Flame retardants and organochlorine pollutants in bald eagle plasma from the Great Lakes region

Occurrence, bioaccumulation, fate, and risk assessment of novel brominated flame retardants (NBFRs) in aquatic environments - A critical review

Novel brominated flame retardants (NBFRs), which have been developed as replacements for legacy flame retardants such as polybrominated diphenyl ethers (PBDEs), are a class of alternative flame retardants with emerging and widespread applications. The ubiquitous occurrence of NBFRs in the aquatic environments and the potential adverse effects on aquatic organisms have initiated intense global concerns. The present article, therefore, identifies and analyzes the current state of knowledge on the occurrence, bioaccumulation, fates, and environmental and health risks of NBFRs in aquatic environments. The key findings from this review are that (1) the distribution of NBFRs are source-dependent in the global aquatic environments, and several NBFRs have been reported at higher concentrations than that of the legacy flame retardants; (2) high bioaccumulative properties have been found for all of the discussed NBFRs due to their strong hydrophobic characteristics and weak metabolic rates; (3) the limited information available suggests that NBFRs are resistant to biotic and abiotic degradation processes and that sorption to sludge and sediments are the main fate of NBFRs in the aquatic environments; (4) the results of ecological risk assessments have indicated the potential risks of NBFRs and have suggested that source areas are the most vulnerable environmental compartments. Knowledge gaps and perspectives for future research regarding the monitoring, toxicokinetics, transformation processes, and development of ecological risk assessments of NBFRs in aquatic environments are proposed.

Trends and Patterns of Perfluoroalkyl Substances in Blood Plasma Samples of Bald Eagle Nestlings in Wisconsin and Minnesota, USA

We analyzed concentrations and trends of perfluoroalkyl substances (PFAS) in blood plasma samples of bald eagle (Haliaeetus leucocephalus) nestlings at 6 study areas in the upper Midwest of the United States, 2006 to 2015, and long-term trends at 2 Lake Superior (USA/Canada) sites, 1995 to 2015. Nestling blood plasma concentrations of the sum of 15 PFAS analytes (∑PFAS) differed among study areas and were highest at the 3 industrialized river sites: pools 3 and 4 of the Mississippi River (pools 3 + 4; geometric mean [GM] = 754 μg/L; range = 633-2930), the Mississippi National River and Recreation Area (GM = 687 μg/L; range = 24-7371), and the lower St. Croix National Scenic Riverway (GM = 546 μg/L; range = 20-2400). Temporal trends in ∑PFAS in nestling plasma differed among study areas; concentrations decreased at pools 3 + 4, Mississippi National River and Recreation Area, and lower St. Croix National Scenic Riverway, but not at the most remote sites, the upper St. Croix River and Lake Superior. Overall, perfluorooctanesulfonate (PFOS) was the most abundant analyte at all study areas, and perfluorodecanesulfonate (PFDS) the second most abundant at industrialized river sites although not at Lake Superior; concentrations of both these analytes declined from 2006 to 2015 over the study area. In addition, nestling age significantly influenced plasma concentrations of ∑PFAS and 7 of the 12 analytes. For these analytes, concentrations increased by 1 to 2%/d as nestlings grew, indicating that age should be considered when using nestling plasma to assess PFAS. Environ Toxicol Chem 2021;40:754-766. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A Review of Environmental Occurrence, Fate, and Toxicity of Novel Brominated Flame Retardants

Use of legacy brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), has been reduced due to adverse effects of these chemicals. Several novel brominated flame retardants (NBFRs), such decabromodiphenyl ethane (DBDPE) and bis(2,4,6-tribromophenoxy) ethane (BTBPE), have been developed as replacements for PBDEs. NBFRs are used in various industrial and consumer products, which leads to their ubiquitous occurrence in the environment. This article reviews occurrence and fate of a select group of NBFRs in the environment, as well as their human exposure and toxicity. Occurrence of NBFRs in both abiotic, including air, water, dust, soil, sediment and sludge, and biotic matrices, including bird, fish, and human serum, have been documented. Evidence regarding the degradation, including photodegradation, thermal degradation and biodegradation, and bioaccumulation and biomagnification of NBFRs is summarized. The toxicity data of NBFRs show that several NBFRs can cause adverse effects through different modes of action, such as hormone disruption, endocrine disruption, genotoxicity, and behavioral modification. The primary ecological risk assessment shows that most NBFRs exert no significant environmental risk, but it is worth noting that the result should be carefully used owing to the limited toxicity data.

Integrated exposure assessment of northern goshawk (Accipiter gentilis) nestlings to legacy and emerging organic pollutants using non-destructive samples

In the present study, concentrations of legacy and emerging contaminants were determined in three non-destructive matrices (plasma, preen oil and body feathers) of northern goshawk (Accipiter gentilis) nestlings. Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs), together with emerging pollutants, including per- and polyfluorinated alkyl substances (PFASs), novel brominated flame retardants (NBFRs), phosphorus flame retardants (PFRs) and Dechlorane Plus isomers (DPs) were targeted. Plasma, preen oil and feather samples were collected from 61 goshawk nestlings in Norway (Trøndelag and Troms) in 2015 and 2016, and pollutant concentrations were compared between the three matrices. In plasma, PFASs were detected in the highest concentrations, ranging between 1.37 and 36.0 ng/mL, which suggests that the nestlings were recently and continuously exposed to these emerging contaminants, likely through dietary input. In preen oil, OCPs (169-3560 ng/g) showed the highest concentrations among the investigated compounds, consistent with their high lipophilicity. PFRs (2.60-314 ng/g) were the dominant compounds in feathers and are thought to originate mainly from external deposition, as they were not detected in the other two matrices. NBFRs and DPs were generally not detected in the nestlings, suggesting low presence of these emerging contaminants in their environment and/or low absorption. Strong and significant correlations between matrices were found for all POPs (r_s = 0.46-0.95, p < 0.001), except for hexachlorobenzene (HCB, r_s = 0.20, p = 0.13). Correlations for PFASs were less conclusive: linear perfluorooctane sulfonate (PFOS), perfluoroundecanoate (PFUnA), perfluorododecanoate (PFDoA) and perfluorotetradecanoate (PFTeA) showed strong and significant correlations between plasma and feathers (r_s = 0.42-0.72, p < 0.02), however no correlation was found for perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA) and perfluorotridecanoate (PFTriA) (r_s = 0.05-0.33, p = 0.09-0.85). A lack of consistency between the PFAS compounds (contrary to POPs), and between studies, prevents concluding on the suitability of the investigated matrices for PFAS biomonitoring.

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).

Contaminants in bald eagles of the upper Midwestern U.S.: A framework for prioritizing future research based on in-vitro bioassays

Several organic contaminants (OCs) have been detected in bald eagle (Haliaeetus leucocephalus) nestling (eaglet) plasma in the upper Midwestern United States. Despite frequent and relatively high concentrations of OCs in eaglets, little is understood about potential biological effects associated with exposure. We screened an existing database of OC concentrations in eaglet plasma collected from the Midwestern United States against bioactivity information from the ToxCast database. ToxCast bioactivity information consists of concentrations expected to elicit responses across a range of biological space (e.g. cellular, developmental, etc.) obtained from a series of high throughput assays. We calculated exposure-activity ratios (EAR) by calculating the ratio of plasma concentrations to concentrations available in ToxCast. Bioactivity data were not available for all detected OCs. Therefore, our analysis provides estimates of potential bioactivity for 19 of the detected OCs in eaglet plasma. Perfluorooctanesulfonic acid (PFOS) EAR values were consistently the highest among all study areas. Maximum EAR values were ≥1 for PFOS, perfluorononanoic acid, and bisphenol A in 99.7, 0.53 and 0.26% of samples, indicating that some plasma concentrations were greater than what may be expected to elicit biological responses. About 125 gene targets, indicative of specific biological pathways, were identified as potentially being affected. Inhibition of several CYP genes, involved in xenobiotic metabolism, were most consistently identified. Other identified biological responses have potential implications for motor coordination, cardiac functions, behavior, and blood circulation. However, it is unclear what these results mean for bald eagles, given that ToxCast data are generated using mammalian-based endpoints. Despite uncertainties and limitations, this method of screening environmental data can be useful for informing future monitoring or research focused on understanding the occurrence and effects of OCs in bald eagles and other similarly-positioned trophic species.

Nest use dynamics of an undisturbed population of bald eagles

Management or conservation targets based on demographic rates should be evaluated within the context of expected population dynamics of the species of interest. Wild populations can experience stable, cyclical, or complex dynamics, therefore undisturbed populations can provide background needed to evaluate programmatic success. Many raptor species have recovered from large declines caused by environmental contaminants, making them strong candidates for ongoing efforts to understand population dynamics and ecosystem processes in response to human-caused stressors. Dynamic multistate occupancy models are a useful tool for analyzing species dynamics because they leverage the autocorrelation inherent in long-term monitoring datasets to obtain useful information about the dynamic properties of population or reproductive states. We analyzed a 23-year bald eagle monitoring dataset in a dynamic multistate occupancy modeling framework to assess long-term nest occupancy and reproduction in Lake Clark National Park and Preserve, Alaska. We also used a hierarchical generalized linear model to understand changes in nest productivity in relation to environmental factors. Nests were most likely to remain in the same nesting state between years. Most notably, successful nests were likely to remain in use (either occupied or successful) and had a very low probability of transitioning to an unoccupied state in the following year. There was no apparent trend in the proportion of nests used by eagles through time, and the probability that nests transitioned into or out of the successful state was not influenced by temperature or salmon availability. Productivity was constant over the course of the study, although warm April minimum temperatures were associated with increased chick production. Overall our results demonstrate the expected nesting dynamics of a healthy bald eagle population that is largely free of human disturbance and can be used as a baseline for the expected dynamics for recovering bald eagle populations in the contiguous 48 states.

Patterns and trends in lead (Pb) concentrations in bald eagle (Haliaeetus leucocephalus) nestlings from the western Great Lakes region

Most studies examining bald eagle (Haliaeetus leucocephalus) exposure to lead (Pb) have focused on adults that ingested spent Pb ammunition during the fall hunting season, often at clinical or lethal levels. We sampled live bald eagle nestlings along waterbodies to quantify Pb concentrations in 3 national park units and 2 nearby study areas in the western Great Lakes region. We collected 367 bald eagle nestling feather samples over 8 years during spring 2006-2015 and 188 whole blood samples over 4 years during spring 2010-2015. We used Tobit regression models to quantify relationships between Pb concentrations in nestling feathers and blood using study area, year, and nestling attributes as covariates. Pb in nestling feather samples decreased from 2006 to 2015, but there was no trend for Pb in blood samples. Pb concentrations in nestling feather and blood samples were significantly higher in study areas located closer to and within urban areas. Pb in feather and blood samples from the same nestling was positively correlated. Pb in feathers increased with nestling age, but this relationship was not observed for blood. Our results reflect how Pb accumulates in tissues as nestlings grow, with Pb in feathers and blood indexing exposure during feather development and before sampling, respectively. Some nestlings had Pb concentrations in blood that suggested a greater risk to sublethal effects from Pb exposure. Our data provides baselines for Pb concentrations in feathers and blood of nestling bald eagles from a variety of waterbody types spanning remote, lightly populated, and human-dominated landscapes.

Organohalogen contaminants in common loons (Gavia immer) breeding in Western Alberta, Canada

We examined the influence of biological and geographical factors on the levels and patterns of organohalogen contaminants in blood of adult common loons (Gavia immer) collected from 20 lakes in Alberta, Canada. The loons were captured in the 2006 and 2007 breeding seasons over a 900 m elevation gradient across the eastern slope of the Canadian Rocky Mountains. While PCBs dominated the composition of these contaminants in loons at all sites (∑PCBs > p,p'-DDE > ∑PBDEs > ∑Chlordanes > HCB), p,p'-DDE and ∑PBDEs were also important, averaging approximately 50% and 20% of total PCB concentrations, respectively. ∑PCBs and ∑PBDEs were higher in males than in females. Inter-lake variation was apparent for contaminant concentrations and patterns and were largely explained by dietary signatures (δ¹⁵N and δ¹³C) and proximity to a large hydroelectric dam. Mean ∑PCB (19.6 ng/g wet weight (ww)) and organochlorine pesticide (OCP) (p,p'-DDE: 11.8 ng/g, cis-nonachlor: 0.10 ng/g, trans-nonachlor: 0.32 ng/g, HCB: 0.34 ng/g ww) concentrations in loons were approximately 4- to 17-fold lower than average concentrations reported in common loons from Atlantic Canada and were well below concentrations which have been associated with impaired reproductive success and eggshell thinning in other piscivorous birds. Dominant PBDE congeners were BDE47, BDE99, and BDE100. The regional mean for ∑PBDEs (4.04 ng/g ww) in loons from the present study was within the range reported for ∑PBDEs in nestling bald eagle plasma from British Columbia. This is the first report of PBDEs in loons and the first report of PCBs and OCPs in common loons from Western North America.

Metals and Organohalogen Contaminants in Bald Eagles (Haliaeetus leucocephalus) from Ontario, 1991-2008

We examined the degree of exposure of lead (Pb), mercury (Hg), and several organohalogen contaminants and its potential impact on survival of bald eagles in Ontario from 1991 to 2008. Overall, results for 43 dead or dying bald eagles collected in the province indicate that 23% (10/43) of birds died of Pb poisoning and 9% (4/43) died of suspected Hg poisoning. Pb poisoning was diagnosed based on exceedances of toxicity thresholds in liver and kidney and supported by clinical observations, necropsy results, and histology findings when available. Evidence for Hg poisoning in eagles was limited; however, Hg concentrations exceeded the toxicity threshold in kidney. Pb concentrations ranged widely in liver and kidney. Total Hg concentrations were relatively higher in kidney compared with liver and were significantly correlated with selenium (Se) concentrations in both tissues. Concentrations of p,p'-DDE and sum PCBs in livers of 12 bald eagles collected from 2001 to 2004 were likely below concentrations associated with adverse effects. Hepatic concentrations of total polybrominated diphenyl ethers were generally higher in birds collected from southern Ontario compared with northern Ontario. Potential impacts of exposure to these flame retardants and others are not known. Elevated metal exposure appears to influence survivorship and may affect the recovery of bald eagles in the province, particularly in southern Ontario and along the Great Lakes where a disproportionate number of poisoned eagles were collected. Increased efforts are needed to identify sources of exposure and develop measures to reduce metal exposure in this top predator.

Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: I. Patterns of occurrence

Human activities introduce a variety of chemicals to the Laurentian Great Lakes including pesticides, pharmaceuticals, flame retardants, plasticizers, and solvents (collectively referred to as contaminants of emerging concern or CECs) potentially threatening the vitality of these valuable ecosystems. We conducted a basin-wide study to identify the presence of CECs and other chemicals of interest in 12 U.S. tributaries to the Laurentian Great Lakes during 2013 and 2014. A total of 292 surface-water and 80 sediment samples were collected and analyzed for approximately 200 chemicals. A total of 32 and 28 chemicals were detected in at least 30% of water and sediment samples, respectively. Concentrations ranged from 0.0284 (indole) to 72.2 (cholesterol) μg/L in water and 1.75 (diphenhydramine) to 20,800 μg/kg (fluoranthene) in sediment. Cluster analyses revealed chemicals that frequently co-occurred such as pharmaceuticals and flame retardants at sites receiving similar inputs such as wastewater treatment plant effluent. Comparison of environmental concentrations to water and sediment-quality benchmarks revealed that polycyclic aromatic hydrocarbon concentrations often exceeded benchmarks in both water and sediment. Additionally, bis(2-ethylhexyl) phthalate and dichlorvos concentrations exceeded water-quality benchmarks in several rivers. Results from this study can be used to understand organism exposure, prioritize river basins for future management efforts, and guide detailed assessments of factors influencing transport and fate of CECs in the Great Lakes Basin.

Bioaccumulation of Dechloranes, organophosphate esters, and other flame retardants in Great Lakes fish

We measured the concentrations of 60 flame retardants (and related compounds) in fish samples collected in the Great Lakes basin. These analytes include dechlorane-related compounds (Decs), organophosphate esters (OPEs), and brominated flame retardants (BFRs). Composite lake trout (Salvelinus namaycush) or walleye (Sander vitreus, from Lake Erie) samples were collected (N=3 for each lake) in 2010 from each of the five Great Lakes (a total of 15 samples). Among the dechlorane-related compounds, Dechlorane, Dechlorane Plus, Dechlorane-602, Dechlorane-603, and Dechlorane-604 (with zero to three bromines and with four chlorines) were detected in >73% of the fish samples. The concentrations of some of these dechlorane-related compounds were 3-10 times higher in Lake Ontario trout than in fish from the other four lakes. Tris(1-chloroisopropyl) phosphate, tri-n-butylphosphate, tris(2-chloroethyl)phosphate, and triphenyl phosphate were found in >50% of the fish samples. Polybrominated diphenyl ethers (PBDEs) were the most abundant of the flame retardants in fish, with a mean concentration of 250ng/g lipid. Our findings suggest that the Decs and BFRs with 3-6 bromines are more bioaccumulative in the fish than the OPEs and high molecular weight BFRs.

Screening for halogenated flame retardants in European consumer products, building materials and wastes

To fulfill national and international fire safety standards, flame retardants (FRs) are being added to a wide range of consumer products and building materials consisting of flammable materials like plastic, wood and textiles. While the FR composition of some products and materials has been identified in recent years, the limited global coverage of the data and the large diversity in consumer products necessitates more information for an overall picture of the FR composition in common products/materials. To address this issue, 137 individual samples of various consumer products, building materials and wastes were collected. To identify and characterize potential sources of FRs in indoor environment, all samples were analyzed for content of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs) and novel flame retardants (NFRs). The most frequently detected were HBCDDs (85%), with the highest median concentration of Σ₄HBCDDs of 300 mg kg^-1 in polystyrenes. The highest median concentration of Σ₁₀PBDEs was found in recycled plastic materials, reaching 4 mg kg^-1. The lowest concentrations were observed for NFRs, where the median of Σ₁₂NFRs reached 0.4 mg kg^-1 in the group of electrical & electronic equipment wastes. This suggests that for consumer products and building materials that are currently in-use, legacy compounds still contribute to the overall burden of FRs. Additionally, contrasting patterns of FR composition in recycled and virgin plastics, revealed using principle component analysis (PCA), suggest that legacy flame retardants are reentering the market through recycled products, perpetuating the potential for emissions to indoor environments and thus for human exposure.

Thyroid Hormones, Retinol and Clinical Parameters in Relation to Mercury and Organohalogen Contaminants in Great Blue Heron (Ardea herodias) Nestlings from the St. Lawrence River, Québec, Canada

The exposure and effects of persistent environmental contaminants were investigated in great blue heron (Ardea herodias) nestlings sampled in 2001, 2002, 2006, and 2007 in freshwater and estuarine heronries along the St. Lawrence River, Québec (Canada). Biomarkers (retinoids, thyroid hormones, and clinical parameters) and contaminants (organochlorine contaminants, polychlorinated biphenyls (PCBs), brominated flame retardants (BFRs), and mercury (Hg)) were analyzed in blood, and Hg was analyzed in feathers (generally 9 nestlings per colony and 4 colonies per year). Feather Hg and most contaminants detected in blood were found in higher concentrations in birds from freshwater than estuarine colonies more distant from the pollution sources. Among freshwater colonies, Ile aux Hérons showed the highest levels of contaminants, with mean Hg concentrations of 8.4 and 0.55 mg/kg in feathers and plasma, respectively, and plasma ΣBFRs of 19.6 ng/g ww. The highest mean ΣPCBs, 56.5 ng/g ww, was measured at Grande Ile in 2001. The levels of contaminants in heron nestlings were generally below critical thresholds for adverse effects observed on reproduction or survival. Retinol, dehydroretinol (DROH), and thyroid hormone concentrations differed significantly among colonies. Retinol concentrations were negatively related to ΣPCBs, whereas DROH concentrations were negatively related to Hg and total and free triiodothyronine (T₃) concentrations were negatively related to ΣBFRs. These results indicate that contaminants from the St. Lawrence River could impair the development and fitness of great blue heron nestlings and emphasize the need for more research on the great blue heron population to assess their health and nutritional status.

An assessment of exposure and effects of persistent organic pollutants in an urban Cooper's hawk (Accipiter cooperii) population

Among the stressors confronting urban wildlife, chemical contaminants pose a particular problem for high trophic feeding species. Previous data from fortuitous carcass collections revealed surprisingly high levels of persistent organic pollutants in raptor species, including the Cooper's hawk (Accipiter cooperii), from urbanized areas of southwestern British Columbia, Canada. Thus, in 2012 and 2013, we followed up on that finding by measuring POPs in blood samples from 21 adult and 15 nestling Cooper's hawks in Vancouver, a large urban area in southwestern Canada. Reproductive success and circulating thyroid hormones were measured to assess possible toxicological effects. Model comparisons showed concentrations of polychlorinated biphenyls (ΣPCBs) were positively influenced by the level of urbanization. Total thyroxin (TT4) was negatively associated with increases in ΣPCBs. Total triiodothyronine (TT3) was negatively associated with ΣPCBs and polybrominated diphenyl ethers (ΣPBDEs). The legacy insecticide, dieldrin, appeared to have some negative influence on reproductive success. There is some evidence of biochemical perturbation by PBDEs and lingering impact of legacy POPs which have not been used for at least 40 years, but overall Cooper's hawks have successfully populated this urban environment.

Transfer of hexabromocyclododecane flame retardant isomers from captive American kestrel eggs to feathers and their association with thyroid hormones and growth

Feathers are useful for monitoring contaminants in wild birds and are increasingly used to determine persistent organic pollutants. However, few studies have been conducted on birds with known exposure levels. We aimed to determine how well nestling feather concentrations reflect in ovo exposure to hexabromocyclododecane (α-, β- and γ-HBCDD), and to determine if feather concentrations are related to physiological biomarkers. Captive kestrels (n = 11) were exposed in ovo to maternally transferred HBCDD-isomers at concentrations of 127, 12 and 2 ng/g wet weight of α-, β- and γ-HBCDD (measured in sibling eggs), respectively, and compared to controls (n = 6). Nestling growth was monitored at 5 d intervals and circulating thyroid hormone concentrations assessed at d 20. Tail feathers were collected prior to the first molt and analyzed for HBCDD isomers. The mean ΣHBCDD concentration in feathers was 2405 pg/g dry weight (in exposed birds) and α-, β- and γ-HBCDD made up 32%, 13%, and 55%, respectively of the ΣHBCDD concentrations. This isomer distribution deviated from the typical dominance of α-HBCDD reported in vertebrate samples. Exposed chicks had significantly higher feather concentrations of β- and γ-HBCDD compared with controls (p = 0.007 and p = 0.001 respectively), while α-HBCDD concentrations did not differ between the two groups. Feather concentrations of α-HBCDD were best explained by egg concentrations of β- or γ-HBCDD concentrations (w_i = 0.50, 0.30 respectively), while feather concentrations of β- and γ-HBCDD were influenced by growth parameters (rectrix length: w_i = 0.61; tibiotarsus length: w_i = 0.28). These results suggest that feather α-HBCDD concentrations may reflect internal body burdens, whereas β- and γ-HBCDD may be subject to selective uptake. The α-HBCDD concentrations in the feathers were negatively associated with the ratio of plasma free triiodothyronine to free thyroxine (T₃:T₄; p = 0.020), demonstrating for the first time that feather concentrations may be used to model the effect of body burdens on physiological endpoints.

Retrospective analysis of "new" flame retardants in the global atmosphere under the GAPS Network

A retrospective analysis was conducted on air samples that were collected in 2005 under the Global Atmospheric Passive Sampling (GAPS) Network around the time period when the Stockholm Convention on Persistent Organic Pollutants came into force. Results are presented for several new flame retardants, including hexabromocyclododecane (HBCD), which was recently listed under the Convention (2013). These results represent the first global-scale distributions in air for these compounds. The targeted compounds are shown to have unique global distributions in air, which highlights the challenges in understanding the sources and environmental fate of each chemical, and ultimately in their assessments as persistent organic pollutants. The study also demonstrates the feasibility of using the PUF disk passive air sampler to study these new flame retardants in air, many of which exist entirely in the particle-phase as demonstrated in this study using a KOA-based partitioning model.

Terrestrial Scavenging of Marine Mammals: Cross-Ecosystem Contaminant Transfer and Potential Risks to Endangered California Condors (Gymnogyps californianus)

The critically endangered California condor (Gymnogyps californianus) has relied intermittently on dead-stranded marine mammals since the Pleistocene, and this food source is considered important for their current recovery. However, contemporary marine mammals contain persistent organic pollutants that could threaten condor health. We used stable carbon and nitrogen isotope, contaminant, and behavioral data in coastal versus noncoastal condors to quantify contaminant transfer from marine mammals and created simulation models to predict the risk of reproductive impairment for condors from exposure to DDE (p,p'-DDE), a major metabolite of the chlorinated pesticide DDT. Coastal condors had higher whole blood isotope values and mean concentrations of contaminants associated with marine mammals, including mercury (whole blood), sum chlorinated pesticides (comprised of ∼95% DDE) (plasma), sum polychlorinated biphenyls (PCBs) (plasma), and sum polybrominated diphenyl ethers (PBDEs) (plasma), 12-100-fold greater than those of noncoastal condors. The mean plasma DDE concentration for coastal condors was 500 ± 670 (standard deviation) (n = 22) versus 24 ± 24 (standard deviation) (n = 8) ng/g of wet weight for noncoastal condors, and simulations predicted ∼40% of breeding-age coastal condors have DDE levels associated with eggshell thinning in other avian species. Our analyses demonstrate potentially harmful levels of marine contaminant transfer to California condors, which could hinder the recovery of this terrestrial species.

Using bald eagles to track spatial (1999-2008) and temporal (1987-1992, 1999-2003, and 2004-2008) trends of contaminants in Michigan's aquatic ecosystems

The bald eagle (Haliaeetus leucocephalus) is an extensively researched tertiary predator. Studies have delineated information about its life history and the influences of various stressors on its reproduction. Due to the bald eagle's position at the top of the food web, it is susceptible to biomagnification of xenobiotics. The Michigan Department of Environmental Quality implemented a program in 1999 to monitor persistent chemicals including polychlorinated biphenols (PCBs) and dichlorodiphenyltrichloroethane (DDE). The objectives of the present study were to evaluate spatial and temporal trends of PCBs and organochlorine pesticides in nestling bald eagles of Michigan. The authors' study found that concentrations of PCBs and DDE were higher in Great Lakes areas with Lakes Michigan and Lake Huron having the highest concentrations of DDE and Lake Erie having the highest concentrations of PCBs. Temporally (1987-1992, 1999-2003, and 2004-2008) the present study found declines in PCB and DDE concentrations with a few exceptions. Continued monitoring of Michigan bald eagle populations is suggested for a couple of reasons. First, nestling blood contaminant levels are an appropriate method to monitor ecosystem contaminant levels. Second, from 1999 to 2008 PCB and DDE concentrations for 30% and 40%, respectively, of the nestling eagles sampled were above the no observable adverse effect level (NOAEL) for bald eagles. Lastly, with the continued development and deployment of new chemistries a continuous long term monitoring program is an invaluable resource. Environ Toxicol Chem 2016;35:1995-2002. © 2016 SETAC.

Retracted: Using bald eagles to track spatial (1999-2008) and temporal (1987-1992, 1999-2003, and 2004-2008) trends of contaminants in Michigan's aquatic ecosystems

Retraction: 'Using bald eagles to track spatial (1999-2008) and temporal (1987-1992, 1999-2003, and 2004-2008) trends of contaminants in Michigan's aquatic ecosystems' by Michael R. Wierda, Katherine F. Leith, Teryl G. Grubb, James G. Sikarskie, David A. Best, and William Bowerman The above article from Environmental Toxicology and Chemistry, published online on 10 February 2015 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief, G.A. Burton, Jr., SETAC and Wiley Periodicals, Inc. The retraction has been agreed since the authors determined that some of the plasma samples run at Clemson University had failed quality assurance/quality control and were retested. The concentrations have since been corrected and validated. Reference Wierda MR, Leith KF, Grubb TG, Sikarskie JG, Best DA, Bowerman W. 2015. Using bald eagles to track spatial (1999-2008) and temporal (1987-1992, 1999-2003, and 2004-2008) trends of contaminants in Michigan's aquatic ecosystems. Environ ToxicolChem doi:10.1002/etc.2859.

Physiological effects of polybrominated diphenyl ether (PBDE-47) on pregnant gartersnakes and resulting offspring

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants and are persistent contaminants found in virtually every environment and organism sampled to date, including humans. There is growing evidence that PBDEs are the source of thyroid, neurodevelopmental, and reproductive toxicity. Yet little work has focused on how this pervasive contaminant may influence the reproduction and physiology of non-traditional model species. This is especially critical because in many cases non-model species, such as reptiles, are most likely to come into contact with PBDEs in nature. We tested how short-term, repeated exposure to the PBDE congener BDE-47 during pregnancy affected physiological processes in pregnant female gartersnakes (thyroid follicular height, bactericidal ability, stress responsiveness, reproductive output, and tendency to terminate pregnancy) and their resulting offspring (levels of corticosterone, bactericidal ability, and size differences). We found potential effects of BDE-47 on both the mother, such as increased size and higher thyroid follicular height, and her offspring (increased size), suggesting the effects on physiological function of PBDEs do indeed extend beyond the traditional rodent models.

Halogenated flame retardants in the Great Lakes environment

Flame retardants are widely used industrial chemicals that are added to polymers, such as polyurethane foam, to prevent them from rapidly burning if exposed to a small flame or a smoldering cigarette. Flame retardants, especially brominated flame retardants, are added to many polymeric products at percent levels and are present in most upholstered furniture and mattresses. Most of these chemicals are so-called "additive" flame retardants and are not chemically bound to the polymer; thus, they migrate from the polymeric materials into the environment and into people. As a result, some of these chemicals have become widespread pollutants, which is a concern given their possible adverse health effects. Perhaps because of their environmental ubiquity, the most heavily used group of brominated flame retardants, the polybrominated diphenyl ethers (PBDEs), was withdrawn from production and use during the 2004-2013 period. This led to an increasing demand for other flame retardants, including other brominated aromatics and organophosphate esters. Although little is known about the use or production volumes of these newer flame retardants, it is evident that some of these chemicals are also becoming pervasive in the environment and in humans. In this Account, we describe our research on the occurrence of halogenated and organophosphate flame retardants in the environment, with a specific focus on the Great Lakes region. This Account starts with a short introduction to the first generation of brominated flame retardants, the polybrominated biphenyls, and then presents our measurements of their replacement, the PBDEs. We summarize our data on PBDE levels in babies, bald eagles, and in air. Once these compounds came off the market, we began to measure several of the newer flame retardants in air collected on the shores of the Great Lakes once every 12 days. These new measurements focus on a tetrabrominated benzoate, a tetrabrominated phthalate, a hexabrominated diphenoxyethane, several brominated benzenes, and a highly chlorinated norbornene compound called Dechlorane Plus. Most recently, we have begun measuring the atmospheric concentrations of several organophosphate esters, which are an increasing part of the flame retardant market. The interesting feature of this story is how one compound or set of compounds has followed another out of and into the marketplace even though none of them have been officially regulated. This replacement of one commercial product by another with similar functions shows that the chemical industry does respond to scientific environmental measurements and to the resulting bad publicity. This is a good thing. The problem is that often the replacement chemicals also become environmentally ubiquitous.

Tracking the sources of polybrominated diphenyl ethers in birds: foraging in waste management facilities results in higher DecaBDE exposure in males

Differences in feeding ecology are now recognized as major determinants of inter-individual variations in contaminant profiles of free-ranging animals, but exceedingly little attention has been devoted to the role of habitat use. Marked inter-individual variations and high levels of polybrominated diphenyl ethers (PBDEs) (e.g., DecaBDE) have previously been documented in ring-billed gulls (Larus delawarensis) breeding in a colony near Montreal (QC, Canada). However, the environmental sources of these compounds, and thus the reasons causing these large inter-individual variations remain unidentified. In the present study, we used GPS-based telemetry (±5 to 10m precision) to track ring-billed gulls from this colony to reconstruct their movements at the landscape level. We related habitat use of individual gulls (n=76) to plasma concentrations (ng/g ww) and relative contributions (percentages) to Σ38PBDEs of major congeners in the internationally restricted PentaBDE and current-use DecaBDE mixtures. Male gulls that visited waste management facilities (WMFs; i.e., landfills, wastewater treatment plants and related facilities; 25% of all GPS-tracked males) exhibited greater DecaBDE (concentrations and percentages) and lower PentaBDE (percentages) relative to those that did not. In contrast, no such relationships were found in females. Moreover, in males, DecaBDE (concentrations and percentages) increased with percentages of time spent in WMFs (i.e., ~5% of total foraging time), while PentaBDE (percentages) decreased. No relationships between percentages of time spent in other habitats (i.e., urban areas, agriculture fields, and St. Lawrence River) were found in either sex. These findings suggest that animals breeding in the vicinity of WMFs as well as mobile species that only use these sites for short stopovers to forage, could be at risk of enhanced DecaBDE exposure.

Hepatic polybrominated diphenyl ether (PBDE) levels in Wisconsin river otters (Lontra canadensis) and Michigan bald eagles (Haliaeetus leucocephalus)

Polybrominated diphenyl ethers (PBDEs) are persistent and toxic flame-retardant chemicals widespread in the Great Lakes ecosystem. These chemicals are now being regulated and phased-out of the region; therefore it remains important to understand the extent of contamination in order to track the efficacy of recent actions. Here, Σ₄PBDE congeners (PBDE-47, 99, 100, 153;wetweight basis unless indicated)were determined in liver tissues from Wisconsin river otters (Lontra canadensis; n = 35; 2009-2010) and Michigan bald eagles (Haliaeetus leucocephalus; n = 33; 2009-2011). In otters, Σ₄PBDE ranged from0.5 to 72.9 ng/g, with a mean (±SD) and median (25th-75th percentile inter-quartile range) of 16.3 ± 16.4 ng/g and 11.3 (5.6-18.9) ng/g, respectively. The mean lipid-adjusted Σ₄PBDE was 1377 ± 1485 ng/g. In eagles, Σ₄PBDE ranged from 0 to 1,538.8 ng/g, with a mean and median of 74.3 ± 266.7 ng/g and 21.2 (5.7-28.9) ng/g, respectively. The mean lipid-adjusted Σ₄PBDE was 5274.5 ± 19,896.1 ng/g. In both species, PBDE-47 accounted for >50% of the Σ₄PBDE, followed by PBDE-99 and PBDE-100 (each ~17-19% of the total). The PBDE levels reported here in otters are similar to mammalian wildlife elsewhere, though the levels in eagles are among the highest worldwide across studied birds. The findings indicate that apex Great Lakes wildlife remain exposed to appreciable levels of PBDEs and more work is needed to understand whether such exposures are associated with adverse health outcomes.

Ecotoxicity and biodegradability of new brominated flame retardants: a review

Brominated flame retardants (BFRs) have been routinely used as additives in a number of consumer products for several decades in order to reduce the risk of fire accidents. Concerns about the massive use of these substances have increased due to their possible toxicity, endocrine disrupting properties and occurrence in almost all the environmental compartments, including humans and wildlife organisms. Several conventional BFRs (e.g. polybrominated diphenylethers (PBDE)) have been included in the list of Persistent Organic Pollutants and their use has been restricted because of their established toxicity and environmental persistence. Over the past few years, these compounds have been replaced with "new" BFRs (NBFRs). Despite the fact that NBFRs are different chemical molecules than traditional BFRs, most of physical-chemical properties (e.g. aromatic moiety, halogen substitution, lipophilic character) are common to both groups; therefore, their fate in the environment is potentially similar to the banned BFRs. Therefore, this article has been compiled to summarize the published scientific data regarding the biodegradability of the most widely used NBFRs, a key factor in their potential persistency in the environment, and their ecotoxicological effects on humans and test organisms. The data reviewed here document that the mechanisms through NBFRs exibit their ecotoxicity and the processes leading to their biotransformation in the environment are still poorly understood. Thus emphasis is placed on the need for further research in these areas is therefore emphasized, in order to avoid the massive use of further potentially harmful and recalcitrant substances of anthropogenic origin.

Polybrominated diphenyl ethers in bald (Haliaeetus leucocephalus) and golden (Aquila chrysaetos) eagles from Washington and Idaho, USA

Little is known about the exposure and accumulation of polybrominated diphenyl ethers (PBDEs) in the 2 species of eagles inhabiting North America. The authors analyzed the livers of 33 bald eagles and 7 golden eagles collected throughout Washington and Idaho, USA, for 51 PBDE congeners. Total PBDEs ranged from 2.4 ng/g to 9920 ng/g wet weight. Bald eagles and eagles associated with large urban areas had the highest PBDE concentrations; golden eagles and eagles from more sparsely populated areas had the lowest concentrations. Congener patterns in the present study (brominated diphenyl ether [BDE]-47, BDE-99, BDE-100, BDE-153, and BDE-154 dominating concentrations) were similar to those reported for other bird species, especially raptors. However, the authors also found elevated contributions of BDE-209 in golden eagles and BDE-77 in both species. Patterns in bald eagle samples reflected those in fillets of fish collected from the same general locations throughout Washington, suggesting local exposure to runoff-based contamination, whereas patterns in golden eagle samples suggest a difference in food chain uptake facilitated by atmospheric transport and deposition of BDE-209 and its degradation products into the terrestrial system. Data from the present study represent some of the first reported on burdens of PBDEs in juvenile and adult eagles from North America. The high PBDE liver concentrations associated with large metropolitan areas and accumulation of deca-BDE congeners are a cause for concern.

Patterns and trends in brominated flame retardants in bald eagle nestlings from the upper midwestern United States

We report on patterns and trends in polybrominated diphenyl ethers (PBDEs) in the plasma of 284 bald eagle nestlings sampled between 1995 and 2011 at six study areas in the upper Midwestern United States. Geometric mean concentrations of total PBDEs (Σ of nine congeners) ranged from 1.78 ng/mL in the upper St. Croix River watershed to 12.0 ng/mL on the Mississippi River. Lake Superior nestlings fell between these two extremes. Between 2006 and 2011, trends differed among study areas with three declining, two remaining stable, and one increasing. Variation in ΣPBDE trends among study areas was linked to trends in individual congeners. The lower brominated PBDEs (BDE-47, -99, and -100) declined 4-10% while the higher brominated congeners (BDE-153 and -154) increased by about 7.0% annually from 2006 to 2011. This increase was the greatest in nestlings from the St. Croix River and below its confluence with the Mississippi River. Region-wide, our data suggest ΣPBDEs increased in bald eagle nestlings from 1995 through the mid-2000s and then declined by 5.5% annually from 2006 to 2011. These regional trends are consistent with the removal of penta- and octa-PBDEs from the global market.

Photodegradation of Dechlorane Plus in n-nonane under the irradiation of xenon lamp

Photodegradation has been regarded as the main mechanism for the removal of many halogenated organic pollutants in the environment. The photodegradation of Dechlorane Plus (DP), an emerging contaminant taken worldwide concerns in recent years, was investigated under the irradiation of a xenon lamp. Rapid photodegradation was found under the irradiation of 200-750 nm light, while the degradation became much slower when the range of light wavelength changed to 280-750 nm. DP degradation followed the pseudo first-order kinetics. The quantum yields of 200-280 nm (UV-C) were about 2-3 orders of magnitude higher than 280-320 nm, and no yields can be detected in 320-750 nm range, in an agreement with the changing photodegradation rates with wavelength. The photodegradation products were identified as lower chlorinated DPs, implicating a mechanism of reductive dechlorination. No photoisomerization or solvent adducts were observed, and the difference of photodegradation rate between syn- and anti-DP isomers was negligible.

Assessing effects of environmental chemicals on neuroendocrine systems: potential mechanisms and functional outcomes

Environmental pollutants encompass a vast array of compounds. Most studies in birds have focused on toxicological effects, with little attention to non-lethal effects. Consequently, it has proven difficult to assess potential risk associated with exposure to endocrine disrupting chemicals (EDCs). Assessing potential adverse effects due to exposure is further complicated by the great variation that occurs across avian species. These include variations in reproductive strategies, life span, sexual differentiation, and migration. Differences in reproductive strategies, particularly in the developmental patterns and mechanisms for precocial and altricial chicks, predispose birds to wide variations in response to steroids and steroid-like EDCs. We have investigated the effects of EDCs in precocial birds including Japanese quail (Coturnix japonica) and mallard ducks (Anas platyrhynchos) as well as in wild altricial songbirds. Studies in Japanese quail characterized endogenous steroid hormone changes during development and have demonstrated that the developing embryo uses the yolk as a 'steroid hormone depot'. It appears that actual embryonic exposure is quantitatively lower than indicated by the treatment in egg injections and that the true amount of compound necessary for bioactivity may be quite low relative to the actual dosage delivered. Additionally, embryonic exposure to specific EDCs adversely affected sexual differentiation in quail, especially impacting male sexual behavior as well as neural systems, immune response, and thyroid hormones. Many of these studies considered single compounds; however, wild birds are exposed to complex mixtures and multiple compounds. We tested complex mixtures of polychlorinated biphenyls (PCBs) at concentrations that bracketed those found in eggs in contaminated regions. Results indicated that the predictive value of the toxic equivalency (TEQ), based on comparative activation of the aryl hydrocarbon receptor (AhR) relative to dioxin was not as accurate as expected. We discuss the potential of developing an endocrine disruption index (EDI) to bridge the inconsistencies observed between responses predicted by the TEQ and those observed in vivo following exposure to EDCs. Further, we will discuss how an EDI would complement the adverse outcome pathways analyses to consider the range of effects of endocrine disruptors in birds.

Accumulation and effects of 90-day oral exposure to Dechlorane Plus in quail (Coturnix coturnix)

While a number of studies have addressed bioaccumulation of the flame retardant Dechlorane Plus (DP), little information is available regarding the adverse effects of DP on animals, especially on bird species. In the present study, male common quails (Coturnix coturnix) were consecutively exposed to commercial DP-25 by gavage for 90 d at 1-mg/kg/d, 10-mg/kg/d, and 100-mg/kg/d dosages. Concentrations of DP isomers in liver, muscle, and serum were determined after exposure. Liver enzyme activity involved in xenobiotic biotransformation processes and oxidative stress was measured, as well as glutathione and maleic dialdehyde content. The results showed that DP was more prone to accumulate in the liver than in muscle and serum in all exposed groups. In tested tissues, syn-DP dominated in the high-exposure groups (10 and 100 mg/kg/d), whereas anti-DP tended to accumulate in the low-exposure group (1 mg/kg/d). The concentration ratios of anti-DP to total DP (fanti values) in the tissues examined were close to commercial DP in the low-exposure group; however, the fanti values were significantly decreased in the high-exposure groups. Enzyme activity of 7-pentoxyresorufin-O-demethylase (PROD) decreased significantly in all exposed groups compared with the control group, whereas activity of erythromycin N-demethylase (ERND) and the antioxidant enzyme catalase significantly increased in high-exposure groups. The results implied that DP exposure levels influenced isomeric compositions in organs and that DP exposure altered hepatic alkoxyresorufin O-dealkylase (AROD) activity and contributed to the biological effects of DP.

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 kingfishers (Alcedo atthis) from an electronic waste recycling site and a reference site, South China: influence of residue levels on the isomeric composition

Dechlorane Plus (DP) isomers were examined in common kingfishers (Alcedo atthis) and their prey fishes collected from an electronic waste (e-waste) recycling site and a reference site in South China, to investigate the possible influence of DP residue levels on the isomeric compositions. ∑DP (sum of syn-DP and anti-DP) concentrations in kingfishers from the e-waste recycling site ranged from 29 to 150 (median of 58) ng/g lipid weight (lw), which were one order of magnitude greater than those from the reference site (median = 3.9 ng/g lw). The isomer fractions of anti-DP (f(anti)) in kingfishers from the e-waste recycling site (mean of 0.65) were significantly smaller than those from the reference site (0.76). Additionally, the f(anti) values were negatively correlated to logarithm of ∑DP concentrations in the kingfishers (r(2) = 0.41, p < 0.0001). These results suggested that DP residue levels could influence its isomeric composition in the piscivorous bird.

Accumulation pattern of Dechlorane Plus and associated biological effects on rats after 90 d of exposure

Recent studies have indicated that Dechlorane Plus (DP) is widespread in the environments. However, different isomer-specific enrichment pattern of syn-DP and anti-DP was reported in biological samples from the field. In this study, Sprague-Dawley rats were consecutively exposed to commercial DP 25 by gavage for 90 d at different doses (0, 1, 10, and 100 mg kg(-1) d(-1)) to investigate the accumulation pattern of syn-DP and anti-DP in liver, muscle, and serum of rats. The possible biological effects of DP on rats were also examined. Results showed that DP preferentially accumulated in the liver rather than in muscle at all exposure levels. No significant stereoselectivity of anti-DP or syn-DP in tissues was observed in the low DP exposure groups (0 and 1 mg kg(-1) d(-1)) with f(anti) values (defined as the concentration of the anti-DP divided by the sum of concentrations of anti- and syn-DP) ranging from 0.74 to 0.78. However, f(anti) values reduced (f(anti) ranged from 0.26 to 0.30) significantly in the high DP exposure groups (10 and 100 mg kg(-1) d(-1)) and syn-DP was predominant in all tissues. Biochemical parameters in serum, the mRNA expression levels of certain enzymes and their activities in liver were detected. There was no observable-effect in histopathology and death during the experiment, although the mRNA expression levels of some genes in the low dosage group decreased significantly and enzyme activity of CYP 2B2 increased.

Environmental Mass Spectrometry in the North American Great Lakes Fish Monitoring and Surveillance Program

The Great Lakes Fish Monitoring and Surveillance Program (GLFMSP) has served to protect the Laurentian Great Lakes of North America for decades. Top predator fish from each lake are employed as bioindicators of chemical stressors within each lake. While a vast database has been created for legacy contaminants, such as polychlorinated biphenyls and organochlorine pesticides, a recent programmatic shift has transformed GLFMSP into a more proactive new chemical discovery/screening endeavour to capture the burden of more contemporary chemicals in the environment. The transition prompted the need for advanced instrumentation and the evaluation of mass spectrometric approaches beyond traditional electron capture detection and unit mass resolution mass spectrometers. Here the advances in detection methods are documented and the current direction of the program in creating a living database of anthropogenic chemicals affecting Great Lakes fish is highlighted.

Species- and tissue-specific accumulation of Dechlorane Plus in three terrestrial passerine bird species from the Pearl River Delta, South China

Little data is available on the bioaccumulation of Dechlorane Plus (DP) in terrestrial organisms. Three terrestrial passerine bird species, light-vented bulbul, long-tailed shrike, and oriental magpie-robin, were collected from rural and urban sites in the Pearl River Delta to analyze for the presence of DP and its dechlorinated products in muscle and liver tissues. The relationships between trophic level and concentration and isomeric composition of DP in birds were also investigated based on stable nitrogen isotope analysis. DP levels had a wide range from 3.9 to 930 ng g(-1)lipid weight (lw) in muscle and from 7.0 to 1300 ng g(-1)lw in liver. Anti-Cl(11)-DP and syn-Cl(11)-DP, two dechlorinated products of DP, were also detected in bird samples with concentrations ranged between not detected (nd)-41 and nd-7.6 ng g(-1)lw, respectively. DP preferentially accumulated in liver rather than in muscle for all three bird species. Birds had significantly higher concentrations of DP in urban sites than in rural sites (mean, 300 vs 73 ng g(-1)lw). The fractions of anti-DP (f(anti)) were higher in birds collected in rural sites than in urban sites. Significant positive correlation between DP levels and δ(15)N values but significant negative correlation between f(anti) and δ(15)N values were found for birds in both urban and rural sites, indicating that trophic level of birds play an important role in determining DP level and isomeric profile.

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.

Measurement of flame retardants and triclosan in municipal sewage sludge and biosolids

As polybrominated diphenyl ethers (PBDEs) face increasing restrictions worldwide, several alternate flame retardants are expected to see increased use as replacement compounds in consumer products. Chemical analysis of biosolids collected from wastewater treatment plants (WWTPs) can help determine whether these flame retardants are migrating from the indoor environment to the outdoor environment, where little is known about their ultimate fate and effects. The objective of this study was to measure concentrations of a suite of flame retardants, and the antimicrobial compound triclosan, in opportunistic samples of municipal biosolids and the domestic sludge Standard Reference Material (SRM) 2781. Grab samples of biosolids were collected from two WWTPs in North Carolina and two in California. Biosolids samples were also obtained during three subsequent collection events at one of the North Carolina WWTPs to evaluate fluctuations in contaminant levels within a given facility over a period of three years. The biosolids and SRM 2781 were analyzed for PBDEs, hexabromobenzene (HBB), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB), di(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), the chlorinated flame retardant Dechlorane Plus (syn- and anti-isomers), and the antimicrobial agent 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan). PBDEs were detected in every sample analyzed, and ΣPBDE concentrations ranged from 1750 to 6358ng/g dry weight. Additionally, the PBDE replacement chemicals TBB and TBPH were detected at concentrations ranging from 120 to 3749 ng/g dry weight and from 206 to 1631 ng/g dry weight, respectively. Triclosan concentrations ranged from 490 to 13,866 ng/g dry weight. The detection of these contaminants of emerging concern in biosolids suggests that these chemicals have the potential to migrate out of consumer products and enter the outdoor environment.

Examination of Eurasian griffon vultures (Gyps fulvus fulvus) in Israel for exposure to environmental toxicants using dried blood spots

The griffon vulture (Gyps fulvus) is one of seven species of Old World Gyps vultures found over a wide range from the Iberian peninsula in the west through the Balkans, Turkey, and the Middle East to India in the east. The population of the griffon vultures in Israel has suffered a dramatic decrease, and in recent years productivity has been severely reduced. In this study, whole-blood samples taken from 25 apparently healthy griffon vultures at various stages of maturity were examined to investigate whether the vultures are being excessively exposed to environmental contaminants that might deleteriously affect their reproduction. Five groups of environmental contaminants, comprising toxic elements, organochlorine pesticides, polychlorinated biphenyls, polybrominated diphenyl ethers, and perfluorinated compounds, were monitored in dried blood spots. Results of the analyses showed low levels of exposure of griffon vultures to environmental contaminants compared with the sparse data available on griffon vultures and other diurnal raptors in other countries.

Emerging brominated flame retardants in the sediment of the Great Lakes

The concentrations of 13 currently used brominated flame retardants (BFRs) were analyzed in 16 sediment cores collected from the North American Great Lakes. Among them, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), hexabromocyclododecane (HBCD), 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), and hexachlorocyclopentadienyl dibromocyclooctane (HCDBCO) were more frequently detected than others. In general, these emerging BFRs have much lower concentrations than polybromodiphenyl ethers (PBDEs) and dechloranes. Inventories of the five BFRs named above, given on a logarithm basis, were found to decrease linearly with the increasing latitude of the sampling locations, but with weaker statistics than those previously reported for the dechloranes. Logarithm of surface fluxes, on the other hand, was found to be a better parameter in correlating with the longitude. With regard to time trends, the exponential increases in concentrations of these BFRs, particularly DBDPE and BTBPE, in recent years are particularly disturbing. The sediment concentration of DBDPE doubles every 3-5 years in Lake Michigan, and approximately every 7 years in Lake Ontario. The corresponding doubling times for BTBPE are about 5 and 7 years in Lakes Ontario and Michigan, respectively, although declines or leveling off were observed in the top sediment layers in Lake Ontario. In contrast to PCBs, PBDEs, and most dechloranes, the correlations between the surface concentration of emerging BFRs and the latitude or longitude of the sampling sites were not strengthened by normalization of the concentration based on the organic matter content of the sediment.

Long term trends in PBDE concentrations in gannet (Morus bassanus) eggs from two UK colonies

We used the eggs of an avian sentinel, the Northern gannet (Morus bassanus), to determine long-term (1977-2007) trends in PBDE contamination in Western Atlantic (Ailsa Craig colony) and North Sea (Bass Rock colony) waters around the UK. BDEs 47, 49, 99, 100, 153, 154 were the most abundant and were found in all eggs. Individual congener and ΣPBDE concentrations in eggs from both colonies increased mainly from the late 1980s, peaked in 1994, and then rapidly declined so that concentrations in 2002 were similar to or lower than those in the 1970s and 1980s. The PBDE congener profile and temporal variation in PBDE concentrations suggests that the Penta-BDE technical formula was the main source of PBDE contamination. However, contributions of heavier BDE congeners to ΣPBDE concentrations have increased over time, suggesting other sources are becoming more important. PBDEs had no measurable effect on egg volume or eggshell index.

Levels of dechlorane plus and polybrominated diphenylethers in human milk in two Canadian cities

Flame retardant dechlorane plus (DP) and several polybrominated diphenylether (PBDE) congeners have been measured in 87 human milk samples collected in two Canadian cities: Kingston and Sherbrooke. The levels of PBDEs in human milk (mean (median), ng g(-1) lipid weight=10 (5.9), 4.1 (2.8), 3.0 (1.6), 5.12 (1.6), and 15 (ND) for BDE-47, BDE-99, BDE-100, BDE-153, and BDE-209, respectively) were comparable to those reported in Europe, U.S.A. and China. The levels of DP, with a mean value of 0.98 ng g(-1) and a median value of 0.60 ng g(-1) (lipid weight), were two to ten times lower than those of concurrently measured major PBDEs including BDE-209. While there is little difference in the levels of measured contaminants in milk samples collected from the two cities, the contaminants levels in human milk show, indicated by Principal Components Analysis, that DP, deca-BDE, and penta-BDE come from three distinct sources. The mean and median isomer ratio values of DP in milk were 0.67 and 0.69, respectively, very similar to that of DP commercial products.

A comparison of non-destructive sampling strategies to assess the exposure of white-tailed eagle nestlings (Haliaeetus albicilla) to persistent organic pollutants

To circumvent difficulties associated with monitoring adult predatory birds, we investigated the feasibility of different non-destructive strategies for nestling white-tailed eagles (Haliaeetus albicilla). We were able to quantify polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorinated pesticides (OCPs) in body feathers (16.92, 3.37 and 7.81ngg(-1) dw, respectively), blood plasma (8.37, 0.32 and 5.22ngmL(-1) ww, respectively), and preen oil (1157.95, 30.92 and 440.74ngg(-1) ww, respectively) of all nestlings (N=14). Strong significant correlations between blood plasma and preen oil concentrations (0.565≤r≤0.801; P<0.05) indicate that preen oil levels closely reflect the internal state of contamination. We found fewer significant correlations between body feather and blood plasma concentrations, which were almost exclusively between PCB concentrations (0.554≤r≤0.737; P<0.05). These results differ from a previous study on younger nestlings, and may indicate that the nestlings studied here, ready to fledge the nest, were possibly undergoing certain physiological changes that may have confounded the use of body feathers as biomonitor matrix. Finally, we provide an integrated discussion on the use of body feathers and preen oil as non-destructive biomonitor strategies for nestling predatory birds.

Dechlorane plus in the atmosphere and precipitation near the Great Lakes

Air (vapor and particle) and precipitation samples were collected at five sites (two urban, one rural, and two remote) on the shores of the Great Lakes from January 1, 2005 to December 31, 2009 as a part of the Integrated Atmospheric Deposition Network (IADN). The concentrations of the syn and anti isomers of Dechlorane Plus (DP), a highly chlorinated flame retardant, were measured in these samples. The highest concentrations of these compounds were generally observed at the rural site at Sturgeon Point, New York, which is located near DP's manufacturing facility in Niagara Falls, New York, and at the urban site at Cleveland, Ohio. A multiple linear regression model was applied to the concentrations of these compounds in the vapor phase, particle phase, precipitation, and for the three phases combined. This regression resulted in an overall (three phases combined) doubling time for the anti-DP isomer of 9.5 ± 3.6 years, but for the syn- and total DP (syn + anti) concentrations, the overall regression was not statistically significant. These results suggest that there has been no significant change in the atmospheric concentrations of these compounds over the 2005-2009 time period. The effect of distance from the source in Niagara Falls was highly significant; for example, doubling the distance from Niagara Falls decreased the DP concentrations by about 30%. The effect of the number of people living and working within a 25-km radius of the sampling site (population density) was also highly significant but small; for example if this population doubled or halved, then the atmospheric DP concentrations would increase or decrease by only a few percent.

A review of the analysis of novel brominated flame retardants

This review provides a summary of various analytical methodologies applied to the determination of "novel" brominated flame retardants (NBFRs) in various environmental compartments, as reported in peer reviewed literature, either in print or online, until the end of 2010. NBFRs are defined here as those brominated flame retardants (BFRs) which are either new to the market or newly/recently observed in the environment. The preparation and extraction of sediment, water, sewage sludge, soil, air and marine biota samples, the extract clean-up/fractionation and subsequent instrumental analysis of NBFRs are described and critically examined. Generally, while the instrumental analysis step mainly relies on mass-spectrometric detection specifically developed for NBFRs, and hyphenated to liquid or gas chromatography, preceding steps tend to replicate methodologies applied to the determination of traditional BFRs such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). Shortcomings and gaps are discussed and recommendations for future development are given.

Sources and environmental behavior of dechlorane plus--a review

Intensive research has been carried out in the past few years on the occurrence and behavior of dechlorane plus (DP) in the environment, biota and humans. This review summarizes the information and research results generated since DP was first identified in the environment in 2006. We describe the reported measurement methods for DP and provide an integrated picture of its occurrence and behavior as an environmental contaminant. DP in ambient air and sediments is characterized by strong source related concentration elevations and temporal trends reflecting commercial use. Long-range atmospheric transportation of DP has been observed in remote regions, indicating a global presence of DP. Levels of DP in biota and in humans further reinforce its source related distribution. The change in DP isomer ratio in various environmental matrices from commercial products indicates that the behavior of the two isomers is not the same in the environment or in biota. With only limited data available so far, the biomagnification of DP in aquatic biota has not been conclusively demonstrated. This review also looks at reported dechlorination products of DP that might be of interest in future research.

Dechlorane Plus in house dust from E-waste recycling and urban areas in South China: sources, degradation, and human exposure

Dechlorane Plus (DP) was measured in house dust from e-waste recycling and from urban and rural areas of South China, with geometric mean concentrations of 604, 14.5, and 2.89 ng/g, respectively. Dechlorane Plus in house dust in the e-waste area originated from e-waste recycling activities, whereas household appliances served as a major source of DP in urban house dust. The isomer ratios (f(anti) ) of DP in most dust samples from the e-waste area were significantly lower than those in the urban and rural dust samples and the commercial mixture. Several [-1Cl + H] and [-2Cl + 2H] dechloro-DPs were identified in house dust from the e-waste area, and an a-Cl(11) DP was qualified with concentrations of <55.1 ng/g. Photolytic degradation experiments were conducted by exposing anti-DP, syn-DP, and commercial DP solutions to ultraviolet (UV) light. The slight difference in isomeric half-life derived by photodegradation, as well as the lower f(anti) values in the e-waste combusted residue, suggest a significant influence of isomer-specific thermal degradation of DP during e-waste burning on isomer composition in house dust in the e-waste area. The average estimated daily intakes (EDIs) of DP via house dust ranged from 0.06 to 30.2 ng/d for adults and 0.14 to 121 ng/d for toddlers in the studied area. The average EDIs of a-Cl(11) DP for adults and toddlers in the e-waste area were 0.07 and 0.18 ng/d, respectively.

Dechlorane plus and related compounds in the environment: a review

Dechlorane Plus (DP) is a high production volume, chlorinated flame retardant. Despite its long production history, it was only recently found in the environment. The first "sightings" of DP were in the North American Great Lakes, but subsequent work has indicated that DP is a global contaminant. For example, DP has recently been detected along a pole-to-pole transect of the Atlantic Ocean. Although it was initially thought that DP was produced only in North America, another DP production plant has recently been identified in China. During the course of characterizing DP in the environment, other "DP-like" compounds were identified. These DP analogs, some created from impurities contained in the starting materials during DP's synthesis, have also been detected globally. Screening-level modeling data are in general agreement with available environmental measurements, suggesting that DP and it analogs may be persistent, bioaccumulative, and subject to long-range transport and that these chemicals may be candidates for Annex D evaluation under the United Nations Stockholm Convention on Persistent Organic Pollutants. However, more research is required to better quantify the emissions, exposures, and toxicological effects of DP and its analogs in the environment. In particular, there is a need to obtain more monitoring, bioaccumulation, degradation rate, and toxicity information.