Abstract  BIOSIS COPYRIGHT: BIOL ABS. Fish and sediments from several places along the Swedish River Viskan, sampled in 1995, were analyzed for polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). The samples were collected up- and downstream from several possible point sources (textile industries) for these compounds. Tetrabromodiphenyl ethers (TeBDEs), pentabromodiphenyl ethers (PeBDEs), and decabromodiphenyl ether (DeBDE (BDE209)) were found in sediment. Tetrabromodiphenyl ethers and PeBDEs were also found in fish. Hexabromocyclododecane was identified in sediment and fish. Large fish to sediment ratios for TeBDE, PeBDEs, and HBCD indicate that these are highly bioavailable, whereas BDE209 seems not to be as bioavailable. The lowest PBDE and HBCD levels were found upstream of the industries and concentrations generally increased progressively further downstream as more industries were passed. This is in agreement with earlier investigations of PBDEs in fish from the same river. Many

Abstract  Polybrominated diphenyl ethers (PBDEs) have been widely studied in sediments from the North American Great Lakes; however, no studies have been conducted of occurrences of methoxylated (MeO-) PBDEs in abiotic compartments in this region. In the present study, 23 tri- to hepta-PBDEs and 12 MeO-PBDEs were analyzed in dated sediment cores collected from two inland lakes (White Lake and Muskegon Lake) in Michigan, USA. Concentrations of Sigma(23)PB DEs ranged from 3.9 x 10(-1) to 2.4 x 10 and from 9.8 x 10(-1) to 3.9 x 10(0) ng/g dry weight in White Lake and Muskegon Lake, respectively. The historical trends of tri- to hepta-PBDEs in the two lakes were different, possibly because of different input and remediation histories. The tri- to hepta-PBDE profiles were similar in the two lakes, with BDE-47 as the predominant congener, followed by BDE-99 and BDE-183. A different temporal trend for BDE-183 was found compared with other PBDEs, which is consistent with debromination of high-brominated PBDEs during sedimentation and aging. Methoxylated-PBDEs were detected only in Muskegon Lake (3.6 x 10 (-3) to 1.2 x 10(-1) ng/g dry wt). Methoxylated PBDEs showed different temporal trends compared with tri- to hepta-PBDEs. The differences in patterns of concentrations of MeO-PBDEs in the two lakes might be due to different aquatic communities in each lake. The occurrences of MeO-PBDEs could be the major source of hydroxylated polybrominated diphenyl ethers (OH-PBDEs) observed in organisms collected in these freshwater systems. Environ. Toxicol. Chem. 2011;30:1236-1242. 2011 SETAC

Abstract  Brominated flame retardants (BFRs) are synthetic organobromide compounds which inhibit ignition and combustion processes. Because of their immense ability to retard fire and save life and property, they have been extensively used in many products such as TVs, computers, foam, plastics etc. The five major classes of BFRs are tetrabromobisphenol-A (TBBPA), hexabromocyclododecane (HBCD), pentabromodiphenyl ether, octabromodiphenyl ether, and decabromodiphenyl ether. The last three are also commonly called PBDEs. BDE-85 and BDE-209 are the two prominent congeners of PBDEs and this study reports the adverse effects of these congeners in rodents. Exposure of rat sciatic nerves to 5 mu g/mL and 20 mu g/mL of BDE-85 and BDE-209 respectively lead to significant, concentration dependent reduction in nerve conduction function. Glucose absorption in the rat intestinal segments exposed to 5 mu g/mL of BDE-85 and BDE-209 was significantly reduced for both the compounds tested. Lastly, mice when exposed to 0.25 mg/kg body weight for four days showed a disruption in oxidant and antioxidant equilibrium. The tissues namely liver and brain have shown increase in the levels of lipid hydroperoxides indicating oxidative stress. Moreover, all the protective enzymes namely superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase, and glutathione S transferase (GST) have shown tissue specific alterations indicating the induction of damaging oxidative stress and setting in of lipid peroxidation in exposed animals. The results indicate monitoring of PBDEs in the environment is essential because levels as low as 5 mu g/mL and 0.25 mg/kg body weight were able to cause damage to the functions of rodents.

Abstract  Brominated flame retardants (BFRs) are a relatively new generation of chemicals used as flame retardants in many types of consumer products. The most commonly used BFRs include tetrabromobisphenol A, polybromodiphenyl ethers, polybromobiphenyls, and hexabromocyclododecanes. Perhaps as a result of their widespread use and their lipophilicity, these compounds have become ubiquitous in the environment. This review summarizes BFR concentrations determined in different environmental media. The main sources of BFRs and the exposure pathways through consumption of contaminated food, ingestion, and inhalation of dust are reviewed. The distribution patterns in the abiotic and biotic environment as well as their toxicity are discussed with a view to provide a better understanding of these emerging environmental pollutants. In addition, it is envisaged that this review will heighten the importance of identifying emerging issues and data gaps, and generate a future research agenda on BFRs.

Abstract  Brominated flame retardants (BFRs) are persistent and widespread chemicals. Therefore human beings are exposed to BFRs. House dust may be one source of exposure and contains a lot of xenobiotics in relatively high concentrations. In contrast to common GC-MS based methods here an online LC-MS/MS method is presented to quantify 16 BFRs in dust using ultrasonic solvent extraction as a single sample work up step. LOQ from 0.6 (tetrabromobisphenol A) to 80 (polybrominated diphenylethers (BDE 28) ng/g dust were achieved. Data for accuracy, precision and recovery are presented and are comparable to common LC-MS/MS methods in different matrices. In addition 5 real house dust samples were analyzed with high concentration (535 ng/g) for bis(2-ethyl-1-hexyl)tetrabromophthalate which is a novel alternative BFRs to replace common BDE's.

Abstract  This chapter provides a comprehensive review of the studies on persistent toxic substances (PTS) in the Philippines environment. Many of these persistent organic pollutants (POPs) including pesticides and industrial chemicals, which were either banned or restricted for use in most northern industrialized countries, are still in use in some developing countries. This review focuses on organochlorine compounds (OCs) such as dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs) and hexachlorobenzene (HCB) in the Philippines environment and biota. It also includes a review of residue levels of industrial chemicals such as polychlorinated biphenyls (PCBs), unintentional contaminants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and also the new candidates of POPs, polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs). Environmental monitoring of POPs in the Asia-Pacific region, including the Philippines, revealed apparent POPs contamination particularly of PCBs and dioxins. Consequently, these studies suggest higher risk and exposure of the general populace to these toxic contaminants, more so for people residing near dumping site areas, where elevated concentrations of PCDD/Fs have been noted. PBDEs and HBCDs in human breast milk samples are widely present in general population of the Philippines as that of OCs. It can be presumed that PBDEs may become a major environmental concern in the Philippines as they were found at elevated levels in our work and were higher than in Japan, an industrially developed country. HBCDs were also higher than those reported in other available reports. Although decrease in POPs contamination may have been observed recently on a global scale, developing countries, such as the Philippines, may act as potential sources for certain contaminants for many more years. Therefore, a more systematic and continuous multi-media monitoring of these toxic substances in the Philippines seem imperative. Human health implications and toxic effects to wildlife must likewise be investigated.

Abstract  This paper presents precise sensitization test data of 15 chemicals with a wide spectrum of sensitization potencies, and proposes a new protocol and criteria for quantitative evaluation of sensitization potencies of chemicals. The tests were performed according to the design of Magnus-son and Kligman, changing the application concentrations for induction as well as for challenge phases. 3-dimensional relationships between mean response (or sensitization rate), induction and challenge concentrations were found in all chemicals tested. The following 2 values are proposed as a quantitative measure of sensitization potency: (a) the minimum induction concentration that induces a positive response; (b) the challenge concentration that induces a mean response approximately equal to 1.0 among the animals applied with the highest concentration for induction. Both values coincided with each other within the range of 1 order of magnitude in every compound except 2. The values varied by 5 orders or more of magnitude among the compounds, showing a wide variation of sensitization potencies among chemicals. A good correlation was found for every chemical between the value of sensitization potency thus obtained and the residual levels in causative products in human cases of allergic contact dermatitis. A new experimental protocol for obtaining values (a) and (b) is proposed.

Abstract  Brominated flame retardants are used in electronic appliances and textiles. They are detected in the environment and in breast milk in increasing concentrations. Their persistence is a matter of concern and poses a potential problem similar to that of polychlorinated biphenlys (PCBs). This report discusses these issues and future trends. Contents: characteristics of flame retardants; brominated flame retardant chemistry; analytical methods for brominated flame retardants; toxicology; environmental concentrations; future trends.

Abstract  The test article, hexabromocyclododecane (HBCD), in the vehicle, corn oil, was administered orally (gavage) to three groups of Crl:CD(SD)BR rats for 28 consecutive days. Dosage levels of 125, 350 and 1000 mg/kg/day were administered at a dose volume of 5 ml/kg. The treated groups consisted of 6 rats/sex in the 125 and 350 mg/kg/day groups and 12 rats/sex in the 1000 mg/kg/day group. A concurrent control group comprised of 12 rats/sex received the vehicle on a comparable regimen. Peameters that were evaluated included survival, clinical condition, body weights, food consumption, functional observational battery performance, motor activity, hematology and serum chemistry. At the conclusion of the four-week dosing period, 6 rats/sex/group were enthanized and necropsied. The remaining 6 rats/sex in the control and 1000 mg/kg/day groups were euthanized and necropsied following a two-week recovery period. Selected organs were weighed and/or preserved and selected tissues were examined microscopically for each animal. summer of 1981 to conduct an independent investigation to determine the effects of exposure to chromium compounds on human health and the environment. Battelle's study included a critical review of selected publications relating to chromina toxicity, a comprehensive survey of all 30 refractory plant locations in the United States, site visits to a representa- tive group of manufacturing plants, and an analytical assessment to determine if trivalent chromium compounds used in manufacturing refractories were con- verted to hexavalent materials during the manufacturing process.

Abstract  Client: Saytech inc.

Abstract  Thyroid hormones (TH) are critical for growth and development and particularly brain development. There are numerous environmental agents that lead to marginal reductions of circulating TH. Although it is clear that severe developmental hypothyroidism is profoundly detrimental to neurodevelopment, there is less information regarding the consequences of modest degrees of thyroid. The impact of low level TH disruptions induced by environmental contaminants has not been defined. This paper is a synopsis from four invited speakers who presented at the 13th International Neurotoxicology Association meeting held in Xi'an, China during the summer of 2011. An overview of the role of TH in brain development and a review of human and animal data on the neurological sequelae of disruption of the thyroid axis in the pre- and early post-natal periods were presented by Mary Gilbert and Joanne Rovet. Iodine deficiency, a common cause of TH insufficiency and mental retardation in many countries, including China, was addressed by Zupei Chen. In this presentation the current incidence of iodine deficiency and neurological outcome in China and the efficacy of recently implemented iodinization programs to eliminate this cause of mental retardation were reviewed. Joanne Rovet described the impact of TH disruption during pregnancy and under conditions of congenital hypothyroidism. Children born with normal thyroid function, but who experienced TH insufficiency in the womb, display subtle cognitive impairments and abnormalities in brain imaging. Despite early detection and treatment, deficiencies also exist in children born with thyroid disorders. Different patterns of cognitive effects result from prenatal versus postnatal TH insufficiency. Mary Gilbert reported on the effects of environmental contaminants with thyroid disrupting action on brain development in animals. Results of neurophysiological, behavioral, structural and molecular alterations that accompany modest perturbations of the thyroid axis were reviewed. Noriyuki Koibuchi described molecular targets of TH-mediated signalling accompanying exposure to persistent organic pollutants. Both polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are prevalent environmental contaminants that disrupt TH signalling at the receptor level. This action by these chemical classes could contribute to the negative impact of these chemicals on brain function. In summary, epidemiological, preclinical and animal research has clearly identified the critical role of TH in brain development. Additional work is required to understand the impact of low level perturbations of the thyroid axis to evaluate the risk associated with environmental contaminants with thyroid action.

Abstract  BACKGROUND: Flame retardant chemicals are used in materials on airplanes to slow the propagation of fire. These chemicals migrate from their source products and can be found in the dust of airplanes, creating the potential for exposure.

METHODS: To characterize exposure to flame retardant chemicals in airplane dust, we collected dust samples from locations inside 19 commercial airplanes parked overnight at airport gates. In addition, hand-wipe samples were also collected from 9 flight attendants and 1 passenger who had just taken a cross-country (USA) flight. The samples were analyzed for a suite of flame retardant chemicals. To identify the possible sources for the brominated flame retardants, we used a portable XRF analyzer to quantify bromine concentrations in materials inside the airplanes.

RESULTS: A wide range of flame retardant compounds were detected in 100% of the dust samples collected from airplanes, including BDEs 47, 99, 153, 183 and 209, tris(1,3-dichloro-isopropyl)phosphate (TDCPP), hexabromocyclododecane (HBCD) and bis-(2-ethylhexyl)-tetrabromo-phthalate (TBPH). Airplane dust contained elevated concentrations of BDE 209 (GM: 500 ug/g; range: 2,600 ug/g) relative to other indoor environments, such as residential and commercial buildings, and the hands of participants after a cross-country flight contained elevated BDE 209 concentrations relative to the general population. TDCPP, a known carcinogen that was removed from use in children's pajamas in the 1970's although still used today in other consumer products, was detected on 100% of airplanes in concentrations similar to those found in residential and commercial locations.

CONCLUSION: This study adds to the limited body of knowledge regarding exposure to flame retardants on commercial aircraft, an environment long hypothesized to be at risk for maximum exposures due to strict flame retardant standards for aircraft materials. Our findings indicate that flame retardants are widely used in many airplane components and all airplane types, as expected. Most flame retardants, including TDCPP, were detected in 100% of dust samples collected from the airplanes. The concentrations of BDE 209 were elevated by orders of magnitude relative to residential and office environments.

Abstract  Brominated flame retardants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28years between 1983 and 2010. Significant linear increases were found for sum polybrominated diphenyl ether (ΣPBDE), BDE100, BDE153, and hexabromocyclododecane (HBCD). Average increases of 5.0% per year (range: 2.9-7.6%/year) were found for the subadult polar bears. BDE47 and BDE99 concentrations did not show a significant linear trend over time, but rather a significant non-linear trend peaking between 2000 and 2004. The average ΣPBDE concentrations increased 2.3 fold from 25.0ng/g lw (95% C.I.: 15.3-34.7ng/g lw) in 1983-1986 to 58.5ng/g lw (95% C.I.: 43.6-73.4ng/g lw) in 2006-2010. Similar but fewer statistically significant trends were found for adult females and adult males likely due to smaller sample size and years. Analyses of δ(15)N and δ(13)C stable isotopes in hair revealed no clear linear temporal trends in trophic level or carbon source, respectively, and non-linear trends differed among sex and age groups. These increasing concentrations of organobromine contaminants contribute to complex organohalogen mixture, already causing health effects to the East Greenland polar bears.

Abstract  Blubber samples from male California sea lions (Zalphophus californianus) stranded between 1993 and 2003 were analyzed for 27 polybrominated diphenyl ether (PBDE) congeners, three isomers of hexabromocyclododecane (HBCD) and 14 methoxylated polybrominated diphenyl ether (MeO-BDE) congeners. Total PBDEs ranged from 450 ng/g to 4740 ng/g wet mass and total HBCD ranged from < 0.3 ng/g to 12 ng/g wet mass. The concentration of HBCD increased from 0.7 ng/g to12.0 ng/g wet mass in sea lion blubber between 1993 and 2003. However, no significant temporal trend was observed for any of the other brominated compounds over this 10 year period. Only one of the 14 MeO-BDE congeners was detected in the blubber samples, 6-methoxy-2,2',4,4'-tetrabromodiphenyl ether (6-MeO-BDE 47), and concentrations ranged from < 0.2 ng/g to 12 ng/g wet mass. A bromo-, chloro-heterocyclic compound, 1,1'-dimethyl-tetrabromo-dichloro-2,2'-bipyrrole (DBP-Br4Cl2), previously reported in marine species along the Pacific coast, was also identified in the sea lion blubber. DBP-Br4Cl2 ranged from 44 ng/g wet mass to 660 ng/g wet mass and was present at concentrations rivaling the dominant PBDE congener, BDE 47 (2,2',4,4'-tetrabromodiphenyl ether). Concentrations of DBP-Br4Cl2 were positively correlated with 6-MeO-BDE 47 (r = 0.7; p < 0.05). Both of these compounds have been identified in marine algae and sponges, and studies suggest they are both produced from natural sources. This study demonstrates that brominated compounds from both anthropogenic and biogenic sources can accumulate to similar levels in marine mammals. In addition, HBCD concentrations appear to be increasing in California sea lion populations, whereas PBDE concentrations, between 1993 and 2003, were highly variable.

Abstract  Since 2000, a surprisingly high number of macroscopical gonad alterations has been reported in whitefish (Coregonus spp.) from Lake Thun, Switzerland. This unique phenomenon is still unexplained and has received much public attention. As one possible trigger for these effects, the presence of persistent, bioaccumulative and toxic compounds acting as endocrine disruptors in the lake has been discussed. In this study, concentrations of selected persistent organic pollutants were examined in two morphs of whitefish from Lake Thun and their link to the observed abnormalities was investigated. Analyzed compound classes included polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated naphthalenes, polybrominated diphenyl ethers and hexabromocyclododecanes. The target substances were identified in all samples and concentrations of the analyzed compounds were highly correlated among each other. These correlations show that the analyzed substances have the same distribution pattern throughout the lake and that uptake, accumulation and elimination processes are similar. Significant differences in contaminant levels within the samples existed between the two analyzed morphs of whitefish, most likely due to different age, food patterns and growth rate. No difference in contaminant levels was observed between fish with abnormal gonads and fish with normal gonads, suggesting no causal link between the investigated lipophilic organohalogen compounds present in fish and the observed gonad abnormalities in whitefish from Lake Thun. A comparison to existing data shows that concentrations in Lake Thun whitefish are at the lower bound of contaminant levels in whitefish from Swiss lakes or from European waters.