Brominated Flame Retardants Research Articles

Quantification of persistent organic pollutants in breastmilk and estimated infant intake, Norway.

Persistent organic pollutants (POPs) are environmental contaminants that can accumulate in human tissues and pose potential health risks. Despite global efforts to reduce their prevalence, follow-up studies are needed to see if the measures are successful. Since most infants in Norway are breastfed for the first 6 months of life, monitoring POP contamination in breastmilk is important for children's health and development. This study aims to evaluate the current levels of various POPs in women's breastmilk in Innlandet County, Norway. A cross-sectional study was conducted measuring concentrations of 35 different POPs, including polychlorinated biphenyls (PCBs), chlordanes (ChlDs), hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), Mirex, and brominated flame retardants in 120 breastmilk samples. The study analysed the impact of maternal age, parity, pre-pregnancy BMI, and infant age on POPs levels and compared the estimated daily intake per body weight of infants to existing health guidelines. The detected percentages for PCBs were 100%, for DDTs 98.3%, and for ChlDs 98.3%. The highest median concentration was found for ΣPCBs (26.9 ng/g lw). Maternal age, parity, and infant age were significant determinants of POP concentrations. Most infants exceeded the health-based guidance values for ΣPCB, and 6.4% percent did so for ΣHCHs. Despite lower POPs concentrations in breastmilk than in earlier studies, many breastfed infants are still exposed to levels exceeding health-based guidance values. Although the study's design had limitations, the study provides updated population-based data on POPs in breastmilk. Continued monitoring and research are necessary to understand and mitigate potential health risks associated with POPs.

Comparative evaluation and QSAR modeling of developmental neurotoxicity of novel brominated flame retardants in zebrafish

The novel brominated flame retardants (NBFRs) have received wide concerns due to their ubiquitous occurrence in the environment and their potential risks to ecosystems and human health. However, the toxicity data of NBFRs are still lacking, especially their toxicity comparison data, and toxicity predictions for untested NBFRs are extremely limited. In this study, eight commonly used NBFRs and decabromodiphenyl ether (BDE209) were selected to compare their toxicity at concentrations between 0.03 and 3.69 μM, by exposing zebrafish embryos until 120 h post-fertilization (hpf) and evaluating 18 toxicity indicators including basic development indicators and a series of behavioral indicators. The toxicity potency of the tested compounds ranked by the total number of significantly affected endpoints were pentabromobenzene (PBB) ≈ 2,4,6-tribromophenol (TBP) > BDE209 ≈ bis(2-ethylhexyl) tetrabromophthalate (TBPH) > pentabromotoluene (PBT) ≈ 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB) > 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) > hexabromobenzene (HBB) > decabromodiphenyl ethane (DBDPE). Almost all the tested compounds affected the locomotor behavior of zebrafish larvae, suggesting that the refined behavioral indicators were sensitive endpoints. Furthermore, the quantitative structure-activity relationship (QSAR) model we developed suggested that molecular surface area (MSA) might be the critical factor for determining the developmental neurotoxicity of NBFRs to zebrafish larvae, except for congeners with larger molecules (e.g. DBDPE, BTBPE). These findings would contribute to elucidating the toxicity differences among various NBFRs and provide important references for their toxicity prediction.

Decabromodiphenyl ethane (DBDPE) inhibited the growth and feeding by disrupting the gut and digestive gland homeostasis in octopus Amphioctopus fangsiao (Mollusca: Cephalopoda)

A novel brominated flame retardant decabromodiphenyl ethane (DBDPE) poses a potential threat to animals, but its effects on cephalopods remain unknown. In this study, Amphioctopus fangsiao, a common octopus in China, was exposed to DBDPE (0, 1, 50, 100, 300 μg/L) for 28 days. Chemical analysis revealed that the digestive gland bore a greater burden of DBDPE compared with other tissues. In addition, accumulated DBDPE could curb the growth and feeding performance of A. fangsiao. The potential effects on the “gut-digestive gland axis” were also elucidated. Specifically, DBDPE in the gut shifted the microorganisms toward a Bacteroidetes-dominated composition, and impaired the intestinal epithelial barrier, thereby triggering oxidative stress and inflammation. Excessive DBDPE also threatens the digestive gland function, including histological damage, immune reaction, oxidative stress, glucolipid metabolism dysfunction, and neurotoxicity. Metabolome plasticity enabled A. fangsiao to develop a DBDPE stress-adaptive metabolic profile via alteration of glucolipid metabolism, immunity, oxidative stress, and signaling molecules. Taken together, we identified a new detoxification mechanism linking the microbiota-gut-digestive gland axis with the growth and food intake of A. fangsiao, which is the first time it has been demonstrated in mollusks. These findings provided important clues for a further mechanism study and risk assessment of DBDPE.

E-Waste and Hazardous Elements: A Comprehensive Study of Chemical Components and Environmental Threats

Electronic waste, or "e-waste," has grown significantly as a result of the exponential rise of electronic gadgets and is currently one of the waste streams with the fastest rate of growth in the world. Many dangerous substances, such as organic pollutants like brominated flame retardants and heavy metals like lead, mercury, and cadmium, can be found in e-waste. The chemical components of e-waste are thoroughly analyzed in this work, with an emphasis on the identification, measurement, and health and environmental effects of these hazardous materials. According to study, e-waste improper disposal and unofficial recycling can release dangerous substances into the environment, posing a major risk to human health including endocrine disruption and neurological damage. This can result in soil, water, and air contamination. The results highlight the necessity of more advanced recycling technology, stringent laws, and environmentally friendly design principles in order to reduce these hazards. This study adds to the expanding body of information on e-waste and urges immediate action to mitigate the risks that electronic trash poses to the environment and public health.

Degradation of Decabromodiphenyl Ether Dispersed in Poly (Acrylo-Butadiene-Styrene) Using a Rotatory Laboratory Pilot Under UV-Visible Irradiation

The growing volume of plastics derived from electronic waste (e-waste) underscores the imperative for environmentally sustainable strategies for the management of this waste. In light of the paramount importance of this issue, a pilot demonstrator for the decontamination of polymers containing Brominated Flame Retardants (BFRs) has been developed. The objective is to investigate the potential for decontaminating BFR-containing polymers from e-waste via UV-visible irradiation using a rotatory laboratory pilot operating under primary vacuum conditions. This report focuses on binary model blends composed of 90 weight% (wt%) poly(Acrylo-Butadiene-Styrene) (ABS) pellets and 10 wt% Deca-Bromo-Diphenyl Ether (DBDE), which is one of the most toxic BFRs. The efficiency of the irradiation process was evaluated as a function of pellet diameter and irradiation time using Fourier Transform InfraRed spectroscopy (FTIR) and High-Resolution Laser Desorption/Ionization Mass Spectroscopy (HR-LDI-MS). As a consequence, ABS + DBDE achieved a decontamination efficiency of 97% when irradiated with pellets of less than 1 mm in diameter for a period of 4 h. Additionally, the thermal behavior of the irradiated samples was investigated through thermogravimetric analysis and differential scanning calorimetry. It was thus established that the application of UV-visible irradiation had no significant impact on the overall thermal properties of ABS.

Emerging pollutants: Risks in salmon fish migration. A review

The release of pollutants into the environment is a serious ecological problem due to the significant risks they pose both to ecosystems and to human health. The review considers the issues of detection and distribution of new pollutants, as well as sources of their entry into the environment and potential impact on ecosystems. The problem of wastewater pollution is especially urgent in the context of conservation of salmonid fish species. Pharmaceutical and veterinary drugs, components of personal hygiene products, microplastics, per- and polyfluorinated substances, brominated flame retardants, oil and a number of other toxicants enter freshwater bodies, which are especially important for the early stages of the salmon development and its following migration. The presence of pollutants in the aquatic environment depends on a source, their ability to bioaccumulate, as well as to degrade in the processes of biological and abiotic purification. High-resolution mass spectrometry in combination with gas or liquid chromatography can be recommended for detection of new pollutants. Due to high mass measurement accuracy and high specificity, this method is able to effectively identify pollutants even in the complex fish matrix. When conducting non-targeted and targeted screening with highly sensitive full scanning, it is advisable to use high-resolution mass analyzers (TOF, Q-TOF, Q-Orbitrap), which allow determining a number of new compounds. A promising direction in the complex assessment of the impact of pollutants on salmon fish species and the identification of indicators characterizing this impact is metabolomics. It is based on the study of low-molecular organic compounds — metabolites, both intermediate and final metabolic products in body fluids and tissues. Metabolomic profiling allows identifying important markers of the state of a water body under the influence of pollutants, which is necessary for the development of comprehensive regulations and guidelines for the effective handling of these pollutants.

The association between brominated flame retardants exposure with Parkinson's disease in US adults: a cross-sectional study of the National Health and Nutrition Examination Survey 2009-2016.

Increasing evidence suggests that environmental factors play a crucial role in the pathogenesis of Parkinson's disease (PD). Humans are simultaneously exposed to multiple brominated flame retardants (BFRs) in the environment. However, the relationship between BFRs and PD remains unclear. This study was designed to investigate the overall association between BFRs and PD in a nationally representative US population and to further identify significant chemicals. This study used data from 7,161 NHANES participants from 2009 through 2016. The serum BFRs registry included PBDE-28, PBDE-47, PBDE-85, PBDE-99, PBDE-100, PBDE-153, PBDE-154, PBDE-183, PBDE-209, and PBB-153. A survey-weighted generalized logistic regression model with restricted cubic splines (RCS) was used to evaluate the association between single BFRs exposure and periodontitis. Meanwhile, weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were used to evaluate the overall association of mixed frankincense powder with periodontitis and to identify significant chemicals. Sensitivity analysis was performed to evaluate the robustness of the results. Among the 7,161 participants, 65 had PD. PD patients were older (mean age 57.79 vs. 46.57 years) and had a higher proportion of females (70.86%) compared to non-PD participants. Serum levels of PBB-153 were significantly higher in those with PD. Logistic regression analyses revealed a non-linear, inverted U-shaped relationship between serum PBB-153 and PD risk. The risk of PD increased with higher PBB-153 levels up to the 3rd quartile (Q3), beyond which the risk declined (Q3 vs. Q1: OR = 4.98, 95% CI = 1.79-13.86; Q4 vs. Q1: OR = 3.23, 95% CI = 1.03-10.08). PBB-153 (43.40%), PBDE-153 (24.75%), and PBDE-85 (19.51%) contributed most to the weighted quantile sum index associated with PD risk. Bayesian kernel machine regression confirmed the inverted U-shaped dose-response pattern for PBB-153 and the overall BFR mixture. Restricted cubic spline analyses corroborated the non-linear relationship between PBB-153 and PD, which was more pronounced among women and those aged 37-58 years. Sensitivity analyses substantiated these findings. This nationally representative cross-sectional study revealed a novel non-linear, inverted U-shaped relationship between serum levels of the brominated flame retardant PBB-153 and Parkinson's disease risk in U.S. adults. The risk increased with higher PBB-153 exposure up to a point, beyond which it declined. This complex dose-response pattern highlights the importance of considering potential hormetic mechanisms and effect modifiers when evaluating environmental exposures and neurodegenerative diseases. Further research is warranted to elucidate the underlying biological pathways and inform risk mitigation strategies.

Toxicological Effects and Mechanisms of 2,2',4,4'-Tetrabromodiphenyl Ether (BDE-47) on Marine Organisms.

2,2',4,4'-tetrabromodiphenyl ether (BDE-47) is a widely used brominated flame retardant belonging to persistent organic pollutants (POPs). After being released into the marine environment, BDE-47 can cause a range of toxic effects on marine organisms through bioaccumulation, biomagnification, and intergenerational transmission. These effects include lethality, impaired motility, photosynthetic toxicity, immune damage, liver toxicity, developmental impairments, and reproductive toxicity. This article reviews the latest research progress on the toxic effects and molecular mechanisms of BDE-47 mentioned above. The primary mechanisms underlying its toxicity include oxidative stress, DNA damage, cellular apoptosis, impaired metabolism, and activation of the MAPK signaling cascade.

The seed germination and seedling phytotoxicity of decabromodiphenyl ethane to tall fescue under citric acid amendment.

The novel brominated flame retardant decabromodiphenyl ethane (DBDPE) has biological toxicity, persistence, long-range migration and bioaccumulation ability. However, there is currently little research on the phytotoxicity of DBDPE in plants. The perennial herbaceous plant tall fescue (Festuca elata Keng ex E. B. Alexeev) was selected as the model organism for use in seed germination experiments, and the phytotoxicity of DBDPE in the soil of tall fescue was studied. The results indicated that DBDPE had a significant effect on the germination and growth of tall fescue seedlings. Citric acid reduced the stress caused by DBDPE in plants, effectively alleviating the phytotoxicity of DBDPE in tall fescue. The root vitality and protein content significantly increased after the application of citric acid, increasing by 74.93-183.90%, 146.44-147.67%, respectively. The contents of proline and soluble sugars significantly decreased after the application of citric acid, decreasing by 45.18-59.69% and 23.03%, respectively (P < 0.05). There was no significant difference in superoxide dismutase (SOD) or peroxidase (POD) activity in tall fescue seedlings, and the catalase (CAT) activity and malondialdehyde (MDA) content were significantly lower after the application of citric acid, decreasing by 64.62-67.91% and 29.10-49.80%, respectively (P < 0.05). Tall fescue seedlings bioaccumulated DBDPE, with biological concentration factors (BCFs) ranging from 4.28 to 18.38 and transfer factors (TFs) ranging from 0.43 to 0.54. This study provides theoretical support for the study of the toxicity of DBDPE to plants and offers a research foundation for exploring the phytoremediation of DBDPE-contaminated soil by tall fescue.

Analysis of brominated flame retardants exposure-associated chronic kidney disease risk in the US population from the NHANES

BackgroundExposure to brominated flame retardants (BFRs) may contribute the advancement of chronic kidney disease (CKD). The objective is to evaluate the renal effects of BFRs in patients with CKD. MethodsTotally 7235 US participants of whom 1187 (16.41 %) were diagnosed with CKD were screened for this investigation from the National Health and Nutrition Examination Survey (NHANES) database spanning from 2005 to 2016. The isotope dilution gas chromatography high-resolution mass spectrometry (GC/IDHRMS) was employed for identification of 11 polybrominated diphenyl ethers (PBDEs) and PBB153 serving as the exposure factor. A set of covariates concerning basic characteristics, renal function indicators and suffering from diseases of these participants was considered as potential confounding factors. Subgroup analyses to examine the impact of age and gender on the relationship between serum BFRs and CKD, estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (UACR), serum creatinine (Scr), and blood urea nitrogen (BUN). Weighted Quantile Sum (WQS) regression and Quantile G-computation (QGC) analyses were applied to identify relationship of individual BFRs and other anthropometric indicators in CKD. ResultsAfter adjusting for available confounding factors, PBDE100, PBDE28, PBDE85, PBDE47, PBDE99, and PBDE154 were positively correlated with CKD. PBDE28, PBDE66, PBDE47, PBDE183, PBDE100, PBDE99, PBDE85, PBDE154, and PBB153 were significantly negatively correlated with eGFR. PBDE66 and PBDE183 were positively correlated with UACR. PBDE28, PBDE17, PBDE66, PBDE100, PBDE47, PBDE85, PBDE154, PBDE99, PBDE183 and PBB153 were positively correlated with Scr. PBDE17, PBDE28, PBDE154, PBDE66, PBDE47, PBDE99, and PBDE209 were negatively associated with BUN. PBB153 was positively correlated with BUN. The subgroup results gender and age are key factors affecting the relationship of PBDEs and renal function indicators. Both WQS and QGS analyses revealed that exposure to mixed BFR was negatively correlated with eGFR and BUN, of which PBB153 and PBDE66 contributed the most, respectively, as well as positively correlated with Scr, in which PBDE66 contributed the most. ConclusionSpecific BFRs exposure was significantly correlated with renal function indicators, enhancing the potential risk of CKD. This pioneer investigation shed light on an overlooked impact of BFR exposure on CKD in US.

Brominated flame retardant in animal feeds from Poland

The safety of food of animal origin is closely related to feed quality. Feed pollution by brominated flame retardants (BFRs) leads to the exposure of animals and consumers of food of animal origin to these substances. The study aimed to assess the concentration of ten PBDE (BDE-28, 47, 49, 99, 100, 138, 153, 154, 183, and 209) congeners and eight nBFRs (TBX, PBT, HBB, PBEB, EH-TBB, BTBPE, BEH-TBPH, and DBDPE) in 59 feed and feed materials from six different feed categories (277/2012/EU). The quantification of analytes was based on isotopic dilution and gas chromatography–high-resolution mass spectrometry (GC-HRMS). All 59 feed samples were contaminated with at least one of the analytes. PBDEs and nBFRs were found in 78% and 91% of the samples, respectively. BFR content ranged from 0.18 to 5.87 μg·kg-1 in feed with a 12% moisture content, and the most contaminated category was vegetable oils, followed by fishmeal, feeds for fish, animal fats, and compound feeds for pigs. The least contaminated samples turned out to be compound feeds for chickens. This study confirms the general trend of decreasing PBDE concentrations in fishmeal. In the investigated samples, BDE-47 and BDE-209 contributed the most to the ∑PBDE content. DBDPE, HBB, and PBT contributed the most to the investigated ∑nBFRs. The widespread occurrence of nBFRs in feed seems disturbing because these compounds have replaced PBDEs. Their concentrations in the feed may most likely exceed those of PBDEs in the coming years.

Temporal and spatial distribution of novel brominated flame retardants in atmosphere of the Beijing-Tianjin-Hebei region, China

The occurrence and spatio-temporal distribution of atmospheric novel brominated flame retardants (NBFRs) were studied across five sampling sites in the Beijing-Tianjin-Hebei (BTH) region over a whole year. By collecting samples (gas and particle) with a high-volume active air sampler (HV-AAS), nine NBFRs were analyzed and the sum concentrations ranged from 1.65 to 344 pg/m3, with the highest value found in the urban sampling site in Shijiazhuang City. Decabromodiphenylethane (DBDPE) was the predominant congener, which accounted for 60% of ∑9NBFRs on average, while it was 90% of ∑9NBFRs in the rural site and significantly higher than those observed in the urban sites (one-way ANOVA, p < 0.05). The levels of particle-bound NBFRs were significantly correlated with the variation of total suspended particulates (TSP) and temperature (p < 0.01), indicating their evident impact on the spatio-temporal distribution of NBFRs. Moreover, a significantly positive correlation was observed between the concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis (2-ethyl-1-hexyl) tetrabromophthalate (BEH-TEBP) (p < 0.01). Monocyclic brominated flame retardants (including PBBz, PBT, PBEB, HBB and TBP-DBPE) were correlated with each other (p < 0.01) in both gas and particle phase, suggesting their co-occurrence and the similar source in the environment. The gas-particle partitioning behavior was well predicted by the Li-Jia Empirical Model, and the results indicated that the target NBFRs did not reach the equilibrium state in air. This is one of very few studies revealed the spatio-temporal distribution of atmospheric NBFRs in the BTH region.

Exposure to an environmentally representative mixture of polybrominated diphenyl ethers (PBDEs) alters zebrafish neuromuscular development

Polybrominated diphenyl ethers (PBDEs) are a prevalent group of brominated flame retardants (BFRs) added to several products such as electronics, plastics, and textiles to reduce their flammability. They are reported as endocrine disruptors and neurodevelopmental toxicants that can accumulate in human and wildlife tissues, thus making their ability to leach out of products into the environment a great cause for concern. In this study, zebrafish (Danio rerio) embryos and larvae were exposed to a wide concentration range (1.5, 15, 150 and 300 pM) of a PBDE mixture from one to six days post-fertilization (dpf). Hatching rates, mortality and general morphology were assessed during the exposure period. A delay in hatching was observed at the two highest PBDEs concentrations and mortality rate increased at 6 dpf. By 4 dpf, larvae exposed to 150 pM and 300 pM PBDEs developed an upcurved phenotype. Analysis of motor behavior at 6 dpf revealed that PBDE exposure acutely reduced locomotion. To further analyze these motor deficits, we assessed the neural network density and motor neuron and neuromuscular junctions (NMJ) development by immunostaining and imaging. Acetylated α-tubulin staining revealed a significant loss of neurons in a dose-dependent manner. Synaptic vesicle protein 2 (SV2) and ⍺-bungarotoxin (⍺-BTX) staining revealed a similar pattern, with a significant loss of SV2 and nicotinic acetylcholine receptors, thus preventing the colocalization of presynaptic neurons with postsynaptic neurons. Consistent with these results, the presence of cleaved caspase-3 and acridine orange positive cells showed increased cell death in zebrafish larvae exposed to PBDEs. Our results suggest that exposure to PBDEs leads to deficits in the zebrafish neuromuscular system through neuron death, inducing morphological and motor deficiencies throughout their development. They provide valuable insight into the neurotoxic effects of PBDEs, further highlighting the relevance of the zebrafish model in toxicological studies.

Activation of persulfate by a layered double oxide supported sulfidated nano zero-valent iron for efficient degradation of 2,2′,4,4′-tetrabromodiphenyl ether in soil

The nano zero-valent iron (nZVI) activated persulfate (PS) is recognized as a promising approach to degrade 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47), which is ubiquitous in the soil at electronic waste sites. However, all the reported studies were performed in liquids, gaps in the real behaviour and microbial contribution to the degradation of BDE-47 in soil media need to be urgently filled. The removal efficiency of BDE-47 is low using traditional nZVI as activator because of its aggregation and corrosion. Herein, we designed a novel layered double oxide supported sulfidated nano zero-valent iron (S-nZVI@LDO) composite and explored the performance of S-nZVI@LDO/PS to remediate BDE-47 contaminated soil. The results showed that S-nZVI@LDO has excellent stability and superior reduction capability. It could couple PS to achieve a rapid and efficient degradation of BDE-47, and the removal efficiency reached 92.31 % (5 mg/kg) within 6 h, which was much higher than that of n-ZVI/PS (53.38 %) or S-nZVI/PS (75.69 %). The kinetic constant of BDE-47 degradation by S-nZVI@LDO/PS was 23.6 and 3.7 times higher than that by single S-nZVI@LDO and nZVI/PS, respectively. It is attributable to the efficient production of SO4•-, •OH, O2•-, and 1O2 in the system, in which SO4•- and •OH dominated. The bioinformatic analysis demonstrate that soil remediation by S-nZVI@LDO/PS significantly enriched aromatic compounds-degrading bacteria and increased the abundance of hydrocarbon degradation functions. Microbial degradation may play important roles in the BDE-47 degradation and soil quality recovery. The identification of degradation pathways suggests that BDE-47 was degraded to very low-toxic products based on GHS toxicity prediction through a series process of debromination, hydroxylation, cleavage central oxygen, and ring opening, or even completely mineralized. The findings may provide significant implications for the in-situ clean-up of brominated flame retardants in contaminated soil using S-nZVI@LDO/PS Fenton-like system.

Variation profiles, formation mechanisms, and emission risks of brominated flame retardant compounds during cement kiln co-processing of hexabromocyclododecane-containing waste

Cement kiln co-processing technique has been suggested as a promising disposal method for hexabromocyclododecane (HBCD)-containing construction wastes. However, concerns persist regarding the potential emissions of secondary brominated flame retardant (BFR) compounds. To address this, we conducted both field and laboratory experiments to elucidate the emission characteristics and formation mechanisms of BFRs during the co-processing of HBCD-containing waste in cement kilns. In the field experiments, which examined a range of HBCD disposal dosages from 0 to 400 kg/day, the concentrations of new brominated flame retardants (NBFRs), polybrominated diphenyl ethers (PBDEs), and polybrominated biphenyls (PBBs) in the stack gas were 0.57–0.80, 0.68–51.56, 0.62–1.79 ng/Nm3, respectively. Over 77 % of the emitted BFRs can be sequestered within solid materials. Further laboratory experiments revealed that the alkaline substances present in cement kilns can absorb HBr thus inhibiting the formation of BFRs. The transformation mechanisms from HBCDs to BFRs were further explored to involve processes including structural re-arrangement, de novo synthesis, and precursor formation. Furthermore, the national annual emission risk associated with the disposal of HBCD-containing construction wastes via cement kilns has been assessed. The findings of our study furnish a critical scientific basis for the development of strategies for managing HBCD-containing waste in the future.

Dermal exposure assessment of formal e-waste dismantlers to flame retardants and plasticizers using passive sampling methodologies

The recycling of e-waste can lead to the release of organic chemicals when materials containing additives are subjected to dismantling and grinding. In this context, the exposure of workers from a Catalonian e-waste facility to flame retardants and plasticizers (including organophosphate esters (OPEs), polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs) and dechloranes) was assessed using T-shirts and wristbands as passive samplers. The study area includes an area exclusively dedicated to cathodic ray-tube (CRT) TVs dismantling, and a grinding area where the rest of e-waste is ground. All the families of compounds were detected in both T-shirts and wristbands, with the highest concentration levels corresponding to OPEs, followed by PBDEs, NBFRs, and dechloranes. The CRT area presented higher concentration levels than the grinding area. The compounds with higher concentrations in T-shirts were 2-ethylhexyl diphenyl phosphate (EHDPP), diphenyl cresyl phosphate (DCP) and triphenyl phosphate (TPHP), and the total concentration of all groups ranged between 293 and 8324 ng/dm2-h (hour). In the case of the wristbands, the most abundant compounds were DCP, TPHP, and BDE-209, with total concentrations between 188 and 2248 ng/dm2-h. The two sampling methods appear to be complementary, as T-shirts collect coarser particles, while wristbands also capture volatile compounds. Based on normalized surface and time concentrations, the estimated daily intake (EDI) through dermal contact was calculated and carcinogenic and non-carcinogenic risks (CR and non-CR) associated with this activity assessed. The results show median CR 29 and 16 times below the threshold in CRT and grinding areas respectively. The non-CR medians were 2 and 3 times below the threshold, although in the CRT area one exceptional value surpassed the threshold, suggesting that risk can exist for some workers in the facility.

Children’s exposure to chemical contaminants: Demographic disparities and associations with the developing basal ganglia

Children are regularly exposed to chemical contaminants that may influence brain development. However, relatively little is known about how these contaminants impact the developing human brain. Here, we combined silicone wristband exposure assessments with neuroimaging for the first time to examine how chemical contaminant mixtures are associated with the developing basal ganglia—a brain region key for the healthy development of emotion, reward, and motor processing, and which may be particularly susceptible to contaminant harm. Further, we examined demographic disparities in exposures to clarify which children were at highest risk for any contaminant-associated neurobiological changes. Participants included 62 community children (average age 7.00 years, 53% female, 66% White) who underwent structural neuroimaging to provide data on their basal ganglia structure and wore a silicone wristband for seven days to track their chemical contaminant exposure. 45 chemical contaminants—including phthalates and their alternatives, brominated flame retardants, organophosphate esters, pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls—were detected in over 75% of wristbands. Notable demographic disparities in exposure were present, such that Non-White and lower-income children were more exposed to several contaminants. Exposure to chemical contaminant mixtures was not associated with overall basal ganglia volume; however, two organophosphate esters (2IPPDPP and 4IPPDPP) were both associated with a larger globus pallidus, a basal ganglia sub-region. Results highlight demographic disparities in exposure and suggest possible risks to a brain region key for healthy emotional development.

Recoverability of zebrafish from decabromodiphenyl ether exposure: The persisted interference with extracellular matrix production and collagen synthesis and the enhancement of arrhythmias

As a widely used brominated flame retardant, the widespread presence of decabromodiphenyl ether (BDE-209) in the natural environment and the toxicity risks it poses are well established, but the recoverability of BDE-209-induced individual injuries remains unknown. Therefore, a 7-day depuration experiment following a 4-day exposure of zebrafish to BDE-209 was conducted to confirm the recoverability and its mode of action. Oxidative stress after depuration was significantly reduced compared with BDE-209 exposure as indicated by the decreased expression level of oxidative stress-related genes and the reduced MDA, Gpx, and GST in zebrafish, indicating a gradual recovery of antioxidant activity. However, BDE-209 inhibition of extracellular matrix (ECM) proteins worsened after depuration. Mechanistically, BDE-209 mediated ECM production and secretion by down-regulating integrin expression. Furthermore, BDE-209 inhibition of collagen synthesis worsened after depuration. Biochemical assays and histopathological observations revealed a same result in zebrafish. Mechanistically, lysine hydroxylation is inhibited thereby affecting collagen synthesis. Interestingly, zebrafish showed arrhythmia after depuration compared to BDE-209 exposure, and abnormal changes in ATPase levels indicated that disturbances in Ca2+ homeostasis contributed to arrhythmia. Collectively, BDE-209-induced interference with ECM production and collagen synthesis persisted after depuration, which will provide new insights for understanding the recovery patterns of individuals under BDE-209 stress.

Environmental toxicants modulate disease severity in pediatric metabolic dysfunction-associated steatohepatitis.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is common in children. We hypothesized environmental toxins could drive progression to metabolic dysfunction-associated steatohepatitis (MASH), and assayed serum toxins and metabolites in children with histologically characterized MASLD/MASH. Environmental chemicals, common in household items, perfluoroalkyl substances (PFAS), brominated flame retardants (PBDEs), and metabolic profiles were assayed in children enrolled in the multicenter NASH Clinical Research Network Pediatric Database 2. Mixture models, using repeated holdout weighted quantile sum regression (WQSrh) were run in addition to single chemical/metabolite logistic regression. For metabolomic analyses, random subset version of WQSrh was used for the large number of predictors versus participants. Nominal and false discovery rate (FDR) p-values (two-sided) were computed. Four hundred and thirty-five children distributed across MASH (n = 293) and MASLD (n = 142), with 304 (69.9%) males. Mean (standard deviation) for Nonalcoholic Steatohepatitis Score (NAS) and alanine aminotransferase (ALT) for MASLD were 3.1 (1.0), 67.9 (43.4), and for MASH 4.2 (1.4), 144 (121). There was an inverse association between PFAS/PBDE mixture and MASH versus MASLD, lobular inflammation (p = 0.026), NAS (p = 0.009, FDR p = 0.04), and log-transformed ALT (p = 0.005, FDR p = 0.025) driven by perfluorohexane sulfonate (PFHxS). Metabolites from positive hydrophilic interaction liquid chromatography mode, biliverdin (p = 0.002) and 1-methylhistidine (associated with meat ingestion, p = 0.02) and reverse phase negative mode, hippuric acid (solvent exposure, p = 0.022) significantly associated with MASH. Significant negative PFAS/PBDE mixture effect and odds of MASH were dominated by PHFXS. Several metabolites are significantly associated with MASH which inform mechanistic pathways and could drive key therapeutic and diagnostic strategies in children.

Phototransformation of tetrabromobisphenol A bis (allyl ether) in an aqueous solution: Role of environmentally persistent free radicals

Tetrabromobisphenol A bis (allyl ether) (TBBPA-BAE) represents an extensively used brominated flame retardant (BFRs) in the production of many fields and their phototransformation in natural water is still unclear. The environmentally persistent free radicals (EPFRs) with preserved activities could exist in the environment for a long time and involve in the phototransformation of many organic pollutants. Here, the photodegradation of TBBPA-BAE with the degradation rate constant (k = 0.060 h−1) under simulate sunlight and the promoting effect of EPFRs on TBBPA-BAE photodegradation (k = 0.135 h−1) were investigated. According to the detected photogenerated electrons (e−) and singlet oxygen (1O2) rather than hydroxyl radicals (•OH) by the electron paramagnetic resonance (EPR), the effect mechanism may not be related to the typical •OH induced by EPFRs. The possible transformation pathways of the ether cleavage, hydrolysis and hydroxylation of propenyl bond and the debromination were proposed by the primary byproducts identified by UPLC-Q-Exactive Orbitrap MS. EPFRs caused a further debromination and ether cleavage and probably be due to EPFRs directly providing electrons to TBBPA-BAE which promoted the photodegradation of TBBPA-BAE, and their reaction mechanism needed further attention. Overall, this study provided useful information to understand the role of EPFRs on phototransformation of TBBPA-BAE in water.