Preliminary study of long-range transport of halogenated flame retardants using Antarctic marine mammals

Co-exposure of decabromodiphenyl ethane and cadmium increases toxicity to earthworms: Enrichment, oxidative stress, damage and molecular binding mechanisms

The increase of electronic waste worldwide has resulted in the exacerbation of combined decabromodiphenyl ethane (DBDPE) and cadmium (Cd) pollution in soil, posing a serious threat to the safety of soil organisms. However, whether combined exposure increases toxicity remains unclear. Therefore, this study primarily investigated the toxic effects of DBDPE and Cd on earthworms at the individual, tissue, and cellular levels under single and combined exposure. The results showed that the combined exposure significantly increased the enrichment of Cd in earthworms by 50.32-90.42 %. The toxicity to earthworms increased with co-exposure, primarily resulting in enhanced oxidative stress, inhibition of growth and reproduction, intensified intestinal and epidermal damage, and amplified coelomocyte apoptosis. PLS-PM analysis revealed a significant and direct relationship between the accumulation of target pollutants in earthworms and oxidative stress, damage, as well as growth and reproduction of earthworms. Furthermore, IBR analysis indicated that SOD and POD were sensitive biomarkers in earthworms. Molecular docking elucidated that DBDPE and Cd induced oxidative stress responses in earthworms through the alteration of the conformation of the two enzymes. This study enhances understanding of the mechanisms behind the toxicity of combined pollution and provides important insights for assessing e-waste contaminated soils.

Legacy and emerging contaminants in marine mammals from Argentina

Marine mammals are recognized sentinels of ecosystem health. They are susceptible to the accumulation and biomagnification of pollutants, which constitute one of the greatest threats to their survival. Legacy, such as organochlorine pesticides, and emerging contaminants, like microplastics and pharmaceuticals, may have effects on marine mammals' health at individual and population levels. Therefore, the evaluation of the risks associated with pollutants in this group is of great importance. The aim of this review is to provide information on the occurrence of legacy and emerging contaminants in marine mammals that inhabit Argentine waters. Also, to identify knowledge gaps and suggest best practices for future research. Reports of legacy contaminants referring to organochlorine pesticides and polychlorinated biphenyls were found in five species of cetaceans and two of pinnipeds. With respect to emerging pollutants, the presence of plastics was only evaluated in three species. Reported data was from at least a decade ago. Therefore, it is necessary to update existing information and conduct continuous monitoring to assess temporary trends in pollutants. All the studies were carried out in the province of Buenos Aires and Northern Patagonia indicating a knowledge gap in the southern zone of the Argentine Sea. In addition, pollutants of global environmental concern that have not been studied in Argentina are discussed. Future studies should fill these gaps and a greater effort to understand the relationships between pollutants and their effects on marine mammals is suggested. This issue will make it possible to determine thresholds for all the substances and species evaluated in order to carry out more detailed risk assessments and make decisions for the conservation of marine mammals in Argentine waters.

A review of polybrominated diphenyl ethers and novel brominated flame retardants in Chinese aquatic environment: Source, occurrence, distribution, and ecological risk assessment

Due to the widespread commercial production and use of brominated flame retardants (BFRs) in China, their potential impact on human health development should not be underestimated. This review searched the literature on Polybrominated diphenyl ethers and Novel brominated flame retardant (PBDEs and NBFRs) (broad BFRs) in the aquatic environment (including surface water and sediment) in China over the last decade. It was found that PBDEs and NBFRs entered the aquatic environment through four main pathways, atmospheric deposition, surface runoff, sewage effluent and microplastic decomposition. The distribution of PBDEs and NBFRs in the aquatic environment was highly correlated with the local economic structure and population density. In addition, a preliminary risk assessment of existing PBDEs and PBDEs in sediments showed that areas with high-risk quotient values were always located in coastal areas with e-waste dismantling sites, which was mainly attributed to the historical legacy of electronic waste. This research provides help for the human health development and regional risk planning management posed by PBDEs and NBFRs.

Levels, tissue distribution and isomer stereoselectivity of Dechlorane Plus in humans: A critical review

Exposure of human tissues to Dechlorane Plus (DP) has raised public concern because of the multiple health threats it may pose to humans. Therefore, it is important to summarize the main findings of previous studies on DP in human tissues and to provide potential guidance for future studies. In this paper, DP levels in different populations and human tissues worldwide since 2009 were systematically reviewed. DP levels in human tissues of workers in e-waste dismantling sites in Guangdong Province, China (median 190 ng·g-1 lw in serum) and DP manufacturing plants in Jiangsu Province, China (mean 857 ng·g-1 lw in whole-blood) are the highest reported worldwide. DP levels in tissues of the general population in recent studies are close to those of residents near e-waste dismantling sites, which should be of concern. DP levels in different human tissues were found to be positively correlated with a pattern of blood > breast milk > adipose tissue. The distribution of DP in different human tissues is mainly lipid-driven and may also be influenced by the interaction of DP with proteins such as human serum albumin. Most of the past studies determined the isomer stereoselectivity of DP in human tissues only by comparing the composition of DP in commercial DP products and human tissues, which lacks evidence of mechanism. Recently, a significantly different affinity of DP isomers for proteins was found, which seems to confirm the isomer selectivity of DP in human tissues. We simulated the binding of DP to human serum albumin and DP to thyroid hormone receptor β by molecular docking and found differences in the binding behavior of syn-DP and anti-DP to the selected proteins. Molecular docking seems to be a feasible approach for future studies to predict and reveal the mechanisms of DP behavior and health effects in human tissues.

Human footprint on the water quality from the northern Antarctic Peninsula region

This study assessed the human footprint on the chemical pollution of Antarctic waters by characterizing inorganic chemicals and selected organic anthropogenic contaminants of emerging concern (CECs) in inland freshwater and coastal seawater and the associated ecotoxicological risk. Nicotine and tolytriazole, present in 74% and 89% of the samples analyzed, respectively, were the most ubiquitous CECs in the investigated area. The most abundant CECs were citalopram, clarithromycin, and nicotine with concentrations reaching 292, 173, and 146 ng/L, respectively. The spatial distribution of CECs was not linked to any water characteristic or inorganic component. The contamination pattern by CECs in inland freshwater varied among locations, whereas it was very similar in coastal seawater. This suggests that concentrations in inland freshwater may be ruled by environmental processes (reemission from ice, atmospheric deposition, limited photo- and biodegradation processes, etc.) in addition to human activities. Following risk assessment, citalopram, clarithromycin, nicotine, venlafaxine, and hydrochlorothiazide should be considered of concern in this area, and hence, included in future monitoring of Antarctic waters and biota. This work provides evidence on the fact that current measures taken to protect the pristine environment of Antarctica from human activities are not effective to avoid CEC spread in its aquatic environment.

Pressurized Liquid Extraction: A Powerful Tool to Implement Extraction and Purification of Food Contaminants

Pressurized liquid extraction (PLE) is considered an advanced extraction technique developed in the mid-1990s with the aim of saving time and reducing solvent with respect to traditional extraction processes. It is commonly used with solid and semi-solid samples and employs solvent extraction at elevated temperatures and pressures, always below the respective critical points, to maintain the solvent in a liquid state throughout the extraction procedure. The use of these particular pressure and temperature conditions changes the physicochemical properties of the extraction solvent, allowing easier and deeper penetration into the matrix to be extracted. Furthermore, the possibility to combine the extraction and clean-up steps by including a layer of an adsorbent retaining interfering compounds directly in the PLE extraction cells makes this technique extremely versatile and selective. After providing a background on the PLE technique and parameters to be optimized, the present review focuses on recent applications (published in the past 10 years) in the field of food contaminants. In particular, applications related to the extraction of environmental and processing contaminants, pesticides, residues of veterinary drugs, mycotoxins, parabens, ethyl carbamate, and fatty acid esters of 3-monochloro-1,2-propanediol and 2-monochloro-1,3-propanediol from different food matrices were considered.

Exposure to flame retardants in European children - Results from the HBM4EU aligned studies

Many legacy and emerging flame retardants (FRs) have adverse human and environmental health effects. This study reports legacy and emerging FRs in children from nine European countries from the HBM4EU aligned studies. Studies from Belgium, Czech Republic, Germany, Denmark, France, Greece, Slovenia, Slovakia, and Norway conducted between 2014 and 2021 provided data on FRs in blood and urine from 2136 children. All samples were collected and analyzed in alignment with the HBM4EU protocols. Ten halogenated FRs were quantified in blood, and four organophosphate flame retardants (OPFR) metabolites quantified in urine. Hexabromocyclododecane (HBCDD) and decabromodiphenyl ethane (DBDPE) were infrequently detected (<16% of samples). BDE-47 was quantified in blood from Greece, France, and Norway, with France (0.36 ng/g lipid) having the highest concentrations. BDE-153 and -209 were detected in <40% of samples. Dechlorane Plus (DP) was quantified in blood from four countries, with notably high median concentrations of 16 ng/g lipid in Slovenian children. OPFR metabolites had a higher detection frequency than other halogenated FRs. Diphenyl phosphate (DPHP) was quantified in 99% of samples across 8 countries at levels ∼5 times higher than other OPFR metabolites (highest median in Slovenia of 2.43 ng/g lipid). FR concentrations were associated with lifestyle factors such as cleaning frequency, employment status of the father of the household, and renovation status of the house, among others. The concentrations of BDE-47 in children from this study were similar to or lower than FRs found in adult matrices in previous studies, suggesting lower recent exposure and effectiveness of PBDE restrictions.

Chlorinated Organophosphate Flame Retardants Impair the Lung Function via the IL-6/JAK/STAT Signaling Pathway

Toxicological studies have revealed the adverse impacts of organophosphate flame retardants (OPFRs) on the respiratory system, while there is a lack of epidemiological evidence, and information for risk assessment remains insufficient. Herein, we investigated the associations of urinary metabolites of OPFRs with the lung function in 987 adults participating in the U.S. National Health and Nutrition Examination Survey 2011-2012. The elevation of three primary metabolites of chlorinated OPFRs [bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), bis(2-chloroethyl) phosphate (BCEP), and bis(1-chloro-2-propyl) phosphate (BCIPP)] was related to pulmonary dysfunction in a sample-weighted regression model. Each one-unit increase in the log-transformed levels of BDCIPP and BCEP was related to 91.52 and 79.34 mL reductions in the forced vital capacity (FVC). Each one-unit elevation in BCIPP was correlated with 130.86, 153.56, 302.26, and 148.24 mL reductions in forced expiratory volume 1st second (FEV₁), FVC, peak expiratory flow rate (PEF), and forced expiratory flow at 25-75% of FVC (FEF_25-75%), respectively. Then, an adverse outcome pathway (AOP) framework was constructed using the Comparative Toxicogenomics Database, the Toxicity Forecaster, and the GeneCards database. Based on the weight of the evidence, BDCIPP, BCEP, BCIPP, and their parent compounds (TDCIPP, TCEP, and TCIPP) may affect the IL-6/Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway, induce airway remodeling, and impair the lung function. Additionally, tobacco smoke exposure may modify the effects of BDCIPP on the lung function (P_int < 0.05) and affect the IL-6-mediated AOP. These results suggested that chlorinated OPFRs were associated with pulmonary dysfunction via the IL-6/JAK/STAT pathway.

Contamination Status of Pet Cats in Thailand with Organohalogen Compounds (OHCs) and Their Hydroxylated and Methoxylated Derivatives and Estimation of Sources of Exposure to These Contaminants

In this study, we analyzed serum samples of pet cats from Thailand and estimated the contribution to organohalogen compounds (OHCs) exposure through cat food and house dust intake. BDE-209 was predominant in cat sera and accounted for 76% of all polybrominated diphenyl ethers (PBDEs). Decabromodiphenyl ether (BDE-209) is a major contaminant in dry cat food and house dust, which has been estimated to be a source of exposure for Thai pet cats. BDE-209 is a major contaminant of OHCs in dry cat food and house dust, which was estimated to be a source of exposure for Thai pet cats. On the other hand, the level of contamination by PCBs was lower than in other countries. Analysis of pet foods suggested that BDE-209 in pet cat serum was attributable to the consumption of dry cat food. On the other hand, house dust also contained high concentrations of BDE-209. Thus, high levels of BDE-209 in pet cat sera can be attributed to the consumption of dry cat food and house dust. These results suggest that pet cats are routinely exposed to non-negligible levels of OHCs.

Assessment of contaminants of emerging concern in European apex predators and their prey by LC-QToF MS wide-scope target analysis

Apex predators are good indicators of environmental pollution since they are relatively long-lived and their high trophic position and spatiotemporal exposure to chemicals provides insights into the persistent, bioaccumulative and toxic (PBT) properties of chemicals. Although monitoring data from apex predators can considerably support chemicals' management, there is a lack of pan-European studies, and longer-term monitoring of chemicals in organisms from higher trophic levels. The present study investigated the occurrence of contaminants of emerging concern (CECs) in 67 freshwater, marine and terrestrial apex predators and in freshwater and marine prey, gathered from four European countries. Generic sample preparation protocols for the extraction of CECs with a broad range of physicochemical properties and the purification of the extracts were used. The analysis was performed utilizing liquid (LC) chromatography coupled to high resolution mass spectrometry (HRMS), while the acquired chromatograms were screened for the presence of more than 2,200 CECs through wide-scope target analysis. In total, 145 CECs were determined in the apex predator and their prey samples belonging in different categories, such as pharmaceuticals, plant protection products, per- and polyfluoroalkyl substances, their metabolites and transformation products. Higher concentration levels were measured in predators compared to prey, suggesting that biomagnification of chemicals through the food chain occurs. The compounds were prioritized for further regulatory risk assessment based on their frequency of detection and their concentration levels. The majority of the prioritized CECs were lipophilic, although the presence of more polar contaminants should not be neglected. This indicates that holistic analytical approaches are required to fully characterize the chemical universe of biota samples. Therefore, the present survey is an attempt to systematically investigate the presence of thousands of chemicals at a European level, aiming to use these data for better chemicals management and contribute to EU Zero Pollution Ambition.

Polybrominated diphenyl ethers and their methoxylated congeners in Douro river estuary biota: Seasonal occurrence and risk assessment

Especially added on many industrial and domestic products as flame retardants (FRs), polybrominated diphenyl ethers (PBDEs) are among the chemicals of high environmental concern because of their potential harmfulness for environmental and human health. Seafood consumption is considered the main source of PBDEs and their methoxylated congeners (MeO-BDEs) for humans. The present study aims to investigate the seasonal occurrence of six PBDEs and eight MeO-BDEs congeners using Douro river biota (different trophic levels) as sentinels, as well as to evaluate the human exposure risk to PBDEs through seafood consumption. Biota samples (n = 273) were collected from one of the most important Portuguese estuaries in the north-western coast of Portugal at four different seasons (2019-2020). The analyses were performed by an environmental-friendly extraction procedure followed by Gas Chromatography coupled to a triple quadrupole detector (GC-MS/MS). PBDEs were detected in all seafood samples analysed, with means ranging from 0.02 ng g^-1 ww (flounder in autumn) to 3.75 ng g^-1 ww (mussel in winter). Levels of lower-brominated PBDE congeners were significantly higher than higher-brominated ones in all seasons (p < 0.01). MeO-BDEs ranged from 0.001 ng g^-1 ww (grey mullet in summer) to 5.66 ng g^-1 ww (green crab in spring). Crabs and mussels presented the highest means of PBDEs and MeO-BDEs. Regarding the health risk assessment of the studied PBDE congeners (47, 99, and 153), consumption of Douro river fish is not a case of concern for consumers.

Endoplasmic reticulum stress manipulates autophagic response that antagonizes polybrominated diphenyl ethers quinone induced cytotoxicity in microglial BV2 cells

Polybrominated diphenyl ethers (PBDEs) were widely used as flame retardants. Previously, we reported that their quinone-type metabolite (PBDEQ) induced selective autophagy, but its biological consequences remain obscure. Here, we illustrated the possible link of PBDEQ-induced autophagy with endoplasmic reticulum (ER) stress and cytotoxicity in microglial BV2 cells. We found PBDEQ increased the formation of autophagosomes, promoted autophagic degradation, suggesting an improved autophagy flux in BV2 cells. Interestingly, both pharmacologic autophagy inhibitors and autophagy-related 5 gene small interfering RNA (ATG5 siRNA) aggravated the cytotoxicity of PBDEQ, suggesting the antagonizing role of autophagy. PBDEQ induced ER stress and activated protein kinase R-like ER kinase (PERK)-eukaryotic translation initiation factor 2α (eIF2α)-activating transcription factor 4 (ATF4)-C/EBP homologous protein (CHOP) axis of classic unfolded protein response (UPR) pathway, whilst ER stress inhibitor blocked PBDEQ-induced autophagy. Moreover, N-acetyl-L-cysteine (NAC) alleviated PBDEQ-induced activation of ER stress and autophagy, suggesting reactive oxygen species (ROS) were involved in regulating PBDEQ-induced ER stress and autophagy. Taken together, our results demonstrate a new mechanism of PBDEQ-associated toxicity.

Feeding behavior toxicity in the marine rotifer Brachionus plicatilis caused by 2,2',4,4'-tetrabromodiphenyl ether (BDE-47): Characteristics and mechanisms

Polybrominated diphenyl ether contamination in marine environments has received special attention due to its accumulation and magnification in the marine food web and toxicity to organisms. In the present study, a series of short-term toxicological tests were conducted with the marine rotifer Brachionus plicatilis to assess the effects on ingestion and digestive performance after treatment with 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) at nonlethal concentrations under controlled laboratory conditions and to analyze the possible mechanism. The results showed that with accumulation in rotifers, BDE-47 caused a significant decline in the filtration and feeding rates in a concentration-dependent manner. Moreover, the activities of amylase (AMS) and protease were affected, indicating that BDE-47 impaired ingestion and digestion efficiency. BDE-47 exposure did not lead to abnormal microstructures in the main digestive tract (e.g., cilia around the corona, mastax, stomach, digestive gland and esophagus), but the gastric parietal cells shrank, suggesting nutritional deficiency. BDE-47 prominently induced the occurrence of irregular mitochondria at the cilia root, and mitochondrial and isocitrate dehydrogenase activity declined, indicating mitochondrial dysfunction. Furthermore, the activity of ATPase, which catalyzes ATP hydrolysis, decreased as the BDE-47 concentration rose, implying that BDE-47 retarded rotifer ATP dynamics, inevitably interfering with cilia movement to ingest food. Additionally, a significant decline in acetylcholine esterase activity was observed, which led to a hindrance in neurotransmission involved in food intake and digestion. Altogether, our results demonstrated that nonlethal concentrations of BDE-47 could induce feeding depression in rotifers, which is mainly attributed to stymied energy metabolism and nerve conduction.

Bioaccumulation and Trophic Transfer of Polybrominated Diphenyl Ethers and Their Hydroxylated and Methoxylated Analogues in Polar Marine Food Webs

Arctic and Antarctic marine ecosystems, which are important components of global biodiversity, have been severely threatened by environmental pollutants in recent decades. In this study, polybrominated diphenyl ethers (PBDEs) and their hydroxylated and methoxylated analogues (OH-PBDEs and MeO-PBDEs) were analyzed in seawater, sediment, and marine organisms (algae, invertebrates, and fishes) collected surrounding the Arctic Yellow River Station (n = 83) and the Antarctic Great Wall Station (n = 72). PBDEs and the analogues were detectable in all polar marine matrices, except MeO-PBDEs in seawater. The concentrations of ∑PBDEs, ∑MeO-PBDEs, and ∑OH-PBDEs in the marine organisms were in the range of 0.33-16 ng/g lipid weight (lw), n.d.-2.6 ng/g lw, and 0.12-2.3 ng/g lw in the Arctic and 0.06-31 ng/g lw, n.d.-5.8 ng/g lw, and 0.17-35 ng/g lw in Antarctica, respectively. Biota-sediment bioaccumulation factor (BSAF, g TOC/g lipid) values of MeO-PBDEs (0.002-0.14) and OH-PBDEs (0.004-0.18) were lower than the BSAF values of PBDEs (0.85-12). Trophic magnification was found for ∑MeO-PBDEs, whereas trophic dilution was observed for ∑OH-PBDEs in both regions. This is one of very few investigations on trophic transfer of PBDE metabolites in the Antarctic and Arctic regions and will further strengthen concerns about the ecological risk of PBDE metabolites in remote areas.

Evaluation of the toxic response induced by BDE-47 in a marine alga, Phaeodactylum tricornutum, based on photosynthesis-related parameters

The pollution of polybrominated diphenyl ethers (PBDEs) is becoming a pressing environmental problem in aquatic environments, and its threat to aquatic organism has received much attention. In this study, Phaeodactylum tricornutum was treated with 0.8 and 4 mg L^-1 2,2',4,4'-tetrabrominated biphenyl ether (BDE-47), the most toxic PBDEs, for 96 h. BDE-47 inhibited cell growth in a time- and concentration-dependent manner. Observation of cell ultrastructure suggested the damage of the chloroplasts morphology. BDE-47 also decreased the chlorophyll content and the oxygen evolution rate, and altered the performance of photosystems. Transcriptomic analysis revealed differential expression of 62 genes related to photosynthesis in BDE-47 treatments (4 mg L^-1) and transcription suppression of 58 genes involved in chlorophyll synthesis, antenna proteins, oxygen evolution, electron transport and downstream carbon fixation, implying potential toxicity targets in cells. Additionally, the levels of reactive oxygen species (ROS) and lipid peroxidation increased under BDE-47 stress and were positively correlated with photosynthesis inhibition. Pretreatment with the ROS scavenger N-acetyl-l-cysteine reduced the extent of inhibition, suggesting that ROS was responsible for these effects. Another experiment with the electron transport chain inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea showed that the generation of ROS was partially blocked, primarily indicating that photosynthetic inhibition induced by BDE-47 contributed to ROS overproduction. Thus, BDE-47 inhibited the photosynthesis by down-regulating the gene expression. This change stimulated ROS production, further leading to chloroplast membrane damage to aggravate this inhibition via a feedback loop. These effects of BDE-47 had adverse outcomes on the entire physiological state and the population growth of the microalgae.

Adélie penguin colonies as indicators of brominated flame retardants (BFRs) in East Antarctica

While persistent organic pollutant (POP) contamination within Antarctica is largely caused by long-range atmospheric transport (LRAT), Antarctic research bases have been shown to be local sources of POPs such as brominated flame retardants (BFRs). This study compared concentrations of seven polybrominated diphenyl ethers (PBDE) congeners and five novel flame retardants (NBFRs) found in Adélie penguin (Pygoscelis adeliae) colony soils near the Australian research stations, Mawson and Davis, to assess the stations as local sources of these contaminants and provide a much needed baseline for contamination of BFRs in East Antarctica. Soil samples (n = 46) were collected from Adélie colonies at close proximity to the research stations as well as further afield during the 2016-17 austral summer. Samples were analysed using selective pressurised liquid extraction (S-PLE) and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). PBDEs (BDE-28, -47, -99, -100, -153, -154 and -183) were detected in 45/46 samples with ∑₇PBDE concentrations ranging from <0.01 to 1.63 ng/g dry weight (dw) and NBFRs (2,3,4,5,6-pentabromotoluene (PBT), 2,3,4,5,6-pentabromoethylbenzene (PBEB), hexabromobenzene (HBB), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis(2,4,6-tribromophenoxy) ethane (BTBPE)) detected in 20/46 samples, with a range of ∑₅NBFR from not detected (ND) to 0.16 ng/g dw. Soils taken from around the Davis and Mawson research stations were more highly contaminated (n = 10) than penguin colonies (n = 27) and control areas not affiliated with breeding seabirds (n = 8). The most common congener detected was BDE-99, reflecting inputs from LRAT. However, the congener profiles of station soils supported the hypothesis that research stations are a local source of PBDEs to the Antarctic environment. In addition, the NBFR pentabromoethylbenzene (PBEB) was quantified for the first time in Antarctic soils, providing essential information for baseline contamination within the region and highlighting the need for ongoing monitoring as global regulations for the use of BFRs continuously change.

First determination of high levels of organophosphorus flame retardants and plasticizers in dolphins from Southern European waters

This study evaluates for the first time organophosphorus flame retardant (OPFR) occurrence in the Alboran Sea delphinids (Spain). OPFRs were detected in all the individuals with concentration levels up to 24.7 µg/g lw. Twelve out of sixteen tested analytes were detected, being TBOEP which presented the highest detection frequency, and IDPP which presented the highest levels of concentration. OPFR distribution in different tissues (blubber, brain, kidney, muscle and liver) was evaluated. The pattern distribution showed the highest contribution for blubber (mean value of 68%) and the lowest contribution for liver (mean value of 2%). Seven OPFRs were detected in brain samples showing their capacity to surpass the blood-brain barrier and reach the brain. Moreover, high affinity for the brain tissue was observed. This is extremely important due to the neurotoxic effects of several compounds such as TCEP and TNBP. OPFR levels were compared with previously published PBDE concentrations, and no significant differences were observed. Taking into account the lower use and lower bioaccumulation and biomagnification capacities of OPFRs, this could indicate an additional OPFR source of pollution in addition to their use as FRs.