Search Results (124)

Developmental exposure to polybrominated diphenyl ethers (PBDEs), which are commonly used as flame retardants, results in irreversible cognitive impairments. Postnatal hippocampal neurogenesis, which occurs in the subgranular zone (SGZ) of the dentate gyrus, is critical for neuronal circuits and plasticity. Wnt7a-Frizzled5 (FZD5) is essential for both neurogenesis and synapse formation; moreover, Wnt signaling participates in PBDE neurotoxicity and also contributes to the neuroprotective effects of melatonin. Therefore, we investigated the impacts of perinatal decabromodiphenyl ether (BDE-209) exposure on hippocampal neurogenesis and synaptogenesis in juvenile rats through BrdU injection and Golgi staining, as well as the alleviation of melatonin pretreatment. Additionally, we identified the structural basis of Wnt7a and two compounds via molecular docking. The hippocampal neural progenitor pool (Sox2+BrdU+ and Sox2+GFAP+cells), immature neurons (DCX+) differentiated from neuroblasts, and the survival of mature neurons (NeuN+) in the dentate gyrus were inhibited. Moreover, in BDE-209-exposed offspring rats, it was observed that dendritic branching and spine density were reduced, alongside the long-lasting suppression of the Wnt7a-FZD5/β-catenin pathway and targeted genes (Prox1, Neurod1, Neurogin2, Dlg4, and Netrin1) expression. Melatonin alleviated BDE-209-disrupted memory, along with hippocampal neurogenesis and dendritogenesis, for which the restoration of Wnt7a-FZD5 signaling may be beneficial. This study suggested that melatonin could represent a potential intervention for the cognitive deficits induced by PBDEs. Full article

Soil washing is an efficient method to remove polybrominated diphenyl ethers (PBDEs) from contaminated soils. The obtained solutions from soil-washing still contain PBDEs, requiring further treatment before disposal or reuse. Although photolysis is effective for PBDE degradation in solutions, the concurrent formation of toxic polybrominated dibenzofurans (PBDFs) may limit its practical application. In this study, 2,8-dibromodibenzofurans (2,8-BDF) formation rate and mechanisms during 2,4,4′-tribromodiphenyl ether (BDE-28) photolysis in various simulated soil-washing solutions was investigated. Results revealed significant effects of solubilizers on 2,8-BDF formation. The nonionic surfactants polysorbate (TW80), polyoxyethylene octylphenyl ether (TX series), and the cationic surfactant cetyltrimethylammonium bromide (CTAB) resulted in low 2,8-BDF formation rate (1–5%), while the β-cyclodextrin led to the highest 2,8-BDF formation rate (about 28%). The nonionic surfactants polyoxyethylene dodecyl ethers (Brij series), and the anionic surfactants sodium dodecylbenzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS), also showed a high level of 2,8-BDF formation rate (7–17%). Solubilizer structure and its interaction with BDE-28 determined the 2,8-BDF formation. The role of the micelle microenvironment on 2,8-BDF formation was verified via an experiment and molecular dynamics simulation. The organic region of micelle exhibited high hydrogen donation ability, which inhibited 2,8-BDF formation. The results indicated distinct risks of PBDE photolysis in various soil-washing solutions, providing an important reference for solubilizer selection and the application of photolysis on the treatment of soil-washing solutions containing PBDEs. Full article

Due to the unregulated handling of e-waste, the co-existence of PBDEs and heavy metals in water bodies and soil has been detected with high frequency. However, the combined toxicity for aquatic creatures remains unclear. This study investigated the single and combined stress of BDE3 and copper on the photosynthesis and antioxidant enzyme system of Salvinia natans (L.). The results indicated that there were no negative effects on photosynthetic pigments under single stress of BDE3 or combined stress with copper. However, to deal with oxidative stress, antioxidant defense enzymes, including SOD and CAT, were activated in S. natans. SOD was sensitive in the first stage, while CAT activity was significantly increased until the end of 14 days of incubation. Malondialdehyde content increased significantly, which indicated that excessive reactive oxygen species from pollution of BDE3 or coexistence with copper could not be eliminated. BDE3 concentration in the aqueous phase declined with time, while copper was accumulated over time in S. natans, with BCF increasing to 0.31 ± 0.073 at the end. Our study indicated that the co-existence of copper could exacerbate the damage caused by BDE3 to S. natans in aqueous environment. Full article

Polybrominated diphenyl ethers (PBDEs) are synthetic halogen compounds, industrially used as flame retardants in many flammable products. PBDEs are environmentally persistent and bioaccumulative substances that were used from the 1970s and discontinued in the 1990s. PBDEs are present in air, soil, water, and food, where they remain stable for a long time. Chronic exposure to PBDEs is associated with adverse human health effects, including cancer, immunotoxicity, hepatotoxicity, reproductive and metabolic disorders, motor and hormonal impairments, and neurotoxicity, especially in children. It has been demonstrated that PBDE exposure can cause mitochondrial and DNA damage, apoptosis, oxidative stress, epigenetic modifications, and changes in calcium and neurotransmitter levels. Here, we conduct a comprehensive review of the molecular mechanisms of the neurotoxicity of PBDEs using different approaches. We discuss the main neurotransmitter pathways affected by exposure to PBDEs in vitro and in vivo in different mammalian models. Excitatory and inhibitory signaling pathways are the putative target where PBDEs carry out their neurotoxicity. Based on this evidence, environmental PBDEs are considered a risk to human public health and a hazard to biota, underscoring the need for environmental monitoring to mitigate exposure to PBDEs. Full article

Organophosphate flame retardants (OPFRs) have increasingly replaced polybrominated diphenyl ethers (PBDEs) in various consumer products and raw materials, due to regulatory restrictions on PBDEs. However, concerns about the toxicity and environmental persistence of OPFRs are growing. This review summarizes current research on the toxicity of OPFRs, with a focus on New Approach Methodologies (NAMs) that aim to eliminate the need for animal testing. NAMs, including in vitro models, omics technologies, and computational methods, provide valuable insights into the cellular and molecular effects of OPFR exposure. Evidence suggests that OPFRs may disrupt multiple organ systems, including the nervous, hepatic, pulmonary, reproductive, and endocrine systems. Additionally, the metabolic transformation of OPFRs can increase their toxicity, raising concerns about long-term exposure risks. While NAM studies provide valuable insights, further research is needed to refine risk-assessment frameworks and improve our understanding of the long-term effects of OPFR exposure, particularly at concentrations found in the environment. This new knowledge will help develop more accurate regulatory guidelines and ensure the better protection of public and environmental health. Full article

Background: Preeclampsia (PE) is a critical complication of pregnancy that affects 3% to 5% of all pregnancies and has been linked to aberrant placentation, causing severe maternal and fetal illness and death. Objectives: This systematic review aims to elucidate the association of in-utero endocrine-disrupting chemical (EDC) exposure and microRNAs and their imprinted genes from prenatal and maternal circulation of PE patients. Methods: Databases such as PubMed, PubMed Central, ScienceDirect, the Comparative Toxicogenomics Database (CTD), ProQuest, EBSCOhost, and Google Scholar were utilized to search for articles that investigate the relationships between selected EDCs and epigenetic events such as DNA methylation and microRNAs that are associated with PE. Results: A total of 29 studies were included in the database search. Altered expression of microRNAs (miR-15a-5p, miR-142-3p, and miR-185) in the placenta of PE patients was positively associated with the urinary concentration of phthalates and phenols in the development of the disease in the first trimester. EDCs such as phenols, phthalates, perfluoroalkyl substances (PFOAs), polybrominated diphenyl ethers (PBDEs), and organochlorine phosphates (OCPs) have been reported to be associated with hypertensive disorders in pregnancy. miRNA-31, miRNA-144, miRNA-145, miRNA-210, placental specific clusters (C14MC, and C19MC) may be used as possible targets for PE because of their potential roles in the onset and progression of PE. Conclusions: Prenatal EDC exposure, including exposure to BPA, showed association with signaling pathways including estrogen, sFlt-1/PlGF, ErbB, MAPK/ERK, and cholesterol mechanisms with placental hemodynamics. Even low EDC exposures leave altered epigenetic marks throughout gestation, which might cause PE complications. Full article

Polybrominated diphenyl ethers (PBDEs), a type of brominated flame retardant, are of global concern due to their environmental persistence, bioaccumulation, toxicity, and resistance to conventional remediation methods. In this study, the electrochemical reduction of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) with Pd/Metal foam electrodes (Ni, Cu, and Ag) was investigated. The effect of Pd loadings was explored, and the results show that Pd loading enhances the debromination performance, with 15.16%Pd/Ni foam exhibiting the best efficiency, followed by 9.37%Pd/Cu and 10.26%Pd/Ag. The degradation mechanisms for Pd/Ni and Pd/Ag are primarily hydrogen atom transfer, while for Pd/Cu, electron transfer dominates. Among the reduction products, Pd/Ni foam shows the highest debromination capability. The impact of electrolytes, current intensity, and bromination degrees of PBDEs was evaluated for 15.16%Pd/Ni. The results reveal that the presence of electrolytes inhibits BDE-47 degradation; the degradation rate of BDE-47 increases with current density, peaks at 4 mA, and decreases as current rises; and 15.16%Pd/Ni foam can effectively degrade PBDEs with varying bromination levels. Additionally, cycling tests show a decrease in efficiency from 94.3% (first cycle) to 56.58% (fourth cycle), attributed to Pd loss and structural damage. The findings offer valuable insights for developing efficient, sustainable catalytic materials for the electrochemical degradation of PBDEs and other persistent organic pollutants. Full article

The prevalence of hyperthyroidism in cats has been steadily increasing worldwide since the late 1970s. The main cause of feline hyperthyroidism remains unknown. The underlying cause was studied from the viewpoint of the “One Health” concept, which is an approach integrating environmental, animal and human health. Looking at the dietary difference between cats which are carnivores and dogs which appear to be omnivores like humans, there is a possibility that cats take in a comparatively greater amount of endocrine-disrupting chemicals such as polybrominated diphenyl ethers (PBDEs) than dogs and humans via the fish-based food web. PBDEs have been used worldwide as flame retardants since the 1970s. It is considered that PBDEs mimic thyroid-stimulating hormones to cause a thyroid adenoma, which is often active and produces excessive thyroid hormones, resulting in symptomatic hyperthyroidism. The increasing prevalence of feline hyperthyroidism may be associated with Minamata disease that was caused by methyl-mercury contamination in the 1950s. This environmental contamination firstly wreaked havoc as neurological disorders in local cats, and this occurrence was a sign that severe neurological disorders would next develop in large numbers of local people. The prevalence of feline hyperthyroidism may be a sign of what will next emerge in human beings. Full article

Microorganisms play a significant role in biofouling and biocorrosion within the maritime industry. Addressing these challenges requires an innovative and integrated approach utilizing marine natural products with beneficial properties. A comprehensive screening of 173 non-toxic EtOAc and H₂O extracts derived from diverse marine organisms collected in Indonesian waters was conducted using a robust panel of assays. These included antimicrobial tests and classical biosurfactant assays (drop collapse and oil displacement), as well as anti-quorum-sensing (QS) and anti-biofilm assays. These screening efforts identified five active extracts with promising activities. Among these, EtOAc extracts of the marine tunicate Sigilina cf. signifera (0159-22e) and the marine sponge Lamellodysidea herbacea (0194-24c) demonstrated significant anti-biofouling activity against Perna indica and anti-biocorrosion performance (mpy 10.70 ± 0.70 for S. cf. signifera; 7.87 ± 0.86 for L. herbacea; 13.60 ± 1.70 for positive control Tetracorr CI-2915). Further chemical analyses of the active extracts, including LC-HR-MS/MS, MS-based molecular networking, and chemoinformatics, revealed the presence of both known and new bioactive compounds. These included tambjamines and polybrominated diphenyl ethers (PBDEs), which are likely contributors to the observed bioactivities. Subsequent investigations uncovered new anti-QS and anti-biofilm properties in synthetic and natural PBDEs 1–12 previously derived from L. herbacea. Among these, 8 exhibited the most potent anti-QS activity, with an IC₅₀ value of 15 µM, while 4 significantly reduced biofilm formation at a concentration of 1 µM. This study highlights the potential of marine-derived compounds in addressing biofouling and biocorrosion challenges in a sustainable and effective manner. Full article

Polybrominated diphenyl ethers (PBDEs) are natural products with potent antimicrobial and antineoplastic activity. We have previously shown that the polybrominated diphenyl ether bromoxib (4,5,6-tribromo-2-(2′,4′-dibromophenoxy) phenol), isolated from the marine sponge Dysidea species, exhibits a strong cytotoxic potential in leukemia and lymphoma cells by targeting mitochondrial metabolism. Here, using a mass spectrometric thermal proteome profiling (TPP) approach, we observed that bromoxib induces a rapid reduction in the levels of 19 nucleoporins (NUPs) that are part of the nuclear pore complex (NPC). This apparently affected the functionality of the NPC, as evidenced by the bromoxib-mediated inhibition of the nuclear translocation and subsequent gene reporter activity of transcription factors such as nuclear factor of activated T cells (NFAT) and nuclear factor κB (NF-κB). In addition, bromoxib inhibited the nuclear export of the mRNA of the human immunodeficiency virus transactivator of transcription (HIV-Tat) and the subsequent import of the HIV-Tat protein into the nucleus as determined by the decrease in Tat-dependent gene reporter luciferase activity. Inhibition of nuclear mRNA-export also affected expression of the short-lived anti-apoptotic Bcl-2 protein Mcl-1, which has been shown to induce apoptosis. Thus, its ability to target both mitochondrial metabolism and the NPC renders bromoxib a promising anticancer agent. Full article

Current studies have paid extensive attention to the occurrence of brominated flame retardants (BFRs) in aquatic environments; however, there is a lack of exploration of BFRs in ice media in freshwater environments, and there are fewer studies on the distribution patterns and ecological risks of BFRs in different media. In order to fill this gap in the current research status, this study conducted four seasonal samplings in the Songhua River wetland in Northeast China. The distribution and risk of 14 polybrominated diphenyl ethers (PBDEs) and 22 new brominated flame retardants (NBFRs) in water, ice, sediment, and soil were analyzed using liquid–liquid extraction sample pretreatment and gas chromatography–mass spectrometry instrumentation. A total of 18, 5, 8, 19, and 18 BFRs were detected in non-ice-covered water, ice-covered water, ice, sediment, and soil, respectively. NBFRs dominated contaminant concentrations in each medium. Significant correlations were found between BFRs in ice and subglacial water, suggesting that the sources of BFRs in these two media are similar and there is an exchange between them. The ice enrichment factor (IEF) revealed the water–ice distribution mechanism of BFRs, indicating that wetland ice acts as a temporary sink for 2-(Allyloxy)-1,3,5-tribromobenzene (ATE), 1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane (α-TBECH), 1,2,5,6-Tetrabromocyclooctane (TBCO), and 2-Bromoallyl 2,4,6-tribromophenyl ether (BATE). In order to achieve dynamic equilibrium, the exchange profile of BFRs between water and sediment requires the release of BFRs into water. The risk quotient (RQ) indicated that TBCO in water and ice poses a moderate risk to aquatic organisms, and its potential impact on wetland ecology cannot be ignored. Full article

Heavy metal-organic pollutants compound pollution at industrial legacy sites and have caused damage to the ecological environment and human health during recent decades. In view of the difficulty and high cost of post-contamination remediation, it is worth studying, and practically applying, cutoff walls to reduce the spread of pollution in advance. In this study, field-scale studies were carried out at e-waste dismantling legacy sites in Taizhou, Zhejiang Province of China, through the process of site investigation, numerical simulation, and cutoff wall practical application. Firstly, the concentrations and spatial distributions of Pb, Cd and polychlorinated biphenyls (PCBs) and poly brominated diphenyl ethers (PBDEs) were identified in both soil and groundwater. Then, potential dispersal routes of key combined contaminants (Pb and PCBs) at the soil–groundwater interface were systematically studied through numerical simulation applying Visual MODFLOW-MT3DMS. One site was chosen to predict the barrier effect of differently sized cutoff walls based on the migration path of compound pollutants. A protocol for a cutoff wall (50 m length × 2 m width × 3 m height) was finally verified and applied at the real contaminated site for the blocking of compound pollutant diffusion. Further, the groundwater quality of the contaminated site was monitored consecutively for six months to ensure the durability and stability of barrier measures. All pollutant indicators, including for Pb and PCB complex pollutants, were reduced to below the national Grade IV groundwater standard value, achieving environmental standards at these polluted sites and providing possibilities for land reuse. In summary, this field-scale test provided new ideas for designing cutoff walls to block the diffusion of complex pollutants; it also laid a basis for the practical application of cutoff walls in pollution prevention and control of complex contaminated sites and for soil–groundwater environmental protection at industrial heritage sites. Full article

Background: Brominated flame retardants (BFRs) are a type of widespread pollutant that can be transmitted through particulate matter, such as dust in the air, and have been associated with various adverse health effects, such as diabetes, metabolic syndrome, and cardiovascular disease. However, there is limited research on the link between exposure to mixtures of BFRs and depression in the general population. Methods: To analyze the association between exposure to BFRs and depression in the population, nationally representative data from the National Health and Nutrition Examination Survey (NHANES; 2005–2016) were used. In the final analysis, a total of 8138 adults aged 20 years and older were included. To investigate the potential relationship between BFRs and outcomes, we used binary logistic regression, restricted cubic spline (RCS), quantile-based g computation (QGC), and weighted quantile sum (WQS) regression. Results: The findings showed that serum BFR concentrations were associated with depressive symptoms over a broad spectrum. Binary logistic regression and RCS analysis showed that certain BFRs, particularly PBB153, were significantly and positively associated with the incidence of depression, even after adjustment for various confounders (p < 0.05). Mixed exposure to BFRs was also found to be associated with depression in the population, with a stronger association in men. The two most influential BFRs, PBB153 and PBDE85, were identified in both mixed exposure models and are potential risk factors of concern. Conclusion: Our study identified new insights into the relationship between BFRs and depression, but sizable population-based cohort studies and toxicology mechanism studies will be needed to establish causality. Full article

Background: Emerging studies demonstrate that exposure to brominated flame retardants (BFRs) can have harmful effects on human health. Our study focused on the relationship between exposure to various BFRs and markers of liver function. Methods: To further explore the association between BFR exposure and liver function impairment, we used data from the National Health and Nutrition Examination Surveys (NHANES) for three cycles from 2009 to 2014, leaving 4206 participants (≥20 years of age) after screening. Nine BFRs and eight liver function tests (LFTs) were measured in the participants’ serum to represent BFRs and liver function impairment in vivo. To investigate whether there is a relationship between BFRs and health outcome, statistical research methods such as the weighted linear regression model, restricted cubic spline (RCS), weighted quantile sum (WQS), quantile-based g computing (QGC), and the Bayesian Kernel Machine Regression (BKMR) were used to evaluate the correlation between serum BFRs and LFTs. Results: The studies reveals that exposure to BFRs is associated with liver function biomarkers. In a weighted linear regression model, we found that PBB153, PBDE99, PBDE154, PBDE209, PBDE85 exposure was positively correlated with AST, ALT, GGT, ALP, TP, and SL risk. In RCS model, the nonlinear relationships between PBB153 and AST, ALT, and GGT and PBDE209 and ALT and TP are the most significant. The exposure to combined BFRs was positively correlated with AST, ALT, and GGT in WQS and QGC models. BKMR analysis showed that BFR exposure was positively correlated with AST, ALT, ALP, and GGT. Conclusions: Exposure to BFRs is associated with liver function impairment, suggesting that BFR exposure is potentially toxic to the human liver, but more in-depth studies are needed to explore this correlation. Full article

Background: The primary flame retardants in vehicles, organophosphates (OPEs) and polybrominated diphenyl ethers (PBDEs), volatilize and accumulate in the enclosed vehicle environment, posing potential health risks. Amidst the rising number of vehicles, the scrutiny of persistent organic pollutants like OPEs and PBDEs in vehicles is increasing. This study investigates occupational and nonoccupational population exposure to specific OPEs (TnBP, TBOEP, TEHP, TCEP, TCiPP, TDCiPP, TPhP, EHDPP) and PBDEs (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, BDE-209) in vehicle dust. Methods: Data on OPEs and PBDEs in vehicle dust were sourced from PubMed and Web of Science. We applied PCA and PMF to identify pollutant sources and assessed health risks using the hazard index (HI) and carcinogenic risk (CR) methods. Monte Carlo simulations were conducted for uncertainty analysis, evaluating variable contributions to the results. Results: The predominant OPE in dust samples was TDCiPP (mean value: 4.34 × 10⁴ ng g⁻¹), and the main PBDE was BDE-209 (mean value: 1.52 × 10⁴ ng g⁻¹). Potential sources of OPEs in vehicle dust include polyvinyl chloride (PVC) upholstery, polyurethane foam (PUF) seats, electronics, carpet wear, hydraulic oil, and plastic wear in the brake system. PBDE sources likely include automotive parts, PVC upholstery, seats, carpets, and electronics. The 90th percentile HI and CR values for occupational and nonoccupational populations exposed to OPEs and PBDEs indicate that the noncarcinogenic and carcinogenic risks are relatively low. A sensitivity analysis showed that the pollutant concentration, time in the vehicle, exposure frequency, and duration significantly influence health risks. Conclusions: The health risks to both occupational and nonoccupational populations from exposure to OPEs and PBDEs in vehicle dust are relatively low. Full article