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

Many products used in our everyday life contain chemicals added to give them specific properties. Flame retardants (FRs) are added to prevent or retard fires in textiles, plastics etc., while plasticizers are supplied to make plastics more flexible. Through their widespread applications chemicals from both groups are emitted and spread in the environment during usage and disposal. For a long time these products were mainly disposed of in landfills, and in many areas they still are. Thus, since some of these chemicals also pose potential environmental risks and health hazards, there is a need to elucidate their fates during exposure to the landfill environmentThe objectives of this thesis were to investigate the leaching and transformation of FRs and plasticizers from products in which they are used under simulated landfill conditions. To assess the importance of changes in these processes as landfills progress through recognised ageing phases (accompanied by large transitions in both physico-chemical and biological conditions) it was desirable to simulate the changes that typically occur in landfills within a short time period, of 1-2 years.. This was achieved using the newly developed intermediate-scale (3 litre) Modular Environmental Test System (METS).The METS were employed in two studies. The first was an investigation of the leaching and degradation of plasticizers from PVC carpet material incubated at different temperatures (20, 37, 55 and 70°C) prevailing in landfills. Plasticizers subjected to this investigation were the phthalates di-2-ethylhexyl phthalate (DEHP) and benzyl-butyl phthalate (BBP), both of which were found to leach from the carpet. The leaching of DEHP and BBP generally increased with increases in the incubation temperature. However, the most rapid leaching of BBP occurred at 37°C, probably due to high microbial activity at this temperature. Both DEHP and BBP were shown to be degraded within the landfill environment and the degradation potential was highest during the methanogenic landfill phase. In the second METS study the leaching of FRs used in both reactive and additive applications (i.e. chemically bonded to and merely blended with the material, respectively) was characterised. The epoxy oligomer tetrabromobishpenol A (TBBPA) and the phosphorus-based Pyrovatex FRs were selected as representatives for the reactive FRs, while the nitrogen-based melamine and phosphorus-based Proban FRs were selected to represent additive classes. During the incubations, which lasted more than two years, the leaching from melamine was shown to be affected by the landfill phase development. The leaching from the Pyrovatex-treated material and the TBBPA epoxy oligomer seemed to result almost entirely from the washout of unreacted manufacturing residuals. This was also probably true for the FR in the Proban-treated material, although it is durable (despite being additively applied) and thus seemed to leach more slowly (manifested as an increase in phosphate levels in the leachate towards the end of the monitoring period).Finally, due to the paucity of knowledge regarding the fate of ether derivatives of TBBPA (which are also used as FRs) an anaerobic degradation assay was performed. The method employed for this assay was a modified, small-scale ISO standard method. In order to evaluate the degradation assay a uniform analytical protocol was developed. The degradation survey showed that losses of TBBPA, TBBPA-dimethyl ether and bisphenol A dimethyl ether occurred, but no losses of the most hydrophobic compound, TBBPA-dibromopropyl ether, were observed. / Många av de varor och produkter vi kommer i kontakt med dagligen innehåller kemikalier, som tillsats för att materialen i produkterna skall få specifika egenskaper. Till dessa sk funktionella kemiska föreningar hör till exempel flamskyddsmedel och mjukgörare. Den förra förhindrar att produkter fattar eld eller minskar omfattningen av brand. Mjukgörare ingår fr a i plaster för att dessa skall bli smidiga och formbara. Eftersom stora mängder av dessa substanser används eller har använts i produkter i samhället har de spridits till många miljöer. Produkterna hamnar ofta på soptipp, då de inte används mer eller är utnötta. Eftersom flera av dessa substanser innebär risk för hälsa och miljö, är det påkallat att utreda hur de beter sig i soptippsmiljön.Syftet med detta avhandlingsarbete är att undersöka eventuell frisättning och omvandling av dessa två typer av funktionella kemikalier i deponimiljö. Sedan tidigare vet man att sådan frisättning kan var starkt kopplad till åldern och därmed utvecklingen av den kemiska och fysiska miljön förändrats fr a genom tillväxten av mikroorganismer i soptippen. För att komma åt att studera frisättningen under de för deponier karakteristiska utvecklingsfaserna utvecklades en metod (Modualr Environmetal Test System; METS) för att simulera faserna över relativt kort tid (ca 1-2 år). I avhandlingen presenteras två studier, där METS utnyttjats: 1) Frisättning av mjukgörare från en PVC-matta i relation till temperaturer, som uppträder i soptippar (20-70oC) samt 2) Läckage av olika flamskyddsmedel i reaktiv respektive additiv användning studerades för olika applikationer. Vid reaktive applikation är flamskyddsmedlet kovalent bundet till polymeren i produktmaterialet, medan det additivt använda flamskyddsmedlet är inblandat i materialet.Två ftalater (di-2-etylhexyl ftalat, DEHP och bensyl-butyl ftalat (BBP), visade sig läcka från mattan, vilket ökade med högre temperature. De frisattes dock som mest vid 37oC, vilket sannolikt beror på den höga mikrobiella aktiviteten vid denna temperatur. Båda ftalterna bröts ned i soptippsmiljön och hastigheten var störst i den metanogena fasen.En epoxyoligomer (tetrabromobishpenol A TBBPA) och Pyrovatex, som bygger på en fosforförening, användes som modeller för reaktiva flamskyddsmedel. Melamin, som klassas som ett kvävebaserat flamskyddsmedel, fick tillsammans med Proban (fosforbaserat) represen-tera de som används additivt. Medan en frisättning av melamin kunde relateras till utvecklingen av deponimiljön simulerad i METS, så verkar den observerade frisättningen av kemikalierna från de reaktivt behandlade Pyrovatexmaterialet och från epoxipolymeren TBBPA förr ha en fysikalisk-kemisk grund oberoende av utvecklingsfaserna i tippmodel-lerna. Flamskyddsmedlen tvättades helt enkelt ut ur de behandlade produkterna. Probanbehandlingen, som motstår förhållandevis många tvättar trots att det används additivt, visade sig läcka långsamt utan en direkt koppling till fasutvecklingen i METS.Kunskaperna om vad som händer med TBBPA:s eterderivat i deponier är i stort sett obefintliga. Flera av dessa derivat används också som flamskyddsmedel. Därför genomfördes en anaerob nedbrytningsstudie av dessa substanser. För att kunna göra denna studie behövdes en omfattande anpassning och utveckling av metodik, vilket resulterade i ett nytt protokoll för analys av dessa ämnen i olika matriser. Studien visade minskning av koncentrationerna av TBBPA, TBBPA-dimetyleter och bisfenol A dimetyl eter, vilket kan tas som ett tecken på att en transformation och/eller nedbrytning skett. Då dessa föreningar kan omvandlas till mer toxiska substanser bör de undersökas vidare.

Ziel dieser Arbeit war es, ein enantiomerenspezifisches Analysenverfahren für die Bestimmung von Hexabromcyclododecan (HBCD) in Biota-Proben zu entwickeln und die bei erhöhten Temperaturen auftretende Isomerisierung der HBCD-Stereoisomere zu untersuchen. Als erstes wurden die sechs HBCD-Enantiomere isoliert, mittels Einkristallstrukturanalyse, NMR- und IR-Spektroskopie charakterisiert und erstmals die spezifischen Drehwinkel der reinen Enantiomere mit den absoluten Konfigurationen und der Elutionsreihenfolge auf einer chiralen beta-PM-Cyclodextrin-Phase korreliert. Die Untersuchungen der HBCD-Enantiomere in Biota-Proben wurden mit einem HPLC-Tandem-MS-System unter Verwendung einer Kombination aus einer C18- und einer chiralen beta-PM-Cyclodextrin-Phase durchgeführt. Das entwickelte Analysenverfahren wurde validiert und ein Messunsicherheitsbudget erstellt. Die mittlere Wiederfindung für die internen Standards lag im Bereich von 96 - 104 % und die Nachweisgrenzen lagen zwischen 6 und 21 pg/g. Mit Hilfe dieses Analysenverfahrens wurden sowohl maritime als auch Süßwasser Biota-Proben von verschiedenen Probenahmepunkten in Europa untersucht. Die ermittelten Enantiomeren-Verhältnisse, die in allen Fällen vom (±)-alpha-HBCD dominiert wurden, zeigten signifikante Abweichungen von den razemischen Zusammensetzungen. Auffällig hierbei war, dass eine bevorzugte Anreicherung der zuerst eluierenden HBCD-Enantiomere ((-)-alpha-, (-)-beta- und (+)-gamma-HBCD) stattfand. Im Ergebnis der Untersuchungen zur thermisch induzierten intramolekularen Isomerisierung der HBCD-Stereoisomere konnten die verschiedenen Isomerisierungsreaktionen eindeutig aufgeklärt und die jeweiligen Geschwindigkeitskonstanten bei einer Temperatur von 160 °C ermittelt werden. Ergänzend wurde die Isomerisierung mit Hilfe der statistischen Thermodynamik unter Verwendung eines neuen Ansatzes für die klassische Hybrid Monte-Carlo-Simulation untersucht. / The major objectives of this thesis were the development of an analytical procedure for the enantio-specific determination of hexabromocyclododecane (HBCD) in biota samples and the investigation of the interconversion of the individual HBCD isomers at elevated temperatures. The six HBCD enantiomers were isolated, characterised by X-ray diffractometry, NMR- and IR-spectroscopy and the sense of rotation was correlated for the first time with the absolute configurations of the HBCD enantiomers as well as their order of elution on a chiral beta-PM-cyclodextrine-phase. Trace quantification of the individual HBCD enantiomers was achieved by means of high performance liquid chromatography coupled to tandem mass spectrometry equipped with a combination of a C18- and a chiral analytical column. Validation data and an uncertainty budget were determined. The mean recoveries of the different enantiomeric internal standards ranged from 96 to 104 % and the limits of detection are in the range of 6 to 21 pg/g. The analytical procedure was successfully applied to marine and freshwater biota samples from different European sites. The enantiomeric pattern of the six HBCD enantiomers, with (±)-alpha-HBCD as the dominant diastereomer, was determined for all biota samples and showed in most cases a significant deviation from the technical racemate. In these cases a preferential enrichment of the first eluted enantiomers ((-)-alpha-, (-)-beta- and (+)-gamma-HBCD) could be observed. The unambiguous elucidation of the individual isomerisation reactions as well as the quantification of all respective rate constants for the interconversion of the HBCD stereoisomers at 160 °C was done. A mechanistic explanation for the differences of the rate constants which govern the composition of HBCD diastereomers at equilibrium was given. Additionally, the interconversion was investigated by means of statistical thermodynamics using a new approach to classical hybrid Monte-Carlo simulations.