Abstract  The availability of indoor dust for human exposure by hand adhesion depends on size of dust particle. This paper investigates the distribution patterns of brominated flame retardants (BFRs) with particle size in indoor dust. A mixed sample of office dust was obtained from twenty eight high-level offices at Haidian District, Beijing, China. The composite dust (<2mm) was classified into thirteen size fractions (F1-F13: 2000-900-500-400-300-200-100-75-50 μm, 39.58 ± 33.56 μm, 27.93 ± 23.79 μm, 20.15 ± 17.92 μm, 11.38 ± 15.01 μm and 5.64 ± 6.78 μm), by which 18BFRs contents were analyzed. Dust adhered to floc (FD) was also sampled for a separate analysis and was found to contain extremely high level of BFR concentration. The BFR level determined from all fractions of the sampled office dust ranged from ND (not detected) (F1, BDE28, 66) to 5455.4 (FD, BDE209) ng g(-1), in which BDE 209 and BTBPE (1,2-bis (2,4,6-tribromphenoxy) ethane) were found to be the most abundant BFR residue. The influencing factors of BFR distribution patterns in office dust were deduced to be specific surface area, organic content of particles, and origin process (fragmentation and absorption) of BFRs. Selection of dust fraction was demonstrated to be influential on both BFR analytical results and human exposure estimation.

Abstract  This report provides information on hexabromocyclododecane (HBCD; CASRN 25637-99-4; 3194-55-6) used as a flame retardant in polystyrene building insulation, possible substitutes, and alternative materials. The report was developed by the U.S. Environmental Protection Agency (EPA) with input from a partnership of stakeholders from business, government, academia, and environmental organizations. According to technical experts on the Partnership, between 2011 and 2014 there were only three viable flame retardant alternatives to HBCD for use in expanded and extruded polystyrene foam (EPS and XPS) insulation under current manufacturing processes. Alternative materials are also available as substitutes to HBCD-containing insulation. These alternatives may require additive flame retardants or other treatment to meet fire safety requirements. This report: 1) Identifies viable and non-viable flame retardant alternatives for HBCD in polystyrene building insulation foam; 2) Describes uses and provides an overview of end-of-life scenarios and exposure to HBCD; 3) Provides hazard profiles for HBCD and the three chemical alternatives; and 4) Provides an overview of relevant alternative materials. Based on DfE AA criteria and guidance, the hazard profile of the butadiene styrene brominated copolymer (CASRN 1195978-93-8) shows that this chemical is anticipated to be safer than HBCD for multiple endpoints. Due to its large size, lack of low molecular weight (MW) components, and un-reactive functional groups, human health and ecotoxicity hazard for this polymer are measured or predicted to be low, although experimental data were not available for all endpoints. In general the exposure potential to the butadiene styrene brominated copolymer is expected to be lower than the other chemicals in this assessment because it is a large polymer and is unlikely to be released from the polystyrene. However, this alternative is inherently persistent and its long-term behavior in the environment is not currently known. Chemical suppliers have commercialized this polymer, and polystyrene manufacturers are testing it in their products to ensure that the polystyrene will meet all performance standards. The hazard designations for this alternative are based upon high MW formulations of the polymer, where all components have a MW >1,000. The polymer is regulated with a Significant New Use Rule that was finalized in June 2013. Manufacture (or import) of the polymer requires notification to EPA except in these cases: (1) the MW of the polymer is in the range of 1,000 to 10,000 daltons, or (2) the MW of the polymer is ≥10,000 daltons and less than 5 percent of the particles are in the respirable range of 10 microns or less (U.S. EPA 2013). The hazard profiles of the tetrabromobisphenol A (TBBPA)-bis brominated ether derivative (CASRN 97416-84-7) and TBBPA bis(2,3-dibromopropyl) ether (CASRN 21850-44-2) show that these chemicals have limited data sets for human health endpoints and hazard designations show a potential for toxicity. These two chemicals are also anticipated to have High potential for bioaccumulation.

Abstract  An input-output balance study was performed for polybrominated diphenyl ethers, polychlorinated biphenyls and some organochlorine pesticides on three captive, juvenile grey seals (Halichoerus grypus). The animals were fed a diet of herring for six months, during the last three months of which this study was performed. A supplement of decabromodiphenyl ether was included in the diet during the second month of the study. Consistently high absorption (>89%) was observed for all of the chemicals studied, whereas work on other animals has generally shown high (>80%) net absorption at log K(OW) < approximately 6, dropping towards higher log K(OW), and very low absorption of decabromodiphenyl ether. The half-life of decabromodiphenyl ether in blood was estimated to be between 8.5 and 13 days. Measurable concentrations of decabromodiphenyl ether were detected in seal blubber at the end of the study, indicating that this chemical can be stored in adipose and may bioaccumulate. Current understanding of the mechanism of absorption of organohalogen chemicals and the potential for accumulation of decabromodiphenyl ether will need reassessing in the light of these results.

Abstract  The Michigan Chemical (also known as Velsicol Chemical) plant located in St. Louis, Michigan operated from 1936-1978. During this time, the plant manufactured polybrominated biphenyls (PBBs), hexabromobenzene (HBB), 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT), and tris(2,3-dibromopropyl) phosphate (TDBPP), among other products. Due to widespread PBB contamination of Michigan, the plant eventually became a Superfund site, and despite years of cleanup activities, many of the compounds can still be found in the local ecosystem. To investigate the current atmospheric levels and to determine their spatial distributions, we collected tree bark samples from around Michigan and measured the concentrations of these pollutants. For comparison, other organic pollutants, such as polybrominated diphenyl ethers (PBDEs) and organophosphate esters (OPEs), which were not manufactured at the Michigan Chemical plant, were also measured in the same tree bark samples. Our results show levels of PBBs, DDT, and HBB in tree bark collected within 10 km of the Velsicol Superfund site (43, 477, and 108 ng/g lipid wgt., respectively) are 1-2 orders of magnitude higher than at sites located more than 10 km from the site (0.36, 28, and 0.36 ng/g lipid wgt., respectively). Levels of PBDEs and OPEs did not depend on distance from St. Louis. This is the first study on the atmospheric distribution of these chemicals around the Superfund site.

Abstract  The measured concentrations of polybrominated diphenyl ethers (PBDEs) in inland sediments, from mono- to deca-BDE congeners, ranged from 0.46 to 1760 ng/g dry weight (dw) with mean and median values of 55 +/- 230 ng/g dw and 12 ng/g dw, respectively. These concentrations were comparable to or lower than those reported in other countries. The large contributions of the nona- and octa-BDE congeners (14.6 +/- 5.0% of total PBDEs) in the present study highlight the necessity of examining these congeners. A high population density and wastewater discharge around the sampling sites are related to the high PBDE concentration. The most predominant congener was DeBDE209 (average proportion, 70.9 +/- 12.4%), which is in good agreement with the large amounts of commercial deca-BDE products used in Korea. Statistical analyses also confirmed the ubiquity of DeBDE209 in river sediment from the use of commercial deca-BDE products, such as Saytex-102E and DE-83R. On the other hand, the relatively large contributions of tri- to hepta-BDE congeners compared to the small quantities of commercial penta- and octa-BDE products used in Korea indicate the debromination potential for highly brominated congeners. (C) 2012 Elsevier B.V. All rights reserved.

Abstract  The history of polybrominated diphenyl ethers (PBDEs) and the major polybrominated biphenyl congener (BB-153) was studied in dated sediment cores taken from Lakes Michigan and Erie. The surficial concentration of total PBDE (65 [corrected] ng/g dry weight) in Lake Michigan was about 1.6 [corrected] times higher than that in Lake Erie (40 ng/g) and about 5 times higher than that [corrected] in Lake Superior (approximately 12 ng/g). The concentrations of total PBDEs in these sediments have increased rapidly, with doubling times of 5-10 years, reflecting the increasing market demand for these flame retardants over the last 30 years. BDE-209 was found to be the predominant congener in both sediment cores, making up approximately 95% [corrected] of the total PBDE load. The inventories of total PBDEs in Lakes Michigan and Erie were both [corrected] 40 ng/cm2 [corrected] The total burdens of these compounds in the sediment of Lakes Michigan and Erie were 23 [corrected] and 10 metric tons, respectively. We estimate [corrected] the total burden of these compounds in all of the Great Lakes is on the order of 100 [corrected] tons. In both lakes, BB-153 was found to increase rapidly during the 1970s and to peak around 1980.

Abstract  Epidemiological studies and case reports show that even a relatively minor degree of maternal hypothyroxinemia during the first half of gestation is potentially dangerous for optimal fetal neurodevelopment. Our experimental approach was designed to result in a mild and transient period of maternal hypothyroxinemia at the beginning of corticogenesis. Normal rat dams received the goitrogen 2-mercapto-1-methyl-imidazole for only 3 d, from embryonic d 12 (E12) to E15. Maternal thyroid hormones decreased transiently to 70% of normal serum values, without clinical signs of hypothyroidism. Dams were injected daily with 5-bromo-2'-deoxyuridine (BrdU) during 3 d, from E14-E16 or E17-E19. Their pups were tested for audiogenic seizure susceptibility 39 d after birth (P39) and killed at P40. Cells that had incorporated BrdU were identified by immunocytochemistry, and quantified: numerous heterotopic cells were found, whether labeled at E14-E16 or E17-E19, that were identified as neurons. The cytoarchitecture and the radial distribution of BrdU-labeled neurons was significantly affected in the somatosensory cortex and hippocampus of 83% of the pups. The radial distribution of gamma-aminobutyric acidergic neurons was, however, normal. The infusion of dams with T4 between E13 and E15 avoided these alterations, which were not prevented when the T4 infusion was delayed to E15-E18. In total, 52% of the pups born to the goitrogen-treated dams responded to an acoustic stimulus with wild runs, followed in some by seizures. When extrapolated to man, these results stress the need for prevention of hypothyroxinemia before midpregnancy, however moderate, and whichever the underlying cause.

Abstract  Dechlorane Plus (DP) and a dechlorination product, 1,6,7,8,9,14,15,16,17,17,18-octadeca-7,15-diene (anti-Cl(11)-DP), were measured in human hair and indoor dust collected from an e-waste recycling area and two control areas (rural and urban) in South China. DP was detected in hair and dust samples at concentrations ranging from 0.02-58.32 ng/g and 2.78-4197 ng/g, respectively. anti-Cl(11)-DP, mainly detected in human hair and dust samples from the e-waste recycling area, ranged from nd (nondetected) to 0.23 ng/g in hair and from nd to 20.22 ng/g in dust. Average values of anti-DP fractional abundance (f(anti) ratio) in hair of e-waste dismantling workers (0.55 ± 0.11) and dust from e-waste recycling workshops (0.54 ± 0.15) were significantly lower than those in other groups (0.62-0.76 means for hair and 0.66-0.76 means for dust). Significantly positive correlation between DP concentrations in dust and hair and similarity in f(anti) ratios between hair and dust suggest that ingestion of dust comprise one of the major routes for DP exposure. Significantly positive relationships were also observed between anti-Cl(11)-DP and anti-DP for both hair and dust samples with similar regression line slopes. The ratios of anti-Cl(11)-DP to anti-DP between hair and dust show no significant difference. These results suggest that anti-Cl(11)-DP in the human body is likely accumulated from the environmental matrix and not formed from biotransformation of the parent DP.

Abstract  Pooling of surplus serum from individual samples, collected between 2007 and 2009 during Cycle 1 of the Canadian Health Measures Survey (CHMS), was performed to develop a national baseline estimate of brominated flame retardants in Canadians. Serum samples were categorized by sex and distributed by five age groups ranging from 6 to 79years. Nearly 5000 (4583) serum samples were used to form 59 composite pools. Serum pools were created to ensure a high detection frequency of these analytes in serum because low volume samples had previously resulted in non-detectable concentrations. The analytes of interest in these serum pools included 23 polybrominated diphenyl ethers (PBDEs) and three hexabromocyclododecane (HBCD) isomers (α-, β- and γ-HBCD). PBDEs were observed in all samples tested and total PBDE concentrations ranged from 27ngg(-1) lipid to 130ngg(-1) lipid (geometric mean [GM] 46ngg(-1) lipid). ∑PBDE concentrations were significantly elevated in samples representing the 6-11year old age group (GM 65ngg(-1) lipid) relative to ages above 40years, although no difference in concentration was observed between the sexes. PBDE concentrations in Canadian sera from the general population were higher than reported in Europe and Asia, but a little lower than observed in the US. PBDE 47 was the greatest contributor to ∑PBDE concentrations and the GM concentration for this congener was 22ngg(-1) lipid. The other dominant contributors to ∑PBDE concentrations were in descending order: 153 [GM 9.4ngg(-1) lipid]>99 [GM 4.6ngg(-1) lipid]≅100 [GM 4.1ngg(-1) lipid]>209 [GM 1.1ngg(-1) lipid] and 183 [GM 0.42ngg(-1) lipid]. ∑HBCD was detected in all samples analysed, although most samples were observed at concentrations <1ngg(-1) lipid, similar to global concentrations. α-HBCD was the dominant contributor to ∑HBCD concentrations in Canadians although β- and γ-HBCD were detected in 23% and 35% of the samples, respectively. No differences in ∑HBCD concentration were associated with age or sex. This dataset represents the first national data describing HBCD isomers and some PBDEs (e.g., 183, 209) in Canadians.

Abstract  Ten normal young males were investigated in order to examine diurnal and short-term variations in serum TSH and serum thyroid hormones. In five subjects blood samples were obtained every 30 min during a 24 h period of daily life. A synchronous diurnal rhythm was found for free T3 and serum TSH with low levels in the day-time and higher levels at night. The mean increase from day to night was 15 and 140 per cent, respectively. There was a tendency to a similar rhythm in free T4, but the increase of 7 per cent fell short of statistical significance. In the other five men blood samples were obtained every 5 min in a 6 to 7 h period starting within the interval from 19.15 to 22.00 h. A significant regular variation with a cycle-length of half an hour was found in TSH, free T3 and free T4. This rhythm accounted for a significant part of the total variation in the levels of TSH, free T3 and free T4. The mean amplitude of the short-term variation is 13, 15 and 11 per cent of the mean level of the respective hormones. The data suggest a pulsatile release of hormones from the thyroid gland governed by a pulsatile TSH secretion.

Abstract  Modern people spend a considerable time of their life indoors, whether at home, at the workplace or at school, or inside vehicles and public transportation, therefore exposure to a variety of contaminants present indoors is constant and profuse. These contaminants released from household products tend to accumulate and concentrate in dust which is thus considered as one of the main human exposure pathways to several chemicals either by inhalation or ingestion. Within this wide range of contaminants polybrominated diphenyl ethers and hexabromocyclododecanes are included. These two brominated flame retardants have been applied in a vast range of materials with the aim to inhibit or delay the combustion and prevent the fire progression thus increasing the available time for people to escape. The extensive usage granted them a ubiquitous presence in the indoor environment and also in humans. Due to their toxicity and their potential to bioaccumulate these flame retardants have been restricted or banned. However, their persistency in the environment and the increasing evidences of deleterious effects towards humans and wildlife renders the study of these contaminants a matter of great importance. In this review we gathered available information on the levels of PBDEs and HBCDs in indoor dust samples collected from different places and different regions around the world and discuss human exposure to these contaminants through dust.

Abstract  Current contamination levels of selected legacy, currently-used and emerging halogenated contaminants were monitored in marine shellfish along French coastlines. The studied contaminants included polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenylethane (DBDPE), hexabromobenzene (HBB), 2,2′,4,4′,5,5′-hexabromobiphenyl (BB-153) and perfluorinated compounds (PFCs).BDE-47, BDE-209, BTBPE, HBB and α-HBCDD were detected in 100% of the analyzed samples, whereas BB-153, DBDPE and PFOS were detected at frequencies of 97%, 90% and 55%, respectively. Concentrations were in the pg g−1 ww range and varied as follows: PFOS > BDE-47 ∼ α-HBCDD > BDE-209 > BTBPE ∼ DBDPE > HBB ∼ BB-153. Overall, non-PBDE Brominated Flame Retardants (BFRs) revealed concentrations between 3 and 59 times lower than those of PBDEs.PBDE pattern was dominated by BDE-47, followed by BDE-99 > BDE-100 > BDE-49 > BDE-209 > BDE-154; these 6 congeners represented 94% of the summed ten PBDEs. PFC pattern determination revealed PFOS as the predominant PFC in samples from the English Channel and Atlantic, whereas perfluorocarboxylic acids (PFCAs) prevailed in Mediterranean samples. Temporal trend investigations on archived samples from the Mediterranean coast collected between 1981 and 2012 showed a prevalence of PFOS until 1998; PFCAs subsequently increased and became more abundant than PFOS. High levels of PFCAs were observed until 2008, followed by a decrease and stabilization in 2010–2012. Amongst PFCAs, perfluorotridecanoic acid (PFTrDA) and perfluoroundecanoic acid (PFUnA) were predominant and exhibited similar time trends, suggesting similar sources at the investigated site, home to major industrial activity.

Abstract  Hexabromocyclododecane (HBCD), an emerging contaminant, is a brominated flame retardant that has been widely detected in the environment. In this study, nanoscale zerovalent iron (NZVI) aggregates are firstly used to treat HBCD and its removal under different geochemical conditions is evaluated. HBCD is almost removed from solutions by NZVI, with a kSA of 4.22×10(-3)Lm(-2)min(-1). An increase in the iron dosage and temperature increases the removal rate. The activation energy for the removal of HBCD by NZVI is 30.2kJmol(-1), which suggests that a surface-chemical reaction occurs on NZVI. HBCD is adsorbed on the NZVI surface, where electrons were transferred to HBCD, and consequently forms byproducts with less bromide. Three common groundwater anions decrease the reaction kinetics and efficiency of NZVI. The kobs of HBCD in the presence of anions is in the order: pure water >Cl(-)>NO3(-)≒HCO3(-). The inhibitory effect of these anions may be a result of the possible complexation of anions with the oxidized iron surface. The oxidized sites on NZVI and oxidized species of iron also contribute to the removal of HBCD by adsorption on NZVI from solutions.

Abstract  BACKGROUND: Reported polybrominated diphenyl ether (PBDE) concentrations in human samples in the United States have been higher than in Europe and Asia. Little is known about factors that contribute to individual variability in body burden.

OBJECTIVE: In this large study we measured PBDE concentrations in human milk from the United States during 2004-2006. We assessed characteristics associated with concentrations in milk and change in milk concentration between 3 and 12 months postpartum.

METHODS: We analyzed 303 milk samples obtained 3 months postpartum for PBDEs. A second sample was analyzed for 83 women still lactating 12 months postpartum. PBDE concentrations in milk and variability by individual characteristics such as age, parity, and prepregnancy body mass index (BMI) were evaluated using generalized linear models.,

RESULTS: PBDE congeners BDEs 28, 47, 99, 100, and 153 were detected in > 70% of samples. BDE-47 concentrations were the highest, ranging from below the limit of detection to 1,430 ng/g lipid, with a median of 28 ng/g lipid. Concentrations of most individual PBDE congeners and the sum of BDEs 28, 47, 99, 100, and 153 (Sigma PBDE) were lower among mothers > 34 years of age compared with those 25-29 years of age and higher among mothers with high compared with normal BMI, after adjustment for other covariates. Parity was not associated with PBDE concentration. The change in Sigma PBDE concentration in milk between 3 and 12 months postpartum was highly variable (median increase, 14%; interquartile range, -26% to 50%).

CONCLUSIONS: PBDEs were detected in nearly all human milk samples, varying by maternal weight and age and over the course of breast-feeding.

Abstract  Levels of polybrominated diphenyl ethers (PBDEs) are increasing in the environment and may cause long-term health problems in humans. The similarity in the chemical structures of PBDEs and other halogenated aromatic pollutants hints on the possibility that they might share similar toxicological effects. In this work, three-dimensional quantitative structure activity relationships (3-D-QSAR) models, using comparative molecular field analysis (CoMFA) and comparative similarity indices analysis (CoMSIA), were built based on calculated structural indices and a reported experimental toxicology index (aryl hydrocarbon receptor relative binding affinities, RBA) of 18 PBDEs congeners, to determine the factors required for the RBA of these HIDES. After performing leave-one-out cross-validation, satisfactory results were obtained with cross-validation Q(2) and R-2 values of 0.580 and 0.995 by the CoMFA model and 0.680 and 0.982 by the CoMSIA model, respectively. The results showed clearly that the nonplanar conformations of PBDEs result in the lowest energy level and that the electrostatic index was the main factor reflecting the RBA of PBDEs. The two QSAR models were then used to predict the RBA value of 46 PBDEs for which experimental values are unavailable at present.

Abstract  Tetrabromobisphenol A (TBBPA) is a ubiquitous flame retardant. A high-throughput immunoassay would allow for monitoring of human and environmental exposures as a part of risk assessment. Naturally occurring antibodies in camelids that are devoid of light chain, show great promise as an efficient tool in monitoring environmental contaminants, but they have been rarely used for small molecules. An alpaca was immunized with a TBBPA hapten coupled to thyroglobulin and a variable domain of heavy chain antibody (VHH) T3-15 highly selective for TBBPA was isolated from a phage displayed VHH library using heterologous coating antigens. Compared to the VHHs isolated using homologous antigens, VHH T3-15 had about a 10-fold improvement in sensitivity in an immunoassay. This assay, under the optimized conditions of 10% methanol in the assay buffer (pH 7.4), had an IC50 for TBBPA of 0.40 ng mL(-1) and negligible cross reactivity (<0.1%) with other tested analogues. After heating the VHH at 90 degrees C for 90 min about 20% of the affinity for coating antigen T3-BSA remained. The recoveries of TBBPA from spiked soil and fetal bovine serum samples ranged from 90.3% to 110.7% by ELISA and agreed well with a liquid chromatography tandem mass spectrometry method. We conclude the many advantages of VHH make them attractive for the development of immunoassays to small molecules.

Abstract  This paper critically examines indoor exposure to semivolatile organic compounds (SVOCs) via dermal pathways. First, it demonstrates that--in central tendency--an SVOC's abundance on indoor surfaces and in handwipes can be predicted reasonably well from gas-phase concentrations, assuming that thermodynamic equilibrium prevails. Then, equations are developed, based upon idealized mass-transport considerations, to estimate transdermal penetration of an SVOC either from its concentration in skin-surface lipids or its concentration in air. Kinetic constraints limit air-to-skin transport in the case of SVOCs that strongly sorb to skin-surface lipids. Air-to-skin transdermal uptake is estimated to be comparable to or larger than inhalation intake for many SVOCs of current or potential interest indoors, including butylated hydroxytoluene, chlordane, chlorpyrifos, diethyl phthalate, Galaxolide, geranyl acetone, nicotine (in free-base form), PCB28, PCB52, Phantolide, Texanol and Tonalide. Although air-to-skin transdermal uptake is anticipated to be slow for bisphenol A, we find that transdermal permeation may nevertheless be substantial following its transfer to skin via contact with contaminated surfaces. The paper concludes with explorations of the influence of particles and dust on dermal exposure, the role of clothing and bedding as transport vectors, and the potential significance of hair follicles as transport shunts through the epidermis. PRACTICAL IMPLICATIONS: Human exposure to indoor pollutants can occur through dietary and nondietary ingestion, inhalation, and dermal absorption. Many factors influence the relative importance of these pathways, including physical and chemical properties of the pollutants. This paper argues that exposure to indoor semivolatile organic compounds (SVOCs) through the dermal pathway has often been underestimated. Transdermal permeation of SVOCs can be substantially greater than is commonly assumed. Transport of SVOCs from the air to and through the skin is typically not taken into account in exposure assessments. Yet, for certain SVOCs, intake through skin is estimated to be substantially larger than intake through inhalation. Exposure scientists, risk assessors, and public health officials should be mindful of the dermal pathway when estimating exposures to indoor SVOCs. Also, they should recognize that health consequences vary with exposure pathway. For example, an SVOC that enters the blood through the skin does not encounter the same detoxifying enzymes that an ingested SVOC would experience in the stomach, intestines, and liver before it enters the blood.

Abstract  Female three-spined sticklebacks were fed freeze-dried chironomids contaminated with polybrominated diphenyl ethers (PBDE) (Bromkal 70-5DE), polychlorinated naphthalenes (PCN) (Halowax 1014) and polychlorinated biphenyls (PCB) (Clophen A50) in low or high doses in the following combinations: Halowax 1014 + Clophen A50, Bromkal 70-5DE + Clophen A50, Halowax 1014 + Bromkal 70-5DE, and Halowax 1014 + Clophen A50 + Bromkal 70-5DE. The control group was fed uncontaminated freeze-dried chironomids. After 2.5 months of exposure, the fish were dissected for chemical, biochemical and morphological analyses. Hepatic cytochrome P450-dependent ethoxyresorufin-O-deethylase (EROD) activity was induced (3-to 7-fold) in all high-dose groups, but not in the low-dose groups. There were no significant differences between the control and exposed groups in liver somatic index (LSI), gonadosomatic index (GSI), progesterone 17α-hydroxylase activity or the mean proportion of atretic oocytes per total number of oocytes. The mean gonadal progesterone 6β-hydroxylase activity in the control group was 0.3 ± 0.2 pmol mg−1 protein min−1. All groups except the one that received a high dose of Halowax 1014 + Clophen A50 + Bromkal 70-5DE had significantly higher gonadal progesterone 6β-hydroxylase activities compared with the control group. The mean activities in the significantly induced groups ranged from 9.4 ± 3.3 to 20.6 ± 5.0 pmol mg−1 protein min−1. Rainbow trout yolk-sac fry were injected with the same substance blends as the sticklebacks, except that Halowax 1014 + Clophen A50 + Bromkal 70-5DE was not included in the study. Furthermore, each substance alone was injected into the fry. The substances were dissolved in dimethyl sulfoxide (DMSO), and three concentrations were prepared. Halowax 1014. Clophen A50, and Halowax 1014 + Bromkal 70-5DE significantly induced the EROD system. In conclusion, the study showed that Halowax 1014 and Clophen A50 were potent inducers of the cytochrome P450 enzyme system in fish, whereas Bromkal 70-5DE was not. Furthermore, the differences in progesterone hydroxylase activities recorded between the control and exposed groups point to the importance of future thorough studies of organohalogen influence on the hormonal cycle.

Abstract  Biomonitoring survey conducted with glaucous gulls from Svalbard have demonstrated that this top-predator-scavenger species accumulates a wide array of chemicals of environmental concern, including organohalogens, trace elements, organometals, and several non-halogenated and non-metallic-compounds. Among these contaminants are those subjected to global bans or restrictions in North America and Europe (e.g., legacy OC's, penta-, and octa-PBDE technical mixtures and mercury). In addition, some currently produced chemicals were found in gulls that lack and global use regulation (e.g., deca-PBDE , HBCD, and other non-PBDE BFR additives, siloxanes, and selected PFASs). Svalbard glaucous gulls are also exposed to contaminant metabolites that, at time, are more bioactive than their precursors (e.g., oxychlordane, p,p'-DDE, OH- and MeSo2-PCBs, and OH-PBDEs) Concentrations of legacy OCs (PCBs, DDTs, CHLs, CBzs, dieldrin, PCDD/Fs, and mirec) in tissues, blood, and eggs of Svalbard glaucous gulls have displayed the highest contamination levels among glaucous gull populations that inhabit Greenland (Cleemann et al. 2000) Jan Mayen (Gabrielsen et al. 1997), Alaska (Vander Pol et al. 2009), and the Canadian Arctic (Braune et a. 2005). To date, measurements obtaines on more novel organohalogens (e.g., OH- and MeSo2-containing metabolites, BFRs and PFASs) in Svalbard glaucous gull samples generally confirm that the spatial and trophodynamic trends of the legacy OC concentrations, whereas no clear trend emerges from surveys of trace elements and organometals. Using the glaucous gull as biosentinel species provides clear evidence that Svalbard and the European Arctic environment is exposed to a complex mixture of legacy and more recently introduced PBT-like substances.

Abstract  Polybrominated diphenyl ethers (PBDEs) and naturally-produced organobrominated compounds, such as methoxylated PBDEs (MeO-PBDEs), have been scarcely studied in the Southern Hemisphere. Yet, sources of the latter group of compounds were found in Southern regions, specifically in Australia. The environmental distribution and biomagnification potential of organobrominated compounds were therefore investigated in a representative aquatic food chain (invertebrates and fish) from the Sydney Harbour, Australia. Mean PBDE concentrations ranged from 6.4ng/g lipid weight (lw) in squid to 115 ng/g lw in flounder. BDE 47 was the dominant congener, followed by BDE 100. Mean levels of MeO-PBDEs (sum of congeners 2'-MeO-BDE 68 and 6-MeO-BDE 47) were as high as 110 ng/g lw in tailor, with a slight dominance of 2'-MeO-BDE 68. Polybrominated hexahydroxanthene derivates (PBHDs), another class of naturally-produced compounds, were found at variable concentrations and ranged from 4.7 ng/g lw in fanbelly and 146ng/g lw in tailor. The tribrominated PBHD isomer dominated in the samples, except for luderick and squid. The lower levels of PBDEs found in luderick from the harbour compared to those obtained from the upper Parramatta River indicated a terrestrial (anthropogenic) origin of PBDEs, while the higher levels of MeO-PBDEs and PBHDs in the samples from the harbour confirmed the marine (natural) origin of these compounds. The highest trophic magnification factor (TMF) was found for sum PBDEs (3.9), while TMFs for sum MeO-PBDEs and sum PBHDs were 2.9 and 3.4, respectively. This suggests that biomagnification occurs in the studied aquatic food chain for anthropogenic brominated compounds, but also for the naturally-produced organobromines.

Abstract  In a previous study the biodegradation of hexabromocyclododecane (HBCD) was reported to occur under realistic environmental concentrations in soils and freshwater aquatic sediments with biotransformation half-lives ranging from approximately 2 days to 2 months. In this study we extend our knowledge as to the environmental behavior of HBCD with respect to the fate of the three major diastereomers of HBCD (alpha, beta, and gamma) as well as to the identification of major intermediate metabolites formed during degradation. Substantial biological transformation of the alpha-, beta-, and gamma-[14C]HBCD diastereomers was observed in wastewater (i.e., digester) sludge and in freshwater aquatic sediment microcosms prepared under aerobic and anaerobic conditions. Concomitant with the loss of [14C]HBCD in these matrixes there was a concurrent production of three [14C]products. Using a combination of high performance liquid chromatography atmospheric pressure photoionization mass spectrometry and gas chromatography electron impact ionization mass spectrometry these metabolites were identified as tetrabromocyclododecene, dibromocyclododecadiene, and cyclododecatriene. We propose that HBCD is sequentially debrominated via dihaloelimination where at each step there is the loss of two bromines from vicinal carbons with the subsequent formation of a double bond between the adjacent carbon atoms. These results demonstrate that microorganisms naturally occurring in aquatic sediments and anaerobic digester sludge mediate complete debromination of HBCD.

Abstract  The biological transformation of hexabromocyclododecane (HBCD), a brominated fire retardant commonly used in a variety of consumer goods, was investigated in aerobic and anaerobic soils and freshwater sediments. Soil, river water, and aquatic sediments were collected from several locations in the United States and transformation of HBCD was evaluated in the correspondingly composed microcosms based on the Organisation for Economic Co-Operation and Development (OECD) Test Guidelines 307 (Aerobic and Anaerobic Transformation in Soil) or 308 (Aerobic and Anaerobic Transformation in Aquatic Sediment Systems). Soil and sediment reaction mixtures, prepared under either aerobic or anoxic conditions, were dosed with HBCD at a concentration ranging from approximately 10 to 80 ng/g dry weight. The soils and sediments were then placed at 20 degrees C for approximately 4 months and the concentration of HBCD in the microcosms was determined at selected time intervals utilizing high-performance liquid chromatography-mass spectrometry (LC-MS). HBCD loss was observed in both the aerobic and anaerobic soils and sediments although the rates were appreciable faster under anoxic conditions. Biologically mediated transformation processes (i.e., biotransformation) accelerated the rate of loss of HBCD when compared to the biologically inhibited (i.e., autoclaved) soils and sediments. Biotransformation half-lives for HBCD were determined to be 63 and 6.9 days in the aerobic and anaerobic soils, respectively, while biotransformation half-lives for HBCD in the two river systems ranged from 11 to 32 days and 1.1 to 1.5 days under aerobic and anaerobic conditions, respectively. Brominated degradation products were not detected in any of the soils or sediments during the course of the study.

Abstract  A new 16-day echinoid early life stage (ELS) bioassay was developed to allow for prolonged observation of possible adverse effects during embryogenesis and larval development of the sea urchin Psammechinus miliaris. Subsequently, the newly developed bioassay was applied to study the effects of key marine persistent organic pollutants (POPs). Mortality, morphological abnormalities and larval development stages were quantified at specific time points during the 16-day experimental period. In contrast to amphibians and fish, P. miliaris early life development was not sensitive to dioxin-like toxicity in the prolonged early life stage test. Triclosan (TCS) levels higher than 500 nM were acutely toxic during embryo development. Morphological abnormalities were induced at concentrations higher than 50 nM hexabromocyclododecane (HBCD) and 1000 nM tetrabromobisphenol A (TBBPA). Larval development was delayed above 25 nM HBCD and 500 nM TBBPA. Heptadecafluorooctane sulfonic acid (PFOS) exposure slightly accelerated larval development at 9 days post-fertilization (dpf). However, the accelerated development was no longer observed at the end of the test period (16 dpf). The newly developed 16-day echinoid ELS bioassay proved to be sensitive to toxic effects of POPs that can be monitored for individual echinoid larvae. The most sensitive and dose related endpoint was the number of developmental penalty points. By manipulation of the housing conditions, the reproductive season could be extended from 3 to 9 months per year and the ELS experiments could be performed in artificial sea water as well.