The Arctic has long been considered to be a pristine environment, far from population centers and pollution sources. The detection of synthetic organochlorine compounds in various elements of the Arctic food web has confirmed the global dispersion of pollutants, particularly of persistent compounds such as organochlorines and heavy metals. Levels of heavy metals, although elevated, appear to be naturally so throughout much of the Arctic. Arctic pollution is both a humanitarian and ecological concern. Many arctic coastal communities depend heavily on marine mammal fat for sustenance, and are therefore potentially exposed to high levels of organochlorines and some metals. From an ecological perspective, the structure of arctic food webs, the importance of lipid mobilization for winter survival, and the adaptive physiologies of arctic organisms may result in an enhanced response to contaminant exposure. This thesis assesses the exposure and effect of organochlorine and heavy metal exposure in inland freshwater ecosystems of Arctic Alaska, and evaluates the physiological response of arctic grayling to experimental polychlorinated biphenyl (PCB) exposure. / Graduation date: 1995

Vitamin A, protein, iron, zinc, and polychlorinated biphenyls (PCBs) were studied in the food system of the Sahtu (Hareskin) Dene/Metis of Fort Good Hope (FGH) and Colville Lake (CL), NWT. Traditional foods contributed significantly more (p 00% of the Canadian Recommended Nutrient Intake (RNI) for protein, iron, and zinc but vitamin A consumption was generally $<$50% RNI. In all seasons, market foods provided significantly more vitamin A (p $ le$ 0.05) than traditional foods for FGH adults. Body weights were assessed for comparison of PCB intakes with the tolerable daily intake level (TDI) $(<$1 ug/kg body wt/day). Women $ ge$19 yrs weighed 59.9 $ pm$ 10.7 kg while men weighed 71.7 $ pm$ 11.4 kg. Most of the adult population consumed $<$25% TDI for PCBs.

Thesis (M.Tech.: Biotechnology)-Dept. of Biotechnology, Durban University of Technology, 2007 xxi, 117 leaves / The aromatic compounds Polychlorinated Biphenyls (PCBs) are one of the largest groups of environmental pollutants. The greatest concern is the release of PCBs in the water systems by industrial effluent, accidental spillages or leaks. PCBs are able to bioaccumulate in the fatty tissues of animals, fish and humans. The impact on human health due to PCBs has prompted interest in their degradation. The application of microbial degradation of PCBs can transform many PCB metabolites. There are a wide variety of microorganisms that can degrade PCBs or utilise them as sole carbon sources. This study focused on isolating microrganisms from industrial wastewater capable of aerobic degradation of PCBs. The degradation potential of the selected isolates were investigated by using different analytical techniques viz. ultra violet or visible spectrophotometer (UV/Vis), thin layer chromatography (TLC) and gas chromatography electron capture detector (GC-ECD).

Recent advancements have uncovered environmental contributions to obesity and diabetes etiology. In fact, perinatal malnutrition resulting in low birth weight (LBW) has been shown to correlate with later life obesity and impaired glucose tolerance in aged offspring. LBW can result from a myriad of developmental perturbations including macronutrient restriction, hypoxia, maternal stress and toxin exposure. Polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants that bioaccumulate in the food chain resulting in dietary exposure in humans. Maternal and cord blood PCB levels are inversely associated with birth weight, and recent studies indicate that perinatal exposures to PCBs contribute to gender-specific obesity development in children. PCBs have also been shown to enter breast milk resulting in direct exposure in early postnatal life. Therefore, we hypothesized that perinatal PCB exposure cause developmental blight resulting in decreased birth weight and increased adiposity and glucose intolerance with aging. We found that mice perinatally exposed to PCBs did not differ in birth weight, but exhibited sex-specific effects on adiposity. Females perinatally exposed to PCBs were significantly more obese at 7 weeks of age while male offspring exhibited no difference in fat mass but had decreased lean mass compared to controls. With aging, the differences in females dissipated while the male offspring decreased lean mass persisted. Male offspring perinatally exposed to PCBs displayed impaired glucose tolerance at 7 weeks of age but normalized over time, while the females were glucose intolerant only after 6 months of age. This impairment of glucose tolerance was not attributed to insulin resistance. These data illustrate time-dependent and sex-specific perturbations of maternal PCB exposure on offspring body composition and glucose homeostasis. As the liver is a major facilitator in glucose homeostasis and xenobiotic detoxification, we investigated PCB-induced alterations in hepatic gene expression and found attenuated expression of glycolytic genes and increased expression of detoxifying and antioxidant genes in both PCB-exposed maternal and offspring livers. Taken together, these data demonstrate a role for perinatal pollutant exposure in the etiology of glucose intolerance. Further studies are required to elucidate the mechanisms causing sex-specific modulation of body composition and glucose intolerance.

The release of 260 kg of polychlorinated biphenyls (PCBs) by a military radar station into Saglek Bay (Labrador) in the eastern Canadian Arctic contaminated adjacent marine sediments, and some fish, seabirds, and ringed seals. However, attributing the PCBs found in high trophic level and highly mobile marine mammals to any point source is, in most cases, impossible. This thesis demonstrated the extent to which a local PCB source at Saglek Bay led to the contamination and health effects in ringed seals. The dominance of PCBs at this contaminated marine site afforded a unique opportunity to evaluate the effects of this single class of industrial chemical in a manner that has not been previously possible in marine mammals. We used a variety of tools to characterize the contribution of local PCB contamination in the Labrador ringed seal food web. These tools included: 1) univariate and multivariate statistical exploration of contaminant patterns; 2) stable isotope ratios and fatty acid signatures to describe feeding ecology; and 3) satellite telemetry to track the movements of seals on the coast. Divergent PCB congener profiles and contaminant ratios enabled an assignment of seals into either ‘local’ or ‘long-range’ categories, with up to 60% of ringed seals sampled exhibiting patterns consistent with the local source. PCB concentrations in locally-contaminated adult males were 2-fold higher than in those exposed only to long-range PCB sources. Seals with smaller home ranges had an increased likelihood of feeding on prey contaminated by the local PCB source. Similar fatty acid profiles between those seals with ‘local’ PCB profiles and those with ‘long-range’ or background profiles indicate little support for the possibility that differential feeding ecologies explained the divergent PCB profiles. Ringed seals fed predominantly on zooplankton (Mysis oculata and Themisto libellula), dusky snailfish (Liparis gibbus) and arctic cod (Boreogadus saida). Heavier PCB profiles in the Saglek food web, compared to the same species exposed to only background contaminants, provided additional insight into the mechanisms of localized PCB contamination of some Labrador ringed seals. In addition to ascertaining the importance of a point source to contamination in ringed seals, we assessed the effects of PCBs on their health through quantitative real-time polymerase chain reaction (qPCR) assay. Levels of mRNA transcripts for five gene targets, including aryl hydrocarbon receptor (Ahr), interleukin-1 beta (Il1b), estrogen receptor alpha (Esr1), insulin-like growth factor receptor 1 (Igf1) and glucocorticoid receptor alpha (Nr3c1), correlated with increasing levels of PCBs, indicating an effect of this persistent organic pollutant (POP) in these seals. Threshold values were calculated for these five genes, with the most conservative value being 1,380 ng/g lipid weight (lw). Approximately 14% of the seals sampled exceeded this threshold, suggesting a risk of adverse effects in a proportion of the local population attributed to PCBs. While the implications for these sublethal molecular changes at the individual or population level are unclear, contaminant-related changes in endocrine, immune, and molecular endpoints have been observed in ringed seals from the Baltic Sea exhibiting reproductive and developments abnormalities, and virus epizootics. Results of this study improve our understanding of the effects of PCBs in free-ranging marine mammals and provide new information needed to inform mitigation and monitoring efforts, both for ringed seals in the north and other seals around the world. / Graduate / 0306 / 0768 / 0383 / tanya@raincoast.org

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.Tech.: Biotechnology)-Dept. of Biotechnology, Durban University of Technology, 2007 xxi, 117 leaves / The aromatic compounds Polychlorinated Biphenyls (PCBs) are one of the largest groups of environmental pollutants. The greatest concern is the release of PCBs in the water systems by industrial effluent, accidental spillages or leaks. PCBs are able to bioaccumulate in the fatty tissues of animals, fish and humans. The impact on human health due to PCBs has prompted interest in their degradation. The application of microbial degradation of PCBs can transform many PCB metabolites. There are a wide variety of microorganisms that can degrade PCBs or utilise them as sole carbon sources. This study focused on isolating microrganisms from industrial wastewater capable of aerobic degradation of PCBs. The degradation potential of the selected isolates were investigated by using different analytical techniques viz. ultra violet or visible spectrophotometer (UV/Vis), thin layer chromatography (TLC) and gas chromatography electron capture detector (GC-ECD).

Les lacs d'altitude sont soumis à des retombées atmosphériques de polluants organiques persistants (POP) issus pour la plupart des activités humaines malgré leur éloignement des sources d'émissions de ces composés. Si les mécanismes de transport atmosphérique de ces polluants jusqu'aux sites d'altitude sont désormais bien connus (« global distillation » ou « grasshopper effect »), on dispose en revanche de très peu d'informations quant à leur devenir dans ces écosystèmes montagnards. Le travail présenté a pour objectif de déterminer les processus internes au lac influençant le devenir de ces polluants, avec un accent plus particulier sur leurs interactions avec les phases organiques et leur intégration dans les réseaux trophiques. En raison de leurs propriétés physico-chimiques très variables entre congénères (e.g., peu à très hydrophobes), les polychlorobiphényles (PCB) ont été choisi comme modèles de POP.L'étude a été conduite sur deux lacs alpins du Parc National des Ecrins (Isère, France): le lac de la Muzelle (2110 m) et le lac de Plan Vianney (2250 m). Le suivi en 2012 et 2013, à fréquence saisonnière,des concentrations en PCB des composants biologiques, des fractions particulaires et dissoutes et des flux atmosphériques déposés sur les lacs a permis d'évaluer à la fois les variations saisonnières, interannuelles, et entre les lacs, de la contamination de la faune piscicole et de les relier aux intrants atmosphériques et aux processus biogéochimiques lacustres.Nos résultats identifient la fonte du manteau neigeux comme vecteur rapide et important de transfert des PCB atmosphériques aux lacs d'altitude (40% des apports annuels en seulement 2 à 3 semaines). Le bilan de masse révèle aussi que les flux de PCB entrants sont supérieurs aux flux sortants des lacs et met ainsi en évidence leur rôle de puits de PCB atmosphériques. La distribution des PCB entre les phases "particules" et "eau" varie à la fois entre lacs et saisons, révélant une succession d'équilibre et de non-équilibre thermodynamiques. En effet, la couverture de glace en hiver isole les lacs de l'atmosphère et donc des sources de polluants, permettant aux PCB d'atteindre l'équilibre thermodynamique de partition entre les phases particulaire et dissoute. A l'opposé, en périodes d'eaux libres, les paramètres d'influence de l'adsorption des PCB sur la matière particulaire (température, concentration et nature des particules, concentration de PCB) répondent à la variabilité environnementale, empêchant l'atteinte de l'état d'équilibre. Enfin, si la contamination de la faune piscicole varie tant entre lacs qu'entre saisons, l'absence de relation entre concentrations en PCB et divers indicateurs trophiques (composition en isotopes stables du carbone ou biomarqueurs lipidiques) révèle que cette contamination ne dépend ni de l'habitat ni de la variabilité trophique des individus. Au contraire, la contamination de la faune piscicole est liée à la concentration des polluants en phase dissoute. Dans les lacs d'altitude, les POP, même s'ils sont présents à faible concentration, seraient donc essentiellement transférés à la faune piscicole par un phénomène de bioconcentration et non par un mécanisme de bioaccumulation.Nos résultats mettent en évidence la nécessité de mieux connaître l'éco-dynamique des POP, y compris dans les milieux faiblement contaminés. Dans un contexte de changement global pour lequel les intrants dans les écosystèmes d'altitude risquent de varier en intensité ou en temporalité, ces connaissances permettront (i) d'évaluer le rôle futur des lacs comme puits ou sources secondaires de POP pour l'atmosphère et (ii) prévoir l'évolution des niveaux de contamination de la faune piscicole dans les écosystèmes aquatiques éloignés des sources de production. / Altitude lakes undergo atmospheric deposition of persistent organic pollutants (POPs) resulting mainly from human activities despite their distance from emission sources. If the mechanisms driving the atmospheric transport of these pollutants to altitude environment are now fairly known ("global distillation" or "grasshopper effect"), there is still few information about their fate in these mountain ecosystems. This work aims to identify the internal lake processes influencing the fate of POPs, with a particular focus on their interaction with the organic phases and their integration into food webs. Due to their variability of physico-chemical properties between congeners (e.g., less to more hydrophobic), polychlorinated biphenyls (PCBs) have been chosen as POP models.The study was conducted on two alpine lakes from the National Park of Ecrins (Isère, France): Lake Muzelle (2110 m) and Lake Plan Vianney (2250 m). A monitoring was conducted in 2012 and 2013 to assess PCBs concentration in aquatic organisms, particulate and dissolved fractions and atmospheric PCBs inputs. Thus, seasonal, interannual and inter-lakes variability of PCBs level in fish have been assessed and linked to atmospheric inputs and biogeochemical lake processes.Our results show that snowmelt corresponds to an important and sudden flux of PCBs to altitude lakes (40% of annual contributions during the few weeks of spring thaw). Mass balance also reveals that PCBs inputs are higher than outputs, highlighting the role of altitude lakes as atmospheric PCBs sinks. PCBs partition between particulate and dissolved phases varies both between lakes and seasons, revealing a succession of thermodynamics equilibrium and non-equilibrium. In fact, when lakes are ice-covered, the water column is isolated from the atmosphere and therefore from sources of pollutants, allowing to reach a thermodynamic equilibrium partition of PCBs between the particulate and dissolved phases. On the contrary, when lakes are ice-free, parameters affecting PCBs adsorption on particulate matter (temperature, concentration and nature of the particles, PCBs concentration) are subject to environmental variability, preventing chemicals to reach thermodynamic equilibrium. Finally, even though PCBs fish contamination varies both between lakes and between seasons, the lack of relationship between PCBs concentrations and trophic indicators (stable isotope composition of carbon or lipid biomarkers) highlights that fish level of PCBs does not depend on habitat use and inter-individual trophic variability. In contrast, the PCBs concentration in fish is related to the concentration of pollutants in the dissolved phase. In altitude lakes, even though POPs are presented at low concentrations, these chemicals are mainly transferred to the fish compartment by bioconcentration rather than bioaccumulation.These results highlight the need to improve our knowledge on POPs ecodynamics even in low contaminated environments. In a context of global change for which pollutant inputs in altitude ecosystems might vary in intensity or temporality, this research appears essential to (i) assess the future role of altitude lakes as atmospheric POPs sinks or secondary sources and (ii) predict any modification of PCBs levels in fish in remote aquatic ecosystems.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The polychlorinated biphenyls (PCBs) production and trading are prohibited in whole world, due its high toxicity. These aromatic compounds were industrially used since the 30 s decade. Significant physics characters, as a high temperature and electric current tolerance, are responsible for the PCBs large employment and worldwide production. Mainly due for the old electric equipments inappropriate discard, a large part of this production came in to the environment, contaminating the soil and water. They are non-biodegradable compounds that becoming accumulated in the environment and in the food chain. They toxic human effects was evidenced from realized studies, and the contaminated food ingestion is the mainly route of exposure to PCBs. The cereals are an essential part of our nutrition, due this human survives historical significance. The corn receives a large notability among the cereals, being the most consumed grain in the world. Due to this, and to the PCBs persistent and malignant effects to human, the objective of this work was to determinate the PCBs levels in corn and cornflour from different regions of Rio Grande do Sul State, collected on 2009 and 2010 years, checking the connect of these levels with the collected region, year of harvest, lipid content and the flour type. The PCBs residues were determinate by gas chromatography coupled with mass spectrometer (GC-MS), using electron impact ionization and a negative chemical ionization, before ultrasonic extraction of the compounds. The mean values detected were 0.01 ng g-1 to the PCB 10, 0.04 ng g-1 to the PCB 28, 0.10 ng g-1 to the PCB 52, 0.14 ng g-1 to the PCB 153, 0,40 ng g-1 to the PCB 138 and 0,38 ng g-1 to the PCB 180. The most frequent was the PCB 138, which was detected in 63,47% of the samples, followed by the PCBs 180 (58.27%), 52 (41.72%), 153 (41.05%), 28 (20.52%) and 10 (7.28%). The samples from the northeast and metropolitan regions showed the higher concentrations. Besides it, there was a decrease in the contamination on the year of 2010 when compared with 2009. Another significant factor was the high contamination detected in the cornflours in relation to the grain, with significantly differences for the PCBs 52, 138, 153 and 180. Concerning about the flour analyses, the fact of the PCBs have a great fat attractive force was confirmed, with all the PCBs congeners showed significant difference in the correlation with their lipid levels. / Devido a alta toxicidade, a produção e comercialização dos bifenilos policlorados (PCBs) estão proibidas em todo mundo. Esses compostos aromáticos foram utilizados industrialmente desde a década de 30. Propriedades físicas interessantes, tais como a resistência a altas temperaturas e correntes elétricas, são responsáveis pela grande utilização e produção mundial dos PCBs. Sendo que desta produção grande parcela entrou para o meio ambiente, principalmente devido ao descarte inadequado de equipamentos eletro-eletrônicos antigos, contaminando a água e o solo. São compostos não biodegradáveis, que se acumulam no meio ambiente, influenciando todos os organismos da cadeia alimentar. A partir de estudos realizados, constatou-se o seu efeito nocivo no homem, sendo a ingestão através de alimentos contaminados a principal via de exposição. Sabe-se, pela sua importância histórica na sobrevivência humana, que os cereais são parte essencial em nossa alimentação. Dentre os cereais, o milho recebe amplo destaque, sendo o grão mais consumido no mundo. Diante disso, aliado com a persistência dos PCBs e seus efeitos maléficos ao homem, o objetivo do presente trabalho foi determinar os níveis de PCBs em milho e farinha de milho de diferentes regiões do estado do Rio Grande do Sul, coletados nos anos de 2009 e 2010, correlacionando os níveis destes compostos a região de coleta, ano de produção, teor de gordura e tipo de farinha. A determinação dos resíduos de PCBs foi realizada por cromatógrafo a gás acoplado a espectrometria de massas (GC-MS), usando modos de ionização por impacto de elétrons e ionização química negativa, após a extração dos compostos através do uso de ultrassom. Foram encontrados valores médios de 0,01 ng g-1 para o PCB 10, 0,04 ng g-1 para o PCB 28, 0,10 ng g-1 para o PCB 52, 0,14 ng g-1 para o PCB 153, 0,40 ng g-1 para o PCB 138 e 0,38 ng g-1 para o PCB 180. O PCB 138 foi o mais freqüente, sendo detectado em 63,57% das amostras, seguido dos PCBs 180 (58,27%), 52 (41,72%), 153 (41,05%), 28 (20,52%) e 10 (7,28%). As amostras provenientes das regiões nordeste e metropolitana foram as que apresentaram as maiores contaminações. Além disso, houve uma diminuição das contaminações no ano de 2010 quando comparado com o ano de 2009. Outro fator relevante foi a maior contaminação encontrada nas farinhas de milho em relação ao grão. Diferença que se mostrou significativa para os PCBs 52, 138, 153 e 180. No que diz respeito às análises das farinhas houve uma diferença significativa para todos os congêneres na correlação com os percentuais de gordura.

A reação de hidrodescloração catalítica (HDC) de bifenilas policloradas (PCB) foi estudada em diversos sistemas reacionais: solventes orgânicos, dióxido de carbono supercrítico, presença e natureza de aditivos (bases e co-solventes) a temperaturas na faixa de 25 &#176;C a 100 &#176;C e pressões de 1 bar até 250 bar. Os reagentes utilizados foram um composto modelo (2,4- diclorobifenil), misturas comerciais de PCB (Aroclor, Ascarel) e outros compostos halogenados (clorobenzenos e bromoclorobenzeno). Os catalisadores avaliados, paládio suportado em carvão ativo (Pd/C), paládio suportado em sílica mesoporosa (Pd/SiO2), nanopartículas ferromagnéticas de paládio (FFSiNH2Pd), e nanopartículas ocas de paládio (PdNP) e de platina (PtNP), mostraram-se versáteis nas mais diversas condições, quer sejam condições supercríticas, presença ou não de água, presença e natureza da base e diferentes doadores de hidrogênio. Em dióxido de carbono, dois regimes reacionais foram avaliados: dióxido de carbono subcrítico, onde o gás atua como agente expansor da fase líquida ao se dissolver nela permitindo que a reação ocorra em uma fase líquida rica em gás hidrogênio; e dióxido de carbono supercrítico, sistema onde a temperatura influencia fortemente a reação e a pressão tende a ter efeito negativo sobre a velocidade de reação, devido a efeitos de diluição e de competição das moléculas do gás com as moléculas dos reagentes. A condição reacional ótima foi determinada para o regime supercrítico e dados cinéticos foram obtidos para os regimes sub- e supercrítico. / The catalytic hydrodechlorination reaction (HDC) of polychlorinated biphenyls (PCB) was studied in several reactional systems: organic solvents, supercritical carbon dioxide, presence and nature of additives (bases and co-solvents), in temperatures of 25 &#176;C to 100 &#176;C and pressures of 1 bar to 250 bar. The reagents used were: a model compound, 2,4-dichlorobiphenyl, commercial mixtures of PCB (Aroclor, Ascarel) and other halogenated compounds (chlorobenzenes and bromochlorobenzene). The catalysts evaluated, palladium supported in activated carbon (Pd/C), palladium supported in mesoporous silica (Pd/SiO2), palladium ferromagnetic nanoparticles (FFSiNH2Pd), and hollow palladium ((PdNP) and platinum (PtNP) nanoparticles, showed to be versatile in several conditions, either supercritical conditions, presence or not of water, nature of the base, and different hydrogen donors. In carbon dioxide, two reaction regimes were evaluated: subcritical carbon dioxide, where the gas acts as an expansion agent of the liquid phase when it dissolves in it, allowing that the reaction happens in a liquid phase rich in hydrogen; and supercritical carbon dioxide, a system where the temperature has a strong influence over the reaction and the pressure has a negative effect on the rate of the reaction, due to dilution and the competition of gas molecules with the reagents molecules for the catalyst. The optimal reaction condition was determined for the supercritical regime and kinetic data were obtained for both the sub and supercritical regimes.