Polybrominated Flame Retardants Research Articles

Determination of bromine and tin compounds in plastics using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)

The polybrominated flame retardants and organotin compounds were screened in terms of bromine and tin content using laser ablation inductively coupled plasma mass spectrometry in plastics. The calibration standards were prepared using the fused-disk technique, and all samples were investigated under optimal conditions. Using a central composite experimental design, laser parameters, laser energy, pulse rate, scan rate and spot size were identified. The detection limits of the method were 1000mgkg−1 and 1600mgkg−1 for bromide and tin, whereas the relative standard deviation (%) values of the analysis were 9% and 6% (n=3) for ERM EC681k with 770±70mgkg−1 Br and 86±6mgkg−1 Sn respectively, and 106–115% of Br and 102–104% of Sn were observed for the tetrabromobisphenol A and butyltin trichloride spike plastics, respectively.

Using performance reference compound-corrected polyethylene passive samplers and caged bivalves to measure hydrophobic contaminants of concern in urban coastal seawaters

Low-density polyethylene (PE) passive samplers containing performance reference compounds (PRCs) were deployed at multiple depths in two urban coastal marine locations to estimate dissolved concentrations of hydrophobic organic contaminants (HOCs), including dichlorodiphenyltrichloroethane (DDT) and its metabolites, polychlorinated biphenyl (PCB) congeners, and polybrominated flame retardants. PE samplers pre-loaded with PRCs were deployed at the surface, mid-column, and near bottom at sites representing the nearshore continental shelf off southern California (Santa Monica Bay, USA) and a mega commercial port (Los Angeles Harbor). After correcting for fractional equilibration using PRCs, concentrations ranged up to 100pgL−1 for PCBs and polybrominated diphenyl ethers (PBDEs), 500pgL−1 for DDMU and 300pgL−1 for DDNU, and to 1000pgL−1 for p,p′-DDE. Seawater concentrations of DDTs and PCBs increased with depth, suggesting that bed sediments serve as the source of water column HOCs in Santa Monica Bay. In contrast, no discernable pattern between surface and near-bottom concentrations in Los Angeles Harbor was observed, which were also several-fold lower (DDTs: 45–300pgL−1, PCBs: 5–50pgL−1) than those in Santa Monica Bay (DDTs: 2–1100pgL−1, PCBs: 2–250pgL−1). Accumulation by mussels co-deployed with the PE samplers at select sites was strongly correlated with PE-estimated seawater concentrations, providing further evidence that these samplers are a viable alternative for monitoring of HOC exposure. Fractional equilibration observed with the PRCs increased with decreasing PRC molar volume indicating the importance of target compound physicochemical properties when estimating water column concentrations using passive samplers in situ.

The EPA/NIEHS Children’s Environmental Health and Disease Prevention Research Centers: More Than 15 Years of Innovative Research on Important Challenges in Children’s Environmental Health

The EPA/NIEHS Children’s Environmental Health and Disease Prevention Research Centers: More Than 15 Years of Innovative Research on Important Challenges in Children’s Environmental HealthAbstract Number:2798 Kimberly Gray* and Nica Louie* Kimberly Gray* U.S. Environmental Protection Agency, United States, E-mail Address: [email protected] Search for more papers by this author and Nica Louie* U.S. Environmental Protection Agency, United States, E-mail Address: [email protected] Search for more papers by this author AbstractBackground: The U.S. Environmental Protection Agency (EPA) and the National Institute of Environmental Health Sciences (NIEHS) have jointly supported the Children's Environmental Health and Disease Prevention Research Centers (‘Children’s Centers’) program since 1998, forming a highly successful and collaborative, interdisciplinary research network.Methods: These multidisciplinary, translational research centers are investigating the role of a wide range of environmental exposures in adverse children's health outcomes and how to protect children's health. Studies include how exposure to chemicals such as ambient air pollutants, arsenic in water and food, endocrine-disrupting compounds (EDCs) including bisphenol A (BPA), manganese, organophosphate pesticides and polybrominated flame retardants may, in combination with other factors such as social and behavioral factors and genetic susceptibility, result in adverse birth and health outcomes including asthma, autism, childhood leukemia, changes in epigenetics/gene expression, changes in neurodevelopment and immune system function -- and how to prevent adverse health outcomes. The Children's Centers are using approaches including longitudinal cohort and case-control studies and environmental epidemiology in conjunction with laboratory-based studies to find novel biomarkers of exposure, early developmental and pubertal effects and gene-environment interactions. Community engagement is a key part of the program.Results: This presentation will review some of the important findings from the program over the past 15 years and summarize some of the research currently being funded.Conclusion: Program grantees have published over 1,000 peer-reviewed publications, some highly cited in high-impact journals and cited in environmental policy. Research from the EPA/NIEHS Children’s Centers program is having a significant impact on the field of children’s environmental health and in protecting children's health.

Modelling of Human Transplacental Transport as Performed in Copenhagen, Denmark

Placenta perfusion models are very effective when studying the placental mechanisms in order to extrapolate to real-life situations. The models are most often used to investigate the transport of substances between mother and foetus, including the potential metabolism of these. We have studied the relationships between maternal and foetal exposures to various compounds including pollutants such as polychlorinated biphenyls, polybrominated flame retardants, nanoparticles as well as recombinant human antibodies. The compounds have been studied in the human placenta perfusion model and to some extent in vitro with an established human monolayer trophoblast cell culture model. Results from our studies distinguish placental transport of substances by physicochemical properties, adsorption to placental tissue, binding to transport and receptor proteins and metabolism. We have collected data from different classes of chemicals and nanoparticles for comparisons across chemical structures as well as different test systems. Our test systems are based on human material to bypass the extrapolation from animal data. By combining data from our two test systems, we are able to rank and compare the transport of different classes of substances according to their transport ability. Ultimately, human data including measurements in cord blood contribute to the study of placental transport.

A rapid throughput approach identifies cognitive deficits in adult zebrafish from developmental exposure to polybrominated flame retardants

A substantial body of evidence has correlated the human body burdens of some polybrominated diphenyl ether (PBDE) flame retardants with cognitive and other behavioral deficits. Adult zebrafish exhibit testable learning and memory, making them an increasingly attractive model for neurotoxicology. Our goal was to develop a rapid throughput means of identifying the cognitive impact of developmental exposure to flame retardants in the zebrafish model. We exposed embryos from 6h post fertilization to 5 days post fertilization to either PBDE 47 (0.1μM), PBDE 99 (0.1μM) or PBDE 153 (0.1μM), vehicle (0.1% DMSO), or embryo medium (EM). The larvae were grown to adulthood and evaluated for the rate at which they learned an active-avoidance response in an automated shuttle box array. Zebrafish developmentally exposed to PBDE 47 learned the active avoidance paradigm significantly faster than the 0.1% DMSO control fish (P<0.0001), but exhibited significantly poorer performance when retested suggestive of impaired memory retention or altered neuromotor activity. Learning in the PBDE 153 group was not significantly different from the DMSO group. Developmental exposure to 0.1% DMSO impaired adult active avoidance learning relative to the sham group (n=39; P<0.0001). PBDE 99 prevented the DMSO effect, yielding a learning rate not significantly different from the sham group (n=36; P>0.9). Our results underscore the importance of vehicle choice in accurately assessing chemical effects on behavior. Active avoidance response in zebrafish is an effective model of learning that, combined with automated shuttle box testing, will provide a highly efficient platform for evaluating persistent neurotoxic hazard from many chemicals.

Modeling human off-site aerosol exposures to polybrominated flame retardants emitted during the land application of sewage sludge

Elevated sewage sludge concentrations of polybrominated diphenyl ethers (PBDEs) are due to their broad utilization in textiles and polymers, their resistance to biological degradation, and also their hydrophobic nature—which drives partitioning into wastewater solids. This study estimated the total U.S. emissions of PBDE due to sewage sludge land application and then determined the human inhalation exposure to sludge-associated PBDEs as a function meteorological conditions and downwind distances from an application site. These aerosol exposures have also been incorporated into pharmacokinetic models to predict contributions to steady-state body burden. Our results suggest that while the amount of PBDEs aerosolized during the land application process is small compared to aerosol emissions associated with product use, the application of sludges onto U.S. soils constitutes a major source of PBDEs entering the outdoor environment. Regarding aerosol exposure to nearby residents, the maximum daily inhalation dosages from a common land application scenario occur immediately after sewage sludges are applied and were 137, 27, 1.9, and 81pg/day for significant congeners PBDE-47, -99, -153 and 209 respectively. These doses are 1–2 orders of magnitude less than the standard daily inhalation exposure to the same PBDEs associated with home indoor air and are similar to doses from inhalation of urban and rural outdoor air. Under the worst-case atmospheric transport scenario, the dosages are reduced by approximately 1 order of magnitude when the setback distance between the sludge aerosolization source and human receptor is increased to 200m. Though the health implications of low-level exposures are not well-understood, these sludge-derived PBDE dosages contribute less than a tenth of 1% to the estimated total body burden of PBDE produced from inhalation of indoor and outdoor air, exposure to house dust, and exposure to PBDE from food and water intake. Overall, the inhalation of PBDE aerosols from sludge-applied fields does not represent a significant contribution to human exposure compared to other common indoor exposures. However, land application is a major environmental source of PBDEs and sludge health impact analyses should focus on the practice's impacts on other exposures, such as biomagnification in aquatic and terrestrial food webs.

Levels of polybrominated diphenyl ethers, hexabromocyclododecanes and organophosphorus flame retardants in house dust samples from Portugal

Flame retardants are industrial chemicals added to flammable materials used in our everyday life (e.g. plastics, electrical/electronic equipment, carpets, wall coverings and textiles) in order to s...

Toxicity Evaluation of Organophosphate Flame Retardants in terms of Cholinesterase Inhibition

Organophosphate flame retardants (OPF) have been widely used as substitute for polybrominated flame retardants. OPF have been recognized as low level harmful substances based on LD50. However, it i...

Associations between prenatal exposure to polybrominated flame retardants and infant birth outcomes

Associations between prenatal exposure to polybrominated flame retardants and infant birth outcomes

A baseline study on levels of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, non-ortho and mono-ortho PCBs, non-dioxin-like PCBs and polybrominated diphenyl ethers in Northeast Arctic cod (Gadus morhua) from different parts of the Barents Sea

This study is one of several baseline studies on commercially important Norwegian wild fish species that will provide information concerning metals and persistent organic pollutants (POPs) and food safety. The cod liver is a traditional food product in Norway and a potential source for POPs in the diet. The concentrations of dioxins and furans (PCDD/Fs), dioxin-like PCBs (DL-PCBs), non-dioxin-like PCBs (NDL-PCBs, PCB6) and polybrominated flame retardants (PBDEs) were determined in the liver of 784 individual Northeast Arctic cod caught at 32 positions in the Barents Sea in the period from 2009–2010. In addition, muscle samples from 30 individual cod were analysed for the same substances. The mean concentration of the sum of PCDD/Fs and DL-PCBs for all samples was 14.2ng TEQwho-2005/kgww with a variation between 1.0 and 151ng TEQ/kgww. The concentrations of POPs in the fillet samples were very low.

Predictors of serum concentrations of polybrominated flame retardants among healthy pregnant women in an urban environment: a cross-sectional study

BackgroundPolybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants commonly used in a wide range of products. Prenatal exposure to PBDEs has been associated with adverse neurodevelopment. Our objective was to characterize predictors of exposure to PBDEs among a multi-ethnic, low-income cohort of pregnant women enrolled from highly urban communities in New York City between years 2009–2010.MethodsDuring the first half of pregnancy we collected 316 maternal serum samples and administered an extensive questionnaire including items on demographics, diet and lifestyle. We measured 12 PBDE congeners in blood samples. Using bivariate and multivariate approaches, we regressed the most commonly detected PBDE congeners (PBDE-47, -99, -100 and -153) against potential demographic, dietary and lifestyle predictor variables.ResultsAt least one PBDE congener was detected in each serum sample. Our analyses demonstrate unique predictor patterns for PBDE-47, -99, -100 and -153 based on demographic, lifestyle and dietary characteristics of women. Higher education and increased use of household electronics were associated with higher levels of all 4 congeners. Six characteristics were associated with PBDE-153 serum concentrations, more than for any other congener. These include maternal education, household income, body mass index, solid dairy consumption, processed meat consumption and frequent use of household electronics.ConclusionsPBDE exposure in this widespread in this cohort, though levels are lower than previous assessments of US pregnant women. Lower levels may be in response to legislation restricting the production, sale and use of these compounds. In our cohort, we did not observe any individual predictor or a consistent pattern of several predictors representing a significant source of PBDE exposure. These data suggest that legislation and policy may be more effective at reducing exposure than personal lifestyle modifications.

Removal of pharmaceuticals, polybrominated flame retardants and UV-filters from sludge by the fungus Trametes versicolor in bioslurry reactor

Conventional wastewater treatments are inefficient in the removal of many organic pollutants. The presence of these contaminants in the final sludge represents a source of environmental pollution due to the increasing use of biosolids in land application. A biotechnological approach which employed the fungus Trametes versicolor in a sludge-bioslurry reactor was assessed in order to remove several groups of emerging pollutants. Biological fungal activity was monitored by means of ergosterol and laccase determinations. Fifteen out of 24 detected pharmaceuticals were removed at efficiencies over 50% after the treatment, including eight completely degraded. Removal ranged between 16–53% and 22–100% for the brominated flame retardants and the UV-filters, respectively. Only two of all the detected compounds remained unchanged after the treatment. Although elimination results are promising, the toxicity of the final sludge increased after the treatment. This finding is contrary to the toxicity results obtained in similar treatments of sludge with T. versicolor in solid-phase.

Determination of bromine using high-resolution continuum source molecular absorption spectrometry in a graphite furnace

An analytical method is described for the quantitative analysis of bromine in water solutions as well as in organic solvents using high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS) in a graphite furnace. Bromine is determined by means of molecular absorption of calcium bromide at 625.315nm. First of all the time-temperature program is optimized and the measurements are accomplished with graphite tubes without integrated PIN platform modified with permanent zirconium modifier and with a Pd/Mg-Modifier. The linear range is extended up to six orders of magnitude (from pg to μg-range, absolute) and a limit of detection of 78pg Br absolute is achieved. The accuracy of the method is verified by the recovery rate of two inorganic and one organic salt, and the determination of a whirlpool disinfectant agent as matrix burdened sample. Also, spectral and non-spectral interferences are investigated, whereby only in the case of concentrations in the higher mgL−1-range, non-spectral interferences are observed for fluorine, chlorine, iodine, aluminum, and iron. Next to determination of bromine in water solutions, analysis of polybrominated flame retardants (BFRs) is presented. BFRs are under suspicion of having partial toxic and neurotoxic effects. That is why an easy-to-handle method for the determination of bromine to calculate afterwards the BFR contents by means of the bromine mass fraction is of current interest. After adaptation of the heating program to organic solvents, bromine in three BFRs is determined quantitatively. So, the determination of bromine via HR-CS-MAS is suited for the analysis of low-matrix burdened samples and also in organic compounds. Anymore, this method is a fast, easy-to-handle technique with a low limit of detection.

Umbilical cord blood levels of perfluoroalkyl acids and polybrominated flame retardants

Perfluoroalkyl acids (PFAAs) and polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants representing two classes of environmental contaminants of toxicological concern, especially for infants. Canadian biomonitoring data on these chemicals are limited. The objectives of this study were to measure PFAAs and PBDEs in umbilical cord blood from approximately 100 hospital deliveries in Ottawa (Ontario, Canada) and examine associations with characteristics of the mother and infant. Geometric means were 1.469 ng/mL for perfluorooctanoate (PFOA) (95% confidence interval of 1.292-1.671 ng/mL), 4.443 ng/mL for perfluorooctane sulfonate (PFOS) (95% CI of 3.735-5.285 ng/mL), 0.359 ng/mL for perfluorononanoic acid (PFNA) (95% CI of 0.318-0.404 ng/mL), and 0.579 ng/mL for perfluorohexanesulfonate (PFHxS) (95% CI of 0.473-0.709 ng/mL). The final multiple regression models indicated that lower gravida, term gestational age, smoking during pregnancy and vaginal delivery were significantly associated with higher levels of PFOS. Similarly, a vaginal delivery was significantly associated with higher PFOA, while weak associations were found with lower gravida and birth weight less than 2500 g. Furthermore, higher PFNA concentrations were significantly associated with older mothers, and vaginal delivery, while weakly associated with term gestational age. Elevated PFHxS concentrations were significantly associated with smoking during pregnancy and lower gravida. Similar to reports from other countries, the preponderant PBDE congener measured in the cord blood was PBDE-47. Questions remain on why various studies have reported conflicting results on the association between PFAAs and birth weight.

Endocrine-Disrupting Chemicals: Associated Disorders and Mechanisms of Action

The incidence and/or prevalence of health problems associated with endocrine-disruption have increased. Many chemicals have endocrine-disrupting properties, including bisphenol A, some organochlorines, polybrominated flame retardants, perfluorinated substances, alkylphenols, phthalates, pesticides, polycyclic aromatic hydrocarbons, alkylphenols, solvents, and some household products including some cleaning products, air fresheners, hair dyes, cosmetics, and sunscreens. Even some metals were shown to have endocrine-disrupting properties. Many observations suggesting that endocrine disruptors do contribute to cancer, diabetes, obesity, the metabolic syndrome, and infertility are listed in this paper. An overview is presented of mechanisms contributing to endocrine disruption. Endocrine disruptors can act through classical nuclear receptors, but also through estrogen-related receptors, membrane-bound estrogen-receptors, and interaction with targets in the cytosol resulting in activation of the Src/Ras/Erk pathway or modulation of nitric oxide. In addition, changes in metabolism of endogenous hormones, cross-talk between genomic and nongenomic pathways, cross talk with estrogen receptors after binding on other receptors, interference with feedback regulation and neuroendocrine cells, changes in DNA methylation or histone modifications, and genomic instability by interference with the spindle figure can play a role. Also it was found that effects of receptor activation can differ in function of the ligand.

Policy options for the management of end of life computers in Mexico

End of life computers have raised public and government concern in Mexico because of several factors including the increase in the generation volumes, the presence of toxic chemicals such as polybrominated flame retardants and heavy metals (lead, mercury, hexavalent chromium, cadmium, and beryllium alloys), and the improper management of computers when they are disposed. This study was developed to evaluate the generation and management of end of life computers in Mexico to propose a policy option according to national conditions and existing infrastructure. The diagnosis identified that end of life computers are taken to three different management options: 7,087 tons are recycled, 5,154 tons are disposed in landfills/dumps and 38,332 tons are reused or remanufactured. From these numbers, three policy alternatives were evaluated and a policy is proposed based in extended responsibility for manufacturers/distributors, government and public.

Environment and women's reproductive health

There is significant evidence that continuous and prolonged exposure to several endocrine disrupting chemicals (EDC) is a risk factor for reduced fertility and fecundity in women. There is also evidence that ED exposure has trans-generational effects. In this systematic review, we evaluate the evidence for an association between EDC exposure and women's reproductive health. Studies were found by searching the PubMed database for articles published up to 2010. Associations between ED exposure and women's reproductive health reported in the PubMed database are summarized and classified as fertility and fecundity, pregnancy outcomes, transgenerational exposure and effects. Epidemiological studies on EDCs are not always consistent, in part due to limitations imposed by practical constraints. In order to make progress in this field, we recommend taking advantage of biomonitoring and biobanks, including the development of appropriate biomarkers, and taking into greater consideration modulating factors such as genetic polymorphisms and dietary habits. Further human studies are warranted with particular focus on impaired fertility/fecundity associated with currently widespread ED (e.g. bisphenol A, phthalates and polybrominated flame retardants). A detailed appraisal of compounds specifically related to adverse reproductive outcomes is very important for prevention and risk-communication strategies. Besides research needs, the current evidence is sufficient to prompt precautionary actions to protect women's reproductive health.

Health effects of persistent organic pollutants: the challenge for the Pacific Basin and for the world

Persistent organic pollutants include some organo-metals, such as methylmercury; lipophilic halogenated organics, such as dioxins, polychlorinated biphenyls, chlorinated pesticides, and polybrominated flame retardants; and perfluorinated compounds used as repellants. These compounds are resistant to degradation both in the environment and in the human body and tend to bioaccumulate within the food chain. Persistent organic pollutants cause a variety of adverse health effects, including cancer, immune system suppression, decrements in cognitive and neurobehavioral function, disruption of sex steroid and thyroid function, and at least some of them increase the risk of chronic diseases, such as hypertension, cardiovascular disease, and diabetes. Some compounds are byproducts of industry and combustion. Although the manufacture and use of most man-made chemicals has been reduced in recent years, the levels currently present in the population are still associated with an elevated risk of human disease. Others are still manufactured and used. These are dangerous chemicals that have contaminated even areas remote from the industrialized world, such as the polar regions.

Analysis of Structurally Analogous Polybrominated Flame Retardants by Derivative Spectrum Chromatogram Method

An individual determination of the structurally analogous polybrominated flame retardants by using the derivative spectrum chromatogram method with an HPLC-diode array detector was investigated. These flame retardants have a high boiling point, and could be hardly analyzed by HPLC-MS/MS and GC-MS. Two octabromodiphenyl ethers (octa BDEs) related congeners, BDE-204 and BDE-205 showed almost the same UV-spectrum and elution behaviors in RP-HPLC. Even for such similar properties, the derivative spectrum chromatogram method allowed a selective determination of the congeners. This method was applied to the polyester resin kneaded octabromodiphenyl ether (technical) to evaluate its qualitative and quantitative properties. The ratio chromatograms of the multi derivative spectrum were effective to confirm the peak purity.

Hypospadias and halogenated organic pollutant levels in maternal mid-pregnancy serum samples

Background Environmental contaminants that disrupt endocrine function may contribute to hypospadias etiology. Objective To compare levels of selected halogenated organic pollutants in women delivering infants with and without hypospadias. Methods This study examined levels of nine polybrominated flame retardants (PBDEs), 30 polychlorinated biphenyls (PCBs) and nine persistent pesticides in mid-pregnancy serum samples from 20 women who delivered infants with hypospadias and 28 women who delivered unaffected infants, in California. Analytes were measured using isotope dilution high-resolution mass spectrometry. Values below individual limits of detection (LOD) for each analyte were imputed based on a truncated multivariate normal distribution. Levels of 17 analytes for which at least 50% of cases and controls had values above the LOD were compared using t-tests and by generating odds ratios from logistic regression analyses. Results Means were greater for cases than controls for 11 of the 17 reported analytes (4 of 5 PBDEs, 7 of 9 PCBs, and 0 of 3 other persistent pesticides), but none of the differences were statistically significant. Eleven of the 17 odds ratios exceeded one (the same analytes that had greater means), but none of the confidence intervals excluded one. After adjustment for sample processing time and foreign-born Hispanic race-ethnicity, only four of the odds ratios exceeded one. Conclusions Levels of the PBDEs and PCBs were not statistically significantly different, but the sample size was small. The current study adds to a relatively limited knowledge base regarding the potential association of specific contaminants with hypospadias or other birth defects.