This thesis deals with a contaminated area in the municipality of Östersund where a gas plant has previously been operating from 1914 to 1951. Operations at the property where the gas plant has been located currently consist of a workshop and commercial premises with associated car parking. In order to be able to build on the gas plant area, the municipality intends to implement post-treatment measures in the area. The substances found in the contaminated area (hotspot area E) are polycyclic aromatic hydrocarbons (PAH), aromatics, arsenic, nickel, lead and benzene. Measurement data indicate that these substances have been found at high levels, above the Swedish Environmental Protection Agency's guideline values for contaminated soil. Many areas today are polluted to the level that they pose great risks to the environment and people, and this thought requires the treatment of contaminated soil. A risk assessment for hotspot area E determined that PAH, aromatics, arsenic, nickel, lead and benzene pose an unacceptable risk, and the area is therefore deemed to need remediation. Based on nearby buildings, in-situ soil remediation is a suitable approach that fits. This study summarizes the progress made in remediation research and shows that soil remediation methods have different advantages and disadvantages, and different strains on human health and the environment. Based on this study, it may be more appropriate to wait for more efficient or cheaper remediation techniques to be developed, but with the idea that these substances are volatile, toxic, and dangerous to us humans and the environment. This means that they pose a potential risk to society and a tendency to spread easily. Conclusions that can be drawn are that all in-situ methods included in this work can be applied in Sweden based on the geological conditions. In order to achieve optimum in-situ soil remediation, site-specific conditions, such as large groundwater flow or heterogeneous soil, control the choice of remediation method.

Thesis are aimed to the optimization and validation of the QuEChERS method for determination of polycyclic aromatic hydrocarbons in solid matrices of hydrosphere. The QuEChERS method was also used for determination of polycyclic aromatic hydrocarbons in real samples and for comparison of measured results, time and material costs of the method with currently employed methods: (1) accelerated solvent extraction connected with gel permeation chromatography (ASE/GPC), and (2) ultrasonic extraction connected with solid phase extraction (UZ/SPE). According to the validation criteria, the QuEChERS method is suitable for the determination of polycyclic aromatic hydrocarbons in solid matrices of hydrosphere. The QuEChERS technique provides comparable results to ASE/GPC and UZ/SPE. In terms of price and time for sample preparation, the QuEChERS method allows (unlike the methods ASE/GPC and UZ/SPE) fast and inexpensive determination of polycyclic aromatic hydrocarbons in solid samples of hydrosphere.

In der vorliegenden Arbeit wurde die elektronische Struktur verschiedener undotierter und mit Alkalimetallen beziehungsweise 2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethan (F 4 TCNQ) dotierter, polyzyklischer aromatischer Kohlenwasserstoffe (PAK) untersucht. Diese Untersuchungen waren motiviert durch verschiedene Veröffentlichungen in denen supraleitendes Verhalten an unterschiedlichen alkalimetalldotierten PAK beschrieben wurde. Erste Studien erfolgten an undotiertem 1,2:8,9-Dibenzopentacen (DBP) und Pentacen unter Nutzung von Photoelektronenspektroskopie (PES), Elektronenenergieverlustspektroskopie (EELS) und Dichtefunktionaltheorie (DFT). Die spektroskopischen Methoden zeigten für beide Materialien eine große Ähnlichkeit der elektronischen Zustände, vor allem im niederenergetischen Bereich, welche durch die theoretischen Ergebnisse bestätigt wurde. Die elektronische Ähnlichkeit beider Materialien ist im starken Gegensatz zu dem in der Literatur bei Dotierung beobachteten Verhalten, bei dem Pentacen zum Mott-Isolator wird, während DBP Supraleitung zeigt. Weitere Untersuchungen erfolgten an Picen und Coronen. Bandstrukturrechnungen zeigten, dass Picen vermutlich ein stark korreliertes Elektronensystem besitzt. Neben dem mit PES ermittelten Ionisationspotential und der Austrittsarbeit waren auch die mit EELS gemessenen optischen Bandlücken der beiden Materialien sehr ähnlich. Unterschiede zeigten sich hingegen vor allem in der Dichte der gemessenen Zustände von Picen und Coronen am Ferminiveau. Bei der Untersuchung der elektronischen Eigenschaften von mit Kalium-dotierten Picen und Coronen wurde trotz der erfolgreichen Dotierung in keinem der untersuchten Filme eine Zustandsdichte am Ferminiveau beobachtet somit wurde auch keiner der untersuchten Filme metallisch. Dasselbe Verhalten konnte auch für Natrium-dotierte Filme beobachtet werden. Eine Diskussion dieses Ergebnisses, welches im Gegensatz zu der von anderen Gruppen in dotierten Molekülen beobachteten Supraleitung steht, erfolgte im Hinblick auf die Bildung unterschiedlich dotierter Phasen, Elektron-Phonon-Kopplung, der Formierung von Bi-Polaronen und Korrelationseffekten. Für ein weitergehendes Verständnis der dotierungsinduzierten elektronischen Eigenschaften in den untersuchten Molekülen wurden diese nicht nur mit Alkalimetallen, sondern teilweise auch mit elektronenziehenden Molekülen wie F 4 TCNQ interkaliert. Dabei entstanden Kristalle verschiedener Ladungstransfersalze. Eine ausführliche Charakterisierung erfolgte für Picen/F 4 TCNQ-Kristalle, welche im Rahmen dieser Arbeit zum ersten Mal hergestellt und untersucht wurden. Dabei wurde zunächst deren Kristallstruktur mit Röntgendiffraktometrie (XRD) bestimmt. Eine Abschätzung der Größe des Ladungstransfers innerhalb der Molekülpaare aus Picen/ F 4 TCNQ erfolgte über Infrarot- und Bindungslängendaten, die auf diese Weise gefunden Werte wurden zusätzlich durch DFT-Rechnungen untermauert. Transportmessungen zeigten außerdem, dass die hergestellten Kristalle entlang ihrer Hauptwachstumsrichtung Isolatoren sind. Die Untersuchung der elektronischen Eigenschaften wurde mit EELS und PES an Picen/ F 4 TCNQ -Dünnfilmen durchgeführt, welche durch die Verdampfung der Einkristalle hergestellt wurden. Die Molekülpaare zeigen einen Ladungstransfer, der neue elektronische Anregungen im Niederenergiebereich der mit EELS gemessenen Verlustfunktion hervorruft. Im weiteren Verlauf der Arbeit erfolgte eine Diskussion bezüglich des Charakters und der Lokalisierung dieser neuen Anregungen. Bei den PES-Messungen zeigte sich der Ladungstransfer durch energetische Verschiebungen in den gemessen Rumpfniveauspektren sowie durch im Vergleich zu den reinen Materialien deutlich veränderte Ionisationspotentiale. Trotz des erfolgreichen Ladungstransfers und der damit verbundenen Füllung von unbesetzten Zuständen mit Elektronen in F 4 TCNQ wurde jedoch in den Valenzbandspektren keine Emission am Ferminiveau beobachtet. DFT-Rechnungen ermöglichten schließlich Aussagen über den Charakter des Ladunstransfers und die daraus resultierende, fehlende Zustandsdichte am Ferminiveau.

Canadian bitumen is mainly transported in a diluted form via pipeline and train, all posing a risk as they can lead to the release of diluted bitumen (dilbit) in the environment. In the summer of 2018, a collaborative large-scale field experiment was conducted at the International Institute for Sustainable Development - Experimental Lakes Area (IISD-ELA), a world-renowned aquatic research facility. The research objectives of the Boreal lake Oil Release Experiment by Additions to Limnocorrals (BOREAL) project were to understand the fate, behaviour, and potential toxic effects of dilbit in a freshwater Boreal lake to inform evidence-based management strategies for the transport of dilbit. A range of controlled dilbit spills was performed in seven 10 m diameter limnocorrals (~100,000 L of water) resulting in environmentally realistic dilbit:water dilutions ranging from 1:69,200 to 1:504, representing the upper half of the distribution of oil spill sizes in North America in the last decade. Additionally, two limnocorrals not treated with dilbit were studied as controls. This thesis identifies the bioaccumulating compounds derived from naturally weathered dilbit in adult giant floater mussels (Pyganodon grandis), to determine the rates at which they were accumulated and excreted. More specifically, the bioaccumulation potential and toxicokinetic parameters of polycyclic aromatic compounds (PACs) and various metals were assessed in mussels exposed ex situ for 41 days (25 days of exposure and 16 days of depuration) to water from the limnocorrals. These compounds have shown to be toxic, carcinogenic, and mutagenic to aquatic organisms. Mussels exposed to dilbit-contaminated water experienced significantly greater TPACs concentrations (0.40 – 0.90 µg L-1, n=12) compared to mussels from the Control (0.017 µg L-1, n=4). Furthermore, dilbit-contaminated water had a higher proportion of alkylated PACs compared to their parent counterpart, demonstrating petrogenic PAC profiles. We detected significantly greater TPACs concentrations in mussels exposed to dilbit-contaminated water (25.92 – 27.79 µg g-1, ww Lipid, n=9, at day 25 of the uptake phase) compared to mussels from the Control (average of 2.62 ± 1.95 µg g-1, ww Lipid; ±SD, n=17). Alkylated PACs represented 96.4 ± 1.8%, ±SD, n=12 of TPACs in mussels from dilbit-contaminated treatments at day 25 of the uptake phase, indicating the importance of conducting a more inclusive assessment of petrochemical mixtures as most studies only focus on parent PACs. From first-order one-compartment models derived from nonlinear curve fitting of the accumulation phase or sequential modelling method, uptake (0.66 – 24.65 L g-1 day-1, n=87) and depuration (0.012 – 0.37 day-1, n=87) kinetic rate constants, as well as bioconcentration factors (log values from 3.85 – 6.12 L kg-1, n=87) for the 29 PACs that bioaccumulated in mussels suggested that alkylated PACs have greater bioaccumulation potential compared to their parent PAC counterpart. Results from this study also demonstrated that giant floater mussels could be used to biomonitor PAC contamination following oil spills as PACs accumulated in mussel tissue and were still present following the 16 day depuration phase. The results of this study are the largest, most comprehensive set of toxicokinetic and bioaccumulation information of PACs (44 analytes) in freshwater mussels obtained to date. Metal contamination following the controlled dilbit spill was minimal, but mussels exposed to water contaminated with naturally weathered dilbit experienced elevated concentrations of dissolved zinc (30.26 – 38.26 µg L-1, n=12) compared to the mussels in the uncontaminated water (6.75 ± 3.31 µg L-1, n=4), surpassing the Canadian water quality guidelines for the protection of aquatic life. However, it is not clear if dilbit contamination caused elevated zinc concentrations in the water as other factors, such as limnocorral building materials and/or galvanized minnow traps used in the limnocorrals, could have contributed to zinc contamination. Nonetheless, giant floater mussels did not accumulate zinc in their tissues.

Polycyclic Aromatic Hydrocarbons (PAHs) are harmful by-products formed during combustion of hydrocarbons under locally fuel-rich conditions followed by incomplete combustion. PAHs act as precursors during the formation of soot. PAHs and soot are harmful for human health and legislation limits the emission of unburned hydrocarbons and soot. Consequently, other measures are necessary in order to limit the production of PAHs and soot in internal combustion engines applications, entailing a possible decrease of fuel efficiency and higher technical requirements for automotive manufactures. The combustion chemistry of PAHs is not fully understood, which prompts the need of further investigations. The chemical dynamics shown by novel pathways of PAH formation involving vinylacetylene addition to the phenyl radical opens up new horizons for the potential contribution to PAH formation through this class of reactions. In the present work novel pathways of the formation of naphthalene and phenanthrene are investigated for a laminar premixed benzene flame and a laminar ethylene diffusion flame. The purpose is to improve the prediction of the aromatic species concentration in the flames. A pathway chosen due the high potential aromatic yield is assessed through preliminary flame calculations relying on simplifying assumptions concerning reaction rates. Certain isomerisation steps of the pathway occur within a time-scale characteristic of thermal relaxation processes. Therefore, the solution of the energy grained master equation is necessary in order to calculate the phenomenological reaction rates resulting from a non-equilibrium kinetic modeling. Quantum chemical calculations are performed in order to calculate molecular properties of the species involved. These properties are subsequently processed to determine the rate constants of the sequence of multi-energy well reactions. Moreover, the chemical dynamics of the pathway is analyzed and the effect of temperature and pressure on the kinetic parameters is investigated. Despite of the potential yield demonstrated through the preliminary flame calculations, the computed rate constants show that the studied reactions are insignificant for the formation of naphthalene and phenanthrene in the studied flames. An effort is put on evaluating if the non-equilibrium kinetic modeling adopted for the calculation of the kinetic parameters is consistent with the kinetic modeling used in the flame calculations. The current work provides an efficient method to compute rate constants of multi-energy well reactions at different thermodynamic conditions, characteristic of flames and of combustion in commercial devices or in internal combustion engines. Pathways with a slightly different chemical dynamics should be tested applying the current methodology. Moreover, further studies should be aimed at overcoming possible limits of the kinetic modeling of multi-energy well reactions occurring in combustion environments.

Les hydrocarbures aromatiques polycycliques (HAPs), tels que le benzo(a)pyrène (B[a]P), sont des contaminants environnementaux ubiquistes générés lors de la combustion de matière organique. Ces composés ont été associés au développement d'effets toxiques sur la santé humaine, notamment des effets cancérigènes et immunotoxiques, principalement liés à l'activation du récepteur aux hydrocarbures aromatiques (RAh). Parmi les cellules du système immunitaire, les lymphocytes T apparaissent comme des cibles majeures des HAPs. Des résultats antérieurs, obtenus au laboratoire, ont montré que l'activation des lymphocytes T humains en culture primaire conduit à l’augmentation de l'expression et de la fonction du RAh, suggérant la capacité accrue de ces cellules à répondre à une exposition aux HAPs. Nos objectifs sont : (1) de déterminer les effets du B[a]P sur les profils d'expression génique dans les lymphocytes humains normaux en utilisant des approches à haut débit telle que l'analyse transcriptomique sur puce à ADN, (2) d’évaluer les effets génotoxiques et immunotoxiques du B[a]P en mesurant respectivement les dommages à l'ADN induits et leurs actions immunosuppressives et (3) d’analyser la modulation de ces effets en présence d'autres HAPs. Notre travail identifie les lymphocytes T humains normaux comme un bon modèle pour étudier les effets génotoxiques et immunotoxiques des HAPs, et pour prédire les problèmes de santé humaine liés à l’exposition à ces contaminants. Il permet également de mieux comprendre la régulation par les HAPs de la réponse immune et propose de nouveaux biomarqueurs potentiels de l'exposition à ces contaminants environnementaux. / Polycyclic aromatic hydrocarbons (PAHs), such as benzo(a)pyrene (B[a]P), are ubiquitous environmental contaminants generated during organic matter combustion. These compounds have been associated with the development of toxic effects on human health, including carcinogenic and immunotoxic effects, mainly related to Aryl hydrocarbon Receptor (AhR) activation. Among the immune system cells, T lymphocytes appear as major targets of PAHs. Previous results, obtained in the laboratory, have shown that activation of primary human T lymphocytes leads to a functional AhR expression increase, suggesting their ability to respond to PAH exposure. Our specific aims are: (1) to determine the effects of B[a]P on gene expression profiles in human normal lymphocytes by using large-scale approaches such as microarray-based transcriptome analysis, (2) to monitor the genotoxic and immunotoxic effects of B[a]P by measuring DNA damage and immunosuppressive actions, respectively and, (3) to analyze the modulation of these effects by the presence of other PAHs. Our work propose primary cultures of activated human T lymphocytes as a good model for studying both genotoxic and immunotoxic effects of environmental contaminants such as PAHs and predicting human health issues. It also gains a comprehensive insight into the immune response regulation after PAH exposure and provides potential new biomarkers of exposure to these environmental contaminants.

Polycyclic aromatic hydrocarbons, produced by anthropological and natural activities, are hazardous through formation of oxidative radicals and DNA adducts. Growth of Mycobacterium sp. strain KMS, isolated from a contaminated soil, on the model hydrocarbon pyrene induced specific proteins. My work extends the study of isolate KMS to the gene level to understand the pathways and regulation of pyrene utilization. Genes encoding pyrene-induced proteins were clustered on a 72 kb section on the KMS chromosome but some also were duplicated on plasmids. Skewed GC content and presence of integrase and transposase genes suggested horizontal transfer of pyrene-degrading gene islands that also were found with high conservation in five other pyrene-degrading Mycobacterium isolates. Transcript analysis found both plasmid and chromosomal genes were induced by pyrene. These processes may enhance the survival of KMS in hydrocarbon-contaminated soils when other carbon sources are limited. KMS also grew on benzoate, confirming the functionality of an operon containing genes distinct from those in other benzoate-degrading bacteria. Growth on benzoate but not on pyrene induced a gene, benA, encoding a benzoate dioxygenase α-subunit, but not the pyrene-induced nidA encoding a pyrene dioxygenase α-subunit; the differential induction correlated with differences in promoter sequences. Diauxic growth occurred when pyrene cultures were amended with benzoate or acetate, succinate, or fructose, and paralleled delayed expression of nidA. Single phase growth and normal expression of benA was observed for benzoate single and mixed cultures. The nidA promoters had potential cAMP-CRP binding sites, suggesting that cAMP could be involved in carbon repression of pyrene metabolism. Growth on benzoate and pyrene requires gluconeogenesis. Intermediary metabolism in isolate KMS involves expression from genes encoding a novel malate:quinone oxidoreductase and glyoxylate shunt enzymes. Generation of C3 structures involves transcription of genes encoding malic enzyme, phosphoenolpyruvate carboxykinase, and phosphoenolpyruvate synthase. Carbon source modified the transcription patterns for these genes. My findings are the first to show duplication of pyrene-degrading genes on the chromosome and plasmids in Mycobacterium isolates and expression from a unique benzoate-degrading operon. I clarified the routes for intermediary metabolism leading to gluconeogenesis and established a potential role for cAMP-mediated catabolite repression of pyrene utilization.

No description available.

Polycyclic aromatic hydrocarbons are environmental chemicals that are produced during incomplete combustion of coal, oil, gas, and garbage. Toxic effects of these compounds are mediated via the ligand activated Aryl Hydrocarbon Receptor (AHR) signaling pathway. To enable the study of the AHR signaling mechanism, our lab has generated many human proteins using recombinant DNA technology. This thesis documents the design and synthesis of a number of proteins of the AHR deletion construct CΔ553. The bacterial expressed and purified fusion proteins could be utilized as antigen to generate antibodies and be used for cellular delivery. The purified protein was immunogenic in rabbits and produced significant amount of polyclonal antibodies. In western blot analysis, the antibodies were able to the detect baculovirus expressed AHR and different recombinant proteins of the AHR. The polyclonal antibodies were also used in the gel-shift assay to show the AHR dependent gel shift. Cellular delivery CΔ553 was achieved using the protein transduction domain from the HIV-1 virus transactivating protein (TAT). In order to deliver the CΔ553 into mammalian cells, an expression vector was constructed to generate the TAT-CΔ553 fusion protein. The TAT-CΔ553 fusion protein was successfully transduced into two mammalian cells-HeLa and HepG2. The in vivo function of TAT-CΔ553 was determined using the luciferase reporter plasmid assay. The transduced protein was functional; it competed with the AHR and heterodimerize with ARNT in both HeLa and HepG2 cells at a concentration of 3.8x103 nM and 18 nM respectively. Since there an apparent similarity between the basic region of TAT-PTD and CΔ553, we examined the transduction potential of CΔ553. Western blot analysis indicated that the extent of denatured protein transduction was comparable for CΔ553 and TAT-CΔ553 in HepG2 cells. Thus CΔ553 might have intrinsic transduction capability.

Crude oil commonly enters freshwater aquatic ecosystems as thin sheens forming on the water surface. Oil contains mixtures of toxic compounds called polycyclic aromatic hydrocarbons (PAHs), some of which are known to be photodynamic, increasing toxicity when combined with ultraviolet radiation. Benthic macroinvertebrate communities are commonly utilized as bioindicators, and as such rely on abundant data in literature concerning benthic macroinvertebrates' relative tolerances to a wide range of pollutants. A series of 10 plastic traps, half of which were filtered from UV radiation, were deployed in an urban pond for 27 days to determine colonization preferences of benthic macroinvertebrates to UV exposure. Results of this in situ experiment indicated that the majority of aquatic insects collected from traps inhabited the UV exposed treatment group, particularly the nonbiting midge, Chironomidae. A series of bioassays were then completed to investigate the sensitivities of a Chironomidae species to thin sheens of crude oil in the presence and absence of UV radiation. All bioassays were conducted using 10 day old Chironomus dilutus larvae cultured in the lab. The series of C. dilutus bioassays were all conducted under the same water quality parameters, temperatures, and oil sheen dosing methods, under a 16:8 photoperiod and exposed to 16 h UV per day. Five replicates (n = 20) were loaded into 350 mL glass crystallizing dishes and exposed to four treatments for 96 hours: no UV/with sheen, with UV/no sheen, both UV and oil sheen, and a control. Three assays with 175 mL water volume were completed, one with no sediment, one with silica sand, and one with fine sand. Sediment type had a significant effect on mortality (p < 0.0001), but significant effects of UV or PAHs were not found. Two more C. dilutus assays were completed with identical parameters as the latter two with sediment, except a decreased water volume of 90 mL was used to bring the sheen closer to sediment. There was a significant effect of PAHs on mortality (p = 0.0003), however, no clear trend showing PAHs driving mortality. Results showed no significant effects of UV, sediment type, or relationship between UV and PAHs. A final bioassay was completed to compare phototoxic effects of PAHs on pelagic organisms with benthic organisms. This bioassay used test species Daphnia magna, for a 48 h exposure period with five replicates (n = 10), 8 h UV exposure and 16:8 photoperiod. All individuals in the control group and UV only group exhibited 0% mortality, and with sheen/with UV treatment group resulted in 100% mortality following the 48 h exposure. The results of the D. magna exposure showed significant effects of PAHs (p < 0.0001), UV (p = 0.037), and photoinduced toxicity (p = 0.024), and were consistent with similar bioassays in the literature. This study suggests that C. dilutus are at low risk to photo-induced oil sheen toxicity.