Higher brominated diphenyl ethers and hexabromocyclododecane found in eggs of peregrine falcons (Falco peregrinus) breeding in Sweden

Temporal trends (1972-2017) and spatial differences of persistent halogenated aromatic hydrocarbons in osprey eggs in Finland

Time trends and regional differences of polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), DDTs, polybrominated biphenyls (PBBs) and polybrominated diphenylethers (BDEs) were studied in unhatched osprey eggs collected by bird ringers in 1972-2017 from four areas in Finland. Two study areas were from Baltic Sea, Northern Quark and Finnish Archipelago Sea, while the two others were inland lake areas, eutrophicated Lake Vanajanselkä affected by industrial emissions, and Pristine SW Lake Area. The highest concentrations of most compound groups were in Lake Vanajanselkä consistent with high emissions, the predominance of bream as a prey, and higher concentrations in bream compared to other prey fish. Concentrations of all chlorinated compounds decreased significantly in all study areas. Average annual decreases were ∑PCDD/F 2.3-4.9%, ∑PCB 2.2-4.2%, ∑PCN 2.6-7.0% and ∑DDT 7.1-9.5%, primarily in line with decreased levels in prey fish. From 1972 PBBs and BDEs increased significantly until 1990s declining rapidly thereafter. PCDD/F congener profile was dominated by 2,3,4,7,8-PeCDF, except in Lake Vanajanselkä by 1,2,3,6,7,8-HxCDD. PCB congener profile was dominated by PCB 153 in all study areas, followed by PCB 180 and PCB 138. Among dioxin-like compounds PCBs contributed 82%, PCDDs 14% and PCDFs 4% to toxic equivalent quantity (∑TEQ). PCB 126 contributed most to ∑TEQ, followed by 1,2,3,7,8-PeCDD. BDE 47 being the dominant BDE congener, followed by BDE 100. ∑DDT concentrations were relatively similar across all study areas, with DDE contributing about 90%. Productivity of chicks per active nest was significantly decreased in Lake Vanajanselkä, and the likely explanation is embryotoxicity of dioxin-like compounds. It is plausible that dioxin-like compounds influenced embryonic survival among highly exposed ospreys prior to 2010, especially in Lake Vanajanselkä and Northern Quark. However, decreased survival due to DDE-induced eggshell thinning seems unlikely after 1985, and BDE levels were below those potentially causing adverse effects.

A Review of the Occurrence of Metals and Xenobiotics in European Hedgehogs (Erinaceus europaeus)

Monitoring data from several European countries indicate that European hedgehog (Erinaceus europaeus) populations are declining, and research exploring the causes of the decline, including exposure to potentially harmful xenobiotics and metals, may inform conservation initiatives to protect this species in the wild. Hedgehogs are ground-dwelling mammals, feeding on a range of insects, slugs, snails, and earthworms, as well as eggs, live vertebrates, and carrion, including carcasses of apex predator species representing higher levels of the food chain. Consequently, hedgehogs come into close contact with contaminants present in their habitats and prey. This review investigated the studies available on the subject of the occurrence of metals and organic xenobiotics in hedgehogs. This study found that a vast range of different pesticides; persistent organic pollutants (POPs), including organochlorine compounds and brominated flame retardants (BFRs); as well as toxic heavy metals could be detected. Some compounds occurred in lethal concentrations, and some were associated with a potential adverse effect on hedgehog health and survival. Due to their ecology, combined with the opportunity to apply non-invasive sampling techniques using spines as sampling material, we suggest that the European hedgehog is a relevant bioindicator species for monitoring the exposure of terrestrial wildlife to potential toxicants in urban and rural environments.

Evaluation of BDE-47-induced neurodevelopmental toxicity in zebrafish embryos

There are growing concerns about the neurodevelopmental toxicity of polybrominated diphenyl ethers (PBDEs), but the toxicological phenotypes and mechanisms are not well elucidated. Here, zebrafish (Danio rerio) were exposed to 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) from 4 to 72 h post-fertilization (hpf). The results showed that BDE-47 stimulated the production of dopamine and 5-hydroxytryptamine, but inhibited expression of Nestin, GFAP, Gap43, and PSD95 in 24 hpf embryos. Importantly, we unraveled the inhibitory effects of BDE-47 on neural crest-derived melanocyte differentiation and melanin syntheses process, evidenced by disrupted expression of wnt1, wnt3, sox10, mitfa, tyrp1a, tyrp1b, tryp2, and oca2 gene in 72 hpf embryos and decreased tyrosinase activities in embryos at 48 and 72 hpf. The transcriptional activities of myosin VAa, kif5ba, rab27a, mlpha, and cdc42 genes, which are associated with intracellular transport process, were also disturbed during zebrafish development. Ultimately, these alterations led to fast spontaneous movement and melanin accumulation deficit in zebrafish embryos upon BDE-47 exposure. Our results provide an important extension for understanding the neurodevelopmental effects of PBDEs and facilitate the comprehensive evaluation of neurotoxicity in embryos.

Toward understanding submersed macrophyte Vallisneria natans-microbe partnerships to improve remediation potential for PAH-contaminated sediment

Rhizodegradation using submersed macrophytes Vallisneria natans (V. natans) is a promising biotechnology with the potential to restore polycyclic aromatic hydrocarbon (PAH)-contaminated sediments. However, how different sediment types influence the rhizoremediation outcome and the characterization of microbial community along the sediment-V. natans continuum is poorly understood. Here, we collect V. natans, sediments and overlying water from two types of vegetation zones with different levels of PAHs pollutions and set up sediment microcosms for phytoremediation tests. V. natans presence was particularly useful for PAHs remediation in the highly contaminated sites and had a significant effect on PAHs rhizodegradation and microbial communities, especially rhizosphere sediments. The structural composition of microbial communities along the sediment-plant continuum was shaped predominantly by compartment niche of V. natans. Moreover, selective enrichment of specific microbial taxa like Herbaspirillum (relative abundance = 94.80%) in endosphere of V. natans was observed. Herbaspirillum could use PAH as carbon source and promote the growth of plants. In the highly contaminated sediment, V. natans could recruit these bacteria for toxicant degradation into the root interior. Thus, understanding the complex V. natans-microbe interactions could help set up novel decontamination strategies based on the rhizosphere and root interior interactions between plants and their microbial associates.

Decabromodiphenylether trends in the European environment: Bird eggs, sewage sludge and surficial sediments

Concern on relatively high levels and the potential bioaccumulation of decabromodiphenylether (BDE209) has led to a European 8-year monitoring program on trends in BDE209 concentrations in birds, sewage sludge and sediments from seven countries. BDE209 was analysed in four environmental matrices: sparrowhawk eggs (UK), glaucous gull eggs (Bear Island, Norway), sewage sludge (UK, Ireland and the Netherlands) and sediment (France, Germany, the Netherlands, UK and Ireland). BDE209 was detected in most of the glaucous gull and sparrow hawk eggs but neither increasing nor decreasing trends in these BDE209 levels were observed. An indication for debromination of BDE209 in sparrowhawk eggs was found. BDE209 concentrations in sediments ranged from very low ng/g (88 ng/g on an organic carbon (OC) basis) concentrations, in the rivers Elbe, Ems, Seine and the Outer Humber, to high μg/g (120 μg/g OC), in the Western Scheldt, Liverpool Bay and River Mersey. Apart from decreasing values in the Western Scheldt sediment no further decreases in BDE209 concentrations were observed over time, neither in sediment nor in sewage sludge showing that the voluntary emissions control program of the bromine industry only had a local effect. In contrast to the sewage sludge samples from the Netherlands (mean 355 ng/g dry weight (dw) or 1026 ng/g OC), the BDE209 concentrations in the UK increased at all sites from 2006 to 2011 (8092 ng/g dw or 22,367 ng/g OC). The BDE209 levels in several UK sediments and sewage sludge were still very high at the end of the program in 2012, most likely caused by frequent use of BDE209 in the textile industry. This may be indicative of the persistence of BDE209 and the limited degradation into lower brominated congeners in sediment, although it cannot be excluded that ongoing BDE209 emissions have played a role as well.

Environmental contamination and public health effects of electronic waste: an overview

Purpose

In recent years, electronic waste has become the fastest growing waste stream globally with potential deleterious environmental and public health effects from its hazardous constituents. This review aims at providing an up-to-date information on the environmental and public health effects of e- wastes, and also identify research gaps that could form basis of further innovative studies on this important subject.

Methods

We carried out literature survey using several search engines. All available literature which reported directly on environmental contamination of air, soil, and water by e-wastes, and their effects on exposed plants, animals, and humans were used in other to generate an updated information.

Results

High production volume coupled with indiscriminate disposal and informal recycling has made electronic waste (e-waste) to become a global public and environmental health issue. E-waste is made up of different hazardous substances such as heavy metals and persistent organic pollutants with the capacity to contaminate the environment if processed or recycled inappropriately. Humans and animals become exposed to e-waste constituents via ingestion, inhalation, and dermal contact. Several health effects have been linked to e-wastes. The most susceptible were children, pregnant women, and workers in primitive recycling sites. Generation of e-waste is predicted to increase drastically in the next decade with the potential complex interactive effects of its constituents.

Conclusion

This review is an up-to-date assessment of studies and reports on e-waste environmental contamination and public health effects. The review has shown that e-waste contains constituents that caused adverse environmental effects and toxicity to the biota. However, there is an enormous data gap between exposure quantification and possible health effects. More studies are needed to elucidate and provide holistic information on environmental and public health dangers posed by e-waste constituents.

Distributions and biomagnification of polybrominated diphenyl ethers in a grassland ecosystem food chain

The concentrations, distributions, and biomagnification of polybrominated diphenyl ethers (PBDEs) in environmental and biological media in a terrestrial grass ecosystem were studied, The total PBDE concentrations in grasses were 4.00 × 10^-2 to 4.28 ng·g^-1. The total PBDE concentration in weasel muscle (23.2 ng·g^-1 l.w.) was the highest concentrations of all animal tissue samples, and the total PBDE concentration in hair from local herdsmen (22.2 ng·g^-1 l.w.) was second highest. Less-brominated PBDEs were found to be more strongly biomagnified than more-brominated PBDEs in the grassland food web. PBDEs were found to be much more strongly biomagnified in the food chains of homothermic animals than heterothermic animals. More-brominated PBDEs were not markedly biomagnified in the grassland food web. For example, BDE-153 was not biomagnified in the grassland wildlife food chain but was clearly biomagnified through the sheep, cattle, or horse hair to human hair route. The biomagnification factors and log K_ows negatively correlated for the toad-snake, lizard-snake, and mouse-weasel food chains. The ability of PBDE congeners to become enriched generally decreased as the log K_ow increased, and this decrease occurred 100-1000 times more strongly for homothermic animals than heterothermic animals.

Evidence for complex sources of persistent halogenated compounds in birds from the south China sea

Persistent halogenated compounds (PHCs), including dichlorodiphenyltrichloroethane and its metabolites (DDTs), polybrominated diphenyl ethers (PBDEs), alternative brominated flame retardants (ABFRs), and dechlorane plus (DP), were analyzed in muscle of six bird species from the South China Sea. DDTs, with concentrations up to 19,000 ng/g lipid weight (lw), were the dominant contaminants contributing to 66-99% of PHCs in birds. Concentrations of PBDEs, ABFRs, and DP ranged from 1.1 to 130, 0.73-40, and 0.21-2.5 ng/g lw, respectively. Historically pollution of DDTs and flame retardants in surrounding Asian lands were the main sources for PHCs in birds. BDE 209 was the primary PBDE congener in all birds. 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) were the main ABFRs. Anti-DP and p,p'-DDE were the dominating compounds of DP and DDTs, respectively. Only concentrations of BDEs 153, 203, 196, and 207, p,p'-DDE, and p,p'-DDD showed significant and positive correlations with δ¹⁵N values in samples. The resident birds, red-footed booby (Sula sula), had much lower levels of p,p'-DDE and most of PBDEs than those in migratory birds from the South China Sea. Results of stable isotope ratios of carbon suggest the highly variable food items for the five migratory bird species. The abundance of DBDPE in red-footed booby might be related with the ingestion of plastic debris, which still warrants further verification.

Allam A, A. El-Serehy H, N. Maodaa S, M. Mahmoud A. Use of Spilopelia senegalensis as a Biomonitor of Heavy Metal Contamination from Mining Activities in Riyadh (Saudi Arabia)

Simple Summary

Bioindicators and biomonitors are living organisms utilized to appraise the health of the environment or natural ecosystem. Mining, which refers to extraction of valuable materials from the earth, represents a source of heavy metals that can impact the environment, biodiversity, and human health. We investigated the value of the laughing dove (Spilopelia senegalensis) as a biomonitor of environmental contamination with heavy metals from mining practices. Our results revealed the accumulation of heavy metals in the liver, kidneys, and lungs of the laughing dove collected from the mining site. The doves exhibited tissue dysfunction and injury, and decreased antioxidants. These results show the value of the laughing dove as a biomonitor of environmental pollution with heavy metals.

Abstract

Environmental pollution with heavy metals (HMs) is of serious ecological and public health concern worldwide. Mining is one of the main sources of HMs and can impact the environment, species diversity, and human health. This study assessed the value of Spilopelia senegalensis as a biomonitor of environmental contamination with metal(loid)s caused by mining activities. S. senegalensis was collected from a gold mining site and a reference site, and metal(loid)s and biochemical parameters were determined. Lead, cadmium, mercury, vanadium, arsenic, copper, zinc, and iron were significantly increased in the liver, kidney, and lung of S. senegalensis from the mining site. Serum transaminases, alkaline phosphatase, creatinine, and urea were significantly elevated in S. senegalensis from the mining site. Lipid peroxidation and nitric oxide were increased, whereas glutathione and antioxidant enzymes were diminished in the liver and kidney of S. senegalensis from the mining site. In addition, multiple histological alterations were observed in the liver, kidney, and lung of S. senegalensis. In conclusion, mining activities provoke the accumulation of metal(loid)s, oxidative stress, and tissue injury in S. senegalensis. Therefore, S. senegalensis is a valuable biomonitor of environmental pollution caused by mining activities and could be utilized in epidemiological avian studies of human health.

Mass balance study of brominated flame retardants in female captive peregrine falcons

Little is known about brominated flame retardant (BFR) dynamics in birds, especially large molecules such as decabromodiphenyl ether (BDE-209). In particular, bioaccumulation from food and transfer dynamics to eggs are poorly understood. Therefore, an input-output mass balance study of tri-decaBDEs, DBDPE and HBCDD was performed in three female peregrine falcons from a captive breeding program by analyzing their naturally contaminated food (quail, chicken (cockerels)), plasma, feces and eggs. Predominant BFRs in cockerels and quail were BDE-209 and DBDPE, as well as HBCDD in quail. The predominant BFRs found in falcon plasma were BDE-209, -153 and -183, in eggs, HBCDD, BDE-209 and -153 and in feces, BDE-209. Mean absorption efficiencies (AE) for the tetra-octabrominated BDEs ranged from 84-100% and 70% for HBCDD. The AEs for BDE-206, -207, -208 and -209 varied due to the large variability seen for feces fluxes. All egg/plasma ratios for BDEs were similar and greater than one (range 1.1-2.7), including for BDE-209, indicating efficient transfer from females to the eggs. Excretion via egg-laying was approximately 6.0-29% of the initial, pre-breeding body burden of individual penta-decaBDE congeners, (15-45% for BDE-206). HBCDD was not detected in plasma but was found in eggs, also indicating efficient transfer and excretion via eggs. Input fluxes from food exceeded the output fluxes (feces, eggs) indicating considerable metabolism for tetra-octaBDEs, possibly also for the nona-decaBDEs and HBCDD. Bioaccumulation factors calculated from lipid weight concentrations in plasma and food (BAFp) were highest for BDE-208 (31), -153 (23), -209 (19) and -207 (16) and from eggs and food (BAFe), were highest for HBCDD (140), BDE-153 (41), -208 (42), BDE-207 (24) and BDE-209 (21). BAFe and BAFp values were below 10 for BDE-47, -99 and -100. For one falcon, egg results were available from three different years and estimated half-lives were 65 d (BDE-99), 624 d (BDE-153), 31 d (BDE-154), 349 d (BDE-183), 77 d (BDE-196) and 89 d (BDE-197).

Accumulation of Short-, Medium-, and Long-Chain Chlorinated Paraffins in Marine and Terrestrial Animals from Scandinavia

Short-, medium-, and long-chain chlorinated paraffins (SCCPs, MCCPs, and LCCPs) have a wide range of physical-chemical properties, indicating their varying bioaccumulation tendencies in marine and terrestrial ecosystems. However, there are few empirical data to reveal such bioaccumulation tendencies. In this study, we analyzed SCCPs, MCCPs, and LCCPs in samples from 18 species at both low and high trophic levels of marine and terrestrial ecosystems from the Scandinavian region collected during the past decade. These included fish, seabirds, marine mammals, and terrestrial birds and mammals. SCCPs, MCCPs, and LCCPs were present in all the species, with concentrations ranging from 26-1500, 30-1600, 6.0-1200 ng/g lipid, respectively. Although MCCPs and SCCPs predominated in most species, many terrestrial species had generally higher concentrations of LCCPs than marine species. Terrestrial raptors in particular accumulated higher concentrations of LCCPs, including C_24/25-which are predominant among very-long-chain components. LCCP concentrations were highest and predominated (55% of total CPs) in peregrine falcons in this study, which is the first report where concentrations of LCCPs surpass those of SCCPs and MCCPs in wildlife. The results also indicate biomagnification of SCCPs, MCCPs, and LCCPs in both marine and terrestrial food chains, but in-depth studies of specific food webs are needed.

Kinetics and stereochemistry of LinB-catalyzed δ-HBCD transformation: Comparison of in vitro and in silico results

LinB is a haloalkane dehalogenase found in Sphingobium indicum B90A, an aerobic bacterium isolated from contaminated soils of hexachlorocyclohexane (HCH) dumpsites. We showed that this enzyme also converts hexabromocyclododecanes (HBCDs). Here we give new insights in the kinetics and stereochemistry of the enzymatic transformation of δ-HBCD, which resulted in the formation of two pentabromocyclododecanols (PBCDols) as first- (P_1δ, P_2δ) and two tetrabromocyclododecadiols (TBCDdiols) as second-generation products (T_1δ, T_2δ). Enzymatic transformations of δ-HBCD, α₁-PBCDol, one of the transformation products, and α₂-PBCDol, its enantiomer, were studied and modeled with Michaelis-Menten (MM) kinetics. Respective MM-parameters K_M, v_max, k_cat/K_M indicated that δ-HBCD is the best LinB substrate followed by α₂- and α₁-PBCDol. The stereochemistry of these transformations was modeled in silico, investigating respective enzyme-substrate (ES) and enzyme-product (EP) complexes. One of the four predicted ES-complexes led to the PBCDol product P_1δ, identical to α₂-PBCDol with the 1R,2R,5S,6R,9R,10S-configuration. An S_N2-like substitution of bromine at C6 of δ-HBCD by Asp-108 of LinB and subsequent hydrolysis of the alkyl-enzyme led to α₂-PBCDol. Modeling results further indicate that backside attacks at C1, C9 and C10 are reasonable too, selectively binding leaving bromide ions in a halide pocket found in LinB. Docking with α₂-PBCDol, also allowed productive enzyme binding. A TBCD-1,5-diol with the 1S,2S,5R,6R,9S,10R-configuration is the predicted second-generation product T_1δ. In conclusion, in vitro- and in silico findings now allow a detailed description of step-wise enzymatic dehalohydroxylation reactions of δ-HBCD to specific PBCDols and TBCDdiols at Å-resolution and predictions of their stereochemistry.

Short-, Medium-, and Long-Chain Chlorinated Paraffins in Wildlife from Paddy Fields in the Yangtze River Delta

Short-chain chlorinated paraffins (SCCPs) were added to Annex A of the Stockholm Convention on Persistent Organic Pollutants in April, 2017. As a consequence of this regulation, increasing production and usage of alternatives, such as medium- and long-chain chlorinated paraffins (MCCPs and LCCPs, respectively), is expected. Little is known about the environmental fate and behavior of MCCPs and LCCPs. In the present study, SCCPs, MCCPs, and LCCPs were analyzed in nine wildlife species from paddy fields in the Yangtze River Delta, China, using atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry. SCCPs, MCCPs, and LCCPs were detected in all samples at concentrations ranging from <91-43 000, 96-33 000, and 14-10 000 ng/g lipid, respectively. Most species contained primarily MCCPs (on average 44%), with the exception of collared scops owl and common cuckoo, in which SCCPs (43%) accumulated to a significantly (i.e., p < 0.05) greater extent than MCCPs (40%). Cl₆ groups were dominant in most species except for yellow weasel and short-tailed mamushi, which contained primarily Cl₇ groups. Principal components analysis, together with CP concentrations and carbon stable isotope analysis showed that habitat and feeding habits were key factors driving CP accumulation and congener group patterns in wildlife. This is the first report of LCCP exposure in wildlife and highlights the need for data on risks associated with CP usage.

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.

Spatiotemporal patterns and relationships among the diet, biochemistry, and exposure to flame retardants in an apex avian predator, the peregrine falcon

Flame retardants (FR) are industrial chemicals and some are proven environmental contaminants that accumulate in predatory birds. Few studies have examined the influence of diet on FR profiles in nestling raptors and the possible physiological implications of such FR exposure. The objectives of this research were (1) to determine spatial patterns of ≤ 48 polybrominated diphenyl ether (PBDE) congeners and ≤ 26 non-PBDE FRs, including organophosphate esters (OPEs), in nestling peregrine falcons (Falco peregrinus) across the Canadian Great Lakes-St. Lawrence River Basin (GL-SLR; 2010) and in the eastern Canadian Arctic (2007); (2) to identify temporal changes in FR concentrations from the mid-2000s to 2010 in GL-SLR peregrine nestlings; (3) to investigate the role of diet using stable isotopes on exposure patterns of quantifiable FRs; and (4) to assess possible associations between circulating FRs and total (T) thyroxine (TT₄) and triiodothyronine (TT₃), tocopherol, retinol and oxidative status (isoprostanes). The summed concentrations of the top 5 PBDEs (Σ₅) (BDE-47, -99, -100, -154, -153) were significantly higher in rural nestlings than urban nestlings in the GL-SLR, followed by the eastern Arctic nestlings. The PBDE congener profile of rural nestlings was dominated by BDE-99 (34‰), whereas BDE-209 (31‰) became dominant in the 2010 urban PBDE profile marking a shift since the mid-2000s. Low (ppb) concentrations of 25 novel non-PBDE FRs (e.g., 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenylethane (DBDPE)) were measured in the nestlings in at least one region, with the first report in peregrines of 15 novel non-PBDE FRs (e.g., 2-ethyl-1-hyxyl 2,3,4,5-tetrabromobenzoate (EHTBB), pentabromo allyl ether (PBPAE), tetrabromoethylcyclohexane (α-, β-DBE-DBCH)) as well as of tris (2-butoxyethyl) phosphate (TBOEP) (0-7.5ng/g ww) > tris(2-chloroisopropyl) phosphate (TCIPP) (0.1-5.5ng/g ww) > tris(2-chloroethyl) phosphate (TCEP) (0.02-2.0ng/g ww) > tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) (0-1.0ng/g ww). Within the GL-SLR, the urban nestlings' diet had significantly more terrestrial sources (greater δ¹³C values) than the broader, more aquatic-based diet of rural peregrines. Dietary source (δ¹³C) was significantly associated with concentrations of Σ₅PBDE, BDE-209, EHTBB, and 2,2-4,4',5,5'-hexabromobiphenyl (BB-153), with trophic level (δ¹⁵N) also positively associated with BDE-209 levels. Compared to urban nestlings, the rural nestlings had significantly lower circulating concentrations of thyroxine (TT₄), triiodothyronine (TT₃), a greater proportion of TT₃ relative to TT₄ (TT₃:TT₄), tocopherol and oxidative status (isoprostanes), but higher retinol levels; the most recalcitrant PBDE congener, BDE-153, in combination with low concentrations of some novel FRs, particularly octabromotrimethylphenyllindane (OBIND), may influence circulating thyroid hormones, especially TT₄, and retinol levels of peregrine falcon nestlings. These associations of FR-endocrine-biochemical measures suggest possible exposure-related changes in these birds and further study is warranted.

Adipose Tissue as a Site of Toxin Accumulation

We examine the role of adipose tissue, typically considered an energy storage site, as a potential site of toxicant accumulation. Although the production of most persistent organic pollutants (POPs) was banned years ago, these toxicants persist in the environment due to their resistance to biodegradation and widespread distribution in various environmental forms (e.g., vapor, sediment, and water). As a result, human exposure to these toxicants is inevitable. Largely due to their lipophilicity, POPs bioaccumulate in adipose tissue, resulting in greater body burdens of these environmental toxicants with obesity. POPs of major concern include polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), and polybrominated biphenyls and diphenyl ethers (PBBs/PBDEs), among other organic compounds. In this review, we (i) highlight the physical characteristics of toxicants that enable them to partition into and remain stored in adipose tissue, (ii) discuss the specific mechanisms of action by which these toxicants act to influence adipocyte function, and (iii) review associations between POP exposures and the development of obesity and diabetes. An area of controversy relates to the relative potential beneficial versus hazardous health effects of toxicant sequestration in adipose tissue. © 2017 American Physiological Society. Compr Physiol 7:1085-1135, 2017.

Motor deficits, impaired response inhibition, and blunted response to methylphenidate following neonatal exposure to decabromodiphenyl ether

Decabromodiphenyl ether (decaBDE) is an applied brominated flame retardant that is widely-used in electronic equipment. After decades of use, decaBDE and other members of its polybrominated diphenyl ether class have become globally-distributed environmental contaminants that can be measured in the atmosphere, water bodies, wildlife, food staples and human breastmilk. Although it has been banned in Europe and voluntarily withdrawn from the U.S. market, it is still used in Asian countries. Evidence from epidemiological and animal studies indicate that decaBDE exposure targets brain development and produces behavioral impairments. The current study examined an array of motor and learning behaviors in a C57BL6/J mouse model to determine the breadth of the developmental neurotoxicity produced by decaBDE. Mouse pups were given a single daily oral dose of 0 or 20mg/kg decaBDE from postnatal day 1 to 21 and were tested in adulthood. Exposed male mice had impaired forelimb grip strength, altered motor output in a circadian wheel-running procedure, increased response errors during an operant differential reinforcement of low rates (DRL) procedure and a blunted response to an acute methylphenidate challenge administered before DRL testing. With the exception of altered wheel-running output, exposed females were not affected. Neither sex had altered somatic growth, motor coordination impairments on the Rotarod, gross learning deficits during operant lever-press acquisition, or impaired food motivation. The overall pattern of effects suggests that males are more sensitive to developmental decaBDE exposure, especially when performing behaviors that require effortful motor output or when learning tasks that require sufficient response inhibition for their successful completion.

Birds and flame retardants: A review of the toxic effects on birds of historical and novel flame retardants

Flame retardants (FRs) are a diverse group of chemicals, many of which persist in the environment and bioaccumulate in biota. Although some FRs have been withdrawn from manufacturing and commerce (e.g., legacy FRs), many continue to be detected in the environment; moreover, their replacements and/or other novel FRs are also detected in biota. Here, we review and summarize the literature on the toxic effects of various FRs on birds. Birds integrate chemical information (exposure, effects) across space and time, making them ideal sentinels of environmental contamination. Following an adverse outcome pathway (AOP) approach, we synthesized information on 8 of the most commonly reported endpoints in avian FR toxicity research: molecular measures, thyroid-related measures, steroids, retinol, brain anatomy, behaviour, growth and development, and reproduction. We then identified which of these endpoints appear more/most sensitive to FR exposure, as determined by the frequency of significant effects across avian studies. The avian thyroid system, largely characterized by inconsistent changes in circulating thyroid hormones that were the only measure in many such studies, appears to be moderately sensitive to FR exposure relative to the other endpoints; circulating thyroid hormones, after reproductive measures, being the most frequently examined endpoint. A more comprehensive examination with concurrent measurements of multiple thyroid endpoints (e.g., thyroid gland, deiodinase enzymes) is recommended for future studies to more fully understand potential avian thyroid toxicity of FRs. More research is required to determine the effects of various FRs on avian retinol concentrations, inconsistently sensitive across species, and to concurrently assess multiple steroid hormones. Behaviour related to courtship and reproduction was the most sensitive of all selected endpoints, with significant effects recorded in every study. Among domesticated species (Galliformes), raptors (Accipitriformes and Falconiformes), songbirds (Passeriformes), and other species of birds (e.g. gulls), raptors seem to be the most sensitive to FR exposure across these measurements. We recommend that future avian research connect biochemical disruptions and changes in the brain to ecologically relevant endpoints, such as behaviour and reproduction. Moreover, connecting in vivo endpoints with molecular endpoints for non-domesticated avian species is also highly important, and essential to linking FR exposure with reduced fitness and population-level effects.

Relationships between polybrominated diphenyl ethers and transcription and activity of type 1 deiodinase in a gull highly exposed to flame retardants

Deca-brominated diphenyl ether (deca-BDE), composed mainly of BDE-209, is subject to usage restrictions in North America and Europe, although global action on its continued use has yet to be undertaken. Relatively large concentrations of polybrominated diphenyl ethers (PBDEs), especially BDE-209 and its higher brominated degradation products, have been reported in tissues of ring-billed gulls (Larus delawarensis) breeding near the densely populated city of Montreal (QC, Canada). There is limited knowledge of BDE-209 biotransformation and toxicokinetics in birds. Deiodinases, a class of enzymes catalyzing thyroid hormone conversion, have been suggested to be involved in BDE-209 debromination in birds. The objective of the present study was to investigate the relationships between PBDE concentrations and type 1 deiodinase (D1) transcription and in vitro activity (microsomes) in livers of Montreal-breeding ring-billed gulls. The ring-billed gulls exhibiting the highest D1 activity in liver microsomes accumulated the greatest liver concentrations of hepta-BDEs and octa-BDEs. Activity of D1 was inversely related to concentration ratios of BDE-209 to octa-BDEs and ∑hepta-BDE. An even stronger inverse relation was found between D1 activity and BDE-209 to ∑nona + octa + hepta-BDE concentration ratios. The messenger ribonucleic acid (mRNA) levels of D1 in gull livers were inversely associated with liver concentrations of ∑octa-BDE. The present study's findings suggest that D1 is potentially involved in BDE-209 biotransformation and accumulation of higher brominated PBDEs in livers of ring-billed gulls. Environ Toxicol Chem 2016;35:2215-2222. © 2016 SETAC.

Effect of decabromodiphenyl ether (BDE-209) on a soil-biota system: Role of earthworms and ryegrass

In the present study, the toxic effect of decabromodiphenyl ether (BDE-209), an important brominated fire retardant, on soil was evaluated by amending with different concentrations (0 mg/kg, 1 mg/kg, 10 mg/kg, and 500 mg/kg dry wt) for 40 d. The activities of 3 soil enzymes (urease, catalase, and alkaline phosphatase) were measured as the principal assessment endpoints. Meanwhile, the effects of natural environmental factors, such as light conditions and soil biota, on BDE-209 intoxication were studied. For the latter, 30 earthworms (Metaphire guillelmi) with fully matured clitella or ryegrass (Lolium perenne) with fully matured leaves were exposed in soil amended with BDE-209. The activities of the soil enzymes were adversely affected by BDE-209, especially for the high-concentration treatments, with greater adverse effects in the dark than in the light. The presence of earthworms reduced toxicity to BDE-209, whereas ryegrass did not. The calculated integrated biomarker response index, which provides a general indicator of the health status of test species by combining different biomarker signals, further validated these findings. Moreover, the antioxidant status (oxidant-antioxidant balance) of these 2 biota was assessed. Results indicated that BDE-209 significantly affected the activities of antioxidant enzymes (superoxide dismutase and catalase) and enhanced the levels of malondialdehyde in both species. The present study may facilitate a better understanding of the toxicity of BDE-209 toward the soil environment. Environ Toxicol Chem 2016;35:1349-1357. © 2015 SETAC.

Tracking pan-continental trends in environmental contamination using sentinel raptors-what types of samples should we use?

Biomonitoring using birds of prey as sentinel species has been mooted as a way to evaluate the success of European Union directives that are designed to protect people and the environment across Europe from industrial contaminants and pesticides. No such pan-European evaluation currently exists. Coordination of such large scale monitoring would require harmonisation across multiple countries of the types of samples collected and analysed-matrices vary in the ease with which they can be collected and the information they provide. We report the first ever pan-European assessment of which raptor samples are collected across Europe and review their suitability for biomonitoring. Currently, some 182 monitoring programmes across 33 European countries collect a variety of raptor samples, and we discuss the relative merits of each for monitoring current priority and emerging compounds. Of the matrices collected, blood and liver are used most extensively for quantifying trends in recent and longer-term contaminant exposure, respectively. These matrices are potentially the most effective for pan-European biomonitoring but are not so widely and frequently collected as others. We found that failed eggs and feathers are the most widely collected samples. Because of this ubiquity, they may provide the best opportunities for widescale biomonitoring, although neither is suitable for all compounds. We advocate piloting pan-European monitoring of selected priority compounds using these matrices and developing read-across approaches to accommodate any effects that trophic pathway and species differences in accumulation may have on our ability to track environmental trends in contaminants.

Steroids in house sparrows (Passer domesticus): Effects of POPs and male quality signalling

At high trophic levels, environmental contaminants have been found to affect endocrinological processes. Less attention has been paid to species at lower trophic levels. The house sparrow (Passer domesticus) may be a useful model for investigating effects of POPs in mid-range trophic level species. In male house sparrows, ornamental traits involved in male quality signalling are important for female selection. These traits are governed by endocrinological systems, and POPs may therefore interfere with male quality signalling. The aim of the present study was to use the house sparrow as a mid-range trophic level model species to study the effects of environmental contaminants on endocrinology and male quality signalling. We analysed the levels of selected PCBs, PBDEs and OCPs and investigated the possible effects of these contaminants on circulating levels of steroid hormones (4 progestagens, 4 androgens and 3 estrogens) in male and female adult house sparrows from a population on the island Leka, Norway. Plasma samples were analysed for steroid hormones by GC-MS and liver samples were analysed for environmental contaminants by GC-ECD and GC-MS. In males, we also quantified ornament traits. It was hypothesised that POPs may have endocrine disrupting effects on the local house sparrow population and can thus interfere with the steroid hormone homeostasis. Among female house sparrows, bivariate correlations revealed negative relationships between POPs and estrogens. Among male sparrows, positive relationships between dihydrotestosterone levels and PCBs were observed. In males, positive relationships were also found between steroids and beak length, and between steroids and ornamental traits such as total badge size. This was confirmed by a significant OPLS model between beak length and steroids. Although sparrows are in the mid-range trophic levels, the present study indicates that POPs may affect steroid homeostasis in house sparrows, in particular for females. For males, circulating steroid levels appears to be more associated with biometric parameters related to ornamental traits.

PBDEs and other POPs in urban birds of prey partly explained by trophic level and carbon source

As urban sprawl and agricultural intensification continue to invade prime wildlife habitat, some animals, even apex predators, are managing to adapt to this new environment. Chemical pollution is one of many stressors that wildlife encounter in urban environments. Predators are particularly sensitive to persistent chemical pollutants because they feed at a high trophic level where such pollution is biomagnified. To examine levels of pollution in urban birds of prey in the Lower Mainland region of British Columbia, Canada, we analyzed persistent organic contaminants in adult birds found dead of trauma injury. The hepatic geometric mean concentration of sum polybrominated diphenyl ethers (∑PBDEs) in 13 Cooper's hawks (Accipiter cooperii) from Greater Vancouver was 1873 ng/g (lipid weight) with one bird reaching 197,000n g/g lipid weight, the highest exposure reported to date for a wild bird. Concentrations of ∑PBDEs, ∑PCBs (polychlorinated biphenyls) and, surprisingly, cyclodiene insecticides were greatest in the urban environment while those of DDE (1,1-dichloroethylene bis[p-chlorophenyl) were highest in a region of intensive agriculture. The level of most chlorinated and brominated contaminants increased with trophic level (δ(15)N). The concentrations of some contaminants, PBDEs in particular, in these birds of prey may have some toxicological consequences. Apex predators in urban environments continue to be exposed to elevated concentrations of legacy pollutants as well as more recent brominated pollutants.

The use of monitoring data in EU chemicals management--experiences and considerations from the German environmental specimen bank

Since the 1970s, environmental specimen banks (ESB) have emerged in many countries. Their highly standardised sampling and archiving strategies make them a valuable tool in tracing time trends and spatial distributions of chemicals in ecosystem compartments. The present article intends to highlight the potential of ESBs for regulatory agencies in the European Union (EU). The arguments are supported by examples of retrospective monitoring studies conducted under the programme of the German ESB. These studies have evaluated the success of regulatory and industry provisions for substances of concern (i.e. PCB, polybrominated diphenyl ethers, perfluorinated compounds, alkylphenol compounds, organotin compounds, triclosan/methyl-triclosan, musk fragrances). Time trend studies revealed for example that levels of organotin compounds in marine biota from German coastal waters decreased significantly after the EU had decided on a total ban of organotin-based antifoulings in 2003. Similarly, concentrations of commercially relevant congeners of polybrominated diphenyl ethers decreased in herring gull eggs from the North Sea only after an EU-wide ban in 2004. The data presented demonstrate the usefulness of ESB samples for (retrospective) time trend monitoring and underline the benefit of a more intensive cooperation between chemicals management and specimen banking.

Tracing organophosphorus and brominated flame retardants and plasticizers in an estuarine food web

Nine organophosphorus flame retardants (PFRs) were detected in a pelagic and benthic food web of the Western Scheldt estuary, The Netherlands. Concentrations of several PFRs were an order of magnitude higher than those of the brominated flame retardants (BFRs). However, the detection frequency of the PFRs (6-56%) was lower than that of the BFRs (50-97%). Tris(2-butoxyethyl) phosphate (TBOEP), tris(isobutyl) phosphate (TIBP) and tris(2-chloroisopropyl) phosphate (TCIPP) were the dominant PFRs in sediment with median concentrations of 7.0, 8.1 and 1.8 ng/g dry weight (dw), respectively. PFR levels in the suspended particular matter (SPM) were 2-12 times higher than that in sediment. TBOEP, TCIPP, TIBP, tris(2-chloroethyl) phosphate (TCEP) and tris(phenyl) phosphate (TPHP) were found in organisms higher in the estuarine food web. The highest PFR concentrations in the benthic food web were found in sculpin, goby and lugworm with median concentrations of 17, 7.4, 4.6 and 2.0 ng/g wet weight (ww) for TBOEP, TIBP, TCIPP and TPHP, respectively. Comparable levels were observed in the pelagic food web, BDE209 was the predominant PBDE in sediment and SPM with median concentrations up to 9.7 and 385 ng/g dw, respectively. BDE47 was predominant in the biotic compartment of the food web with highest median levels observed in sculpin and common tern eggs of 79 ng/g lipid weight (lw) (2.5 ng/g ww) and 80 ng/g lw (11 ng/g ww), respectively. Trophic magnification was observed for all PBDEs with the exception of BDE209. Indications of trophic magnification of PFRs were observed in the benthic food web for TBOEP, TCIPP and TCEP with tentative trophic magnification factors of 3.5, 2.2 and 2.6, respectively (p<0.05). Most of the other PFRs showed trophic dilution in both food webs. The relative high PFR levels in several fish species suggest high emissions and substantial exposure of organisms to PFRs in the Western Scheldt.

Brominated flame retardant trends in aquatic birds from the Salish Sea region of the west coast of North America, including a mini-review of recent trends in marine and estuarine birds

Polybrominated diphenyl ethers (PBDEs) increased in many matrices during the 1990s and early 2000s. Since voluntary restrictions and regulations on PBDEs were implemented in North America circa early 2000s, decreases in PBDEs have occurred in many of these same matrices. To examine temporal trends in the North Pacific, we retrospectively analysed PBDEs and eight non-PBDE flame retardants (FR) in eggs of two aquatic bird species, great blue herons, Ardea herodias, and double-crested cormorants, Phalacrocorax auritus, collected along the British Columbia coast, Canada from 1979 to 2012. Increasing PBDE concentrations were observed in both species followed by significant decreases post-2000 for all dominant congeners and ΣPBDE. Non-PBDE FRs were generally undetected in cormorant eggs, or detected at very low levels in heron eggs, except for hexabromocyclododecane (HBCDD). HBCDD, currently unregulated in North America, was not detected in early sampling years; however low concentrations were observed in both species in recent sampling years (2003-2012). Dietary tracers (δ(13)C and δ(15)N) did not change significantly over time, indicating that temporal changes in PBDEs are likely caused by implemented regulations. A comparison with recently published temporal trends of ΣPBDE in marine birds from North America and Europe is given.

Polybrominated diphenyl ethers (PBDEs) in eggshells of the Southern Ground-Hornbill (Bucorvus leadbeateri) and Wattled Crane (Bugeranus carunculatus) in South Africa

This study was undertaken to assess the levels of eight PBDE congeners, namely: PBDE-17, 47, 100, 99, 154, 153, 183 and 209 in eggshells of Southern Ground-Hornbill (SGH) Bucorvus leadbeateri and Wattled Crane (WC) Bugeranus carunculatus obtained from different nesting sites within the eastern savanna of Limpopo Province and the midlands of KwaZulu-Natal, respectively. Analyses were performed using gas chromatography–mass spectrometry employing the electron impact ionization technique. The results obtained indicated that the lower brominated congeners were predominant in both species. The total PBDEs ranged between not detected (ND) to 264 μg g−1 lipid weight and 5.98–7146 μg g−1 lipid weight in the SGH and WC samples, respectively. More so, the mean recoveries of the 13C-labelled surrogate standards ranged between 40% (PBDE-100) and 136% (PBDE-99). The potential hazards to these birds via PBDEs exposure were evaluated by determining the hazard quotients (HQs) by employing the established Lowest Observed Effect Level (LOEL) values associated with impaired pipping and hatching success as well as that associated with impaired reproduction. HQs values varying from 0.58 to 0.94 and 27.71 to 45.27, respectively were obtained for SGH and WC species. This implies that the SGH populations are exposed to low to moderate hazards, while the WC populations are susceptible to high hazards. Considering the potential threats posed by PBDEs, particularly to the WC species, it is likely that exposure to the current environmental levels of PBDEs by these birds may contribute to their reduced breeding success and declining population trends.

Hexabromocyclododecanes in surface sediments from Shanghai, China: spatial distribution, seasonal variation and diastereoisomer-specific profiles

The concentrations, spatial distribution, diastereoisomer-specific profiles of hexabromocyclododecanes (HBCDs) in surface sediments from three major rivers in Shanghai as well as the seasonal variation of HBCDs were investigated. The concentrations of total HBCD diastereoisomers ranged from 0.05 to 6.87ngg(-1)dw. Significant spatial distribution of total HBCDs concentrations were observed. The mean concentration of total HBCDs followed the order of Suzhou Creek (2.00ngg(-1))>Huangpu River (1.59ngg(-1))>Yunzao Creek (0.77ngg(-1)). The concentration was a relatively low HBCDs level compared to levels measured in domestic and other parts of the world. The proportions of α-HBCD in sediment samples were generally higher than that of commercial formulations. This might be due to thermal isomerization from γ-HBCD to α-HBCD and slower degradation rate of α-HBCD compared to γ-HBCD in anaerobic conditions. The concentrations of ΣHBCD in the summer were significantly higher than those in the winter (paired t test, p<0.01). This seasonal variation could probably be attributed to a combined effect of temperature and wet deposition. Moreover, a poor and no significant correlation between ΣHBCD levels and TOC content in sediments was observed, suggesting that the spatial distributions of HBCDs were not constrained by the TOC in sediments of Shanghai.

Polybrominated diphenyl ether accumulation in an agricultural soil ecosystem receiving wastewater sludge amendments

Few studies have addressed bioaccumulation of organic pollutants associated with land-application of biosolids. We thus examined PBDE burdens within a soil ecosystem receiving long-term sludge amendments and a reference soil ecosystem receiving only manure inputs. No PBDEs were detected in reference site samples, but sludge-amended soils contained 17 600 ± 2330 μg/kg ∑3-7PBDE (total organic carbon (TOC) basis). ∑3-7PBDE burdens were highest in soil invertebrates with the greatest contact with sludge-amended soil (e.g., ∑3-7PBDE of 10 300 ± 2670 and 3000 ± 200 μg/kg lipid for earthworms and detritivorous woodlice, respectively). PBDEs were below quantitation limits in vegetation from the sludge-amended site. Surprisingly, we measured quantifiable PBDE burdens in only a single sample of predaceous ground spiders from the sludge-amended site. BDE-209 burdens in sludge-amended soil and earthworms were 7500 ± 2800 μg/kg TOC and 6500 ± 4100 μg/kg lipid, respectively. BDE 209 was detected in fewer taxa, but the burden in a detritivorous millipede composite was high (86 000 μg/kg lipid). PBDE congener patterns differed among species, with worms and ground beetles exhibiting Penta-BDE-like patterns. Penta-BDE biota-soil accumulation factors (BSAFs) ranged from 0.006 to 1.2, while BDE-209 BSAFs ranged from 0.07 to 10.5. δ(13)C and δ(15)N isotope signatures were poorly correlated with PBDE burdens, but sludge-amended samples were significantly δ(15)N enriched.

Legacy and current-use brominated flame retardants in the Barn Owl

The present study investigated the current-use brominated flame retardants (BFRs) tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD), simultaneously with legacy polybrominated diphenyl ethers (PBDEs), in Barn Owls (Tyto alba) collected from two regions with a contrasting degree of urbanisation and vicinity to point sources (Flanders in Belgium versus Normandy in France). Both tissues (muscle, liver, adipose and preen gland) and feathers (primary, tail and body feathers) showed elevated HBCD concentrations in Flanders, close to Europe's sole HBCD production plant in the Netherlands, and identified Normandy as a historical source region for PBDEs. In sharp contrast, the reactive BFR TBBPA bioaccumulated poorly (2.3%) in tissue samples, but was present in 96% of all body feather samples (0.36-7.07ngg(-1)dw), equally in both regions. PBDE concentrations in tissues (7.46-903 ng g(-1)lw) were considerably lower in the investigated Flemish Barn Owls, collected in 2008/2009, compared to specimens collected in 2003/2004 (46-11,000 ng g(-1)lw), possibly suggesting the effectiveness of the 2004 European ban of Penta- and Octa-BDE mixtures. Feathers showed a similar trend and additionally exhibited HBCD concentrations (0.02-333 ng g(-1)dw) surpassing those of PBDEs (0.50-10.4 ng g(-1)dw). While body feathers were a reliable matrix to predict both internal PBDE (0.21 ≤ R(2)≤ 0.67) and HBCD body burdens (0.20 ≤ R(2) ≤ 0.37), the suitability of primary and tail feathers appeared to be confounded by external contamination and moult. In conclusion, the present study clearly showed that the reactive versus additive use of BFRs results in contrasting exposure scenarios in a species higher up the food chain, and therefore may have profound implications for environmental health. In addition, the presented results extend the promising use of feathers as a non-destructive sampling strategy for current-use BFRs, and show that birds of prey are valid early-warning systems for environmental contamination.

Dietary exposure of American kestrels (Falco sparverius) to decabromodiphenyl ether (BDE-209) flame retardant: uptake, distribution, debromination and cytochrome P450 enzyme induction

Accumulation and evidence of debromination of the flame retardant 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE-209) have been reported for biota, including raptorial birds, based on PBDE congener residues in tissues and eggs. However, in vivo studies with BDE-209-exposed birds are rare and unknown for a raptorial species. In the present study, males (n=22) of raptorial American kestrels (Falco sparverius) were exposed to 116,000ng of BDE-209 (high purity, >98%; in safflower oil) per day for 21days (~2,436,000ng total BDE-209 exposure over this uptake period), followed by a 25-day depuration period. Control males (n=11) received the safflower vehicle only. In the exposed birds, BDE-209 was quantifiable in all plasma (end of uptake and depuration period) as well as liver and fat (end of depuration only) samples. The mean (±SE) BDE-209 level in plasma was 1474±1145ng/g wet weight (ww) at the end of the uptake period, and was significantly (p<0.001) lower (88%) at 174±148ng/g ww after the 25day depuration period. This equates to a mean reduction rate of 52ng/g ww per day and a rough estimation of the BDE-209 half-life in plasma of approximately 14days. The mean (±SE) BDE-209 levels were 4668±6192ng/g ww in the fat, and 338±311ng/g ww in the liver, of exposed individuals, which were significantly (p≤0.001) greater than mean concentrations (25±20 in fat and 2.6±0.9ng/g ww in liver) in the control birds. In addition to BDE-209, lower brominated PBDE congeners, and mainly meta- and para-debromination products of BDE-209 were also quantified in plasma, liver and/or fat. We estimated based on the dose that at least 80% of the non-BDE-209 concentration in the kestrel tissues and plasma must be derived from BDE-209 debromination by the kestrels. Where quantifiable, lower brominated PBDE concentrations were significantly (0.023>p>0.001) higher in the exposed relative to the control bird samples (except for BDE-154 and -153 in fat). Additional PBDE congeners found in plasma included nona-BDEs (208, 207 and 206), followed by octa-BDEs (197, 196, 201 and 203), and in liver and/or fat, the hepta-BDEs 180 and 183 and BDE-153. Higher hepatic EROD activity (cytochrome P450 1A1 monooxygenase-mediation) in the exposed birds compared to control birds was strongly suggested to be PBDE-induced, and was consistent with BDE-209 and congener metabolism in the exposed kestrels. The mean EROD activity rate was 36.1pmol/min/mg protein relative to the (n=4) control birds whose activity was just above the detection limit (10.3pmol/min/mg protein). Overall, the results demonstrated that following diet exposure of kestrels to high purity BDE-209, uptake occurred as well as BDE-209 degradation via debromination to lower brominated PBDE congeners.

Elevated serum polybrominated diphenyl ethers and alteration of thyroid hormones in children from Guiyu, China

Informal electronic waste (e-waste) recycling results in serious environmental pollution of polybrominated diphenyl ethers (PBDEs) and heavy metals. This study explored whether there is an association between PBDEs, heavy metal and key growth- and development-related hormones in children from Guiyu, an e-waste area in southern China. We quantified eight PBDE congeners using gas chromatographic mass spectrometry, lead and cadmium utilizing graphite furnace atomic absorption spectrometry, three thyroids with radioimmunoassay and two types of growth hormones by an enzyme-linked immune-sorbent assay (ELISA) in 162 children, 4 to 6 years old, from Guiyu. In blood, median total PBDE was 189.99 ng/g lipid. Lead and cadmium concentrations in blood averaged 14.53±4.85 µg dL-1 and 0.77±0.35 µg L-1, respectively. Spearman partial correlation analysis illustrated that lead was positively correlated with BDE153 and BDE183. Thyroid-stimulating hormone (TSH) was positively correlated with almost all PBDE congeners and negatively correlated with insulin-like growth factor binding protein-3 (IGFBP-3), whereas free triiodothyronine (FT3) and free thyroxine (FT4) were negatively correlated with BDE154. However, no correlation between the hormones and blood lead or cadmium levels was found in this study. Adjusted multiple linear regression analysis showed that total PBDEs was negatively associated with FT3 and positively associated with TSH. Notably, FT4 was positively correlated with FT3, house functions as a workshop, and father's work involved in e-waste recycling and negatively correlated with vitamin consumptions. TSH was negatively related with FT4, paternal residence time in Guiyu, working hours of mother, and child bean products intake. IGFBP-3 was positively correlated with IGF-1 and house close to an e-waste dump. These results suggest that elevated PBDEs and heavy metals related to e-waste in Guiyu may be important risk factors for hormone alterations in children.

Effects of low-level hexabromocyclododecane (HBCD) exposure on cardiac development in zebrafish embryos

Hexabromocyclododecane (HBCD) is one of the most widely used brominated flame retardants. In the present study, zebrafish embryos were exposed to HBCD at the low concentrations of 0, 2, 20 and 200 nM. The results showed HBCD exposure resulted in an increase in heart rate and cardiac arrhythmia after exposure for 72 h, though the survival rate and the whole malformation rate were not significantly affected. These results demonstrated that the heart might be a target of HBCD. Low-level HBCD exposure may not share the same mechanisms as exposure to high concentrations, since no obvious increase of apoptotic cells around the heart was observed in the HBCD-treated groups. It was observed that the expression of Tbx5 and Nkx2.5 was significantly elevated by HBCD treatment in a dose-dependent manner using real-time quantitative PCR, which may be mainly responsible for the alteration of heart rate, given that Tbx5 and Nkx2.5 are two factors regulating ventricle conduction. The mRNA expression of RyR2 and Atp2a2b (SERCA2a) was up-regulated in the exposure group, which may be one of reasons to affect the normal heart rate, since SERCA2a and RyR2 play an important role in calcium ion transport of cadiomyocytes. However, HBCD exposure did not significantly change the expression of Actc1l, Tnnt2, and Myh6, which are mainly muscle contractile genes that play key roles in the formation of cardiac structure. These results were consistent with the lack of effect seen on the other measurements of cardiac function, end diastolic volume, end-systolic volume, stroke volume, and cardiac output.

Bioaccumulation and trophic transfer of polybrominated diphenyl ethers (PBDEs) in a marine food web from Liaodong Bay, North China

The concentrations of 21 polybrominated diphenyl ethers (PBDEs) congeners were analyzed in organisms within a marine food web collected from the Liaodong Bay, North China. The total concentrations of PBDEs in all samples ranged from 0.87 to 91.4 ng g(-1) lipid weight (lw). BDE-47 was the predominant congener and had a concentration ranging from 0.30 to 36.1 ng g(-1) lw. The trophic magnification factors (TMF) of the PBDEs were calculated using the trophic levels obtained from the stable nitrogen isotope ratios. The TMF value of ∑PBDEs was 3.50 for the entire food web and 2.21 for the food web excluding seabirds. Four concentration ratios, BDE-99/BDE-100, BDE-99/BDE-47, BDE-153/BDE-154 and BDE-183/BDE-154, decreased linearly with the increase of the trophic levels in the invertebrates and the fishes (p<0.01). The results suggested that the PBDEs were steadily metabolized in the trophic transfer process along the food chain.

Developmental exposure to a brominated flame retardant: an assessment of effects on physiology, growth, and reproduction in a songbird, the zebra finch

Mixtures of polybrominated diphenyl ethers (PBDEs) have been widely used as additive flame retardants, and BDE-99 is one of the most predominant congeners found in the environment. BDE-99 has been reported in avian samples worldwide, yet knowledge of its toxicity to birds is minimal. We assessed the short- and long-term effects of nestling exposure to environmentally relevant levels of BDE-99 in a model passerine, the zebra finch. Early exposure to BDE-99 did not affect hematocrit, oxidative stress, or thyroid hormones in either the juvenile or adult stages, and there were no effects on chick growth or survival. BDE-99 exposure caused a dose-dependent delay in timing of reproduction, but there were no other effects on reproductive success. In zebra finches, endpoints related to reproductive behavior appear to be the most sensitive to BDE-99. However, passerines overall appear to be less sensitive than birds of prey or mammals to PBDE exposure.

Key factors affecting liver PBDE concentrations in sparrowhawks (Accipiter nisus)

High PBDE concentrations have been detected in the eggs of the sexually dimorphic Eurasian sparrowhawk (Accipiter nisus) but little is known about contamination levels in adult birds and how this may vary with age and sex. We characterised liver PBDE concentrations in 59 sparrowhawks that had died in central Britain between 1998 and 2009 and determined how concentrations varied with sex, age, body condition and breeding status. Five BDE congeners (99 > 153 > 47 > 100 > 154) predominated and ΣPBDE concentrations were 10-15 fold and 2-3 fold higher in starved than non-starved adult and juvenile sparrowhawks, respectively. This was likely due to a combination of remobilisation of residues from other tissues and liver wastage. Liver ΣPBDE concentrations did not vary with sex but were greater in adults than juveniles, suggestive of accumulation with age. Overall, liver ΣPBDE concentrations ranged from 43.4 to 68,040 ng/g lipid weight, amongst the highest concentrations reported in birds anywhere.

In vitro biotransformation of decabromodiphenyl ether (BDE-209) and Dechlorane Plus flame retardants: a case study of ring-billed gull breeding in a pollution hotspot in the St. Lawrence River, Canada

Decabromodiphenyl ether (deca-BDE) mixture (~97% of BDE-209) is now facing usage restrictions worldwide, which is leading to increased utilization of a series of alternative, replacement flame retardant (FR) products. Among these, Dechlorane Plus (DP) is receiving growing attention as this FR is increasingly being detected in wildlife samples, including birds from North America, Europe and Asia. Recent survey conducted in a known FR hotspot in the St. Lawrence River basin near Montreal (QC, Canada) revealed unexpectedly high detection frequencies and concentrations of BDE-209 and DP isomers (syn- and anti-DP) in the liver of breeding ring-billed gulls (Larus delawarensis) (RBGUs). Despite the global distribution of these current-use FRs, there is to our knowledge no study that has addressed the in vitro biotransformation of BDE-209 and DP isomers in birds. This study aimed at understanding the in vitro metabolism of BDE-209 and syn- and anti-DP using liver microsomes of Montreal-breeding RBGUs. Although BDE-15 (positive assay control) was consistently and positively depleted over the 90-min time frame of the in vitro assay, no depletion was observed for BDE-209 and DP isomers. These results suggest that CYP isoenzyme-mediated reductive dehalogenation of BDE-209 and DP is not likely to be a substantial metabolic pathway in RBGUs. However, investigations on deiodinases (expression, activity) should be considered in future studies as these enzymes have been suggested to be involved in the sequential debromination of BDE-209 in fish and human studies. High levels of BDE-209 determined in liver of RBGUs that strongly correlated with those of known or suggested BDE-209 debromination products (hepta- through nona-BDEs) may thus be indicative of concomitant dietary (e.g., fish consumption) and environmental exposure in the greater Montreal area, combined with poor or lack of metabolic capability toward these FRs.

Dechlorane Plus flame retardant in terrestrial raptors from northern China

While a number of studies have addressed the environmental presence and behavior of the Dechlorane Plus (DP) flame retardant, there is still a dearth of information in terrestrial ecosystems. The present study revealed that median ∑DP (including anti- and syn-DP isomers) concentrations ranged from 10 to 810 ng/g lipid weight in muscle and liver tissues of six terrestrial raptor species collected in 2004-2006 from Beijing, China. Some concentrations rival the greatest DP burdens ever reported in global wildlife. Significant, positive correlations were observed between fanti (concentration ratio of anti-isomer to ∑DP) and ∑DP concentrations in the Eurasian sparrowhawk (Accipiter nisus) tissues. These results suggested that the DP burdens could be substantially driven by the accumulation of the anti-isomer in terrestrial birds. The tissue-specific accumulation of DP further suggested that factors (e.g., hepatic binding enzymes) other than lipid solubility could be important in determining tissue deposition of DP.

European Initiatives for Selecting Sustainable Flame Retardants

Flame retardants, also often referred to as fire retardants, are a diverse group of chemical substances or formulations which are added to plastics, wood or textiles to reduce their propensity to ignite. Since the 1990s, flame retardants have started to raise environmental concerns, because some brominated flame retardants [e.g. polybrominated diphenyl ethers (PBDEs)] were found to form halogenated dioxins and furans in uncontrolled combustion and because the flame retardants were found in various environmental compartments and biota, including humans. This also led to regulatory restrictions in Europe and elsewhere, e.g. the RoHS (European Directive on the Restriction of certain Hazardous Substances in Electric and Electronic Equipment, 2011/65/EU) and WEEE (European Directive on Waste of Electric and Electronic Equipment, 2012/19/EU) legislation. A number of flame retardant producers have responded to these concerns and formed the industry group pinfa (Phosphorus, Inorganic and Nitrogen Flame Retardants Association) in order to develop and promote more environmentally compatible products, focussing on non‐halogenated alternatives. This group has successfully engaged in European research initiatives for sustainable flame retardants and also alternatives assessments by the GreenScreen™ methodology or the US Environmental Protection Agency (EPA) design for environment projects. Other European drivers and activities towards the sustainability of flame retardants are also presented in this chapter.

Individual variation in body burden, lipid status, and reproductive investment is related to maternal transfer of a brominated diphenyl ether (BDE-99) to eggs in the zebra finch

Avian eggs are exposed to hydrophobic contaminants through maternal transfer. How maternal transfer of contaminants within a species is influenced by individual variation in characteristics such as body burden, yolk precursor levels, or reproductive investment is not understood. The authors investigated sources of variation in the maternal transfer of 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) in zebra finches (Taeniopygia guttata). The authors dosed adult female zebra finches with levels of BDE-99 relevant to exposure in wild birds (0, 33.7 or 173.8 ng/g body wt/d) for three weeks prior to pairing. Maternal BDE-99 and very-low-density lipoprotein (VLDL) in plasma were measured during egg formation and at clutch completion, and BDE-99 was measured in the corresponding egg. The lipid-normalized egg-to-maternal tissue BDE-99 relationship decreased with increasing maternal burden. Individual variation in maternal VLDL was related to BDE-99 transfer to the eggs when BDE-99 was at background levels in control birds, but not when BDE-99 was elevated in dosed birds. The decrease in maternal plasma BDE-99 over the laying period was only significant (p < 0.05) in the high-dose birds. Finally, the decrease in BDE-99 in maternal plasma during egg-laying was significantly positively correlated with clutch mass in the high-dose group. These results suggest that the relationship between maternal and egg contaminant levels can be highly variable. This has significant implications for using eggs as indicators of adult or environmental concentrations.

European starlings ( Sturnus vulgaris ) suggest that landfills are an important source of bioaccumulative flame retardants to Canadian terrestrial ecosystems

Landfills are used as the primary means for the disposal of municipal solid waste in Canada. In the present study, polybrominated diphenyl ethers (PBDEs) and other flame retardants (FRs) were determined in fresh European starling ( Sturnus vulgaris ) eggs collected in 2009, 2010, and 2011 from nest boxes established within, adjacent to, and 10 and 40 km distant to five major urban centers across Canada, i.e., Vancouver, British Columbia (BC); Calgary, Alberta (AB); Hamilton, Ontario (ON); Montréal, Québec (QC); and Halifax, Nova Scotia (NS). Nest boxes were located in several land use types: urban industrial areas (districts of industrial activity within city limits), landfill sites (adjacent to cities), and rural (agricultural) sites located 10 and 40 km distant from the major urban centers, as well as a national reference site. Of the 14 PBDE congeners and 16 non-PBDE FR substances determined in the starling eggs, BDE-17, -28, -47, -49, -66, -85, -99, -100, -138, -153, -154, -183, and -209, Dechlorane Plus isomers (anti and syn), and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEHTBP) were most frequently quantifiable. The data revealed orders of magnitude greater PBDE concentrations in eggs from starlings nesting in landfill sites (median: 28-280 ng/g wet weight) relative to those from urban industrial and rural environments. However, the percent fractional composition of the PBDE congener patterns did not vary significantly between the types of land uses or between years. Additionally, the median ∑PBDE concentration in eggs from landfill sites and the human population density of the metropolitan region that the landfill serves were highly correlated (r(2) = 0.998, p < 0.001). As the first transcontinental effort in assessing FR contamination in Canadian terrestrial ecosystems, the present study strongly suggest that landfills are an important FR source to starlings nesting nearby and that other terrestrial organisms could also be similarly exposed.

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.

Hexabromocyclododecane in terrestrial passerine birds from e-waste, urban and rural locations in the Pearl River Delta, South China: levels, biomagnification, diastereoisomer- and enantiomer-specific accumulation

Diastereoisomers and enantiomers of hexabromocyclododecane (HBCD) were determined in muscle and stomach contents of three terrestrial passerine birds from e-waste, urban and rural locations in South China. The highest HBCD concentration was found at the urban site, followed by the e-waste site, suggesting that HBCD was linked to urbanization and industrialization, as well as e-waste recycling activities. Trophic magnification for α-HBCD was observed in the terrestrial food chain. Diastereisomeric pattern in birds showed the predominance of α-isomer, with a minor contribution of γ-isomer. The enantiomeric analysis revealed a preferential enrichment of (-)-α-HBCD and (+)-γ-HBCD. The similarity in enantiomeric fractions of HBCD isomers between muscle and stomach contents of birds suggested that dietary uptake may be responsible for the observed nonracemic distribution of HBCD isomers in the studied birds although in vivo enantioselective biotic processes cannot be ruled out.

2,5,6,9,10-Pentabromocyclododecanols (PBCDOHs): a new class of HBCD transformation products

Pentabromocyclododecanols (PBCDOHs) are potential environmental transformation products of hexabromocyclododecanes (HBCDs). They are also potential stage one metabolites of biological HBCD transformations. Herein, we present analytical evidence that PBCDOHs are also constituents of technical HBCDs and flame-proofed polystyrenes (FP-PSs). PBCDOHs are possibly formed during the synthesis of technical HBCD, presumably during the bromination of cyclododecatrienes in aqueous isobutanol together with isobutoxypentabromocyclododecanes (iBPBCDs), which have been identified in these materials recently. Of the 64 stereoisomers possible, eight pairs of enantiomers, named α-, β-, γ-, δ-, ε-, ζ-, η-, and θ-PBCDOHs were separated with a combination of normal-, reversed- and chiral-phase LC. Crystal structure analysis revealed the stereochemistry of the α-PBCDOH pair of enantiomers, which was assigned to (1S,2S,5R,6S,9S,10R)-2,5,6,9,10-pentabromocyclododecanol and its enantiomer. Mass spectrometric data are in accordance with the expected isotope patterns. On a C(18)-RP-column, the polar PBCDOHs eluted before the HBCD and iBPBCD classes of compounds. PBCDOHs were also found in FP-PS materials. The stereoisomer patterns varied considerably in these materials like those of HBCDs and iBPBCDs. Expanded polystyrenes were rich in late-eluting stereoisomers, similar to technical HBCD mixtures. Extruded polystyrenes contained more of the polar, faster-eluting isomers. The presented chromatographic and analytical methods allow a stereoisomer-specific search for PBCDOHs in biota samples, which might have experienced metabolic HBCD transformation reactions. Besides this potential source, it has to be recognized that PBCDOHs are by-products in technical HBCDs and in flame-proofed polystyrenes. Therefore, it is likely that PBCDOHs and iBPBCDs are released to the environment together with HBCD-containing plastic materials.

Emerging and historical brominated flame retardants in peregrine falcon (Falco peregrinus) eggs from Canada and Spain

Comparisons of brominated flame retardants (BFRs) in the eggs of peregrine falcons (Falco peregrinus) recently collected (2003-2007), are made between Canada (N=12) and Spain (N=13). Overall, concentrations of sum (Σ) polybrominated diphenyl ethers (PBDEs; 16 di-deca-BDE congeners) exceeded Σhexabromocyclododecane (HBCD) and were an order of magnitude higher than 2,2'4,4',5,5'-hexabromobiphenyl (BB-153)>hexachlorocyclopentenyl-dibromocyclooctane (HCBDCO)>1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE)>decabromodiphenylethane (DBDPE)>octabromotrimethylphenyllindane (OBIND)>hexabromobenzene (HBB)>bis(2-ethyl-1hexyl)tetrabromophthalate (BEHTBP). This is the first report of detectable HBCDCO and BEHTBP concentrations in biota, and the highest in ovo concentration of ∑HBCD (14,617 ng/glw; Montreal, Canada) to date. There were significantly greater egg concentrations of BB-153, ΣHBCD, and ΣPBDE including BDE-153, -99, -100 and -183, in Canadian than Spanish peregrines with a terrestrial diet. HBB, BTBPE, and OBIND were detected in eggs from both countries, but only Canadian peregrine eggs had detectable levels of HCDBCO (25%) and DBDPE (N=1). The in ovo PBDE congener profile was dominated by BDE-153>BDE-99>BDE-47>BDE-183>BDE-100>BDE-209, with the isomeric HBCD pattern being α-HBCD>γ-HBCD (β-HBCD undetected). The Canadian peregrine eggs had lower enantiomeric HBCD values consistent with their higher fractions of (-) α-HBCD, suggesting selective enantiomeric enrichment or that the (+) α-isomer is more readily metabolized and so deposited in the egg through maternal transfer. Continental differences in egg burdens of peregrines are discussed relative to BFR usage patterns and exposure of peregrines on their breeding grounds.

Early exposure to 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) affects mating behavior of zebra finches

2,2',4,4',5-Pentabromodiphenyl ether (BDE-99) is a brominated flame retardant congener that has pervaded global food chains, being reported in avian egg and tissue samples throughout the world. Its effects on birds are not well known, but there is evidence in exposed mammals that it directly mediates and causes neurotoxicity, alters thyroid hormone homeostasis, and lowers sex steroid hormone concentrations. In birds, those processes could disrupt the song-control system and male mating behavior. In this study, the effects of nestling exposure to environmentally relevant levels of BDE-99 were assessed in a model songbird species, the zebra finch (Taeniopygia guttata). A tissue residue study in which zebra finch nestlings were orally exposed to 0, 2.5, 15.8, or 50.7 ng BDE-99/g body weight (bw) per day over the 21-day nesting period validated dosing methods and confirmed dose levels were environmentally relevant (332.7 ± 141.0 to 4450.2 ± 1396.2 ng/g plasma lipid). A full-scale study exposing nestlings to 0, 2.5, 15.8, 50.7, or 173.8 ng BDE-99/g bw/day was carried out to investigate long-term effects of BDE-99 on the adult song-control nuclei volumes, song quality, and male mating behavior. Early exposure to BDE-99 had significant effects on male mating behavior and the response of clean experienced females to exposed males. There was no effect on male song-control nuclei or song quality, and there were nondose-dependent effects on female song-control nuclei. The results demonstrate that early exposure to environmentally relevant levels of BDE-99 affects the behavior of zebra finches.