Polychlorinated Biphenyl Concentrations and Estimated Intakes in Fish Oil Supplements on the Japanese Market.

Polychlorinated biphenyls (PCBs) are synthetic organic contaminants that are widespread in the environment. There are 209 PCB congeners. Fish oil produced from marine fish is widely used as a health supplement. PCB contamination of fish oil is of concern. We determined the concentrations of all 209 PCB congeners in commercially available fish oil supplements from Japan and estimated PCB intakes for humans consuming the supplements. We determined the concentrations of non-dioxin-like PCBs separately. The total PCB concentrations in 37 fish oil supplements purchased in Japan were 0.024-19 ng/g whole weight, and the non-dioxin-like PCB concentration range was also 0.024-19 ng/g whole weight. The total PCB intakes calculated for a 50 kg human consuming the supplements were 0.039-51 ng/day (0.00078-1.0 ng/(kg body weight per day)) and the non-dioxin-like PCB intake range was also 0.039-51 ng/day (0.00078-1.0 ng/(kg body weight per day)). The total PCB intakes were much lower than the tolerable daily intake of 20 ng/(kg body weight per day) recommended by the WHO. The results indicated that PCBs in the fish oil supplements pose acceptable risks to humans consuming the fish oil supplements daily.

The residues and health risk assessment of polychlorinated biphenyls (PCBs) in Pheretima (an earthworm-derived traditional medicine) from southeastern China.

Minimal research exists on polychlorinated biphenyl (PCB) exposure from traditional Chinese medicines (TCMs), despite their significant contributions to domestic and international health protection. This study is the first to investigate the levels, profiles, and health risks of PCB residue in Pheretima, a typical TCM produced from earthworm. Seventy-seven Pheretima samples from different regions of China were analyzed for 45 PCB congeners. PCBs were found in all samples exhibiting species-dependent discrepancies. ∑45PCBs was ranging from 0.532 to 25.2 µg/kg (mean 4.46 µg/kg), with CB-11 being the most abundant congener contributing 71.8% ± 10.8% to ∑45PCBs, followed by CB-47, which were all non-Aroclor congeners called unintentionally produced PCBs (UP-PCBs). The average estimated daily intake of ∑45PCBs, ∑7ID-PCBs (indicative polychlorinated biphenyls), and CB-11 were 0.71, 0.04, and 0.51 ng/kg bw/d, respectively. The ∑HQ of PCBs in Pheretima samples was 2.97 × 10-4-2.46 × 10-2 (mean 2.77 × 10-3, 95th 4.21 × 10-3), while the ∑RQ ranged from 1.19 × 10-8 to 2.88 × 10-6 (mean 4.87 × 10-7, 95th 2.31 × 10-6). These findings indicate that Pheretima ingestion does not pose significant non-carcinogenic risks. However, certain individual samples exhibit an acceptable level of potential risks, particularly when considering that PCBs are recognized as endocrine disruptors and classified as probable carcinogens. These results contribute to the safety evaluation of traditional medicines and suggest the potential use of Pheretima as a bioindicator for PCB pollution. It is advisable to monitor UP-PCBs as indicator congeners and gather additional toxicological data.

Levels, patterns and risk assessment of PCDD/Fs and dl-PCBs through dietary exposure in the Valencian Region (Spain).

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin like polychlorinated biphenyls (dl-PCBs) levels were measured in representative vegetable oils and animal origin foodstuffs collected in a Total Diet Study carried out in the Valencian Region (Spain). A total amount of 3,300 food samples were collected and grouped into 5 main food groups: vegetable oils, meat and meat products, eggs, milk and dairy products and fish and sea products. The samples were analysed using gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS). The food group which presented the highest concentration in wet weight (ww) for the sum of PCDD/Fs and dl-PCBs was fish and sea products (0.5 pg TEQ g-1 ww), whereas meat and meat products (0.6 pg TEQ g-1 lipid) showed the highest levels expressed in lipid terms. Occurrence data of PCDD/F and dl-PCBs were combined with consumption data to estimate the dietary exposure of adults (>15 years) and children (6-15 years). Finally, the estimated weekly intake (EWI) was calculated using a deterministic approach and considering the food consumption of the population, with fish and sea products being the main food group contributor. Likewise, considering the worst-case scenario (Upper Bound, UB), average EWI were 1.8 and 3.4 pg TEQ kg-1 body weight (bw) week-1 for adults and children, respectively. For children, the average EWI was almost twice above the tolerable weekly intake (TWI) of 2 pg TEQ kg-1 bw week-1 set by EFSA in 2018. In terms of risk characterisation, the overall obtained results showed that 19 % of adults and 43 % of children may exceed the TWI when using UB.

Short-chain fatty acids facilitated long-term dechlorination of PCBs in Taihu Lake sediment microcosms: Evidence from PCB congener and microbial community analyses.

Microbial reductive dechlorination hosts great promise as an in situ bioremediation strategy for polychlorinated biphenyls (PCBs) contamination. However, the slow dechlorination in sediments limits natural attenuation. Short-chain fatty acids, as preferred carbon sources and electron donors for dechlorinating microorganisms, might stimulate PCB dechlorination. Herein, two sets of short-chain fatty acids, sole acetate and a fatty acid mixture (acetate, propionate, and butyrate), were amended periodically into Taihu Lake (China) sediment microcosms containing nine PCB congeners (PCB5, 12, 64, 71, 105, 114, 149, 153, and 170) after 24 weeks of incubation. Short-chain fatty acids facilitated the long-term PCB dechlorination and the promoting effect of the fatty acid mixture compared favorably with that of sole acetate. By the end of 108 weeks, the total PCB mass concentrations in acetate amended and fatty acid mixture amended microcosms significantly declined by 7.6% and 10.3% compared with non-amended microcosms (P < 0.05), respectively. Short-chain fatty acids selectively favored the removal of flanked meta and single-flanked para chlorines. Notably, a rare ortho dechlorination pathway, PCB25 (24-3-CB) to PCB13 (3-4-CB), was enhanced. Supplementary fatty acids significantly increased reductive dehalogenases (RDase) gene pcbA5 instead of improving the growth of Dehalococcoides. These findings highlight the merits of low cost short-chain fatty acids on in situ biostimulation in treating PCBs contamination.

Site-specific response of sediment microbial community to supplementation of polyhydroxyalkanoates as biostimulants for PCB reductive dechlorination.

The use of biodegradable plastics is constantly raising, increasing the likeliness for these polymers to end up in the environment. Environmental applications foreseeing the intentional release of biodegradable plastics have been also recently proposed, e.g., for polyhydroxyalkanoates (PHAs) acting as slow hydrogen releasing compounds to stimulate microbial reductive dehalogenation processes. However, the effects of their release into the environment on the ecosystems still need to be thoroughly explored. In this work, the use of PHAs to enhance the microbial reductive dechlorination of polychlorobiphenyls (PCBs) and their impact on the metabolic and compositional features of the resident microbial community have been investigated in laboratory microcosms of a polluted marine sediment from Mar Piccolo (Taranto, Italy), and compared with recent findings on a different contaminated marine sediment from Pialassa della Baiona (Ravenna, Italy). A decreased biostimulation efficiency of PHAs on PCBs reductive dechlorination was observed in the sediment from Mar Piccolo, with respect to the sediment from Pialassa della Baiona, suggesting that the sediments' physical-chemical characteristics and/or the biodiversity and composition of its microbial community might play a key role in determining the outcome of this biostimulation strategy. Regardless of the sediment origin, PHAs were found to have a specific and pervasive effect on the sediment microbial community, reducing its biodiversity, defining a newly arranged microbial core of primary degraders and consequently affecting, in a site-specific way, the abundance of subdominant bacteria, possibly cross-feeders. Such potential to dramatically change the structure of autochthonous microbial communities should be carefully considered, since it might have secondary effects, e.g., on the natural biogeochemical cycles.

Toxic effects of Aroclor 1254 on rat liver and modifying roles of selenium.

Polychlorinated biphenyls (PCBs) were used in different industrial areas and banned due to their high toxicity. Aroclor 1254 (A1254), commercial PCB congener, accumulates in environment leading to high human exposure. A1254 may cause hepatotoxicity, metabolic and endocrine disorders. In our study, 3-week-old male rats were separated into 6 groups: C (0.15 mg/kg Se in diet); SeS (1 mg/kg Se in diet); SeD (0.05 mg/kg Se in diet); A1254 receiving groups (A; ASeS; ASeD) were given 10 mg/kg/day A1254 orally for last 15 days of feeding period with control, SeD or SeS diet, respectively, for 5 weeks. Histopathology, oxidant/antioxidant balance, apoptosis and cell cycle proteins (p53, p21) in liver were evaluated. Our results suggest that A1254 leads to changes in histology, oxidative stress and apoptosis. Selenium deficiency augments oxidative stress and apoptosis while selenium supplementation is partially protective. More mechanistic in vivo experiments are necessary for evaluation of hepatotoxicity of PCBs.

POPs and PAHs in fish oil-based food supplements at the Czech market.

The objectives of this study were to assess concentrations of three groups of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in 44 fish oil-based food supplements, to estimate their daily intake by consumers and, to evaluate the compliance of the oil samples with the oil origin declarations (cod liver oil or fish oil). The concentrations of ∑PCBs (7 congeners), OCPs (19 compounds, represented mainly by ∑DDTs), ∑PBDEs (10 congeners), and ∑PAHs (16 compounds) found in samples ranged between 0.15-55.7 µg kg-1, 0.93-72.8 µg kg-1, 0.28-27.5 µg kg-1, and 0.32-51.9 µg kg-1, respectively. Besides, the authenticity of the oils was assessed based on the fingerprints obtained by DART-HRMS, an ambient mass spectrometry technique. Four samples declared as fish oil were probably prepared from cod liver oil, which is much cheaper. Furthermore, these samples contained elevated concentrations of halogenated POPs when compared to supplements produced from fish oil.

A robust and ultra-high-surface hydrogen-bonded organic framework promoting high-efficiency solid phase microextraction of multiple persistent organic pollutants from beverage and tea.

Persistent organic pollutants (POPs) are widely distributed in the environment and are toxic, even at low concentrations. In this study, we first used hydrogen-bonded organic framework (HOF) to enrich POPs, based on solid phase microextraction (SPME). The HOF called PFC-1 (self-assembled by 1,3,6,8-tetra(4-carboxylphenyl)pyrene) has an ultra-high specific surface area, excellent thermochemical stability, and abundant functional groups, making it potential to be an excellent coating in SPME. And the as-prepared PFC-1 fiber have demonstrated outstanding enrichment abilities for nitroaromatic compounds (NACs) and POPs. Furthermore, the PFC-1 fiber was coupled with gas chromatography-mass spectrometry (GC-MS) to develop an ultrasensitive and practical analytical method with wide linearity (0.2-200 ng·L-1), low detection limits for organochlorine pesticides (OCPs) (0.070-0.082 ng·L-1) and polychlorinated biphenyls (PCBs) (0.030-0.084 ng·L-1), good repeatability (6.7-9.9%), and satisfactory reproducibility (4.1-8.2%). Trace concentrations of OCPs and PCBs in drinking water, tea beverage, and tea were also determined precisely with the proposed analytical method.

Network Toxicology Guided Mechanism Study on the Association between Thyroid Function and Exposures to Polychlorinated Biphenyls Mixture.

Polychlorinated biphenyls (PCBs) are persistent and highly toxic pollutants, which can accumulate in organisms and produce toxic effects, especially damaging the function of thyroid hormones. So far, the molecular mechanism of PCBs mixture and their metabolites interfering with thyroid hormones has not been studied thoroughly except for individual compounds. In this study, PubMed, Web of Science, and STITCH databases were used to search PCBs and their corresponding target proteins. The intersection of PCBs and thyroid hormone dysfunction target proteins was obtained from GeneCards. The "compounds-targets-pathways" network was constructed by Cytoscape software. And KEGG and Go analyses were performed for key targets. Finally, molecular docking was used to verify the binding effect. Four major active components, five key targets, and 10 kernel pathways were successfully screened by constructing the network. Functional enrichment analysis showed that the interference was mediated by cancer, proteoglycans, PI3K-Akt, thyroid hormone, and FoxO signaling pathways. The molecular docking results showed that the binding energies were less than -5 kcal·mol-1. PCBs and their metabolites may act on the key targets of MAPK3, MAPK1, RXRA, PIK3R1, and TP53. The toxic effect of sulfated and methyl sulfone PCBs is greater. The method of screening targets based on the simultaneous action of multiple PCBs can provide a reference for other research. The targets were not found in previous metabolite toxicity studies. It also provides a bridge for the toxic effects and experimental research of PCBs and their metabolites in the future.

Developmental exposure to indoor flame retardants and hypothalamic molecular signatures: Sex-dependent reprogramming of lipid homeostasis.

Polybrominated diphenyl ethers (PBDEs) are a class of flame-retardant organohalogen pollutants that act as endocrine/neuroendocrine disrupting chemicals (EDCs). In humans, exposure to brominated flame retardants (BFR) or other environmentally persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) and novel organophosphate flame retardants has been associated with increasing trends of diabetes and metabolic disease. However, the effects of PBDEs on metabolic processes and their associated sex-dependent features are poorly understood. The metabolic-disrupting effects of perinatal exposure to industrial penta-PBDE mixture, DE-71, on male and female progeny of C57BL/6N mouse dams were examined in adulthood. Dams were exposed to environmentally relevant doses of PBDEs daily for 10 weeks (p.o.): 0.1 (L-DE-71) and 0.4 mg/kg/d (H-DE-71) and offspring parameters were compared to corn oil vehicle controls (VEH/CON). The following lipid metabolism indices were measured: plasma cholesterol, triglycerides, adiponectin, leptin, and liver lipids. L-DE-71 female offspring were particularly affected, showing hypercholesterolemia, elevated liver lipids and fasting plasma leptin as compared to same-sex VEH/CON, while L- and H-DE-71 male F1 only showed reduced plasma adiponectin. Using the quantitative Folch method, we found that mean liver lipid content was significantly elevated in L-DE-71 female offspring compared to controls. Oil Red O staining revealed fatty liver in female offspring and dams. General measures of adiposity, body weight, white and brown adipose tissue (BAT), and lean and fat mass were weighed or measured using EchoMRI. DE-71 did not produce abnormal adiposity, but decreased BAT depots in L-DE-71 females and males relative to same-sex VEH/CON. To begin to address potential central mechanisms of deregulated lipid metabolism, we used RT-qPCR to quantitate expression of hypothalamic genes in energy-regulating circuits that control lipid homeostasis. Both doses of DE-71 sex-dependently downregulated hypothalamic expression of Lepr, Stat3, Mc4r, Agrp, Gshr in female offspring while H-DE-71 downregulated Npy in exposed females relative to VEH/CON. In contrast, exposed male offspring displayed upregulated Stat3 and Mc4r. Intestinal barrier integrity was measured using FITC-dextran since it can lead to systemic inflammation that leads to liver damage and metabolic disease, but was not affected by DE-71 exposure. These findings indicate that maternal transfer of PBDEs disproportionately endangers female offspring to lipid metabolic reprogramming that may exaggerate risk for adult metabolic disease.

Feed as a source of dioxins and PCBs.

Dioxins (PCDD/PCDF) and polychlorinated biphenyls (PCBs) are a group of undesirable chemicals classified as persistent organic pollutants (POPs). The main route of human exposure to these compounds is through the diet (about 80%), with food of animal origin being the predominant source. For this reason, animal feed can contribute significantly to the presence of these compounds in food. The aim of this study was to present the concentrations of dioxins and PCBs as well as congener profiles in feed exceeding the acceptable limits (277/2012/EU). In addition, an attempt was made to identify the source of contamination for the different types of contaminated feedstuffs. Among a total of 743 samples of feed materials from the Polish market tested between 2013 and 2021, exceedances of the maximum levels of dioxins and PCBs were found in 21 samples (2.8%). The largest group among the non-compliant feed samples were feed materials of plant origin (43%) followed in decreasing order by vegetable oils and fats of animal origin (24%), materials of mineral origin (9%), and fish oils and meals (5%). The exceedances of the dioxin limits in the category feed materials of plant origin were only caused by dried materials (pulp, dried alfalfa, dried apple). Furthermore, for 8 (1%) samples, the concentrations of test substances exceeding the Action Levels (AL) were recorded.

Gestational PCB52 exposure induces hepatotoxicity and intestinal injury by activating inflammation in dam and offspring mice: A maternal and progeny study.

Although Polychlorinated biphenyl (PCB) levels are decreased in the environment, the adverse effects of gestational exposure on the mother and offspring cannot be ignored due to the vulnerability of the fetus. In the present study, pregnant Balb/c mice were administered PCB52 (1 mg/kg BW/day) or corn oil vehicle by gavage until parturition. In the dams, PCB52 caused histopathological changes in the liver, higher serum levels of aminotransferase and alanine aminotransferase, and activated apoptosis and autophagy, suggesting hepatotoxicity. Overexpressed indicators of TLR4 pathway were observed in the liver of PCB52-exposed dams, indicated hepatic inflammation. Moreover, PCB52 exposure weakened the intestinal barrier and triggered inflammatory response, which might contribute to the hepatic inflammation by gut-liver axis. In the pups, prenatal PCB52 exposure affected the sex ratio at birth and reduced birth length and weights. Similar to the dams, prenatal PCB52 exposure induced hepatotoxicity in the pups without gender difference. Consistent with the alteration of gut microbiota, intestinal inflammation was confirmed, accompanying the disruption in the intestinal barrier and the activation of apoptosis and autophagy in the PCB52-exposed pups. Intestinal injury might be responsible for hepatotoxicity at least in part. Taken together, these findings suggested that gestational PCB52 exposure induced hepatic and intestinal injury in both maternal and offspring mice by arousing inflammation.

Impact of chronic exposure to legacy environmental contaminants on the corpus callosum microstructure: A diffusion MRI study of Inuit adolescents.

Exposure to environmental contaminants is an important public health concern for the Inuit population of northern Québec, who have been exposed to mercury (Hg), polychlorinated biphenyls (PCBs) and lead (Pb). During the last 25 years, the Nunavik Child Development Study (NCDS) birth cohort has reported adverse associations between these exposures and brain function outcomes. In the current study, we aimed to determine whether contaminant exposure is associated with alterations of the corpus callosum (CC), which plays an important role in various cognitive, motor and sensory function processes. Magnetic resonance imaging (MRI) was administered to 89 NCDS participants (mean age ± SD = 18.4 ± 1.2). Diffusion-weighted imaging was assessed to characterize the microstructure of the CC white matter in 7 structurally and functionally distinct regions of interest (ROIs) using a tractography-based segmentation approach. The following metrics were computed: fiber tract density, fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD). Multiple linear regression models adjusted for sex, age, current alcohol/drug use and fish nutrients (omega-3 fatty acids and selenium) were conducted to assess the association between diffusion-weighted imaging metrics and Hg, PCB 153 and Pb concentrations obtained at birth in the cord blood and postnatally (mean values from blood samples at 11 and 18 years of age). Exposures were not associated with fiber tract density. Nor were significant associations found with cord and postnatal blood Pb concentrations for FA. However, pre- and postnatal Hg and PCB concentrations were significantly associated with higher FA of several regions of the CC, namely anterior midbody, posterior midbody, isthmus, and splenium, with the most pronounced effects observed in the splenium. FA results were mainly associated with lower RD. This study shows that exposure to Hg and PCB 153 alters the posterior microstructure of the CC, providing neuroimaging evidence of how developmental exposure to environmental chemicals can impair brain function and behavior in late adolescence.

A multipollutant low-grade exposure regulates the expression of miR-30b, Let-7a and miR-223 in maternal sera: Evidence from the NEHO cohort.

There is growing evidence that environmental pollutants can induce epigenetic modifications altering the balance of miRNAs and inducing the onset of pathological conditions in animals. In this study, we measured the serum concentration of a suite of inorganic and organic pollutants (Cu, Zn, Se, Hg, HCB, p,p'-DDE, PCBs) and their association to serum miR-30b, miR-223 and Let-7a microRNA expression in 68 healthy pregnant women from the NEHO birth cohort sited in a highly industrialized area. The effects of the pollutants on the modulation of circulating miRNAs' expression were first investigated using linear continuous regression models with a single-compound approach showing that miR-223 expression was significantly associated with serum concentration of Se and Zn (pSe = 0.0336; pZn = 0.0225) and miR-30b was associated with Hg levels (pHg = 0.019). Furthermore, when contaminants were categorized into tertiles, miR-223 and miR-30b showed a positive association with higher tertiles of Zn, p,p'-DDE (pZn = 0.023; pDDE = 0.041) and Hg (pHg = 0.008), respectively. Moreover, Let-7a expression was exclusively influenced by medium tertiles levels of Se (low vs medium tertiles, p = 0.001). Simultaneous exposure to multi-pollutant mixture was approached by WQS regression model. Statistical analysis shows a driving effect of Zn, Se, Cu, Hg and HCB on significant increased expression of Let-7a (p = 0.045). Mercury and Se significantly amplified the expression for miR-30b (p = 0.038). Differently, the combined effect of p,p'-DDE, Zn and Se decreased miR-223 expression (p = 0.0001). The documented modified expression of circulating miRNAs in the serum of pregnant women, exposed to low-medium dose contaminants mixtures offers innovative early-warning approaches to human health risk assessment.

The influence of anaerobic dechlorination on the aerobic degradation of PCBs in e-waste-contaminated soils in an anaerobic-aerobic two-stage treatment.

The combination of microbial reductive dechlorination and aerobic oxidation (RD-AO) process was proposed to be a promising strategy for extensive bioremediation of highly chlorinated polychlorinated biphenyls (PCBs). Nonetheless, experimental evidence on the impact of the RD on subsequent AO in anaerobic-aerobic two-stage treatment remains scarce. The present study applied stable-isotope probing (SIP) to explore the RD-AO mediated degradation of PCBs in an e-waste-contaminated soil. The RD-AO treatment resulted in 37.1 % and 48.2 % degradation of PCB180 and PCB9, respectively, while the PCB9 degradation efficiency decreased compared to the sole AO (81.2 %). The inhibition of PCB aerobic degradation might be caused by the alteration of aerobic bacterial community, which was proved by a higher abundance of anaerobic bacteria and a lower abundance of aerobic bacteria being observed in the aerobic stage of RD-AO. Further evidence was obtained using DNA-SIP that the anaerobic stage altered the PCB degraders' community structures and changed three of the five degraders. There were four lineages (Arenimonas, Steroidobacter, Sulfurifustis, and Thermoanaerobacterales) identified as PCB degraders for the first time. Interestingly, three of them were found in RD-AO microcosm, suggesting that anaerobic-aerobic two-stage treatment can recruit novel bacteria involved in PCBs aerobic degradation. The present study provided novel insight into the synergistic integration of anaerobic and aerobic processes for extensive degradation of highly chlorinated PCBs.

Pollution and edaphic factors shape bacterial community structure and functionality in historically contaminated soils.

Studies about biodegradation potential in soils often refer to artificially contaminated and simplified systems, overlooking the complexity associated with contaminated sites in a real context. This work aims to provide a holistic view on microbiome assembly and functional diversity in the model site SIN Brescia-Caffaro (Italy), characterized by historical and uneven contamination by organic and inorganic compounds. Here, physical and chemical analyses and microbiota characterization were applied on one-hundred-twenty-seven soil samples to unravel the environmental factors driving bacterial community assembly and biodegradation potential in three former agricultural fields. Chemical analyses showed a patchy distribution of metals, metalloids and polychlorinated biphenyls (PCB) and allowed soil categorization according to depth and area of collections. Likewise, the bacterial community structure, described by molecular fingerprinting and 16S rRNA gene analyses, was significantly different according to collection site and depth. Pollutant concentrations (i.e., hexachloro-biphenyls, arsenic and mercury), nitrogen content and parameters related to soil texture were identified as main drivers of microbiota assembly, being significantly correlated to bacterial community composition. Moreover, bacteria putatively involved in the aerobic degradation of PCBs were enriched over the total bacterial community in topsoils, where the highest activity was recorded using fluorescein hydrolysis as proxy. Metataxonomic analyses revealed the presence of bacteria having metabolic pathways related to PCB degradation and tolerance to heavy metals and metalloids in the topsoil samples collected in all areas. Overall, the provided dissection of soil microbiota structure and its degradation potential in the SIN Brescia-Caffaro can contribute to target specific areas for rhizoremediation implementation. Metagenomics studies could be implemented in the future to understand if specific degradative pathways are present in historically polluted sites characterized by the co-occurrence of multiple classes of contaminants.

Presence and risks of polycyclic aromatic hydrocarbons, dioxins and dioxin-like PCBs in dietary plant supplements as elucidated by a combined DR CALUX® bioassay and GC-HRMS based approach.

Plant-based dietary supplements may contain undesirable contaminants such as polycyclic aromatic hydrocarbons, dioxins and dioxin-like polychlorinated biphenyls (dl-PCBs) due to the sources of raw materials or processing methods used. The presence of these contaminants in a series of herbal supplements sold on the Ghanaian market for improving sexual performance was examined using the DR CALUX® bioassay in combination with GC-HRMS analysis. Overall, cell responses at 4 and 48 h exposure to extracts prepared without an acid-silica clean-up were relatively higher than the responses obtained from extracts prepared with an acid-silica clean-up. This indicated that the 40 supplements contained only low levels of stable aryl hydrocarbon receptor (AhR) agonists like polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dl-PCBs, while some contained substantial amounts of less stable AhR-agonists. Ten supplements selected for confirmation with GC-HRMS analysis contained PCDD/Fs and dl-PCBs at levels ranging from 0.01 to 0.19 pg toxic equivalent (TEQ)/g only, while the level of the sum of 4 polycyclic aromatic hydrocarbons (Σ4PAHs) representing less stable AhR agonists, ranged from not detected (ND) to 25.5 ng/g. These concentrations were in line with the responses observed in the DR CALUX® bioassay. The concentration of PCDD/Fs and dl-PCBs corresponded to estimated daily intakes (EDIs) ranging from 0.01 to 1.20 pg TEQ/day, or 0.001 to 0.12 pg TEQ/kg bw/week for a 70 kg bw consumer, which was below the established tolerable weekly intake (TWI) of 2 pg TEQ/kg bw/week, thus indicating low concern for consumers' health. Similarly, the EDIs based on the detected Σ4PAHs in supplements ranged from 7.2 to 111 ng/day, or 0.1 to 1.6 ng/kg bw/day, which corresponded to MOE values above 10,000, indicating a low health concern.

Concentration levels and an assessment of human health risk of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in honey and pollen.

Persistent organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) accumulate in the food chain due to their physical and chemical properties and adversely affect human health. For this reason, this study aimed to determine the PAH and PCB concentration levels in pollen and honey samples in urban and semi-urban areas and to evaluate the risk of cancer that may occur by ingestion in Bursa, Turkey. The average total concentrations of 14 PAH (∑14PAH) compounds in pollen and honey samples were found to be 304.3 ± 192.3 ng/g (average ± standard deviation) and 650.2 ± 118.1 ng/g for the urban area, and 329.6 ± 160.6 ng/g and 464.3 ± 66.4 ng/g for the semi-urban area, respectively. Similarly, ∑14PCB concentrations in pollen and honey samples were found to be 8.7 ± 3.6 ng/g and 13.0 ± 4.8 ng/g for the urban area and 7.7 ± 2.2 ng/g and 17.4 ± 4.0 ng/g for the semi-urban area, respectively. It was determined that the pollen and honey samples in both sampling areas were affected by local PCB sources. The Pearson correlation coefficient (PCC) method determined the relationship between pollen and honey samples. According to the PCC values obtained, it was observed that pollen and honey in both sampling regions exhibited a significant relationship with each other. Finally, while there was no cancer risk for PCBs due to ingestion of honey and pollen in both sampling areas, acceptable cancer risk has been calculated for PAHs.

Dioxin-like polychlorinated biphenyl 126 (PCB126) disrupts gut microbiota-host metabolic dysfunction in mice via aryl hydrocarbon receptor activation.

Exposure to environmental pollutants, including dioxin-like pollutants, can cause numerous health issues. A common exposure route to pollutants is through contaminated foods, and thus the gastrointestinal system and gut microbiota are often exposed to high amounts of pollutants. Multiple studies have focused on the imbalance in intestinal microbiota composition caused by dioxin-like pollutants. Here, we examined the effects of polychlorinated biphenyl 126 (PCB126) on the composition and functions of gut microbes through metagenomic sequencing, and explored the correlations between microflora dysbiosis and aryl hydrocarbon receptor (AHR) signaling. Adult male wild-type and Ahr-/- mice with a C57BL/6 background were weekly exposed to 50 µg/kg body weight of PCB126 for 8 weeks. Results showed that PCB126 had the opposite effect on gut microbiota composition and diversity in the wild-type and Ahr-/- mice. Functional prediction found that PCB126 exposure mainly altered carbon metabolism and signal regulatory pathways in wild-type mice but impacted DNA replication and lipopolysaccharide biosynthesis in Ahr-/- mice. In wild-type mice, PCB126 exposure induced liver injury, decreased serum lipid content, and delayed gastrointestinal motility, which were significantly correlated to several specific bacterial taxa, such as Helicobacter. Following AHR knockout, however, the holistic effects of PCB126 on the host were lessened or abolished. These results suggest that PCB126 may disrupt host metabolism and gut microbiota dynamics via AHR activation. Overall, our findings provide new insight into the complex interactions between host metabolism and gut microbiota, which may contribute to grouped assessment of environmental pollutants in the future.

Comprehending the Role of Endocrine Disruptors in Inducing Epigenetic Toxicity.

Endocrine disruptors are natural or man-made chemicals that interfere with the body's endocrine system leading to hormone synthesis and production defects. These chemicals are categorized as plasticizers and cosmetic chemicals, heavy metals, phytoestrogens, pesticides, detergents, surfactants, and flame retardants. Some of the most common endocrine disruptors are dioxins, bisphenol A, phthalates, perchlorate, perfluoroalkyl, and poly-fluoroalkyl substances (PFAs), phytoestrogens, polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCB), triclosan, atrazine, lead, arsenic, mercury, organophosphate pesticides, and glycol ethers. Epigenetic alterations such as DNA methylation, histone modification, and miRNA regulation have been observed to play a major role in many diseases such as cancer, neurodegenerative diseases, PCOS, cardiovascular diseases, and various other disorders. In recent times, there has been a focus on endocrine-disrupting chemicals in epigenetic alterations. This review concentrates on estrogen and androgen disrupting effects, placental, and fetal effects, thyroid disrupting effects, and transgenerational effects of endocrine disruptors.