined heavy metals (cadmium, lead, and mercury), PCBs (12 congeners), dioxins (7 congeners), and furans (10 congeners) in relation to eight liver biomarkers (albumin, ALP, ALT, AST, GGT, LDH, total bilirubin, and total protein). We applied multi-exposure linear regression, weighted quantile sum (WQS) regression, quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR), with parallel TEQ-based models using WHO 2005 TEFs for dioxin-like PCBs, dioxins, and furans. Across mixture methods, the mixture structure was chemically sparse, with a limited set of recurring contributors. Total bilirubin showed the most consistent positive mixture association across qgcomp and BKMR and persisted under TEQ weighting, with prominent PCB- and dioxin-like contributions (notably PCB81/PCB TEQs and dioxin-related components). Albumin demonstrated inverse mixture patterns in BKMR and TEQ-BKMR, with dioxin-like components (notably Dioxin3 and Dioxin3_TEQ) repeatedly emerging as key drivers. For ALT, ALP, AST, GGT, LDH, and total protein, overall mixture effects were frequently attenuated or null in qgcomp despite structured component weights, indicating bidirectional sub-mixtures and internal counterbalancing. BKMR PIPs similarly concentrated on a small number of dominant predictors (e.g., lead for ALP, mercury for ALT, PCB28 for AST, and cadmium and PCB189 for LDH), while interaction summaries provided limited evidence of stable non-additivity. Using multiple complementary mixture methods, we identified outcome-specific mixture patterns suggesting hepatobiliary vulnerability. TEQ concordance supports toxicological relevance of the dioxin-like axis, while metals and non–dioxin-like mechanisms likely contribute additional pathways. Full article

Polychlorinated biphenyls (PCBs) remain a major concern in marine ecosystems, where bioaccumulation in fish occurs as complex congener mixtures whose dynamics challenge conventional indicator approaches. This study develops and evaluates a data-driven framework for refining mixture-based indicators of PCB contamination by integrating ensemble machine learning with explainable artificial intelligence. Focusing on PCB-138 as a target indicator of cumulative PCB burden, we analyse concentrations of 24 organochlorines together with biological covariates in four Mediterranean edible pelagic fish species (sardine, anchovy, horse mackerel, and chub mackerel). Comparative evaluation of indicator performance shows that alternative congener combinations, including i4 PCBs (-138, -153, -170, -180), i6 PCBs (-138, -153, -170, -180, -118, -123), and mixtures incorporating DDD and DDE, more effectively represent total PCB burden than traditional indicator groups. Clustering identifies two distinct bioaccumulation settings, characterized by high-concentration coherent congener effects and low-concentration heterogeneous responses, demonstrating that indicator performance depends on concentration range and mixture context. The study illustrates how interpretable machine learning approaches can serve as formal tools for indicator evaluation and optimisation, strengthening long-term monitoring and management of legacy contaminants in marine ecosystems, particularly under conditions of persistent exposure and renewed inputs from sediment remobilization and riverine transport. 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

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that remain widely detectable in the environment and human tissues decades after their ban, raising concerns for brain health. Both dioxin-like (DL) and non-dioxin-like (NDL) congeners interfere with neuronal function through partially distinct pathways, including aryl hydrocarbon receptor activation, disruption of calcium and dopaminergic signaling, oxidative stress, and epigenetic remodeling. Experimental and epidemiological studies indicate that developmental PCB exposure is associated with impaired cognition, attention, motor function, and increased risk of neurodevelopmental disorders. Furthermore, chronic exposure in adulthood has been linked to neurodegenerative diseases. At the cellular level, NDL-PCBs sensitize ryanodine receptors, alter dendritic and axonal growth, promote mitochondrial dysfunction, generate reactive oxygen and nitrogen species, and compromise blood–brain barrier integrity, thereby fostering neuroinflammation, synaptic dysfunction, and neuronal loss. This review synthesizes current evidence on the molecular and cellular mechanismtable s underlying PCB-induced neurotoxicity across the lifespan, highlighting oxidative stress as a central factor, integrating calcium dysregulation, neurotransmitter imbalance, and apoptotic and epigenetic pathways. Finally, potential neuroprotective roles of antioxidant strategies are discussed, emphasizing their relevance for mitigating PCB-related neurodevelopmental and neurodegenerative risk. Full article

Polychlorinated biphenyls (PCBs) are persistent environmental contaminants associated with neurotoxicity and increased risk of neurodegenerative diseases. PCB 153, a highly abundant non-coplanar congener, bioaccumulates in human tissues and impairs homeostasis. This study investigated the transcriptomic effects of PCB 153 (2,2′,4,4′,5,5′-Hexachlorobiphenyl) in retinoic acid (RA)-differentiated SH-SY5Y neuronal cells to identify early, sub-cytotoxic molecular alterations. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after 24 h exposure to increasing PCB 153 concentrations. RNA-Seq was performed on cells treated with 5 μM PCB 153, the highest non-cytotoxic dose. Sequencing reads were quality-filtered, aligned to the human genome, and analyzed with DESeq2. Functional enrichment was conducted using Gene Ontologies and KEGG pathways. Western blot analyses were performed to assess protein level changes in selected targets. RNA-Seq identified 1882 significantly altered genes (q-value < 0.05). Gene Ontology analysis revealed strong enrichment of proteasome-related terms, with most proteasomal subunits displaying coordinated upregulation. KEGG analysis further showed significant enrichment of Alzheimer’s (AD), Parkinson’s (PD), amyotrophic lateral sclerosis (ALS), and other neurodegenerative disease pathways. These findings indicate that PCB 153 triggers a pronounced proteostatic response in neuron-like cells, suggesting early disruption of protein homeostasis that may contribute to mechanisms associated with neurodegeneration. Full article

This study systematically analyzed the pollution levels, distribution characteristics, and associated health risks of 17 organochlorine pesticides (OCPs) and 9 polychlorinated biphenyls (PCBs) in Oviductus Ranae (Rana dybowskii) from major production areas in Heilongjiang Province, China. OCPs and PCBs were detected in all samples. The total concentration of OCPs ranged from 11.7 to 67.9 ng/g (dry weight), while that of total PCBs ranged from 4.43 to 8.06 ng/g. Endosulfans constituted the predominant OCP group, accounting for 54.5% of ∑OCPs, with an α/β-endosulfan ratio (~2:1) indicative of recent agricultural input. Among DDTs, the dominance of p,p′-DDE and the absence of parent DDT suggested aerobic degradation of historical residues. For HCHs, the isomer profile (β-HCH predominance, α/γ-HCH = 0.27) pointed to weathered lindane sources. The PCB profile was uniquely dominated by lower-chlorinated congeners (PCB1 and PCB29), implying influences from atmospheric transport and/or in situ microbial dechlorination of legacy PCBs. The persistent organic pollutants (POPs) contamination profile in Oviductus Ranae reflects a combined influence of recent pesticide application, weathered historical residues, and long-range transport. Although the concentrations are below current regulatory limits, the cumulative and persistent nature of these POPs, coupled with the product’s medicinal use, justifies a precautionary stance regarding long-term consumption. The distinct congener patterns underscore the necessity for future research to prioritize the environmental behavior and toxicology of dominant transformation products within such specific agro-ecosystems. 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

In this study, the presence of seven polychlorinated biphenyl (PCB) congeners proposed by ICES-7 (International Council for the Exploration of the Sea) (PCBs 28, 52, 101, 118, 138, 153, and 180) in milk, dairy products, and beverages was investigated, and potential risks to consumer health were assessed. A total of 130 samples were analyzed using gas chromatography–mass spectrometry (GC–MS/MS). Most PCBs levels were below the limits of detection and quantification, but trace amounts, particularly of PCB 153 and PCB 180, were detected. Overall, 35% of milk and dairy products and 20% of beverage samples exceeded the reference limits for ICES-7, with higher accumulation observed in high-fat dairy products. Packaging type also appeared to influence contamination levels. The study findings indicate that PCBs contamination levels may vary depending on product type, content, production method, and packaging structure. Three consumption scenarios were modeled for children and adults, and the estimated daily intake (EDI) was calculated. All hazard index (HI) values found to be below 1. This result suggests no significant non-carcinogenic health concern across the examined products and packaging types. Nevertheless, given the persistence and bioaccumulation potential of PCBs, continuous monitoring remains essential. Full article

This study presents the level of polychlorinated biphenyl (PCB) pollution in the transboundary Ile River in 2015, 2018, 2019, 2023, and 2024. PCB contamination of water, as well as the presence of a large number of individual congeners, including strictly controlled ‘marker’ and dioxin-like congeners, were detected along the entire length of the river within Kazakhstan. Water samples were analyzed using a Chromos GH-1000 gas chromatograph. Significant interannual variability of river water contamination and a noticeable decrease in 2023 and 2024 compared to the previous periods have been identified. The study examined the PCB concentration transformation in the Ile River, from the transboundary section to the river’s confluence with Lake Balkhash, assessing not only fluctuations in total PCB concentration, but also their congener composition. The main natural and anthropogenic PCB sources and factors causing the transformation of the toxicant along the river course were identified. The total amount of transboundary PCB discharge both into Kazakhstan and into Lake Balkhash was calculated. The results can be used by state and local environmental protection agencies for the development of measures to protect rivers from pollution by these highly toxic pollutants, which is in line with the requirements of the Stockholm Convention on POPs. Full article

Viral and chemical analyses were performed on 80 dead cats and 51 dead dogs from the Campania Region (Southern Italy), with the aim of evaluating in vivo the potential correlation between coronavirus (CoV) infections and levels of environmental pollutants such as dioxins and PCSs (PCDD/F, DL-PCB and NDL-PCB). The overall viral prevalence was 16.3% in cats and 23.5% in dogs. Both feline coronavirus (FCoV) and canine coronavirus (CCoV) were identified, with variable detection rates in all the other organs investigated, supporting studies that provide evidence of systemic viral spread. The highest prevalence of coronaviruses (CoVs) was observed in Naples (19.2% for FCoV; 30.7% for CCoV) and Caserta (11.1% for FCoV; 50.0% for CCoV), areas that include municipalities with the highest Municipality Index of Environmental Pressure (MIEP) scores. Chemical analyses showed that DL-PCBs were present at more elevated concentrations in CoV-infected dogs and cats than in non-infected animals, whereas ∑NDL-PCB and ∑PCDD/F were detected in greater amounts in non-infected subjects. Among PCDDs, the congener 2,3,7,8-TCDD displayed different distribution patterns between infected and non-infected animals. In cats, 70.0% of FCoV-positive individuals had 2,3,7,8-TCDD levels above the limit of quantification (LOQ), compared with 38.0% of FCoV-negative cats. In dogs, 78.0% of CCoV-infected animals exceeded the LOQ, compared with 20.0% of non-infected ones; this difference was statistically significant. The results of the study suggest that elevated levels of 2,3,7,8-TCDD may be associated with CCoV infection and replication in dogs, suggesting a possible relationship between environmental pollution and susceptibility to coronavirus infections. Full article

Taranto is the main harbor in Southern Italy and one of the most industrialized cities in the country, largely due to the presence of a large industrial area that includes a major oil refinery, a cement plant, and the former ILVA steel factory, which is one of the largest steel plants in Europe. A human biomonitoring study was conducted on breast milk from two groups of women residing in areas with different levels of exposure to polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and polychlorobiphenyls (PCBs). The study aimed to assess the differences in exposure between the two groups of general people, with one group classified as “exposed” and the other as “non-exposed”. Between 2015 and 2018, 150 breast milk samples were collected: 76 from the exposed group and 74 from the non-exposed group. A specific questionnaire was also administered to the donors. The data were analyzed using a robust regression approach. The results showed significant differences in the concentrations of all analyte classes between the two groups. The difference in concentration from the non-exposed to the exposed group was highly significant (TOT_TE, 5.70 vs. 7.35 pgWHO-TE/g, PCDD + PCDF 3.34 vs. 4.53 pgWHO-TE/g, DL-PCB 2.35 vs. 2.80 pgWHO-TE/g; p << 0.05), with the most notable difference observed for the Σ₁₀ (PCDFs) family (~37%). Additionally, two distinct theoretical exposure profiles were identified: one for women residing in urban peripheries and another for those living in city/town centers. Women in the peripheries were characterized by a profile of four to six chlorinated dioxin/furan congeners plus two PCB congeners, while women in the city centers exhibited a profile of six to eight chlorinated PCDD and PCDF congeners plus five to six chlorinated PCBs. Among women residing in urban peripheries, those living in the peripheries of Statte and Taranto showed the highest exposure levels. All the results appear to witness the highest exposure of the exposed women deriving from the steel plant of concern. In addition, the highest exposure levels for the analytical sum of Σ₆ (NDL-PCBs) were found in women from a municipality classified as non-exposed: Ginosa (periphery). Full article