Predominance of BDE-209 and other higher brominated diphenyl ethers in eggs of white stork (Ciconia ciconia) colonies from Spain

Influence of climatic conditions on the link between oxidative stress balance and landfill utilisation as a food resource by white storks

Landfills have played a significant role in the recovery of white storks (Ciconia ciconia) populations across various European countries. While there is ample information about the populational-level effects, there is a lack of knowledge regarding the individual effects of using this food resource for feeding nestlings. This study aims to assess the nutritional status and oxidative stress balance of nestlings with varying degrees of exposure to landfill-provided food This study aims to assess the nutritional status and oxidative stress balance of nestlings with different use of landfill-provided food. Nestlings fed with food foraged by breeding pairs from landfills exhibited better nutritional status compared to individuals located farther from landfills. This can be attributed to a higher ingestion rate, resulting in increased plasmatic values of cholesterol, triglycerides, and HDL in plasma. However, the oxidative stress balance varied across different years, with individuals raised in 2014 showing higher values of Vitamin E and lower values of LDH compared to those raised in 2013. Furthermore, the impact of landfills on certain oxidative stress parameters also depended on the year of study. In 2013, the Total Antioxidant Capacity (TAC) of plasma showed a positive correlation with the distance to landfills, while the concentration of Malondialdehyde (MDA), an indicator of lipid peroxidation, exhibited a negative correlation. These findings suggest that the use of landfills as a food resource has a consistently positive effect on the nutritional status of white stork nestling. However, the relationship with oxidative stress is highly dependent on the climatic conditions of each year, emphasizing the importance of considering these factors when evaluating the use of landfills as a food resource.

Levels of organic pollutants and metals/metalloids in infant formula marketed in Brazil: Risks to early-life health

Infant formula intake is recommended to ensure comprehensive nutritional and caloric fulfillment when exclusive breastfeeding is not possible. However, similarly to breast milk, infant formulas may also contain pollutants capable of inducing endocrine-disrupting and neurotoxic effects. Thus, considering the sensitivity of their developing physiological systems and that infants have heightened susceptibility to environmental influences, this study was aimed at assessing the contents of essential elements, and inorganic and organic pollutants in infant formulas marketed in Brazil. Additionally, health risk assessments for selected contaminants were also performed. Measured contents of essential elements (Ca, Fe, Mg, Mn, Cu, Se, and Zn) were congruent with label information. Nevertheless, some toxic elements (Pb, Cd, As, Ni, and Al) were also detected. Notably, in the upper-bound scenario, Pb and Cd surpassed established threshold values when comparing the estimated daily intake (EDI) and tolerable daily intake (TDI - 3.57 and 0.36 μg/kg bw, respectively). Bisphenol P (BPP) and benzyl butyl phthalate (BBP) were frequently detected (84 % detection rate both) with elevated contents (BPP median = 4.28 ng/g and BBP median = 0.24 ng/g). Furthermore, a positive correlation (0.41) was observed between BPP and BBP, implying a potential co-occurrence within packaging materials. Methyl-paraben also correlated positively with BBP (0.57), showing a detection rate of 53 %. The cumulative PBDE contents ranged from 0.33 to 1.62 ng/g, with BDE-154 and BDE-47 the dominant congeners. When comparing EDI values with TDIs, all organic pollutants remained below the thresholds across all exposure scenarios. Moreover, non-carcinogenic risks were below the threshold (HQ > 1) when dividing the EDIs by the respective reference doses for chronic exposure. While the current findings may suggest that infant formula intake poses no immediate risk in terms of the evaluated chemicals, it remains imperative to conduct further research to safeguard the health of infants considering other chemicals, as well as their potential cumulative effects.

Global PBDE contamination in cetaceans. A critical review

This review summarizes the most relevant information on PBDEs' occurrence and their impacts in cetaceans at global scale, with special attention on the species with the highest reported levels and therefore the most potentially impacted by the current and continuous release of these substances. This review also emphasizes the anthropogenic and environmental factors that could increase concentrations and associated risks for these species in the next future. High PBDE concentrations above the toxicity threshold and stationary trends have been related to continuous import of PBDE-containing products in cetaceans of Brazil and Australia, where PBDEs have never been produced. Non-decreasing levels documented in cetaceans from the Northwest Pacific Ocean might be linked to the increased e-waste import and ongoing production and use of deca-BDE that is still allowed in China. Moreover, high levels of PBDEs in some endangered species such as beluga whales (Delphinapterus leucas) in St. Lawrence Estuary and Southern Resident killer whales (Orcinus Orca) are influenced by the discharge of contaminated waters deriving from wastewater treatment plants. Climate change related processes such as enhanced long-range transport, re-emissions from secondary sources and shifts in migration habits could lead to greater exposure and accumulation of PBDEs in cetaceans, above all in those species living in the Arctic. In addition, increased rainfall could carry greater amount of contaminants to the marine environment, thereby, enhancing the exposure and accumulation especially for coastal species. Synergic effects of all these factors and ongoing emissions of PBDEs, expected to continue at least until 2050, could increase the degree of exposure and menace for cetacean populations. In this regard, it is necessary to improve current regulations on PBDEs and broader the knowledge about their toxicological effects, in order to assess health risks and support regulatory protection for cetacean species.

Evaluation of PCDD/Fs, PCBs and PBDEs in two penguin species from Antarctica

Persistent Organic Pollutants (POPs) are a global threat, but impacts of these chemicals upon remote areas such as Antarctica remain unclear. Penguins can be useful species to assess the occurrence of POPs in Antarctic food webs. This work's aim was the evaluation of polychlorodibenzo-p-dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in eggs of two penguin species, chinstrap (Pygoscelis antarticus) and gentoo penguins (Pygoscelis papua), breeding in the South Shetland Islands. Results showed a common pattern in POP levels regardless of the species, characterized by a major abundance of PCBs (98 %), followed by PBDEs (1-2%) and PCDD/Fs (<1 %). Concentrations of POPs in chinstrap and gentoo penguin eggs were 482 and 3250 pg/g l.w., respectively. PCBs, PBDEs and PCDD/Fs were found at higher concentrations in chinstrap penguin eggs, being these differences significant for PBDEs. Interspecies differences in POP levels agree well with potential trophic position differences among species due to changes in prey composition and foraging areas. POP profiles were dominated by congeners with a low degree of halogenation. Our results therefore suggest similar sources of POPs in the food webs exploited by both species and in both cases attributable to the long-range transportation rather than to the presence of local sources of POPs. TEQs were found between 1.38 and 7.33 pg/g l.w. and followed the pattern non-ortho dl-PCBs > PCDFs > PCDDs > mono-ortho dl-PCBs. TEQ values were lower than the threshold level for harmful effects in birds of 210 pg/g WHO-TEQ/g l.w.

Ingested plastics in northern fulmars (Fulmarus glacialis): A pathway for polybrominated diphenyl ether (PBDE) exposure?

Although it has been suggested that plastic may act as a vector for pollutants into the tissue of seabirds, the bioaccumulation of harmful contaminants, such as polybrominated diphenyl ethers (PBDEs), released from ingested plastics is poorly understood. Plastic ingestion by the procellariiform species northern fulmar (Fulmarus glacialis) is well documented. In this study, we measured PBDEs levels in liver tissue of northern fulmars without and with (0.13-0.43 g per individual) stomach plastics. PBDE concentrations in the plastic sampled from the same birds were also quantified. Birds were either found dead on beaches in southern Norway or incidentally caught in longline fisheries in northern Norway. PBDEs were detected in all birds but high concentrations were only found in liver samples from beached birds, peaking at 2900 ng/g lipid weight. We found that body condition was a significant factor explaining the elevated concentration levels in livers of beached birds. BDE209 was found in ingested plastic particles and liver tissue of birds with ingested plastics but was absent in the livers of birds without ingested plastics. This strongly suggests a plastic-derived transfer and accumulation of BDE209 to the tissue of fulmars, levels of which might prove useful as a general indicator of plastic ingestion in seabirds.

The trade-offs of foraging at landfills: Landfill use enhances hatching success but decrease the juvenile survival of their offspring on white storks (Ciconia ciconia)

During the last decades, landfills have become a valuable food source for wildlife, being in some cases determinants of large avian population increases. Superabundant food resources at landfills can increase reproductive and/or survival parameters; however, negative effects such as intoxication, plastic ingestion, skeletal deformities, unbalanced oxidative stress, and other health problems have also been reported. White stork (Ciconia ciconia) commonly benefits from landfill resources. Here, we evaluate potential landfill effects on demographic parameters (reproduction and offspring survival) at the individual level in a single population. Our results show that a more intense use of landfills by breeders has a positive effect on hatching success but a negative effect on juvenile survival probability after emancipation, at least during the first year of life. High amount of food and proximity to landfill may explain their beneficial effect on reproductive parameters. On the other hand, poor quality food, pollutants, and pathogens acquired during early development from a diet based on refuse may be responsible for reduced future survival probability. Consequently, both positive and negative effects were detected, being foraging at landfills at low to medium levels the better strategy. Although our study shows that intense foraging on rubbish can imply both costs and benefits at an individual level, the benefits of superabundant food provisioning observed at population level by other studies cannot be ignored. Management actions should be designed to improve natural food resources, reduce non-natural mortality and/or human disturbances to guarantee the species viability under current European Union regulations designed to ban open-air landfills in a near future.

A multidisciplinary approach to the evaluation of the effects of foraging on landfills on white stork nestlings

The use of landfills as foraging areas by white storks (Ciconia ciconia) is a recent well-known behaviour. While several studies have highlighted positive effects at a populational level others suggest that the presence of pollutants, pathogens and the lower presence of antioxidants in the food could pose a health risk for individuals. The objective of this study was to evaluate potential effects of the use of landfills as a food resource on the physiology and health of white stork nestlings, by a multidisciplinary approach based on the analysis of nutritional status, body condition, blood parameters, oxidative stress balance and the presence of pathogens. Results showed better body condition in individuals associated with landfills compared to the ones feeding on natural resources, as well as better nutritional status, as indicated by higher levels of albumin, cholesterol, and triglycerides in plasma. As many pollutants have a pro-oxidant effect, we evaluated oxidative stress balance, with no differences in the indicators of damage except for methaemoglobin (metHb), significantly higher in nestlings associated with landfill-origin food. Regarding antioxidants, GSH was higher in nestlings associated with landfills, which may suggest a hormetic response induced potentially by the presence of pollutants in waste. Nestlings fed food from landfills also had a higher presence of Escherichia coli with a multiresistant phenotype to antibiotics. In conclusion, our results show that nestlings fed with a higher proportion of food from landfills present a better nutritional status and body condition than those fed with a higher proportion of natural diet, being the only indicators of negative effects of the use of this food resource the higher percentage of metHb in the peripheral blood and the presence of antibiotic-resistant E. coli.

Interspecies comparisons of brominated flame retardants in relation to foraging ecology and behaviour of gulls frequenting a UK landfill

This study quantifies and compares concentrations and profiles of legacy and alternative (alt-) brominated flame retardants (BFRs) in the eggs of three gull (Laridae) species of international/UK conservation concern - great black-backed gulls (Larus marinus; n = 7), European herring gulls (L. argentatus; n = 16) and lesser black-backed gulls (L. fuscus; n = 11) in relation to their foraging ecology and behaviour in order to investigate potential exposure pathways at a remote landfill in western Scotland, UK. Egg concentrations of sum (∑) polybrominated diphenyl ethers (∑₈PBDEs) in all three species exceeded those for most reported avian species using landfill, except for those in North America. Despite relatively high detection frequencies of ∑hexabromocyclododecanes (∑₃HBCDDs) (94-100%), concentrations of ∑₈PBDEs exceeded ∑₃HBCDDs and ∑₅alt-BFRs, with ∑₈PBDE levels similar in all three species. Egg carbon isotopic (δ¹³C) values highlighted a greater marine dietary input in great black-backed gulls that was consistent with their higher BDE-47 levels; otherwise, dietary tracers were minimally correlated with measured BFRs. ∑₃HBCDD egg concentrations of herring gulls markedly exceeded those reported elsewhere in Europe. Decabromodiphenylethane (DBDPE) was the only alt-BFR detected (6-14% detection rate), in a single egg of each species. The great black-backed gull egg contained the highest concentration of DBDPE measured in biota to date globally and provides strong evidence for its emerging environmental presence as a BDE-209 replacement in UK wildlife. Correlations between δ¹³C (dietary source) and some measured BFRs in eggs suggest multiple routes of BFR exposure for gulls frequenting landfill through their diet, behaviour, preening, dermal exposure and likely inhalation. The frequent use of landfill by herring gulls and their increased egg BFR burdens suggest that this species may be an important bioindicator of BFR emissions from such sites.

4,5,6,7-Tetrabromo-2,3-dihydro-1,1,3-trimethyl-3-(2,3,4,5-tetrabromophenyl)-1H-indene (OBTMPI): Levels in humans and in silico toxicological profiles

Limited human exposure and toxicity data are currently available for 4,5,6,7-Tetrabromo-2,3-dihydro-1,1,3-trimethyl-3-(2,3,4,5-tetrabromophenyl)-1H-indene (OBTMPI), a flame retardant often used for high temperature application of various polymer materials. Levels of OBTMPI in a cohort population that includes children and their co-residing parents (n = 217) in Canada were determined. Detection frequency of OBTMPI in the samples was 22.6%. OBTMPI levels were in general at sub-to low ng/g lipid weight level with a 95th percentile at 15.6 ng/g lipid weight. Compared to an earlier study conducted in 2008-2009 in the same region, results from this study show an increase in both detection frequency and concentration of OBTMPI. In silico toxicity predictions using Multicase CaseUltra and Leadscope Model Applier suggested that OBTMPI, and its possible metabolites in humans, while unlikely to be carcinogenic or mutagenic, exhibit some estrogen antagonist, androgen antagonist and estrogen binding capability reflective of possible endocrine disrupting properties.

Decreasing but still high levels of halogenated flame retardants in wetland birds in central Spain

The occurrence of classical and emerging halogenated flame retardants in bird samples collected between 2010-17 from the Castrejón reservoir (central Spain) was studied. Different wetland bird samples were analysed, including unhatched bird eggs and liver of dead nestlings. Polybrominated diphenylethers (PBDEs) were detected in all the samples at high concentration values, with levels up to 5167 ng/g lw. Dechloranes were found in 78% of analysed samples, but at lower concentration levels, between not detected (nd) and 2153 ng/g lw. The time trend evaluation over the sampling period showed an approximately 50% decline in mean concentrations of PBDEs. However, the most recent data for PBDEs (2016-17) still indicate that, in some cases, and based on reported LOECs, wetland birds were exposed to PBDE concentrations that are associated with possible ecological hazards.

Flame retardant concentrations and profiles in wild birds associated with landfill: A critical review

Given factors such as their persistence and toxicity, legacy brominated flame retardants (BFRs) like polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD), are designated as persistent organic pollutants (POPs) and are subject to regulation. Waste streams likely represent a substantial reservoir of legacy BFRs given that they were once widely applied to goods which are increasingly likely to be obsolete. Waste streams are also increasingly likely to be a source of emerging flame retardants, in particular, novel BFRs (NBFRs), the halogenated norbornene flame retardant Dechlorane Plus (DDC-CO) and the brominated, chlorinated or non-halogenated organophosphate triester flame retardants (PFRs). Many bird populations rely on landfill and its surrounding land-use for inter alia the opportunities it provides for activities such as foraging and resting. However, studies on captive and wild (free-living) birds have demonstrated deleterious effects of several FRs. Globally, approximately 250 bird species, including many of conservation concern, are reported to use landfill and surrounding habitat (including wastewater treatment operations), thus putting birds potentially at risk of exposure to such chemicals. We synthesise and critically evaluate a total of 18 studies covering eight avian species published between 2008 and 2018 (inclusive) across four continents that report flame retardant (FR) burdens in birds utilising landfill. Several such studies found FRs at among the highest concentrations detected in wild biota to date. We recommend that ongoing research be focused on landfill-associated birds, given that landfill is an important source of FRs and other anthropogenic chemicals, and particularly at sites where species are of conservation concern. We suggest ways in which the comparative power of studies could be enhanced in the future, the reporting of a minimum common suite of key chemicals, and where feasible, standardisation of the tissue compartments (i.e., eggs) to be studied. We conclude by identifying future research directions.

Embryotoxic effects of in-ovo triclosan injection to the yellow-legged gull

Triclosan (TCS) is an antimicrobial agent used in diverse personal care products that is considered as an emerging contaminant of both aquatic and terrestrial ecosystems. Although TCS aquatic ecotoxicity is well known, information on the presence and effects on terrestrial organisms is still scarce. This study was aimed at exploring the embryotoxicity of TCS to the yellow-legged gull (Larus michahellis) induced by the in-ovo injection of 150 ng TCS/g egg weight. Effects of TCS on embryo morphological traits (i.e. body mass, tarsus length and head size). Moreover, oxidative and genetic effects were assessed in the embryo liver, by measuring the amount of reactive oxygen species (ROS), the activity of antioxidant (superoxide dismutase and catalase) and detoxifying (glutathione S-transferase - GST) enzymes, the levels of lipid peroxidation and DNA fragmentation. After the injection, the concentration of TCS measured in the yolk of unincubated eggs (159 ± 35 ng/g wet weight, ww) was close to the expected concentration. Triclosan was found in residual yolk (2.9 ± 1.1 ng/g ww), liver (2.3 ± 1.1 ng/g ww) and brain (0.2 ± 0.1 ng/g ww) of embryos soon before hatching. Triclosan did not significantly affect embryo morphological traits, while it increased ROS levels and promoted GST activity, inducing the onset of both oxidative and genetic damage. This study demonstrated, for the first time in a wild euriecious bird species with mixed habits, that TCS can be maternally transferred to developing embryos, representing a potential threat for offspring.

Evaluation of PCDD/Fs, dioxin-like PCBs and PBDEs in sperm whales from the Mediterranean Sea

Numerous studies to date have reported concentrations of Persistent Organic Pollutants (POPs) in different marine mammal species worldwide. Yet data on sperm whales are scarce from rich and unique biodiverse areas such as the Mediterranean Sea. This work aimed to assess levels of dioxin-like polychlorinated biphenyls (dl-PCBs), polybrominated diphenyl ethers (PBDEs), and polychlorodibenzo-p-dioxins and furans (PCDD/Fs) in blubber of sperm whales stranded along the Italian coast between 2008 and 2016. POP mean concentrations (dl-PCBs: 6410 ng/g l.w.; PBDEs: 612 ng/g l.w.; PCDD/Fs: 57.8 pg/g l.w.) were mostly in line with what has been previously reported on the same species in the Mediterranean environment and tended to be higher than those reported from other geographical regions. The relative abundance followed the order dl-PCBs > PBDEs ≫ PCDD/Fs. Interestingly, the non-ortho dl-PCB pattern (126 > 169 > 77) was similar to that described in other studies worldwide and different from what is described in its main prey. This could be linked to particular metabolic activities in sperm whales against these highly toxic contaminants. Total TEQs ranged from 275 to 987 pg/g l.w. and showed the pattern Σnon-ortho-dl-PCBs > Σortho-dl-PCBs > PCDDs > PCDFs, with PCBs' contribution about 96%. These findings highlight the high abundance of PCBs still found in the Mediterranean environment despite having been banned for decades. All sperm whales analyzed in this study surpassed the threshold of 210 pg WHO-TEQ/g l.w. proposed as starting point of immunosuppression in harbour seals; a level of contamination that may have contributed to an impairment of their immune system.

Distribution of polybrominated diphenyl ethers (PBDEs) in feather and muscle of the birds of prey from Beijing, China

Polybrominated diphenyl ethers (PBDEs) in the feather and muscle of common kestrels (Falco tinnunculus), eagle owls (Bubo bubo) and little owls (Athene noctua) collected from Beijing, China were investigated. The concentrations of ∑₂₃PBDEs in the muscle and feather of all the birds of prey ranged from 46 to 7.77 × 10⁴ ng/g lipid weight (lw; median 241 ng/g lw) and 1.50-191 ng/g dry weight (dw; median 21.1 ng/g dw), respectively. Higher brominated congeners, e.g., BDE-209, -153, -207 and -196 were the dominant congeners in both feather and muscle. However, the concentrations of lower brominated congeners in feather were significantly correlated with those in muscle (p < 0.05), which suggested that feather could efficiently reflect lower brominated BDEs in the internal tissue of birds of prey. The calculated hazard quotients (HQs) > 10 in common kestrel and little owl suggested that the high levels of PBDEs posed potentially high risk to some birds of prey living in Beijing area.

Presence and impact of Stockholm Convention POPs in gull eggs from Spanish and Portuguese natural and national parks

The aim of the present work was to comparatively assess the occurrence and impact of persistent organic pollutants (POPs) in nine natural and national parks from Spain and Portugal using gull eggs (Larus michahellis and L. audouinii) as bioindicators of environmental contamination. Sampling was performed during the breeding season of 2016. Compounds studied include polychlorinated biphenyls (PCBs), organochlorinated pesticides (OC pesticides), perfluorooctane sulfonic acid (PFOS) and polybrominated diphenyl ethers (PBDEs), and were analyzed using mass spectrometric based techniques. The results showed a high contamination by PCBs in all colonies, with total levels ranging from 59 to 1278ng/g wet weight (ww), despite their use is not currently authorized. OC pesticides were also present in all colonies, with a high incidence of 4,4'-DDE in gull eggs at levels up to 218±50ng/g ww in L. michahellis and 760±412ng/g ww in L. audouinii from the Ebro Delta natural park. PBDEs and PFOS were also detected at levels up to 91.7±21.3ng/g ww, which can be attributed to a more recent use. Except for PBDEs, the POP levels in eggs from L. audouinii were higher than in L. michahellis, presumably associated to the fish-based diet of the former. Finally, the effect of POP levels on eggshell parameters (volume, eggshell thickness and desiccation index) were investigated for each colony and gull species in order to evaluate the egg viability and, therefore, the reproduction success.

Enrichment and physiological responses of dechlorane plus on juvenile marine macroalgae (Ulva pertusa)

Dechlorane Plus (DP), a chlorinated flame retardant, is increasingly reported in aquatic ecosystems worldwide. But little information is available regarding the toxicity of DP in marine organisms, especially in macroalgae. The objective of this study was to investigate effects of DP exposure on photosynthesis, oxidative stress and its enrichment in juvenile marine macroalgae (Ulva pertusa). Following 21- day uptake and 21- day depuration (10^-8 mol/L), algae accumulated 1.18 times of DP compared to the initial concentration. Anti-DP was prone to accumulate in juvenile macroalgae. The enrichment of DP affected the physiological responses in algae. After 1, 7 and 14 days DP exposure (10^-8, 10^-7 and 10^-6 mol/L), antioxidant enzymes (SOD and CAT) activities and MDA content changed in a dose and time depended manner. Chlorophyll fluorescence parameters, including F_v/F_m, Φ_PSII and ETR decreased with the increasing DP concentration. It indicated that DP leads to a low rate of light energy utilization in algae which may ascribe to the oxidative damage induced by DP enrichment. Present study provides insight into the toxicological effects of DP on marine macroalgae, which is useful for risk assessment of DP in intertidal zone ecosystems.

Exposure to polybrominated diphenyl ethers (PBDEs) and child behavior: Current findings and future directions

Polybrominated diphenyl ethers (PBDEs) are recognized neurotoxicants, but the extent to which PBDEs influence various domains of behavior in children is not fully understood. As such, we reviewed epidemiologic studies published to date to provide an overview of the current state of knowledge on PBDEs' potential role in behavioral development. We identified 19 epidemiologic studies reporting on associations of prenatal and childhood concentrations of PBDEs with behaviors assessed in children from 1 to 12years, including executive function, attention, externalizing and internalizing behaviors, adaptive skills, and social behaviors/Autism Spectrum Disorder (ASD). While the mechanisms of PBDE neurotoxicity in humans are still not clearly elucidated, findings from this review indicate that PBDE exposure during fetal development is associated with impairments in executive function and poorer attentional control in children. Results from large prospective cohorts demonstrate that prenatal and postnatal PBDE exposure adversely impacts externalizing behavior (e.g., hyperactivity and conduct problems). Additional studies are needed to determine whether PBDEs are associated with internalizing problems, adaptive skills, and social behaviors/ASD in children. Future studies will help better understand the potential neurotoxic effects of PBDE exposures during adolescence, possible sex-dependent effects, and the impact of exposure to BDE-209 and alternative flame retardants. Future studies should also examine chemical mixtures to capture real-world exposures when examining PBDEs and their impact on various behavioral domains in the context of multiple chemical exposures.

Tissue distribution and maternal transfer of persistent organic pollutants in Kentish Plovers (Charadrius alexandrines) from Cangzhou Wetland, Bohai Bay, China

Several persistent organic pollutants, including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), were comprehensively investigated in the egg, muscle and liver samples of Kentish Plover (Charadrius alexandrines) collected from Cangzhou Wetland in western Bohai Bay, China. DDTs were the most abundant contaminants (35.4-9853ngg^-1 lipid weight, lw), followed by HCHs, PCBs, PBDEs and HCB. PCDD/Fs exhibited the lowest concentrations in all tissues (8.74-4763pgg^-1 lw). PCBs and PCDD/Fs were dominated by penta- and hexa-homologs, and PBDEs mostly consisted of the signature congeners of BDE formulations, such as BDE-209, -47, -153 and -99. Significant correlations were found between the lipid-normalized concentrations in muscle and liver (r: 0.37-0.90, p<0.05) and no significant differences (p<0.05), indicating the homogenous distribution of POPs in tissue lipids at steady state. The ratios of concentrations in muscle and liver (M/L) ranged from 0.20 to 1.51, and higher ratios of M/L were found for those compounds with log K_ow in the range of 6.5-7.0, suggesting the preferential accumulation of mid-halogenated compounds in muscle. Significant correlations were generally observed between the concentrations in egg and the maternal tissue (p<0.05). The concentration ratios of egg to liver (E/L) were in the range of 0.10-1.24 except for p,p'-DDT (12.7), and compounds with log K_ow of 6.5-7.0 exhibited higher E/L ratios, suggesting the selective maternal transfer of mid-halogenated compounds.

Brominated flame retardants (BFRs) in eggs from birds of prey from Southern Germany, 2014

In Southern Germany, peregrine falcons (Falco peregrinus), which almost exclusively prey on other birds, are top predators of the terrestrial food chain. These animals accumulate persistent organic pollutants (POPs) and halogenated flame retardants (HFRs) with mothers transferring these lipophilic contaminants to their eggs. Here we analyzed unhatched eggs of eleven peregrine falcons and six of other species, and report concentrations of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), hexabromobenzene (HBB), 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) and its metabolites, pentabromoethylbenzene (PBEB), pentabromotoluene (PBT), and tribromophenol (TBP). The extract of one purified peregrine falcon egg sample was comprehensively analyzed in a non-target (NT) approach by gas chromatography with mass spectrometry in the electron capture negative ion mode. A total of ∼400 polyhalogenated compounds were detected, among them dechloranes and possibly transformation products, two tetrabrominated metabolites of PBT and several compounds unknown to us which could not be identified.

Pyrethroids in chicken eggs from commercial farms and home production in Rio de Janeiro: Estimated daily intake and diastereomeric selectivity

In this study, pyrethroids were determined in chicken eggs from commercial farm (n = 60) and home egg production (n = 30). These pyrethroids were investigated: bifenthrin, phenothrin, permethrin, cyfluthrin, cypermethrin and fenvalerate, including most diastereomers. Quantification was done using GC-MS in a negative chemical ionization mode. Pyrethroids residues were found in 79% of the analyzed samples. Cypermethrin presented the highest occurrence, being quantified in 62 samples (69%) in concentrations (lipid weight - l w.) varying between 0.29 and 6408 ng g^-1, followed by phenothrin (24%), 21-3910 ng g^-1, permethrin (14%), 2.96-328 ng g^-1, and bifenthrin (11%), 3.77-16.7 ng g^-1. Cyfluthrin and fenvalerate were not detected. Home-produced eggs had a higher occurrence of pyrethroids (97%), with a greater predominance of phenothrin. In commercial production, 70% of the samples presented pyrethroid residues (predominantly cypermethrin). This is the first report about the presence of pyrethroids in home-produced eggs and the first description of a selectivity pattern with the predominance of cis diastereomers in chicken eggs. In general, estimated daily intake does not present a risk to human consumption, according to Brazilian and international standards (FAO/WHO). However, one third of the samples (30 eggs) had concentrations above the maximum residue limits (MRLs). The maximum cypermethrin concentration was 66 times the MRL, while the maximum phenothrin concentration was 11 times the limit. Further studies about transfer dynamics, bioaccumulation and metabolic degradation of stereoisomers are required, as well as determining if this selectivity pattern in food can increase consumer's health risk.

Prenatal transfer of decabromodiphenyl ether (BDE-209) results in disruption of the thyroid system and developmental toxicity in zebrafish offspring

Decabromodiphenyl ether (BDE-209) was one of most widely-used polybrominated diphenyl ether (PBDE) flame retardants and is frequently detected in both abiotic and biotic samples from environment. However, knowledge of its transgenerational risks is limited. Here, 4-month-old zebrafish were exposed to various concentrations of BDE-209 (0, 3, 30 or 300μg/L) for 28days and spawned in clean water without BDE-209. Concentrations of triiodothyronine (T3) and thyroxine (T4) as well as expressions of genes involved in the hypothalamic-pituitary-thyroid (HPT) axis were measured in offspring after exposure of adult zebrafish to BDE-209. BDE-209 was accumulated in adult fish and F1 eggs, which suggests transfer of this compound from adult fish to their offspring. Exposure of BDE-209 to parents resulted in developmental abnormalities in offspring and a significant decrease in T4 concentrations in F1 larvae 120h post-fertilization (hpf). Furthermore, expressions of several genes involved in the HPT axis were also altered. Expressions of thyroid hormone receptor α (tr-α), thyrotropin releasing hormone (trh), thyroid stimulating hormone β (tsh-β) and deiodinase 1 (dio 1) were significantly down-regulated in F1 individuals, while expressions of thyroid stimulating hormone receptor (tshr) and transthyretin (ttr) were significantly up-regulated. These results suggest that exposure of parent zebrafish to BDE-209 can cause developmental toxicity in offspring and disruption of the thyroid endocrine system of offspring.

Relationship between legacy and emerging organic pollutants in Antarctic seabirds and their foraging ecology as shown by δ13C and δ15N

Foraging ecology and the marine regions exploited by Antarctic seabirds outside of breeding strongly influence their exposure to persistent organic pollutants (POPs). However, relationships between them are largely unknown, an important knowledge gap given that many species are capital breeders and POPs may be deleterious to seabirds. This study investigates the relationship between Antarctic seabird foraging ecology (measured by δ¹³C and δ¹⁵N) and POPs accumulated in their eggs prior to breeding. Organochlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dechlorane plus (DP) were measured in eggs of chinstrap, Adélie, and gentoo penguins (Pygoscelis antarctica, P. adeliae, P. papua), as well as south polar skua (Catharacta maccormicki), sampled on King George Island. Total POP levels were as follows: skua (3210±3330ng/g lipid weight)>chinstrap (338±128ng/g)>Adélie (287±43.3ng/g)>gentoo (252±49.4ng/g). Trophic position and pre-breeding foraging sites were important in explaining POP accumulation patterns across species. The most recalcitrant compounds were preferentially accumulated in skuas, occupying one trophic level above penguins. In contrast, their Antarctic endemism, coupled with influence from cold condensation of pollutants, likely contributed to penguins exhibiting higher concentrations of more volatile compounds (e.g., hexachlorobenzene, PCB-28 and -52) than skuas. Regional differences in penguin pre-breeding foraging areas did not significantly affect their POP burdens, whereas the trans-equatorial migration and foraging sites of skuas were strongly reflected in their pollutant profiles, especially for PBDEs and DPs. Overall, our results provide new insights on migratory birds as biovectors of POPs, including non-globally regulated compounds such as DP, from northern regions to Antarctica.

Influence of trophic ecology on the accumulation of dioxins and furans (PCDD/Fs), non-ortho polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in Mediterranean gulls (Larus michahellis and L. audouinii): A three-isotope approach

The impact of pollution caused by severe anthropogenic pressure in the Mediterranean Sea, an important biodiversity hotspot, requires continuous research efforts. Sources of highly toxic chemicals such as Persistent Organic Pollutants (POPs) are misunderstood in representative Mediterranean species, which limits our capability to establish proper conservation strategies. In the present study, eggs of Audouin's and yellow-legged gulls (Larus audouinii and L. michahellis) were used to investigate the trophic sources, as measured by δ(13)C, δ(15)N, and δ(34)S, of legacy POPs, in particular, polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and non-ortho polychlorinated biphenyls (no-PCBs), as well as recently-regulated POPs, e.g., polybrominated diphenyl ethers (PBDEs). Special attention was paid to the usefulness of rarely-explored δ(34)S ratios in explaining POP exposure in wildlife, and δ(34)S was the isotopic ratio that best explained POP variations among gulls in most cases, thus demonstrating its usefulness for understanding POP exposure in wildlife. Significant relationships between stable isotope signatures and POP concentrations revealed increasing levels of no-PCBs and low halogenated PCDD/Fs and PBDEs in Mediterranean gulls as the consumption of marine resources increases. In contrast, highly chlorinated and brominated congeners appeared to preferentially accumulate in gulls feeding primarily on refuse from dump sites and terrestrial food webs. The use of suitable dietary tracers in the study of POPs in yellow-legged gulls revealed the importance of dump sites as a source of POPs in Mediterranean seabirds, which has not previously been reported. In contrast, the preferential accumulation through marine food webs of low chlorinated PCCD/Fs and no-PCBs, which show the highest toxic equivalents factors (TEFs), led to a significantly greater toxicological concern in Audouin's as compared to yellow-legged gulls. Audouin's gull exposure to POPs appears primarily related to the pelagic food webs commonly exploited by fisheries, highlighting the need for further research given the potential impact on human consumption.

Evaluation of the Genotoxic and Physiological Effects of Decabromodiphenyl Ether (BDE-209) and Dechlorane Plus (DP) Flame Retardants in Marine Mussels (Mytilus galloprovincialis)

Dechlorane Plus (DP) is a proposed alternative to the legacy flame retardant decabromodiphenyl ether (BDE-209), a major component of Deca-BDE formulations. In contrast to BDE-209, toxicity data for DP are scarce and often focused on mice. Validated dietary in vivo exposure of the marine bivalve (Mytilus galloprovincialis) to both flame retardants did not induce effects at the physiological level (algal clearance rate), but induced DNA damage, as determined by the comet assay, at all concentrations tested. Micronuclei formation was induced by both DP and BDE-209 at the highest exposure concentrations (100 and 200 μg/L, respectively, at 18% above controls). DP caused effects similar to those by BDE-209 but at lower exposure concentrations (5.6, 56, and 100 μg/L for DP and 56, 100, and 200 μg/L for BDE-209). Moreover, bioaccumulation of DP was shown to be concentration dependent, in contrast to BDE-209. The results described suggest that DP poses a greater genotoxic potential than BDE-209.

Temporal trends in classical and alternative flame retardants in bird eggs from Doñana Natural Space and surrounding areas (south-western Spain) between 1999 and 2013

Several halogenated flame retardants were detected in black kite, white stork and greater flamingo unborn eggs from Doñana Natural Space (Spain) collected in 1999, 2003, 2011 and 2013. The main components of Penta-BDE commercial mixture (BDE-47, -99 and -100) showed a decrease in the studied time interval, concurring with the ban of this mixture in the European Union (EU) in 2006. On the other hand, BDE-209, the main component of Deca-BDE mixture showed a clear trend in black kites but further monitoring is needed since its production ceased at the end of 2013. Besides, even if Dechlorane Plus (DP) was proposed by the EU as an alternative to BDE-209 no time trends were observed. Furthermore, total concentrations of PBDEs (classical FRs) are still higher than concentrations of hexabromocyclododecane (HBCD) and alternative FRs halogenated norbornenes (HNs), which are theoretically substitutes of the already banned PBDEs.

Facilitated Leaching of Additive-Derived PBDEs from Plastic by Seabirds' Stomach Oil and Accumulation in Tissues

Our previous study suggested the transfer of polybrominated diphenyl ether (PBDE) flame retardants from ingested plastics to seabirds' tissues. To understand how the PBDEs are transferred, we studied leaching from plastics into digestive fluids. We hypothesized that stomach oil, which is present in the digestive tract of birds in the order Procellariiformes, acts as an organic solvent, facilitating the leaching of hydrophobic chemicals. Pieces of plastic compounded with deca-BDE were soaked in several leaching solutions. Trace amounts were leached into distilled water, seawater, and acidic pepsin solution. In contrast, over 20 times as much material was leached into stomach oil, and over 50 times as much into fish oil (a major component of stomach oil). Analysis of abdominal adipose, liver tissue, and ingested plastics from 18 wild seabirds collected from the North Pacific Ocean showed the occurrence of deca-BDE or hexa-BDEs in both the tissues and the ingested plastics in three of the birds, suggesting transfer from the plastic to the tissues. In birds with BDE209 in their tissues, the dominance of BDE207 over other nona-BDE isomers suggested biological debromination at the meta position. Model calculation of PBDE exposure to birds based on the results of the leaching experiments combined with field observations suggested the dominance of plastic-mediated internal exposure to BDE209 over exposure via prey.

Trends of polybrominated diphenyl ethers and hexabromocyclododecane in eggs of Canadian Arctic seabirds reflect changing use patterns

Due to the substantial use and release of polybrominated diphenyl ether (PBDE) flame retardants in North America, PBDE concentrations in North American marine biota are among the highest in the world. In this study, we compared PBDE concentrations and congener patterns in eggs of five seabird species (thick-billed murres, northern fulmars, black guillemots, glaucous gulls, black-legged kittiwakes) breeding at a colony in the Canadian Arctic in 1993, 2008 and 2013. Temporal trends of PBDEs (1975-2014) and another flame retardant, hexabromocyclododecane (HBCD) (2003-2014), were also examined in eggs of two seabird species, the thick-billed murre and northern fulmar. BDE-47 generally dominated the BDE congener profiles in eggs of all five species. Glaucous gulls had the highest concentrations of both ΣPBDE and BDE-47, and northern fulmars, the lowest. ΣPBDE concentrations increased exponentially in eggs of both thick-billed murres and northern fulmars from 1975 to 2003 with doubling times of 9.1 years in the murres and 7.2 years in the fulmars. From 2003 to 2008/09, ΣPBDE decreased rapidly in the murres and fulmars to concentrations not significantly different from those recorded in 1975 and 1987 for each species. After 2008/09, ΣPBDE concentrations plateaued. BDE-47 followed a similar temporal trend to that of ΣPBDE concentrations. These concentration trends were consistent with the phase-out of the penta- and octa-BDE products from the North American market in the mid-2000s. There was an overall decline in concentrations of HBCD in murre eggs from 2003 to 2014, whereas concentrations in the fulmar eggs increased from 2003 to 2006 followed by a decline to 2014. The ratio of HBCD to BDE-47 suggests that northern fulmars showed more of a European contaminant signature, and thick-billed murres, more of a North American signature.

Halogenated Natural Products in Dolphins: Brain-Blubber Distribution and Comparison with Halogenated Flame Retardants

Halogenated natural products (MHC-1, TriBHD, TetraBHD, MeO-PBDEs, Q1, and related PMBPs) and halogenated flame retardants (PBDEs, HBB, Dec 602, Dec 603, and DP) in blubber and brain are reported from five Alboran Sea delphinids (Spain). Both HNPs and HFRs were detected in brain, implying that they are able to surpass the blood-brain barrier and reach the brain, which represents a new finding for some compounds, such as Q1 and PMBPs, MHC-1, TriBHD, TetraBHD, or Dec 603. Moreover, some compounds (TetraBHD, BDE-153, or HBB) presented higher levels in brain than in blubber. This study evidence the high concentrations of HNPs in the marine environment, especially in top predators. It shows the importance of further monitoring these natural compounds and evaluating their potential toxicity, when most studies focus on anthropogenic compounds only. While no bioaccumulation was found for ∑HNPs, ∑HFRs increased significantly with body size for both common and striped dolphins. Studies evaluating BBB permeation mechanisms of these compounds together with their potential neurotoxic effects in dolphins are recommended.

A first European scale multimedia fate modelling of BDE-209 from 1970 to 2020

The European Variant Berkeley Trent (EVn-BETR) multimedia fugacity model is used to test the validity of previously derived emission estimates and predict environmental concentrations of the main decabromodiphenyl ether congener, BDE-209. The results are presented here and compared with measured environmental data from the literature. Future multimedia concentration trends are predicted using three emission scenarios (Low, Realistic and High) in the dynamic unsteady state mode covering the period 1970-2020. The spatial and temporal distributions of emissions are evaluated. It is predicted that BDE-209 atmospheric concentrations peaked in 2004 and will decline to negligible levels by 2025. Freshwater concentrations should have peaked in 2011, one year after the emissions peak with sediment concentrations peaking in 2013. Predicted atmospheric concentrations are in good agreement with measured data for the Realistic (best estimate of emissions) and High (worst case scenario) emission scenarios. The Low emission scenario consistently underestimates measured data. The German unilateral ban on the use of DecaBDE in the textile industry is simulated in an additional scenario, the effects of which are mainly observed within Germany with only a small effect on the surrounding areas. Overall, the EVn-BTER model predicts atmospheric concentrations reasonably well, within a factor of 5 and 1.2 for the Realistic and High emission scenarios respectively, providing partial validation for the original emission estimate. Total mean MEC:PEC shows the High emission scenario predicts the best fit between air, freshwater and sediment data. An alternative spatial distribution of emissions is tested, based on higher consumption in EBFRIP member states, resulting in improved agreement between MECs and PECs in comparison with the Uniform spatial distribution based on population density. Despite good agreement between modelled and measured point data, more long-term monitoring datasets are needed to compare predicted trends in concentration to determine the rate of change of POPs within the environment.

Could feeding habit and migratory behaviour be the causes of different toxicological hazard to cetaceans of Gulf of California (Mexico)?

In this work, a suite of diagnostic biomarkers was applied to seven cetacean species to evaluate the role of the feeding habits and migratory behavior in the toxicological status of these species from the Gulf of California, Mexico. We investigate the interspecific differences in cytochrome P450 1A1 and 2B (CYP1A1 and CYP2B, respectively), aryl hydrocarbon receptor and E2F transcription factor 1 and the contaminants levels [organochlorine compounds, polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs)] in four odontocete species (common bottlenose dolphin, long-beaked common dolphin, sperm whale and killer whale) and three mysticete species (blue whale, fin whale, and Bryde's whale) using skin biopsy. Differences in contaminant levels and molecular biomarker responses between the odontocete and mysticete species have been pointed out. The canonical discriminant analysis on principal component analysis factors, performed to reveal clustering variables, shows that odontocete are characterised by the highest levels of lipophilic contaminants compared to the mysticete, with the highest levels of polychlorinated biphenyls, dichlorodiphenyltrichloroethanes and PBDEs detected in killer whale and the lowest levels in Bryde's whale. The biomarker data show interspecific differences amongst the seven species, revealing highest CYP1A and CYP2B protein levels in the mysticete fish-eating species (Bryde's whale). In conclusion, three main factors seem to regulate the biomarker responses in these species: (a) the inductive ability of persistent organic pollutants and PAHs; (b) the different evolutionary process of the two CYPs related to the different feeding habits of the species; (c) the migratory/resident behaviour of the mysticete species in this area.

Effects of BDE-209 and its mixtures with BDE-47 and BDE-99 on multiple biomarkers in Carassius auratus

In the present study, the sublethal effects of BDE-209 and its mixtures with BDE-47 and BDE-99 on goldfish (Carassius auratus) were investigated, and the biomarkers including acetylcholinesterase (AChE) in brain, catalase (CAT), ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST) and superoxide dismutase (SOD) in liver were determined after 4 days of exposure. AChE and CAT activities were significantly inhibited by BDE-209 and the mixtures at higher dosages (≥1mg/kg), and exhibited obvious dose-response relationships. EROD, GST and SOD activities were significantly induced by BDE-209 and the mixtures in most cases. Integrated biomarker response (IBR) was calculated by combining multiple biomarkers to single value and used to quantitatively evaluate the toxicological effects of PBDEs. The order of IBR values was BDE-209/BDE-99>BDE-209/BDE-99/BDE-47>BDE-209/BDE-47>BDE-209. It suggests that IBR might be a useful tool for quantification of integrated biological effects induced by coexisted contaminants toward fish.

Bioaccumulation and biomagnification of emerging and classical flame retardants in bird eggs of 14 species from Doñana Natural Space and surrounding areas (South-western Spain)

The occurrence of classical (polybrominated diphenyl ethers, PBDEs) and emerging FRs (dechloranes, hexabromobenzene (HBB), pentabromoethyl benzene (PBEB) and decabromodiphenyl ethane (DBDPE)) in unborn eggs of 14 different species from Doñana Natural Space and surrounding areas was studied. PBDEs, Dec-602, Dec-603 and DP were detected in all the species, whereas HBB, PBEB, DBDPE and Dec-604 were not detected in any sample. ΣPBDE and ΣDechlorane levels ranged from 1.40 to 90.7, and from 0.77 to 260 ng/g lw, respectively. BDE-209 was the most abundant BDE congener in almost all the species, whereas Dec-602 was the predominant among dechloranes. In general, levels of PBDEs and dechloranes were similar and even higher for dechloranes, probably indicating the increasing use of dechloranes as a result of legal restrictions on PBDEs. In both cases, the most contaminated specie was the white stork. Using stable isotope characterization, differences among species and possible biomagnification processes were also evaluated. PBDE levels increased as the trophic position increased, showing biomagnification capacity. The same behavior was observed for Dec-602 and Dec-603; however, DP levels were not linearly correlated with trophic level. These results show that more attention should be given to emerging FRs such as dechloranes since they show similar environmental behavior as PBDEs.

Polybrominated diphenyl ethers and multiple stressors influence the reproduction of free-ranging tree swallows (Tachycineta bicolor) nesting at wastewater treatment plants

Reproductive success of birds is influenced by maternal factors, ambient temperatures, predation, food supply, and/or exposure to environmental contaminants e.g., flame retardants (FRs). Reproduction of tree swallows (Tachycineta bicolor) was compared among waste water treatment plants (WWTPs) and a reference reservoir in Ontario, Canada (2007-2010), to determine the importance of exposure to polybrominated diphenyl ether (PBDEs) FRs within a complex contaminant cocktail, relative to natural and biological factors known to influence avian reproduction. The birds primarily consumed insects emerging from the reference reservoir and WWTP outflows, where effluent mixed with receiving waters. FR egg concentrations were dominated by 5 PBDE congeners (∑5PBDEs): 2,2'.4,4',5-pentabromodiphenyl ether (BDE-99), 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), 2,2'4,4',6-pentabromodiphenyl ether (BDE-100), 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153), and 2,2',4,4',5,6'-hexabromodiphenyl ether (BDE-154), with much lower concentrations of decabromodiphenylether (BDE-209), hexabromocyclododecane (HBCDD), and novel FRs. Although higher than ∑5PBDEs, polychlorinated biphenyls (PCBs) egg concentrations were unlikely to affect the swallows' reproduction. Clutch size and timing, fledging, breeding success, and predation, varied significantly among sites, generally being poorer at WWTP1 and better at WWTP2. The early reproductive stages were sensitive to some FRs at measured concentrations. The ∑5PBDEs, maternal age, and minimum ambient temperatures predicted onset of egg laying in the most parsimonious statistical model, and there were positive relationships between egg size and HBCDD or BDE-209 concentrations. However, there were no significant correlations with any reproductive measures, individual BDE congeners or low concentrations of novel FRs, in this first such report for novel FRs and wild birds. Tree swallows are passerines, and passerines may differ from birds of prey in their reproductive sensitivity to PBDE exposure: lay date, minimum temperatures, and predation, but not PBDE exposure, predicted reproductive productivity. Overall, there was some influence of the PBDEs available in these WWTP outflows on early reproductive parameters, but not reproductive output, of these passerines.

Effects of BDE-209 contaminated sediments on zebrafish development and potential implications to human health

Polybrominated diphenyl ethers are compounds widely used as flame-retardants, which are of increasing environmental concern due to their persistence, and potential adverse effects. This study had two objectives. First, we assessed if BDE-209 in sediment was bioavailable and bioaccumulated into zebrafish embryos. Secondly, we assessed the potential impact on human and environmental health of bioavailable BDE-209 using human in vitro cell assays and zebrafish embryos. Zebrafish were exposed from 4h to 8days post-fertilization to sediments spiked with 12.5mg/kg of BDE-209. Zebrafish larvae accumulated ten fold more BDE-209 than controls in unspiked sediment after 8days. BDE-209 impacted expression of neurological pathways and altered behavior of larvae, although BDE-209 had no visible affect on thyroid function or motoneuron and neuromast development. Zebrafish data and in silico predictions suggested that BDE-209 would also interact with key human transcription factors and receptors. We therefore tested these predictions using mammalian in vitro assays. BDE-209 activated human aryl hydrocarbon receptor, peroxisome proliferator activating receptors, CF/b-cat, activator protein 1, Oct-MLP, and the estrogen receptor-related alpha (ERRα) receptor in cell-based assays. BDE-209 also inhibited human acetylcholinesterase activity. The observation that BDE-209 can be bioaccumulated from contaminated sediment highlights the need to consider this as a potential environmental exposure route. Once accumulated, our data also show that BDE-209 has the potential to cause impacts on both human and environmental health.

Species-specific accumulation of halogenated flame retardants in eggs of terrestrial birds from an ecological station in the Pearl River Delta, South China

Little information is available on the bioaccumulation of halogenated flame retardants (HFRs) in terrestrial ecosystem. Eggs of light-vented bulbul, yellow-bellied prinia, plain prinia, and dark green white-eye were collected from an ecological station in the Pearl River Delta, South China to investigate the occurrence of polybrominated diphenyl ethers (PBDEs) and several alternative HFRs, including decabromodiphenyl ethane (DBDPE), dechlorane plus (DP), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), pentabromotoluene (PBT), and 2,3,5,6-tetrabromo-p-xylene (pTBX). Concentrations of PBDEs, DBDPE, DP, HBB, PBEB, BTBPE, PBT, and pTBX ranged from 53-423, 6.1-609, 4.6-268, not detected (nd)-10, nd-1.4, nd-1.7, nd-7.5, and nd-3.2 ng g(-1) lw, respectively. Light-vented bulbul exhibited significantly lower levels of PBDEs, DBDPE, DP, and HBB than other three bird species due to its phytophagy and the other three bird species' insectivores. PBDEs were the predominant HFRs in bird eggs, followed by DBDPE and DP. Significant negative relationship between the fraction of anti-DP and DP concentrations was observed in bird eggs, suggesting that DP levels play an important role in determining the isomeric composition. Anti-Cl11-DP, the dechlorinated products of DP, was found in bird eggs with concentrations ranging from nd to 0.86 ng g(-1) lw and its source is worth further research.

Halogenated pollutants in terrestrial and aquatic bird eggs: converging patterns of pollutant profiles, and impacts and risks from high levels

We investigated the presence, levels, relationships, and risks of HCHs, DDTs, chlordanes, mirex, PCBs, and brominated flame retardants (BFRs) in terrestrial and aquatic bird eggs from an area in South Africa where DDT is used for malaria control. We found one of the highest ΣDDT levels reported this century; 13,000 ng/g wm (wet mass) in Grey Heron eggs which exceeds critical levels for reproductive success (3000 ng/g wm) calculated for Brown Pelicans, with a no-effect level estimated at 500 ng/g wm. Even higher ΣDDT levels at 16,000 ng/g wm were found in House Sparrow eggs (possibly the highest ever recorded for sparrows), with a maximum of 24,400 ng/g wm. Significant eggshell thinning in Cattle Egrets (33% between thickest and thinnest) was associated with increased levels of p,p'-DDT and p,p'-DDE. There were indications of unknown use of DDT and lindane. Relative to DDT, PCBs and BFRs levels were quite low. Ordinated data showed that different terrestrial pollutant profiles converged to a homogenised aquatic profile. Converging profiles, high levels of DDT in heron and sparrow eggs, and thinning eggs shells, indicate risk and impacts at release, in the aquatic environment, and in between. If characteristic life-strategies of birds in warm areas (e.g. longer-lived and fewer eggs per clutch) increases the risk compared with similar birds living in colder regions when both experience the same environmental pollutant levels, then malaria control using DDT probably has more significant impacts on biota than previously realised. Therefore, risk assessment and modelling without hard data may miss crucial impacts and risks, as the chemical use patterns and ecologies in Africa and elsewhere may differ from the conditions and assumptions of existing risk assessment and modelling parameters. Consideration of other findings associated with DDT from the same area (intersex in fish and urogental birth defects in baby boys), together with the findings of this study (high levels of DDT in bird eggs, eggshell thinning in the Cattle Egrets, and the apparent absence of breeding piscivore birds in the sprayed area) are strongly suggestive of negative impacts from DDT spraying for Malaria control. Our data presents strong arguments for an expedited process of replacing DDT with sustainable methods.

Occurrence and behavior of natural and anthropogenic (emerging and historical) halogenated compounds in marine biota from the Coast of Concepcion (Chile)

Fifty-five biota samples from the Coast of Concepcion (Chile) were analyzed for PBDEs, emerging brominated FRs, halogenated norbornenes and naturally-occurring MeO-PBDEs. PBDEs, MeO-PBDEs and halogenated norbornenes were detected at concentration levels ranging from 11 to 170, nd to 118 and nd to 5.8 ng/g lw, respectively. However, emerging brominated FRs such as decabromodiphenylethane (DBDPE), hexabromobenzene (HBB) and pentabromoethylbenzene (PBEB) were not detected in any sample. Bioaccumulation and bioconcentration processes were evaluated for the different families of compounds. Biomagnification factors (BMFs) were calculated, and some PBDE congeners (BDE-28, BDE-183 and BDE-209) as well as MeO-PBDEs presented BMF>1, being values of the naturally occurring MeO-PBDEs higher than those obtained for PBDEs. As regards halogenated norbornenes, BMF<1 were found.

Filling the gap: estimating physicochemical properties of the full array of polybrominated diphenyl ethers (PBDEs)

Physicochemical properties of PBDE congeners are important for modeling their transport, but data are often missing. The quantitative structure-property relationship (QSPR) approach is utilized to fill this gap. Individual research groups often report piecemeal properties through experimental measurements or estimation techniques, but these data seldom satisfy fundamental thermodynamic relationships because of errors. The data then lack internal consistency and cannot be used directly in environmental modeling. This paper critically reviews published experimental data to select the best QSPR models, which are then extended to all 209 PBDE congeners. Properties include aqueous solubility, vapor pressure, Henry's law constant, octanol-water partition coefficient and octanol-air partition coefficient. Their values are next adjusted to satisfy fundamental thermodynamic equations. The resulting values then take advantage of all measurements and provide quick references for modeling and PBDE-contaminated site assessment and remediation. PCBs are also compared with respect to their properties and estimation methods.

The Pelagos Sanctuary for Mediterranean marine mammals: Marine Protected Area (MPA) or marine polluted area? The case study of the striped dolphin (Stenella coeruleoalba)

The concurrence of man-made pressures on cetaceans in the Mediterranean Sea is potentially affecting population stability and marine biodiversity. This needs to be proven for the only pelagic marine protected area in the Mediterranean Sea: the Pelagos Sanctuary for Mediterranean Marine Mammals. Here we applied a multidisciplinary tool, using diagnostic markers elaborated in a statistical model to rank toxicological stress in Mediterranean cetaceans. As a case study we analyzed persistent, bioaccumulative and toxic chemicals combined with a wide range of diagnostic markers of exposure to anthropogenic contaminants and genetic variation as marker of genetic erosion in striped dolphin (Stenella coeruleoalba) skin biopsies. Finally, a statistical model was applied to obtain a complete toxicological profile of the striped dolphin in the Pelagos Sanctuary and other Mediterranean areas (Ionian Sea and Strait of Gibraltar). Here we provide the first complete evidence of the toxicological stress in cetaceans living in Pelagos Sanctuary.

Estimating European historical production, consumption and atmospheric emissions of decabromodiphenyl ether

A European scale production, consumption and environmental emissions inventory is produced for decabromodiphenyl ether (DecaBDE) for the period 1970-2020. A dynamic substance flow analysis model of DecaBDE is developed and emission of the main congener, BDE-209, to environmental compartments is estimated. From 1970 to 2010, it is estimated that a total of 185,000-250,000 tonnes of DecaBDE was consumed in Europe. Consumption peaked in the late 1990s at approximately 9,000 tonnes/year and has declined by ~30% in 2010. Predicted BDE-209 atmospheric emissions peak in 2004 at 10 tonnes/year. The waste management phase of the BDE-209 life cycle is responsible for the majority of atmospheric emissions via volatilisation and particle bound emissions from landfills, whilst leakage from Sewerage systems is the major source of emissions to the hydrosphere. Use of sewage sludge from wastewater treatment works as an agricultural fertiliser is the most important pathway of BDE-209 to soil. Although DecaBDE consumption has declined in recent years, the stock in use for 2010 remains considerable (60,000 tonnes) and is likely to act as a source of atmospheric emissions for several decades. Uncertainties exist in these estimations and more field or experimental data is needed to clarify the significance of certain emission pathways, in particular, emissions from landfill sites.

Long-term trends in PBDEs in sparrowhawk (Accipiter nisus) eggs indicate sustained contamination of UK terrestrial ecosystems

PBDE contamination in terrestrial biota is poorly characterized, and robust data on temporal trends are scarce. We measured temporal (1985-2007) and spatial trends in PBDE contamination in the eggs of the sparrowhawk (Accipiter nisus), a sentinel for the terrestrial environment. Five BDEs were the most abundant (BDE 99 > 47 > 153 > 100 > 154). Their concentrations, and that of the sum PBDEs (ΣPBDE), increased from the mid-1980s, peaking in the midlate 1990s at levels that were sustained until the end of the study. This and the predominance of BDE99 contrast with patterns in piscivorous species and suggest sparrowhawks, and perhaps terrestrial species more widely, may be relatively poor metabolizers of penta-BDEs. BDE 196, 197, 201, and 203 concentrations increased linearly through the study, indicating increasing contamination possibly from the presence of these congeners in, and/or debromination of, deca-BDE formulations. Variation in egg ΣPBDE concentration was not explained by % urban land cover, human population density or % of arable land in proximity to the nest site, or by land use. Overall, egg ΣPBDE concentrations (34-2281 ng/g wet weight) were some of the highest reported in birds from Europe. We found no relationship between ΣPBDE concentrations and eggshell thickness.

Novel flame retardants in urban-feeding ring-billed gulls from the St. Lawrence River, Canada

This study investigated the occurrence of a comprehensive suite of polybrominated diphenyl ethers (PBDEs) and current-use flame retardants (FRs) in ring-billed gulls breeding in a highly industrialized section of the St. Lawrence River, downstream from Montreal (QC, Canada). Despite major point-sources and diffuse contamination by FRs, nearly no FR data have been reported in birds from this area. Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEHTBP) was detected in 89% of ring-billed gull livers (mean: 2.16 ng/g ww; max: 17.6 ng/g ww). To our knowledge, this is the highest detection frequency and highest concentrations reported thus far in any avian species or populations. Dechlorane Plus (DP) isomers were also particularly abundant (anti-DP detected in 100% and syn-DP in 93% of livers). Other detected FR compounds (3-14% detection) included 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), hexachlorocyclopentenyl-dibromocyclooctane (HCDBCO) and β-1,2-dibromo-4-(1.2-dibromoethyl)-cyclohexane (β-TBECH). Mean BDE-209 (57.2 ± 12.2 ng/g ww) in ring-billed gull livers was unexpectedly high for this midtrophic gull species, exceeding levels reported in several apex raptors such as peregrine falcons. BDE-209's relative contribution to ∑PBDEs was on average 25% (exceeding BDE-47 and BDE-99) and contrasted with profiles typically reported for fish-eating gull species. The present study highlighted preoccupying gaps in upcoming FR regulations and stressed the need for further investigation of the sources of FR exposure in highly urbanized areas.

Persistent Organic Pollutants in gull eggs of two species (Larus michahellis and Larus audouinii) from the Ebro delta Natural Park

The aim of this study was to determine the impact of priority and emerging Persistent Organic Pollutants (POPs) in gull eggs from two species, the scavenger Larus michahellis and the protected species, Larus audouinii. These two species share habitat in the Natural Park of the Ebro delta (Catalonia, Spain). Compounds studied are included or under consideration in the Stockholm Convention and comprise polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), organochlorinated compounds (OCs), perfluorinated compounds (PFCs) and short chain chlorinated paraffins (SCCPs). Four methods based in selective extraction and gas or liquid chromatography coupled to mass spectrometry were used and quality parameters are provided. OC pesticides and marker PCBs were the most abundant chemical families detected in eggs from the two species, followed by PFCs, PBDEs (especially BDE 209) and SCCPs. Dioxin-like PCBs and PCDD/Fs were also detected in all samples. The overall widespread presence of POPs is discussed in terms of feeding habits, bird ecology and anthropogenic pressures in the protected Ebro delta breeding area.