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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Leaching Potential of Metals and Brominated Flame Retardants in Obsolete Notebook Computers

Barnes, Otho 08 August 2009 (has links)
Due to the increasing use of electronic components and the accelerated rate in which these components become obsolete, there has been a dramatic increase of discarded electronic waste (E-waste). E-waste includes obsolete electronic products such as computers, scanners, cellular phones, etc. These electronic components are manufactured using a variety of hazardous materials. As these components are discarded, the toxic and hazardous substances may become mobile and could impact human health and the environment. The toxic substances of concern contained in E-waste include heavy metals and brominated flame retardants (BFRs). This study attempts to identify the leaching potential of BFRs and metals.
2

Effects of Four New Brominated Flame Retardants on Hepatic Messenger RNA Expression, In Vitro Toxicity and In Ovo Toxicity in the Domestic Chicken (Gallus gallus)

Egloff, Caroline 09 May 2011 (has links)
Brominated flame retardants (BFR) such as hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), bis(2-ethylhexyl)tetrabromophthalate (BEHTBP), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE) are contaminants of environmental concern. These BFRs are replacement alternatives for some of the major production BFRs, which have been restricted from the marketplace due to their adverse health effects. Their presence in environmental matrices, including wild birds, suggests they should be tested for possible toxic effects. BFR alternatives have been detected in the eggs of colonial fish-eating birds, suggesting maternal transfer during ovogenesis and the potential for these chemicals to bioaccumulate through the food chain. However, information regarding the toxicity of HCDBCO, BEHTBP, BTBPE and DBDPE exposure in birds is lacking. This thesis consisted of a combined in vitro/in ovo approach to determine: 1) the concentration-dependent effects of these four BFR alternatives in chicken embryonic hepatocytes (CEH), and 2) the dose-dependent effects of HCDBCO and BTBPE in chicken embryos following injection into the air cell of eggs prior to incubation. Changes in the mRNA expression levels of genes previously found to be responsive to other BFRs were assessed in CEH and liver tissue, in addition to examining overt toxicity (i.e. cytotoxicity, pipping success). None of the BFRs tested were cytotoxic up to 60 µM HCDBCO, 60 µM BEHTBP, 1.4 µM BTBPE or 0.2 µM DBDPE in CEH. Injection doses up to 50 µg/g egg HCDBCO and 10 µg/g egg BTBPE had no effect on embryonic pipping success. The accumulation of HCDBCO and BTBPE was variable in liver and did not follow a linear uptake pattern with respect to injection dose, due in part to difficulties with the solubility of these chemicals in the dimethyl sulfoxide (DMSO) vehicle. In, CEH, HCDBCO caused a decrease in CYP1A4/5 mRNA at all concentrations tested, while CYP2H1 and CYP3A37 were induced only at 10 µM. In contrast, only TTR mRNA was down-regulated in hepatic tissue at all injection concentrations of HCDBCO. The highest concentration of BTBPE induced CYP1A4/5 mRNA to 115- and 18-fold in CEH, and 6.5- and 1.8-fold in liver tissue. In vitro and in ovo exposure to BTBPE caused a concentration-dependent decrease in DIO3 mRNA, while CYP3A37 was down-regulated 2-fold at 10 µg/g in liver tissue. In CEH, DBDPE induced CYP1A4/5 mRNA to a maximum of 29- and 59-fold at 0.2 µM, and increases in DIO1 mRNA and decreases in CYP3A37 mRNA were also observed. None of the gene targets were responsive to BEHTBP exposure in CEH. This is the first study to report on the toxicological and molecular effects of HCDBCO, BEHTBP, BTBPE and DBDPE in an avian species. Using this combined in vitro/in ovo approach has permitted the characterization of these four BFR alternatives by defining possible mechanisms of biological action in a model avian species, the chicken.
3

Effects of Four New Brominated Flame Retardants on Hepatic Messenger RNA Expression, In Vitro Toxicity and In Ovo Toxicity in the Domestic Chicken (Gallus gallus)

Egloff, Caroline 09 May 2011 (has links)
Brominated flame retardants (BFR) such as hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), bis(2-ethylhexyl)tetrabromophthalate (BEHTBP), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE) are contaminants of environmental concern. These BFRs are replacement alternatives for some of the major production BFRs, which have been restricted from the marketplace due to their adverse health effects. Their presence in environmental matrices, including wild birds, suggests they should be tested for possible toxic effects. BFR alternatives have been detected in the eggs of colonial fish-eating birds, suggesting maternal transfer during ovogenesis and the potential for these chemicals to bioaccumulate through the food chain. However, information regarding the toxicity of HCDBCO, BEHTBP, BTBPE and DBDPE exposure in birds is lacking. This thesis consisted of a combined in vitro/in ovo approach to determine: 1) the concentration-dependent effects of these four BFR alternatives in chicken embryonic hepatocytes (CEH), and 2) the dose-dependent effects of HCDBCO and BTBPE in chicken embryos following injection into the air cell of eggs prior to incubation. Changes in the mRNA expression levels of genes previously found to be responsive to other BFRs were assessed in CEH and liver tissue, in addition to examining overt toxicity (i.e. cytotoxicity, pipping success). None of the BFRs tested were cytotoxic up to 60 µM HCDBCO, 60 µM BEHTBP, 1.4 µM BTBPE or 0.2 µM DBDPE in CEH. Injection doses up to 50 µg/g egg HCDBCO and 10 µg/g egg BTBPE had no effect on embryonic pipping success. The accumulation of HCDBCO and BTBPE was variable in liver and did not follow a linear uptake pattern with respect to injection dose, due in part to difficulties with the solubility of these chemicals in the dimethyl sulfoxide (DMSO) vehicle. In, CEH, HCDBCO caused a decrease in CYP1A4/5 mRNA at all concentrations tested, while CYP2H1 and CYP3A37 were induced only at 10 µM. In contrast, only TTR mRNA was down-regulated in hepatic tissue at all injection concentrations of HCDBCO. The highest concentration of BTBPE induced CYP1A4/5 mRNA to 115- and 18-fold in CEH, and 6.5- and 1.8-fold in liver tissue. In vitro and in ovo exposure to BTBPE caused a concentration-dependent decrease in DIO3 mRNA, while CYP3A37 was down-regulated 2-fold at 10 µg/g in liver tissue. In CEH, DBDPE induced CYP1A4/5 mRNA to a maximum of 29- and 59-fold at 0.2 µM, and increases in DIO1 mRNA and decreases in CYP3A37 mRNA were also observed. None of the gene targets were responsive to BEHTBP exposure in CEH. This is the first study to report on the toxicological and molecular effects of HCDBCO, BEHTBP, BTBPE and DBDPE in an avian species. Using this combined in vitro/in ovo approach has permitted the characterization of these four BFR alternatives by defining possible mechanisms of biological action in a model avian species, the chicken.
4

Environmental Fate and Toxicity of Three Brominated Flame Retardants in Aquatic Mesocosms

de Jourdan, Benjamin, Hanson, Mark, Muir, Derek, Sibley, Paul, Solomon, Keith 10 September 2012 (has links)
Tradtional brominated flame retardants (BFRs), namely the polybrominated diphenyl ethers (PBDEs), have persistent, bioaccumulative, and toxic properties that have resulted in the phase out of their production and their be banned in certain jurisdictions. To meet regulatory flame retardancy requirements, non-PBDE BFRs have entered the marketplace. Much remains unknown regarding the environmental fate and toxicity of these emerging BFRs. The objective of this thesis was to use outdoor mesocosms to examine the fate and toxicity of three emerging BFRs; bis(tribromophenoxy)ethane (BTBPE), tetrabromobisphenol A bis(dibromopropyl ether) (TBBPA-DBPE), and BZ-54, which consists of two BFRs, ethylhexyl-tetrabromobenzoate (EHTeBB) and bis(ethylhexyl)tetrabromophthalate (BEHTBP). While it was difficult to accurately determine degradation rates because of fluctuating concentrations, the estimated half-lives indicated these compounds are persistent (> 60 days in sediments). The partitioning of the compounds between the particulates and the sediment resulted in differential degradation rates (greater in the particulates), and products formed; those formed on the particulates were consistent with photodegradation products. The effects of these emerging BFRs on Hyalella azteca and the benthic macroinvertebrate community were assessed through the use of in situ exposure and sampling techniques. The in situ Hyalella cages showed a high degree of variability for most endpoints, regardless of their placement (e.g., water column vs. sediment) in the mesocosm. BTBPE accumulated in the H. azteca (0.03 – 1.4 ng/g ww), however this was not associated with any changes in growth or reproduction. There was high variability in abundance and diversity between the mesocosms, which limited the ability to detect statistically significant differences. Interestingly, the BZ-54 treated mesocosms had the greatest abundance, and the least amount of community diversity. This thesis examined the bioaccumulation potential of these compounds in fathead minnow (Pimephales promelas), as well as the associated effects on growth and development as measured through physical and biochemical endpoints. There was considerable uptake and persistence of BTBPE and TBBPA-DBPE, as well as indication of metabolism of these compounds, but limited physical effects observed. There were indications of increased oxidative stress in the BZ-54 treatment, and increased induction of vitellogenin in fathead minnow from the BTBPE treatment. / Environment Canada's Chemicals Management Plan
5

Use of fish cell lines to compare the cytotoxicity of Tetrabromobisphenol A with its degradation products and with an alternative brominated flame retardant

Wong, Janice 06 November 2014 (has links)
Tetrabromobisphenol A, (TBBPA or Br4BPA), is a widely used brominated flame retardant (BFR). Although TBBPA and its breakdown products been found in river sediments, the environmental impact of their contamination is largely unknown. One breakdown product of TBBPA is bisphenol A (BPA), which has been studied intensively for its toxicology because it is used in the manufacturing of plastics and leaches from food containers, water bottles and pipes. Other breakdown products of TBBPA include tribromobisphenol A (Br3BPA), dibromobisphenol A (Br2BPA), and monobromobisphenol A (BrBPA) but little is known about their toxicology. Since TBBPA is toxic, there is a need to search for an alternative BFR, with one being tetrabromobisphenol A bis(2,3-dibromopropylether) or TBBPA-DBPE. However, almost nothing is known about the toxicology of this compound. Hence, two rainbow trout cell lines, RTL-W1 from liver and RTgill-W1 from gill, were used to evaluate the cellular toxicity of TBBPA, BPA, BrBPA, Br2BPA, Br3BPA and TBBPA-DBPE. The cells were exposed to these compounds for 24 h in the basal medium, L-15, to study their cytotoxicity and in L-15 with fetal bovine serum (FBS) to evaluate their capacity to induce 7-ethoxyresorufin o-deethylase (EROD) activity. Viability was measured with three fluorometric indicator dyes: Alamar Blue (AB) for metabolism, 5-carboxyfluorescein diacetate acetoxymethyl (CFDA AM) for cell membrane integrity, and Neutral Red (NR) for lysosomal activity. The concentrations causing a 50 % reduction in viability (EC50) as measured with these three dyes were used to compare the relative cytotoxicity of these chemicals. For both cell lines and with all viability endpoints, TBBPA was the most cytotoxic, with EC50s ranging from 2.33 to 3.11 ug/ml. BPA, BrBPA, Br2BPA, and Br3BPA also caused dose-dependent declines in cell viability but showed no consistent order of potency. None of the six compounds induced EROD activity, which suggests that they do not activate the aryl hydrocarbon receptor (AhR). Regardless of the endpoint or cell line, TBBPA-DBPE was not cytotoxic. This suggests that, from a toxicological perspective, this compound may be a suitable replacement for TBBPA as a BFR. BPA stood out from the other compounds in two regards. BPA caused a dose-dependent decline in cell viability for cultures in L-15 with FBS, whereas for the other compounds, little or no change in viability was seen in cultures with FBS. BPA elicited a decline in the ability of cells to reduce AB almost immediately upon its addition to cultures in a simple buffer, whereas as for other compounds a decline took time to develop. These results suggest that BPA exerts its cytotoxicity by a different mechanism different from the other compounds.
6

Effects of Four New Brominated Flame Retardants on Hepatic Messenger RNA Expression, In Vitro Toxicity and In Ovo Toxicity in the Domestic Chicken (Gallus gallus)

Egloff, Caroline 09 May 2011 (has links)
Brominated flame retardants (BFR) such as hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), bis(2-ethylhexyl)tetrabromophthalate (BEHTBP), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE) are contaminants of environmental concern. These BFRs are replacement alternatives for some of the major production BFRs, which have been restricted from the marketplace due to their adverse health effects. Their presence in environmental matrices, including wild birds, suggests they should be tested for possible toxic effects. BFR alternatives have been detected in the eggs of colonial fish-eating birds, suggesting maternal transfer during ovogenesis and the potential for these chemicals to bioaccumulate through the food chain. However, information regarding the toxicity of HCDBCO, BEHTBP, BTBPE and DBDPE exposure in birds is lacking. This thesis consisted of a combined in vitro/in ovo approach to determine: 1) the concentration-dependent effects of these four BFR alternatives in chicken embryonic hepatocytes (CEH), and 2) the dose-dependent effects of HCDBCO and BTBPE in chicken embryos following injection into the air cell of eggs prior to incubation. Changes in the mRNA expression levels of genes previously found to be responsive to other BFRs were assessed in CEH and liver tissue, in addition to examining overt toxicity (i.e. cytotoxicity, pipping success). None of the BFRs tested were cytotoxic up to 60 µM HCDBCO, 60 µM BEHTBP, 1.4 µM BTBPE or 0.2 µM DBDPE in CEH. Injection doses up to 50 µg/g egg HCDBCO and 10 µg/g egg BTBPE had no effect on embryonic pipping success. The accumulation of HCDBCO and BTBPE was variable in liver and did not follow a linear uptake pattern with respect to injection dose, due in part to difficulties with the solubility of these chemicals in the dimethyl sulfoxide (DMSO) vehicle. In, CEH, HCDBCO caused a decrease in CYP1A4/5 mRNA at all concentrations tested, while CYP2H1 and CYP3A37 were induced only at 10 µM. In contrast, only TTR mRNA was down-regulated in hepatic tissue at all injection concentrations of HCDBCO. The highest concentration of BTBPE induced CYP1A4/5 mRNA to 115- and 18-fold in CEH, and 6.5- and 1.8-fold in liver tissue. In vitro and in ovo exposure to BTBPE caused a concentration-dependent decrease in DIO3 mRNA, while CYP3A37 was down-regulated 2-fold at 10 µg/g in liver tissue. In CEH, DBDPE induced CYP1A4/5 mRNA to a maximum of 29- and 59-fold at 0.2 µM, and increases in DIO1 mRNA and decreases in CYP3A37 mRNA were also observed. None of the gene targets were responsive to BEHTBP exposure in CEH. This is the first study to report on the toxicological and molecular effects of HCDBCO, BEHTBP, BTBPE and DBDPE in an avian species. Using this combined in vitro/in ovo approach has permitted the characterization of these four BFR alternatives by defining possible mechanisms of biological action in a model avian species, the chicken.
7

Effects of Four New Brominated Flame Retardants on Hepatic Messenger RNA Expression, In Vitro Toxicity and In Ovo Toxicity in the Domestic Chicken (Gallus gallus)

Egloff, Caroline January 2011 (has links)
Brominated flame retardants (BFR) such as hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), bis(2-ethylhexyl)tetrabromophthalate (BEHTBP), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE) are contaminants of environmental concern. These BFRs are replacement alternatives for some of the major production BFRs, which have been restricted from the marketplace due to their adverse health effects. Their presence in environmental matrices, including wild birds, suggests they should be tested for possible toxic effects. BFR alternatives have been detected in the eggs of colonial fish-eating birds, suggesting maternal transfer during ovogenesis and the potential for these chemicals to bioaccumulate through the food chain. However, information regarding the toxicity of HCDBCO, BEHTBP, BTBPE and DBDPE exposure in birds is lacking. This thesis consisted of a combined in vitro/in ovo approach to determine: 1) the concentration-dependent effects of these four BFR alternatives in chicken embryonic hepatocytes (CEH), and 2) the dose-dependent effects of HCDBCO and BTBPE in chicken embryos following injection into the air cell of eggs prior to incubation. Changes in the mRNA expression levels of genes previously found to be responsive to other BFRs were assessed in CEH and liver tissue, in addition to examining overt toxicity (i.e. cytotoxicity, pipping success). None of the BFRs tested were cytotoxic up to 60 µM HCDBCO, 60 µM BEHTBP, 1.4 µM BTBPE or 0.2 µM DBDPE in CEH. Injection doses up to 50 µg/g egg HCDBCO and 10 µg/g egg BTBPE had no effect on embryonic pipping success. The accumulation of HCDBCO and BTBPE was variable in liver and did not follow a linear uptake pattern with respect to injection dose, due in part to difficulties with the solubility of these chemicals in the dimethyl sulfoxide (DMSO) vehicle. In, CEH, HCDBCO caused a decrease in CYP1A4/5 mRNA at all concentrations tested, while CYP2H1 and CYP3A37 were induced only at 10 µM. In contrast, only TTR mRNA was down-regulated in hepatic tissue at all injection concentrations of HCDBCO. The highest concentration of BTBPE induced CYP1A4/5 mRNA to 115- and 18-fold in CEH, and 6.5- and 1.8-fold in liver tissue. In vitro and in ovo exposure to BTBPE caused a concentration-dependent decrease in DIO3 mRNA, while CYP3A37 was down-regulated 2-fold at 10 µg/g in liver tissue. In CEH, DBDPE induced CYP1A4/5 mRNA to a maximum of 29- and 59-fold at 0.2 µM, and increases in DIO1 mRNA and decreases in CYP3A37 mRNA were also observed. None of the gene targets were responsive to BEHTBP exposure in CEH. This is the first study to report on the toxicological and molecular effects of HCDBCO, BEHTBP, BTBPE and DBDPE in an avian species. Using this combined in vitro/in ovo approach has permitted the characterization of these four BFR alternatives by defining possible mechanisms of biological action in a model avian species, the chicken.
8

Occupational exposure to brominated flame retardants : With emphasis on polybrominated diphenyl ethers

Thuresson, Kaj January 2004 (has links)
<p>Brominated flame retardants (BFRs) are a diverse group of chemicals, which are used to slow down or inhibit the development of fires. BFRs are incorporated into a wide range of consumer products that are considered as potential fire hazards, such as TV-sets, household appliances, computers, and textiles. The production and use of BFRs is extensive and consists of mainly tetrabromobisphenol A (TBBPA), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecan (HBCD). BFRs in general, but in particular the PBDEs, have led to both scientific and public concern since they have been found to bioaccumulate in humans and wildlife. The general population is targeted by the PBDEs due to their applications and via the food web. Occupational exposure occurs not only during direct handling of BFRs, but also during handling, repair and dismantling of flame retarded goods.</p><p>This thesis is aimed to assess occupational exposure to BFRs. It is mainly focused PBDEs and especially the PBDEs with high bromine content, such as decabromodiphenyl ether (BDE-209). The work has been accomplished by analysis of BFRs in indoor air at industries handling BFRs or flame retarded goods, and by analysis of blood drawn from workers with potential exposure to BFRs. A referent group, abattoir workers with no occupational exposure to PBDEs, was also investigated. Data from these cross-sectional investigations and from serum sampling during vacation in PBDE-exposed workers have been used for calculation of apparent halflives of hepta- to decaBDE in serum.</p><p>The results clearly show that the workers were exposed to PBDEs when handling PBDE containing products or goods. The serum PBDE levels in computer technicians were found to correlate to the estimated cumulative work hours with computers. Exceptionally high concentrations of BDE-209, almost up to 300 pmol/g lipid weight (l.w.) were observed in serum from rubber workers manufacturing or handling rubber compound that was flame retarded with a technical mixture of decabromodiphenyl ether (DecaBDE). Elevated concentrations of PBDEs with eight or nine bromine substituents were also observed. In an electronics dismantling plant, where elevated levels of PBDEs previously had been observed, reduced serum levels of some, but not all PBDE congeners were observed after industrial hygiene improvements. Notably, it was observed that the BDE-209 concentrations in referents with no occupational exposure were similar to the concentrations of 2,2’,4,4’- tetrabromodiphenyl ether (BDE-47), often referred to as the most abundant PBDE congener in humans and wildlife. Additionally, PBDEs with high bromine content were found to have a fast rate of elimination or transformation in humans, based on serum analysis. BDE-209 had an apparent half-life in serum of only 15 days.</p><p>The possibility of quantifying BFRs, such as PBDEs, in human serum at low levels of detection has been achieved by reducing the contamination of the samples and procedural blanks. Major efforts have been done to develop routines and clean up methodology to enable an almost contamination-free environment at the laboratory. The use of a clean room has decreased PBDE levels in the blanks to acceptable limits. The modifications of the original analytical method have made it possible to quantify almost all PBDE congeners of interest in one GC/MS run.</p><p>Occupational and general background exposure of BFRs to humans will continue as long as these chemicals are a part of our daily life and present as environmental contaminants. The present scientific knowledge of the potential health risks of these BFRs still needs to be further developed. It should be stressed that health effects to PBDEs have not been assessed in this work. It is the author's wish that this thesis should add another piece of knowledge to the puzzle of BFRs and BFR exposure to humans and that these data will be used in future risk assessments of PBDEs in particular.</p>
9

Occupational exposure to brominated flame retardants : With emphasis on polybrominated diphenyl ethers

Thuresson, Kaj January 2004 (has links)
Brominated flame retardants (BFRs) are a diverse group of chemicals, which are used to slow down or inhibit the development of fires. BFRs are incorporated into a wide range of consumer products that are considered as potential fire hazards, such as TV-sets, household appliances, computers, and textiles. The production and use of BFRs is extensive and consists of mainly tetrabromobisphenol A (TBBPA), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecan (HBCD). BFRs in general, but in particular the PBDEs, have led to both scientific and public concern since they have been found to bioaccumulate in humans and wildlife. The general population is targeted by the PBDEs due to their applications and via the food web. Occupational exposure occurs not only during direct handling of BFRs, but also during handling, repair and dismantling of flame retarded goods. This thesis is aimed to assess occupational exposure to BFRs. It is mainly focused PBDEs and especially the PBDEs with high bromine content, such as decabromodiphenyl ether (BDE-209). The work has been accomplished by analysis of BFRs in indoor air at industries handling BFRs or flame retarded goods, and by analysis of blood drawn from workers with potential exposure to BFRs. A referent group, abattoir workers with no occupational exposure to PBDEs, was also investigated. Data from these cross-sectional investigations and from serum sampling during vacation in PBDE-exposed workers have been used for calculation of apparent halflives of hepta- to decaBDE in serum. The results clearly show that the workers were exposed to PBDEs when handling PBDE containing products or goods. The serum PBDE levels in computer technicians were found to correlate to the estimated cumulative work hours with computers. Exceptionally high concentrations of BDE-209, almost up to 300 pmol/g lipid weight (l.w.) were observed in serum from rubber workers manufacturing or handling rubber compound that was flame retarded with a technical mixture of decabromodiphenyl ether (DecaBDE). Elevated concentrations of PBDEs with eight or nine bromine substituents were also observed. In an electronics dismantling plant, where elevated levels of PBDEs previously had been observed, reduced serum levels of some, but not all PBDE congeners were observed after industrial hygiene improvements. Notably, it was observed that the BDE-209 concentrations in referents with no occupational exposure were similar to the concentrations of 2,2’,4,4’- tetrabromodiphenyl ether (BDE-47), often referred to as the most abundant PBDE congener in humans and wildlife. Additionally, PBDEs with high bromine content were found to have a fast rate of elimination or transformation in humans, based on serum analysis. BDE-209 had an apparent half-life in serum of only 15 days. The possibility of quantifying BFRs, such as PBDEs, in human serum at low levels of detection has been achieved by reducing the contamination of the samples and procedural blanks. Major efforts have been done to develop routines and clean up methodology to enable an almost contamination-free environment at the laboratory. The use of a clean room has decreased PBDE levels in the blanks to acceptable limits. The modifications of the original analytical method have made it possible to quantify almost all PBDE congeners of interest in one GC/MS run. Occupational and general background exposure of BFRs to humans will continue as long as these chemicals are a part of our daily life and present as environmental contaminants. The present scientific knowledge of the potential health risks of these BFRs still needs to be further developed. It should be stressed that health effects to PBDEs have not been assessed in this work. It is the author's wish that this thesis should add another piece of knowledge to the puzzle of BFRs and BFR exposure to humans and that these data will be used in future risk assessments of PBDEs in particular.
10

Validation of a Cleanup Method for Analysis of Novel Brominated Flame Retardants in Biota Matrices Sofie Björklund 2015-05-30 Supervisors Ingrid Ericson

Björklund, Sofie January 2015 (has links)
Brominated flame retardants is a group of compounds present in numerous types of materials in our surroundings. Although their purpose is to slow the progression of a fire, many has been shown to be toxic to the environment. Novel brominated flame retardants have been introduced to the market as old ones have been removed. Reliable methods are crucial to be able to monitor how the novel brominated flame retardant spread and accumulate in the environment. To achieve this, a method validation of a cleanup method using multilayer silica followed by analysis by atmospheric pressure gas chromatography coupled to tandem mass spectroscopy was performed. This method had been previously used for polybrominated diphenyl ethers and the aim was to see if it could be used for analysis of novel brominated flame retardants as well. Spiking experiments showed generally good results, with recoveries of the native compound ranging from 40% to 174%. To apply the method on real matrix samples, eight samples of osprey eggs and five samples of adipose tissue of ringed seal was analyzed. Several novel brominated flame retardants were found, most abundant being the methoxylated polybrominated diphenyl ethers. Dominant congener was 2'-Methoxy-2,3',4,5'-tetrabromodiphenyl ether (2PMBDE#68) followed by 6-Methoxy-2,2',4,4'-tetrabromodiphenyl ether (6PMBDE#47), 5-Methoxy-2,2',4,4'-tetrabromodiphenyl ether (5PMBDE#47) and 5-Methoxy-2,2',4,4',6-pentabromodiphenyl ether (5PMBDE#100) with concentrations ranging from &lt;0,13-13 ng/g lipid weight in osprey eggs and &lt;0,003-249 ng/g lipid weight in ringed seal blubber. Also 1,2-Bis(2,4,6-tribromophenoxy)ethane and pentabromobenzene were found in both osprey eggs and ringed seal blubber. Hexabromobenzene was found in ringed seal blubber and 2,3,5,6-tetrabromo-p-xylene was identified in osprey eggs. / Bromerade flamskyddsmedel är en grupp ämnen närvarande i många olika typer av material i vår omgivning. Även om deras syfte är att bromsa förloppet vid en eldsvåda har många visat sig vara toxiska för miljön. Nya bromerade flamskyddsmedel har kommit ut på marknaden i takt med att gamla tagits bort. Pålitliga metoder är nödvändiga för att övervaka hur nya bromerade flamskyddsmedel sprids och ackumulerar i miljön. För att uppnå detta validerades en metod bestående av flerskiktskiseldioxid och analys med atmosfärstryck-gaskromatografi kopplat till tandem-masspektroskopi. Denna metod hade tidigare använts för analys av polybromerade difenyletrar och målet var att undersöka om samma metod kunde användas för analys ad nya bromerade flamskyddsmedel. Spikning gav generellt goda resultat - utbytet för de nativa ämnena var mellan 40% och 174%. För att pröva metoden på prov med riktigt matris analyserades åtta prov med fiskgjuseägg och fem prov med späck från vikare. Flera nya bromerade flamskyddsmedel hittades, mest förekommande var de metoxylerade polybromerade difenyletrarna. Dominerande kongen var 2'-metoxy-2,3',4,5'-tetrabromodifenyleter, följt av 6-metoxy-2,2',4,4'- tetrabromodifenyleter, 5-metoxy-2,2',4,4'- tetrabromodifenyleter och 5-metoxy-2,2',4,4',6- pentabromodifenyleter i koncentrationer från &lt;0,13-13 ng/g lipidvikt (fiskgjuseägg) och &lt;0,003-249 ng/g lipidvikt (sälspäck). Även 1,2-bis(2,4,6-tribromofenoxy)etan (fiskgjuseägg och sälspäck), pentabromobensen (fiskgjuseägg och sälspäck), hexabromobensen (sälspäck) och 2,3,5,6-tetrabromo-p-xylene (fiskgjuseägg) identifierades.

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