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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.
61

Analysis of dioxins and related compounds in biological samples using mass spectrometry: from method development to analytical quality assurance

Eppe, Gauthier 14 September 2007 (has links)
The quality of food is an increasingly important matter of concern in Europe. The feeding stuffs poisoning episode that occurred in Belgium in May 1999 pointed out the vulnerability of the food chain and the lack of appropriate monitoring. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorobiphenyls (PCBs) were the key contaminants involved. This has triggered new EU legislation, including maximum and action limits for relevant food and feed products as well as requirements for analytical method used to verify compliance. Large monitoring programs to test food and feed have been launched and, in many countries, efforts to monitor dioxins and related compounds strongly increased. To cope with the large number of samples statistically required for monitoring, the recommanded strategy involves the use of screening methods based on low resolution mass spectrometry (LRMS) and/or bio-assays, and high resolution mass spectrometry (HRMS) method, used to bear out their presence. Major analytical challenges had to be met to face with the large number of samples including the authoritys requests on developing screening and alternative methods for monitoring programs of PCDD/Fs and PCBs in food and feed. The first part of this document is devoted to the development of an alternative LRMS-based method for PCDD/Fs and PCBs measurement in food and feed. The second part of this thesis is an answer to the basic questions commonly addressed to all analytical chemists developing method but here in a particular context due to very specific family of compounds involved: How to make sure that my method is able to achieve sufficient accuracy on results? Are there any analytical benchmarks available for validation purposes? How to evaluate measurement uncertainty expressed in toxic equivalent (TEQ) units? How to report results right? How can the proficiency of my laboratory be measured? To ensure the quality of data obtained, laboratories in charge of the food control on PCDD/Fs and dioxin-like PCBs encounter a number of severe problems. One has to mention the lack of sufficient and reliable certified reference materials that are necessary to validate methods, too scarce data available on current analytical method performances, and the absence of quality criteria approach for analytical method. During the course of this work, I contributed to answer these questions to the general analytical effort by providing useful tools and methodologies. At that time, straightforward answers could not be found in the scientific literature. One of the reasons was the scarce data of dioxins in food and feed available. One can also mention the unusual part the dioxins play in chemical analysis. Indeed, the main features that characterize a dioxin measurement are the low levels at which these compounds occur in biological samples (sub parts-per-trillion), levels that are currently not explored by any other applications in chemical analysis in the food sector and therefore the difficulty to cope with precision models available; the reporting of results expressed in total tetrachloro dibenzo-p-dioxin (TCDD) toxic equivalent concentration for compliance assessment with statutory limits; and, what necessarily follows from the decision-making: the statement of the uncertainty interval also expressed in toxic units. To answer the foregoing questions in an international frame, notions such as validation of analytical procedures, fitness for purpose, internal quality control, interlaboratory studies, proficiency testing, measurement uncertainty, traceability had to be introduced. They are all encompassed in the analytical quality assurance management a laboratory should implement. These concepts are strongly connected to statistical techniques. This branch of analytical chemistry that consists in extracting relevant information from data using statistical and mathematical methods adapted to the specific needs for the chemists is called chemometrics. Quality is an essential preoccupation of chemometrics but it cannot be only limited to these aspects. Chemometrics relates also to other topics such as experiments and experimental design methodologies, (new) knowledge about chemical systems. Chemometrics and quality This thesis treats several aspects and new approaches of quality assurance for an ultra-trace contaminant laboratory: external method validation through interlaboratory studies and estimation of repeatability, reproducibility and trueness using simple statistics based on normal distributions (ISO 5725) but also more complex statistical tests for heavily tailed, skewed or even bimodal distributions; the production and the use of a reference material for internal validation and internal quality control (QC) purposes; advanced statistics in quality control chart and multi-level control charts for sensitive detection of bias; proposal of quality criteria for assessment of proficiency of dioxin laboratories; proposal of benchmark precision for internal validation purposes; estimation of measurement uncertainty. The thesis is divided in the following chapters: Chapter 1 is a general introduction for dioxins and related compounds. It consists of a brief introduction to general characterization, mechanism of toxicity, human exposure and European legislation in food and feed. Chapter 2 provides an overview of the analytical procedures for mass spectrometry based methods. It gives a brief summary of the most frequently used techniques to extract and purify PCDDs, PCDFs and dioxin-like PCBs (DL-PCBs) from food and feed matrices. Regarding detection, special attention of the principles of detection and quantification by HRMS in selected ion monitoring mode (SIM) and the quadrupole ion storage low resolution mass spectrometer in MS/MS mode is addressed. Chapter 3 discusses the development and optimization of a large volume injection (LVI)-gas chromatography (GC)-ion trap MS/MS method as an alternative to GC-HRMS for the measurement of PCDD/Fs in food and feed. Instrumental detection limits were lowered by a factor 2 to 3 with the development, in collaboration with the manufacturer, of a system of damping gas pressure inside the trap that improves precursor ions trapping efficiency. We achieved 5:1 signal to noise with the injection of 200 fg of 2,3,7,8 TCDD. With slight adjustments to sample size and final extract volume, we demonstrated on QC samples the good agreement between this method and the reference GC/HRMS method for PCDD/Fs and DL-PCBs in food and feed. In chapter 4, the first European inter-laboratory study on dioxins, furans and dioxin-like PCBs using the HRGC/HRMS method in animal feed samples is described with two main objectives. The first objective was to produce a reference material for internal validation and QC purposes. The second objective was to assess the analytical performances of the GC-HRMS method close to maximum levels as no data were available at that time and to check whether EU directives requirements were met. Chapter 5 is a general discussion on the capability of the state-of-the-art HRGC/HRMS method to provide reliable results at decreasing maximum levels. Levels have to decrease according to EU policy regarding human exposure to those contaminants. In this case, we present the issue from a different angle, i.e. the analytical point of view for the future establishment of target levels. Based on the results of PCDD/Fs and DL-PCBs interlaboratory study in animal feedingstuffs described in chapter 4, we demonstrated for the sum of the 17 PCCD/Fs toxic congeners that reliable results can be easily provided up to a value of 0.17 ng WHO-TEQ/kg. The ability to reliably quantify a minute trace of these contaminants has been pointed out with the aim of providing an analytical benchmark for the future establishment of target dioxin levels in animal feedingstuffs. Hence, both analytical and toxicological aspects should be examined together to set realistic target levels achievable for most dioxin laboratories involved in monitoring programs. One of the central themes of this thesis is the establishment of an empirical relationship between reproducibility standard deviation and the dioxin congeners level in food and feed. Chapter 6 deals with raw data from numerous performances interlaboratory studies of PCDD/Fs and DL-PCBs in food and feed. Striking linear functions in log scale between reproducibility standard deviation and congeners level over a concentration range of 10-8 to 10-14 g per g fresh weight were observed. The data fit very well to a Horwitz-type function of the form sR = 0.153c0.904, where sR and c are dimensionless mass ratios expressed in pg/g on fresh weight, regardless of the nature of the toxic congeners, food and feed matrices, or sample preparation methods. I called this relationship the dioxin function. One of the main features of the dioxin function could be its use as a suitable fitness-for-purpose criterion for dioxins and related compounds in proficiency testing (PT) exercises. We illustrated its use with practical example with data from the largest international PT in this field. Another application is its use as benchmark precision criteria for internal validation. Chapter 7 discusses the role of internal quality control (IQC) to monitor analytical processes. Introducing new QC methods derived from the industrial practice to analytical chemistry, improving data evaluation and allowing to detect shifts or trends, are elements that are difficult to point out with classical approach (Shewhart chart). The importance of ARL (average run length) as a key-criteria of the efficiency of a quality control procedure will be emphasized. The introduction of the multivariate approach of multilevel control with the Hotelling's T2-test will lead to a better detection of random errors than the independently managed conventional Shewhart charts. Moreover, the Exponentially Weighted Moving Average (EWMA) will offer a flexible tool for detecting the inacurracy of a method, especially where small shifts or bias are of interest. All these concepts, recently introduced in clinical chemistry, were applied here for the monitoring of PCDD/Fs and DL-PCBs in food and feed. Chapter 8 introduces the concept of measurement uncertainty (MU). Three top-down approaches for uncertainty estimation are proposed on the example of the GC-HRMS method for PCDD/Fs and DL-PCBs in various food and feed matrices: the approach which combines long-term precision and trueness data to obtain an estimate of MU (Barwick and Ellision method); the approach which uses the reproducibility estimate from interlaboratory-studies as uncertainty estimate; the concept of accuracy profile used in the context of validation and internal quality control to assess MU. Chapter 9 presents a general conclusion
62

Brominated natural products at different trophic levels in the Baltic Sea : Identification of polybrominated dioxins, hydroxylated and methoxylated diphenyl ethers

Malmvärn, Anna January 2007 (has links)
Over time, the Baltic Sea has been contaminated by increasing discharges of pollutants from human activities. Persistent organic pollutants (POPs) have caused toxic effects in wildlife and excess of nutrients have led to eutrophication. Furthermore, there are indications that certain polyhalogenated compounds similar in structure to man-made POPs are produced by the biota present in this sea. In the late 1990’s both methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and hydroxylated-PBDEs (OH-PBDEs) were identified in fish and seals living in this environment. OH-PBDEs can originate from metabolism of PBDEs, but both OH- and MeO-PBDEs are also known to be natural products in marine environments. Another group of POPs, the polybrominated dibenzo-p-dioxins (PBDDs), are not produced commercially, but are known to be by-products of chemical industry and of the combustion of, e.g., brominated flame retardants (BFRs). In contrast to the OH- and MeO-PBDEs, PBDDs have not previously been shown to be natural products, although certain related compounds have been indicated to have a natural origin. This thesis describes the identification of PBDDs, OH-PBDEs and MeO-PBDEs in algae, blue mussels and fish living in the Baltic Sea. Several of these compounds were also detected in cyanobacteria. Moreover, PBDDs were present in fish, mussels, shrimp and crabs from different regions of the Baltic Sea and from the west coast of Sweden, but not in organisms from freshwater environments. The levels of these compounds in Baltic fish generally exceeded those of their chlorinated analogues. The origin of the PBDDs identified is somewhat unclear, but the high levels present in blue mussels and the pattern of congeners observed indicate natural production. The presence of PBDDs, OH-PBDEs and MeO-PBDEs in fish and shellfish constitutes a potential risk to both humans and wildlife and requires further investigation.
63

Predicting Ecosystem Response from Pollution in Baltic Archipelago areas using Mass-balance Modelling

Karlsson, Olof Magnus January 2011 (has links)
Baltic archipelago areas have high nature values despite being polluted from various antrophogenic activities within the Baltic Sea catchment area and from long-range transport of airborne substances. The discovery of environmental problems in the Baltic Sea in the 1960s led to countermeasures that gradually gave results in reducing the toxic pollution, e.g. from PCBs. Today, much of the environmental management is focused on reducing the effects of eutrophication. There is a demand from society on science to develop strategies that can direct remedial actions so that the cost-effectiveness is maximised. This work focuses on how mass-balance models can be used to understand how coastal ecosystems are controlled by abiotic processes and to predict the response to changes in loading of different substances. Advection, sedimentation and burial are examples of general transport processes that are regulated by morphometrical characteristics, e.g. size, form, effective fetch and topographical openness. This is why different coastal areas have different sensitivity to loading of pollutants. A comparison of six phosphorus and chlorophyll models of different complexity showed that the model performance was not improved with more state variables of total phosphorus (TP) than two water and two sediment compartments. Modelling chlorophyll as a separate state variable did not improve the results for individual values compared to a simple regression against total phosphorus in surface water. Field investigations of the phosphorus content in accumulation sediments along the coast of Svealand showed a distribution pattern that probably is related to differences in the redox status. The average content of mobile phosphorus was much higher than previously found in offshore Baltic sediments indicating that sediments may play an important role for the phosphorus turnover in Baltic archipelago areas. A one-year field study to measure the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in water, sediments and fish during different seasons was carried out in Kallrigafjärden Bay. The collected data set was used to test a mass-balance model for PCCD/F-turnover. It was possible to reproduce the concentrations of different PCDD/F-congeners with high accuracy using a general model approach, including one water compartment and two sediment compartments, indicating that the applied model has the necessary qualifications for successful predictions of PCDD/F-turnover in Baltic coastal areas. / Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 736
64

Investigação de dioxinas, furanos, hidrocarbonetos policíclicos aromáticos no material particulado e gases emitidos por motores diesel / Investigation of dioxins, furans and polycyclic aromatic hydrocarbons in particulate material and gases emitted by diesel engines.

Raimundo Paiva da Nobrega 16 April 2007 (has links)
Investigar, em motores veiculares pesados, alimentados com combustível diesel, a emissão de dioxinas e furanos clorados (PCDD/Fs) e hidrocarbonetos policíclicos aromáticos (PAHs), através da análise de material particulado e gases do sistema de exaustão. Investigar a mutagenicidade do material particulado e gases coletados. Material e Métodos: Os testes de emissão foram feitos em banco de provas dinamométrico de bancada de acordo com Ciclo 13 Pontos de testes, utilizando-se motores Diesel nacionais de aplicação veícular. Um mini-túnel de diluição foi usado para obtenção de amostras de material particulado. As análises de PCDD/Fs e PAHs foram realizadas em laboratório nacional. Para a análise de PCDD/Fs utilizou-se o método USEPA 8290 (1994) e para a análise de PAHs foi utilizado o método USEPA TO 13A (1999). A análise de mutagenicidade foi realizada de acordo com o Teste de Ames (TA98). Resultados: As medições de PCDD/Fs indicaram em geral valores abaixo do limite de detecção do método analítico. Em uma das amostras foi verificado que o OCDD ficou acima do limite de detecção, enquanto em outra isto ocorreu para o OCDF e para o 1,2,3,7,8-PeCDF. Em relação aos PAHs analisados verificou-se a presença dos seguintes compostos: Naftaleno, Acenaftileno, Acenafteno, Fluoreno, Fenantreno, Antraceno, Fluoranteno, Pireno, Benzo[a]antraceno, Criseno, Benzo[b]fluoranteno, Benzo[k]fluoranteno. A média encontrada para 5 amostras analisadas foi de 3.580,5 µg/g de material particulado. Os PAHs encontrados neste trabalho indicam alguma similaridade com a literatura disponível, para valores em % e µg/g de material particulado total coletado. O teste de Ames indicou que o material particulado coletado de motores diesel tem alta atividade mutagênica. Conclusões: A emissão de PCDD/Fs, para o nível de tecnologia dos motores Diesel testados mostrou-se pouco significativa, considerando-se combustível conforme especificado e método e limite de detecção utillizados. Em relação aos PAHs, os resultados indicaram que motores diesel têm uma contribuição importante na formação destes compostos. A alta atividade mutagênica observada mostra que as emissões de veículos Diesel são potencialmente tóxicas. Recomenda-se a continuidade de estudos para definição da regulamentação desses poluentes. / To investigate emission of chlorinated dioxins and furans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) in heavy duty diesel engines, through the analysis of particulate material and gases in the exhaust.To verify mutagenicity of collected particulate material and gasesous sample extracts. Material and Methods: The engine emissions tests were done in dynamometer test bench according to 13-Mode Cycle, using brazilian engines, vehicle application. A mini dilution tunnel was used to obtain particulate matter and gaseous sample. PCDD/Fs and PAHs analyses were carried out in a certified national laboratory. Dioxins and furans were analyzed according with Method 8290 (USEPA, 1994) and PAHs by Method TO13A (USEPA, 1999). The mutagenicity analyses were done in accordance with Ames test (TA98) Results: The measurements of dioxins and furans in diesel engines operating in controlled conditions in dynamomter bench test, had indicated emissions values in general below the detention limit of the analytical method. In one of the samples it was verified that the OCDD was above the detention limit, while in another one this occurred for OCDF and 1,2,3,7,8-PeCDF. In relation to 16 PAHs it was verified the presence of the following compounds: Naphthalene, Acenaphthylene, Acenaphthene, Fluorene, Phenanthrene, Antracene, Fluorantene, Pyrene, Benzo[a]antracene, Chrysene, Benzo[b]fluoranthene and Benzo[k]fluorantene. The average value of the sum of PAHs found in five samples was 3,580.5 µg.g-1. The PAHs found in this study indicates some similarity with available literature for values in % and µg/g of particulate matter.The Ames test showed that the collected particulate material from diesel engines presents high mutagenic activity. Conclusion: The emission of PCDD/Fs, for the level of technology of the tested Diesel engines revealed little significant, considering the specified fuel, method of analysis and limit of detention used. In relation to the 16 PAHs, the tests results had indicated that diesel engines has an important contribution in the formation of these compounds. The high mutagenic activity observed shows that the emissions of Diesel vehicles are potentially toxic. The continuity of studies for definition of the regulation of these pollutants is recommended.
65

Species-specific effects of dioxin exposure on xenobiotic metabolism and hard tissue in voles

Murtomaa-Hautala, M. (Mari) 25 March 2012 (has links)
Abstract The evaluation of the effects and levels of contaminants in wildlife is an essential part of assessing risks for chemical exposure in the environment. Although the circumstances are not as controlled as in laboratory, wildlife studies offer the concept of environmental exposure in its entirety, with all the natural variation. In the present study, two wild vole species, bank vole (Myodes glareolus) and field vole (Microtus agrestis), were used in assessing environmental levels of dioxins. The effects of dioxin exposure on tooth and bone development were studied in order to determine whether they could be used as biomarkers for environmental exposure. Xenobiotic metabolism activity after dioxin exposure – both natural and experimental – was studied by quantifying selected cytochrome P-450 (CYP) enzymes. The results confirmed the fact that dioxins are ubiquitous in the environment, also in areas far from contaminant sources and human activity. The development of the third molar in bank vole was found to be a sensitive biomarker for dioxin exposure. The two vole species under study do not respond similarly to environmental concentrations of dioxins; there were significant differences in body burdens and activity levels of xenobiotic metabolizing enzymes. / Tiivistelmä Haitallisten kemikaalien tason ja vaikutusten arviointi ympäristössä on olennainen osa kemikaalien riskin arviointia. Vaikka laboratoriossa olosuhteita kontrolloidaan ja tutkimukseen vaikuttava variaatio on paremmin hallittavissa, luonnonvaraisten lajien tutkiminen luo kokonaisvaltaisen ja todenmukaisen kuvan ympäristön kemikaalialtistuksesta kaikkine todellisine vaihteluineen. Tässä väitöskirjassa tarkastellaan kahden luonnonvaraisen pikkunisäkkään, metsämyyrän (Myodes glareolus) ja peltomyyrän (Microtus agrestis), käyttöä ympäristön kemikaalitason arvioinnissa. Pääpaino on dioksiinien kaltaisissa yhdisteissä. Työssä tutkitaan yhdisteiden kertymistä myyriin kahdessa ympäristössä: voimakkaasti dioksiineilla saastuneella maa-alueella sekä kaukana ihmistoiminnasta sijaitsevassa erämaassa. Herkiksi tiedettyjä vasteita – hampaiden ja luiden kehitystä – käytetään dioksiinialtistuksen indikaattoreina. Vierasainemetaboliasta vastaavien entsyymien (sytokromi P450 eli CYP) aktiivisuutta kartoitetaan molemmilla myyrälajeilla, jotta saadaan tietoa entsyymien indusoinnista luonnonvaraisilla myyrillä yleensä ja selvitetään havaittuja lajien välisiä eroja dioksiinivasteissa. Tulokset vahvistavat, että dioksiinit ovat laajalle levinneitä yhdisteitä, joita löytyy paitsi läheltä päästölähdettä myös kaukana ihmistoiminnasta olevilta alueilta. Metsämyyrällä kolmannen poskihampaan kehitys osoittautuu herkäksi dioksiinialtistuksen biomarkkeriksi. Samasta elinympäristöstä huolimatta tutkituista myyrälajeista mitatut dioksiinipitoisuudet eroavat huomattavasti toisistaan, samoin kuin vierasainemetaboliasta vastaavien entsyymien aktiivisuus ja niiden induktio TCDD-altistuksen jälkeen.
66

Field and Greenhouse Studies of Phytoremediation with California Native Plants for Soil Contaminated with Petroleum Hydrocarbons, PAHs, PCBs, Chlorinated Dioxins/Furans, and Heavy Metals

Poltorak, Matthew Robert 01 December 2014 (has links)
Native and naturalized California plant species were screened for their phytoremediation potential for the cleanup of soil contaminated with petroleum hydrocarbons (PHCs), poly-aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorinated dioxins/furans, and heavy metals. This screening was followed by controlled greenhouse experiments to further evaluate the phytoremediation potential of the best candidates. Field specimens and soils used for this study were collected from the former Energy Technology Engineering Center (ETEC) at the Santa Susana Field Laboratory in Southern California that was operated by the Department of Energy (DOE). Soils at this site contain all of the contaminants of interest (COIs). Nine plant species were screened in the field: Purple Needlegrass (Nassella pulchra), Blue Elderberry (Sambucus nigra), Laurel Sumac (Malosma laurina), Mule Fat (Baccharis salicifolia), Palmer’s Goldenbush (Ericameria palmeri), Summer Mustard (Hirschfeldia incana), Narrowleaf Milkweed (Asclepias fascicularis), Coyote Brush (Baccharis pilularis), and Thickleaf Yerba Santa (Eriodictyon crassifolium). In the field three samples of each species growing in contaminated soil and one of each species growing in uncontaminated soil were selected for harvesting and analysis. The roots, above ground plant tissue, and soil around the roots were sampled separately and analyzed for the COIs: PHCs, PAHs, PCBs, chlorinated dioxins/furans, and metals (which include mercury, silver, cadmium, and lead). All of the plants in the field appeared to generate compounds which result in higher measured PHC concentrations than those measured in the associated soil. The highest concentrations of PAHs in the roots were observed for Blue Elderberry (1740 ug/kg), Purple Needlegrass (703 ug/kg), and Yerba Santa (200 ug/kg). No uptake of PCBs was observed in the roots or foliage of any species. The highest concentrations of total chlorinated dioxins/furans in the roots were observed for Purple Needlegrass (2237 ng/kg), Blue Elderberry (1026 ng/kg), Palmer’s Goldenbush (432 ng/kg), and Yerba Santa (421 ng/kg). The highest concentrations of total chlorinated dioxins/furans in the foliage were observed for Yerba Santa (901 ng/kg), Palmer’s Goldenbush (757 ng/kg), and Purple Needlegrass (694 ng/kg). No uptake of mercury was observed in the roots or foliage of any species. The highest concentration of silver in the roots was observed for Laurel Sumac (7.34 mg/kg). Summer Mustard (SM) was the only species that showed uptake of silver into the foliage (0.405 mg/kg). The highest concentrations of cadmium in the roots and foliage were observed for Mule Fat (1.84 mg/kg and 3.64 mg/kg) and Coyote Brush (1.52 mg/kg and 2.12 mg/kg) and the greatest concentration of lead in the roots and foliage was observed for Purple Needlegrass (8.92 mg/kg and 1.17 mg/kg). Plants with a wide variety of observed contaminant uptake in the field were selected for a second phase of research in which three of the most promising species were grown in greenhouse microcosms to quantify the removal of contaminants from the soil. The three species selected based on preliminary results from the field study were Coyote Brush, Mule Fat, and Purple Needlegrass. Microcosms consisted of 2.17 kg of soil in 4-L glass jars with glass marbles for an underdrain. Plants were watered with deionized water and no leachate was collected. Five replicates of each microcosm type were created and incubated for 211 days with soil sampling at 85 and 211 days. Soil, plant roots/above ground tissue, and volatilization from the plants were analyzed for COIs to determine the mechanisms of phytoremediation. One set of microcosms was used to test the effect of addition of achelating agent (ethylenediaminetetraacetic acid) and another set was used to test the effect of fertilizer addition on phytoremediation potential. Three control treatments were tested: sterilized (gamma irradiation) soil planted with Purple Needlegrass, unplanted soil, and sterilized unplanted soil. None of the plant species demonstrated volatilization of COIs under these conditions. Volatilization of mercury was not tested for. The average PCB concentration (measured as Aroclor 1260) reductions in soils with Purple Needlegrass and chelated Coyote Brush were 49.4% and 51.4% respectively (p < 0.05). However, the sterilized unplanted control also had a decrease of Aroclor 1260 concentrations in the soil of 36.6% (p < 0.05). None of the species phytoextracted PCBs, so the mechanism of PCB remediation appears to be phytostimulation of the rhizosphere. Purple Needlegrass showed the greatest uptake of dioxins/furans into the foliage but did not appear to reduce the dioxin/furan concentrations in the soil. Coyote Brush, fertilized Coyote Brush, and Mule Fat also showed uptake of dioxins/furans into the roots and foliage. Only the Coyote Brush and fertilized Coyote Brush significantly (p = 0.036, p = 0.022) reduced the total dioxin/furan concentration in the soil (17.8% and 19.8% respectively). Coyote Brush may have stimulated microbes in the rhizosphere to better degrade the dioxins/furans. None of the plants were identified as hyper-accumulators of metals, and none of the soil metal concentrations significantly decreased in any of the microcosms. All of the metals (except mercury) were taken into the roots of plants to some degree, with Purple Needlegrass showing the most promise for metal extraction as it showed some of the highest concentrations of metals in roots and was the only species that contained mercury and silver in the foliage. This study suggests that there is some potential for phytoremediation of PCBs and chlorinated dioxins/furans. The results for petroleum hydrocarbons were inconclusive. Metal uptake was not substantial enough to lower metal concentrations in the soils. Thus phytoremediation of COIs at the site is limited and more aggressive forms of remediation may be required to reduce the concentrations of COIs quickly.
67

Stanovení obsahu organických sloučenin v pevném uhlíkatém zbytku / Determination of content of organic compounds in biochar

Novotná, Martina January 2020 (has links)
Biochar is created during the pyrolysis of organic biomass. Once added into the soil, it can improve its features. Biochars made from sewage sludge have various compositions. It is because of the vast difference between entrance materials. Organic pollutants can be absorbed into its surface during the cooling proces sof pyrolysis. If released into the enviroment, these compounds can cause inhibition of plant growth, get into food chains and adversely affect living organisms. Organic pollutans are determined most often by GC/MS after organic solvent extraction.
68

Développement et application de méthodologies d'évaluation des expositions atmosphériques chroniques aux dioxines et au cadmium dans le cadre d'études épidémiologiques / Development and application of assessment methodologies for chronic airborne dioxin and cadmium exposures to be used in epidemiological studies

Coudon, Thomas 01 June 2018 (has links)
Un certain nombre d'études ont étudié le lien entre cancer du sein et exposition aux dioxines et au cadmium. Toutefois, les résultats de ces études ne sont pas concluants et présentent des limites méthodologiques. L'objectif principal de cette thèse était de développer un indicateur spatial permettant d'estimer les expositions atmosphériques chroniques aux dioxines et au cadmium des femmes issues de la cohorte E3N en France, entre 1990 et 2008. Nous avons créé une base de données de 2620 sources de dioxines et 2700 sources de cadmium et estimé et géolocalisé leurs émissions. L'estimation des émissions à la source et leur localisation ont servi de base pour la construction de l'indicateur spatial. Nous avons identifié une sélection de paramètres permettant d'obtenir un accord « substantiel » entre les classifications des expositions des femmes de la cohorte E3N, localisées à l'adresse de résidence, estimées avec l'indicateur, et avec le modèle gaussien SIRANE. En utilisant le modèle SIRANE, nous avons également étudié la variabilité spatio-temporelle (1990-2008) des concentrations de dioxines et de cadmium sur la métropole de Lyon. Pour la première fois des concentrations modélisées ont été comparées à des mesures de concentrations de dioxines en air ambiant. L'indicateur développé dans cette thèse a été utilisé pour estimer le risque de cancer du sein associé à l'exposition atmosphérique aux dioxines dans une étude cas-témoins niché au sein de la cohorte E3N. Il est utilisé actuellement dans une étude sur le lien entre exposition au cadmium et risque de cancer du sein, et pourra être appliqué dans de futures études portant sur d'autres polluants ou d'autres pathologies / A number of studies have examined the link between breast cancer and exposure to air pollution, including dioxins and cadmium. However, the results of these studies are inconclusive and present a number of methodological limitations. The main objective of this thesis was to develop a spatial indicator to assess chronic atmospheric exposure to dioxins and cadmium of women from the E3N cohort in France between 1990 and 2008. We first performed an inventory and created a database of 2620 dioxins and 2700 cadmium emitting sources in France between 1990 and 2008 and estimated and geolocated their annual emissions. The location of the sources and their estimated emissions were used as the basis for the construction of the indicator. Combination of additional spatial parameters, allowed us to obtain a "substantial" agreement between the dioxin and cadmium exposure classifications of the E3N subjects geolocalised at their residential address, using the estimated bythe indicator and exposures estimates derived from the Gaussian model. We also evaluated the spatial-temporal variability of dioxin and cadmium concentrations over nearly two decades in the Lyon metropolitan area, taking into account a wide variety of source types. This is the first study comparing concentrations predicted by a dispersion model to dioxin concentrations measured in ambient air. The exposure indicator was used in a case-control study within the E3N cohort to estimate the risk of breast cancer associated with atmospheric exposure to dioxins. It is currently being used in another study on cadmium exposure and breast cancer risk and may be applied in future studies on other pollutants or pathologies
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La phytoremédiation assistée par les champignons mycorhiziens à arbuscules des sols historiquement contaminés par les dioxines/furanes : Conséquences sur le microbiote du sol et sur la dissipation des polluants / Arbuscular mycorrhizal fungi - assisted phytoremediation of aged dioxin/furan-contaminated soil : Consequences on microbiota and pollutant dissipation

Meglouli, Hacène 15 September 2017 (has links)
Célèbres depuis l'accident de Seveso en 1976, les dioxines/furanes (PCCD/F) restent, malgré une forte baisse de leurs émissions, un sujet de préoccupation permanent en France et dans le monde. Le rémanence de ces composés organochlorés dans le sol et le risque toxique qu'ils représentent pour l'homme et l'environnement font que la gestion et la remédiation des sols contaminés par les PCDD/F sont devenues une priorité des industriels, législateurs et scientifiques. La phytoremédiation compte parmi les méthodes émergentes de dépollution des sols contaminés en raison de son adéquation avec le développement durable. Elle combine les capacités naturelles des plantes et de leur microbiote rhizosphérique à biodégrader les polluants organiques. Cependant, l'efficacité de cette phytotechnologie est encore souvent limitée, en particulier lorsqu'il s'agit de composés chlorés, à cause de leur récalcitrance, de leur phytotoxicité et leur faible biodisponibilité dans le sol. Ainsi, l'objectif de ce travail de thèse a consisté à étudier les performances de la phytoremédition assistée, en particulier par les champignons mycorhiziens arbusculaires, d'un sol agricole historiquement pollué par les PCDD/F prélevé sur une parcelle expérimentale située à proximité d'un ancien incinérateur. L'ensemble des résultats obtenus mettent en évidence, en particulier, le potentiel de deux espèces végétales, la luzerne et la fétuque, dans la rhizodégradation des PCCDD/F. La végétalisation du sol permet de moduler les communautés microbiennes du sol (bactéries, Archées et champignons) et notamment celles qui semblent impliquées dans la dissipation des PCCDD/F. En revanche, bien que la mycorhization agisse sur les communautés microbiennes du sol, celle-ci n'a pas eu d'impact, dans nos conditions expérimentales, sur la dissipation des PCCDD/F quelles que soit l'origine de l'inoculum utilisé et les espèces mycorhiziennes qui le compose. La dégradation de ces composés organochlorés est plus marquée dans un sol préalablement stérilisé, puis recolonisé par certaines communautés microbiennes spécifiques, impliquées dans la dissipation des PCCDD/F. L'utilisation combinée d'un mélange de rhamnolipides avec l'introduction dans le sol d'une bactérie Sphingomonas wittichii RWI, décrite pour ses capacités de dégradation des PCCDD/F, permet d'accroitre l'efficience de la rhizodégradation des PCDD/F qui se traduit par une baisse significative de la cytotoxicité du sol après phytoremédiation. / Famous since the Seveso accident in 1976, dioxins/furans (PCCD/F) remain, despite a sharp decline in emissions, a subject of permanent concern in France and in the world. The remanence of these organochlored compounds in soil and the toxic risk they represent for humans and the environment mean that the management and remediation of PCDD/F contaminated soil has become a priority for industrialists, legislators and scientists. Phytoremediation is one of the emerging depollution methods of contaminated soils due to Its suitability for sustainable development. It combines the natural capacities of plants and their rhizospheric microbiota to biodegrade organic pollutants. However, the effectiveness of this phytotechnology is still often limited, especially in the case of chlorinated compounds, due to their recalcitrance, phytotoxicity and low bioavailability in the soil. Thus, the thesis aims to study the performance of assisted phytoremission, in particular by mycorrhizal fungi, of an agricultural PCDD / F based-polluted soil from an experimental plot near an old incinerator. The results obtained show the potential of two plant species, alfalfa and tall fescue, in the rhizodegradation of PCCDD/F. Soil vegetation shows to modulate soil microbial communities (bacteria, archaea and fungi) includind those that appear to involved in the dissipation of the PCCDD/F. On the other hand, although mycorrhization affects soil microbial communities, it has not had any impact on the dissipation of PCCDD/F in our experimental conditions, whatever the inoculums origin and the mycorrhizal species which compose it. The degradation of these organochlorined compounds is more significant in a previously sterilized soil and then recolonized by specific microbial communities involved in the PCCDD/Fdissipation. The combined use of rhamnolipids mixture and Sphingomonas wittichii RWI bactrerium described for its degradation capabilities of PCCDD/F makes it possible to increase the efficiency of PCDD/F rhizodegradation which results in a significant decrease in soil cytotoxicity after phytoremediation.
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Hazardous Waste Site Proximity and Type 2 Diabetes: From Youths to Adults

Johnson, Theresa Ann 01 January 2019 (has links)
Type 2 diabetes has reached epidemic proportions in adults and youths. Persistent organic pollutants and endocrine-disrupting chemicals (EDCs), such as pesticides, dioxins, and organochlorines, are omnipresent and persist in the environment with potential for human exposure via contaminated air, waterways, soil, and human food supply. EDCs have been correlated with diabetes incidence and risks. Residential proximity to hazardous waste sites (HWS) has been correlated with increased hospital admission rates for diabetes. The study used a sample population (N = 1,724), ages ≥ 12 years from the 2005-2012 Continuous NHANES and HWS data from the National Priorities List of Superfund Sites. The ecosocial theory of disease distribution, and geocoordinates provided theoretical support. Mann-Whitney U test and binary logistic regression analysis were used to investigate the relationship between residence ≤ 1 mile compared with residence >1 mile from a HWS in NHANES surveyed counties of NJ, PA, NY, and CA on the outcome abnormal A1c ≥ 5.7% while controlling the effect of the moderators: abnormal body mass index (BMI), age, sex, and race/ethnicity on the relationship. Participants with a BMI ≥ 28.95 kg/m2 were 1.8 times and persons ≥ 58 years of age were 2.1 times more likely to have an A1c ≥ 5.7%. Also, non-Hispanic Whites residing >1 mile of a HWS had 82.1 % reduced risk of abnormal A1c compared with the same group residing ≤ 1 mile of a HWS. The results forge opportunities for future studies to consider border distance between residence and HWS. In addition, the results may promote positive social change through diabetes risks education, environmental health education, and practices and raise dialogue about social justice and the geographic distribution of hazardous waste sites.

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