A presente tese se baseia no estudo das rochas ornamentais e de revestimento em relação aos seus aspectos de alterabilidade que irá influenciar diretamente no aumento da adição do gás radioativo radônio no interior de um ambiente com o passar do tempo de uso, fato devido as interações com o meio de onde é instalado a rocha, como exemplo da sua manutenção e limpeza, que implicará no seu padrão estético e na qualidade do ar do ambiente interior. Temas como a qualidade do ar interior relacionado a qualidade de vida do usuário, a radioatividade natural, o perigo do gás radiotivo radônio no interior do ambiente e as rochas ornamentais como composição e uso na arquitetura são apresentados para embasamento da Tese e auxiliando no entendimento dos ensaios realizados. Para isso, cinco rochas ornamentais foram escolhidas e realizados ensaios de alterabilidade química, ensaios tecnológicos de caraterização e ensaios de caracterização radiométrica a fim de prever o comportamento de uma dada rocha em seu ambiente ao ser aplicado na arquitetura. O ataque do ácido HCl nas rochas diminuiu sua resistência e aumentou a quantidade de radônio exalado relacionado diretamente ao aumento direto na porosidade, aumentando também a eficiência de exalação da rocha. O ataque do álcali KOH apesar de diminuir a resistência da rocha, interferiu na porosidade e diminuindo assim a quantidade de radônio exalado em alguns casos. Isso demonstra que mesmo conhecendo o material e a sua contribuição na adição do Rn no interior do ambiente, com o passar do tempo a rocha irá aumentar sua exalação quando não conservadas podendo aumentar o nível de radônio acumulado no ambiente. Com isso, a tese realça a importância de conhecer o material que irá compor o interior do ambiente afim de prevenir futuros danos à saúde da edificação e dos usuários, facilitando assim o entendimento desses materiais e como interfere na qualidade do ambiente construído. / This thesis is based on the study of dimension stone in relation to aspects of changeability which will directly influence the increased addition of radon radioactive gas within an environment over time of use, a fact due to interactions with the environment where it is installed rock, as an example of its maintenance and cleaning, which will result in its aesthetic standard and quality of indoor air environment. Topics such as the quality of the related indoor air to the user\'s quality of life, natural radioactivity, the danger of radiotivo radon gas into the atmosphere and dimension stone as composition and use in architecture are presented to foundation this Thesis and aiding in the understanding of tests. For this, five ornamental stones were chosen and performed chemical tests changeability, technological characterization of assays and radiometric characterization tests to predict the behavior of a given rock in your environment to be applied in architecture. The attack of the HCl acid in the rocks decreased its strength and increased the amount of exhaled radon related directly to the direct increase in porosity, also increasing exhalation efficiency of the rock. The attack KOH alkali spite of reducing the resistance of the rock, and interfere with the porosity thereby decreasing the amount of radon vented in some cases. This shows that even knowing the material and its contribution to the addition of Rn into the environment, with the passage of time the rock will increase your exhalation when not maintained can increase the level of accumulated radon in the environment. Thus, the thesis highlights the importance of knowing the material that will form the inside of the environment in order to prevent further damage to the health of the building and users, thus facilitating the understanding of these materials and how it interferes in the quality of the built environment.

Mytilus edulis est un mollusque bivalve de grand intérêt économique et écotoxicologique. Cette espèce sentinelle est connue pour sa résistance aux contaminants chimiques et biologiques. Néanmoins, depuis quelques années la moule bleue est touchée par des mortalités dans les élevages des Pertuis Charentais ayant pour dénominateur commun la présence de bactéries virulentes de type Vibrio. Le premier axe de cette thèse décrit les interactions des isolats de V. Splendidus avec la moule bleue au niveau cellulaire et physiologique. Les infections expérimentales ont permis la sélection de deux isolats bactériens affiliés à V. splendidus/V. hemicentroti : une souche virulente codée 10/068 1T1 et une souche inoffensive codée 12/056 M24T1. Ces deux bactéries ont été marquées à la GFP et validées en tant que modèles authentiques d’exposition à travers leurs caractéristiques de croissance et de virulence. Par ailleurs, V. hemicentroti 10/068 1T1 est capable d’altérer différentes fonctions hémocytaires incluant la motilité, l’adhésion, l’internalisation, la production de ROS, la maturation du phagosome et la viabilité contrairement à la bactérie non virulente. Les produits extracellulaires bactériens semblent être toxiques et inhibent certaines réponses cellulaires (internalisation et production de ROS). Enfin, nous avons reproduis avec succès l’infection des animaux par le pathogène via un modèle expérimental de cohabitation. Le suivi de l’infection montre que V. hemicentroti 10/068 1T1 a pour cible principale les branchies. Le deuxième axe explore le fonctionnement du système MXR (MultiXenobiotic Resistance) chez la moule bleue. La séquence codante complète d’un nouveau transporteur ABCG2 a été établie et la protéine résultante a été identifiée. La caractérisation moléculaire montre la présence du transcrit dans les hémocytes ainsi que dans les branchies et son homologie avec les autres protéines appartenant à diverses espèces. L’utilisation des sondes fluorescentes bodipy prazosin et pheophorbide A, combinées avec des bloqueurs spécifiques, démontre l’activité d’efflux de ce transporteur et son hétérogénéité dans les tissus et cellules. Par ailleurs, il est également démontré que l’expression des trois transporteurs ABC (abcb, abcc, abcg2) identifiés chez la moule bleue est modulée par les contaminants chimiques. Les animaux exposés au BaP au laboratoire ou prélevés sur un terrain contaminé montrent une surexpression des transcrits abc dans les branchies et une sous expression dans les hémocytes. La saisonnalité, sur le terrain, a également un effet sur les niveaux des transcrits et interfère avec les réponses liées aux contaminants. Seul le transporteur abcb exprimé dans les branchies n’est pas affecté par des variations saisonnières et montre une surexpression dans le site contaminé tout au long de l’année. En conclusion, nos résultats démontrent la vulnérabilité de la moule bleue face un pathogène. L'impact immunotoxique des xénobiotiques et le rôle que peuvent jouer les transporteurs ABC dans le fonctionnement du système immunitaire des moules reste à explorer. / Mytilus edulis is a bivalve mollusc representing an economic and ecotoxicological interest. This sentinel species is known for its resistance to chemical and biological contaminants. However, for few years, abnormal mortality events have been reported for farmed blue mussels in France where different Vibrio strains were isolated. The first section of this thesis describes cellular and physiological interactions of V. Splendidus isolates with the blue mussel. Experimental infections allowed the selection of two isolates affiliated to V. splendidus/V. hemicentroti type strains: a virulent 10/068 1T1 and an innocuous 12/056 M24T1. These two strains were GFP-tagged and validated for their growth characteristics and virulence as genuine models for exposure. V. splendidus 10/068 1T1 is capable to alter different functions of hemocytes including motility, adhesion, internalization, ROS production, phagosome maturation and viability, unlike the avirulent strain. Furthermore, bacterial extracellular products appeared toxic and inhibit cellular responses (internalization and ROS production). Finally, we successfully reproduced experimental infection by water tank cohabitation assays with septic animals. Infection monitoring shows the targeting of gills by bacteria. The second section explores the MXR (MultiXenobiotic Resistance) system functioning in the blue mussel. For the first time, a complete ABCG2 amino acid sequence was established. Molecular characterization shows the presence of the abcg2 transcript in hemocytes and gills and its homology with other proteins from various species. The combination of the fluorescent probes bodipy prazosin and pheophorbide A with specific blockers demonstrate the transporter efflux activity and its heterogeneity in tissues and cells. Moreover, the expression of three ABC transporters (abcb, abcc, abcg2) identified in the blue mussel has been shown to be modulated by chemical contaminants. Mussels exposed to BaP in the laboratory or collected from contaminated mussel beds in the field show upregulated abc transcripts in gills whereas these mRNA undergone a downregulation in hemocytes. Season had also an effect on mRNA levels and interacted with site effects. Only the abcb gene displayed a more abundant mRNA level in gills dissected from animals collected in the more polluted area all over the diachronic study. In conclusion, our results demonstrate the vulnerability of the blue mussel towards a pathogen. The immunotoxic impact of environmental xenobiotics and the precise role of ABC efflux pumps in the immune system of the mussel has yet to be explored.

Les populations sont exposées dans leur habitat à un nombre croissant de composés chimiques, dont les composés organiques semi-volatils (COSV). Ils se distribuent sur les surfaces, les phases particulaire et gazeuse de l’air et les poussières, participant ainsi à l’exposition des populations par ingestion, par inhalation et par contact cutané. Plusieurs de ces composés sont suspectés d’être toxiques pour l’Homme. L’objectif de cette thèse est d’évaluer, par une démarche d’évaluation des risques sanitaires, l’impact sur la santé publique des expositions aux COSV fréquemment détectés dans les logements français. Dans un premier temps, les expositions ont été estimées pour 32 composés à partir de données de contamination et de facteurs humains d’exposition comme le poids, le volume respiratoire, le temps passé dans l’habitat, etc. Les voies orale, pulmonaire et cutanée ont été agrégées pour les COSV les plus préoccupants présents dans l’habitat et pour plusieurs tranches d’âge de la naissance à 30 ans. Dans un second temps, les risques pour la santé humaine ont été modélisés à partir de ces expositions et des données disponibles sur leur toxicité. Chaque composé a été pris en compte individuellement mais également en mélange sous l’hypothèse d’additivité des doses. Ce travail a permis l’obtention de distributions représentatives des expositions des populations dans l’habitat en France et d’identifier les voies et les médias dominants pour chaque composé ainsi que les COSV les plus à risque pour une certaine proportion de la population française. / In housing, people are exposed to an increasing number of chemicals, including semivolatile organic compounds (SVOCs). SVOCs are present on surfaces, in the gas phase, airborne particles and settled dust. Humans are exposed through ingestion, inhalation and dermal contact. Many of these compounds have suspected toxic effects on human health. The objective of this thesis is to assess, by a risk assessment approach, the public health risk posed by the exposure to SVOCs frequently detected in French dwellings. At first, indoor exposures were estimated for 32 compounds from contamination data and human parameters such as body weight, inhalation rate, time spent in dwellings etc. Ingestion, inhalation and dermal contact exposure pathways were aggregated for the indoor SVOCs of greatest concern and for several age groups from birth to age 30. In a second step, human health risks were modeled from these exposures and from available toxicity data. Each SVOC was considered separately and also in mixtures, based on the assumption of dose additivity. This work provided exposures distributions representative of the French population and identified the dominant media and exposure routes for each compound as well as the most at risk SVOCs for a certain portion of the French population.

Abstract Gas removal from the papermaking process is currently a standard practice, whereas purification of the internal water circulation has become common only recently. Both unit processes have progressed greatly during recent decades and new concepts are constantly being developed. The aim of this thesis was to analyse the efficiency and applicability of a channel flow design introduced by Metso for passive white water deaeration and to study the dynamics of passive bubbly gas removal. In addition, separation of the detrimental process water components by selective flotation during deaeration was studied to add further functionality to the channel flow design. Turbulent mixing at the flow discharge and the consequent air entrainment were seen to limit the gas separation efficiency. Also, the properties of different white waters notably affect their deaeration through viscous forces, the concentration of surface active components and bubble-particle interactions. Thus similar levels of gas separation cannot be achieved with all process waters. The analysis showed that the drag of small microbubbles is mostly caused by hydrophobic contamination and the dispersed particles that readily attach to the bubbles. Correlations were derived based on experimental data to provide new information on the drag force experienced by small bubbles in white waters. Chemically unaided flotation of white water in the channel flow was shown to be efficient in separating hydrophobic contaminants that have adverse effects on paper machine production and product quality. Both good reductions in contaminant content and high selectivity in their removal were achieved. Channel flow with an overflow can be considered well suited for the first stage of froth separation, while further treatment of the channel flow reject may consist of a secondary flotation or other process that enables the recirculation of fines and fillers. Although a certain level of losses of fines and fillers must be expected, substantial fraction of these solid components can be returned to the process stream. The proposed multifunctional process, channel flow deaeration and frothing of white water, was seen to be straightforward, economical and feasible while also providing benefits in terms of total process efficiency that are not delivered by any current process scheme. The experimental parameters presented here regarding bubble dynamics and flotation efficiency can be used to achieve better models of these processes.

Doctor of Philosophy / Department of Biochemistry / Lawrence C. Davis / The fate and bioavailability of organic contaminants in plants is a major ecological and human health concern. Current wet chemistry techniques that employ strong chemical treatments and extractions with volatile solvents, such as GC-MS, HPLC, and radiolabeling, although helpful, degrade plant tissue resulting in the loss of spatial distribution and the production of artifacts. Synchrotron radiation infrared microspectroscopy (SR-IMS) permits direct analysis of plant cell wall architecture at the cellular level in situ, combining spatially localized information and chemical information from the IR absorbances to produce a chemical map that can be linked to a particular morphology or functional group. This study demonstrated the use of SR-IMS to probe biopolymers such as cellulose, lignin, and proteins in the root tissue of hydroponically grown sunflower and maize plants as well as to determine the fate and effect of several organic contaminants in those root tissues. Principal components analysis (PCA), a data compression technique, was employed to reveal the major spectral variances between untreated and organic contaminant treated root tissues. Treatment with 1H-benzotriazole (BT) caused alterations to the lignin component in the root tissue of plants. The BT was found in xylem and epidermal tissue of sunflower plants but not associated with any particular tissue in maize roots. 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT) altered the pectin and polysaccharide structure in both maize and sunflower. SR-IMS revealed the reduction of DNTs to their aromatic amine form in the vascular and epidermal tissues at low concentration. At high concentration, DNTs appeared to be associated with all the plant tissues in maize and sunflower. Exposure of sunflower and maize to 2,6-dichlorophenol (2,6-DCP) caused alterations to the polysaccharide and protein component of the root tissue. In some cases, phenolic compounds were observed in the epidermal tissue of maize and sunflower roots. The results of this research indicate that SR-IMS has the potential to become an important analytical tool for determining the fate and effect of organic contaminants in plants.

Contaminants of emerging concern (CECs) are continuously being released into the environment mainly because of their incomplete removal in the sewage treatment plants (STPs). The CECs selected for the study include antibiotics (macrolides, sulfonamides and ciprofloxacin), sucralose (an artificial sweetener) and dioctyl sulfosuccinate (DOSS, chemical dispersant used in the Deepwater Horizon oil spill). After being discharged into waterways from STPs, photo degradation is a key factor in dictating the environmental fate of antibiotics and sucralose. Photodegradation efficiency depends on many factors such as pH of the matrix, matrix composition, light source and structure of the molecule. These factors exert either synergistic or antagonistic effects in the environment and thus experiments with isolated factors may not yield the same results as the natural environmental processes. Hence in the current study photodegradation of 13 CECs (antibiotics, sucralose and dicotyl sulfosuccinate) were evaluated using natural water matrices with varying composition (deionized water, fresh water and salt water) as well as radiation of different wavelengths (254 nm, 350 nm and simulated solar radiation) in order to mimic natural processes. As expected the contribution of each factor on the overall rate of photodegradation is contaminant specific, for example under similar conditions, the rate in natural waters compared to pure water was enhanced for antibiotics (2-11 fold), significantly reduced for sucralose (no degradation seen in natural waters) and similar in both media for DOSS. In general, it was observed that the studied compounds degraded faster at 254 nm, while when using a simulated sunlight radiation the rate of photolysis of DOSS increased and the rates for antibiotics decreased in comparison to the 350 nm radiation. The photo stability of the studied CECs followed the order sucralose > DOSS > macrolides > sulfonamides > ciprofloxacin and a positive relationship was observed between photo stability and their ubiquitous presence in natural aquatic matrices. An online LC-MS/MS method was developed and validated for sucralose and further applied to reclaimed waters (n =56) and drinking waters (n = 43) from South Florida. Sucralose was detected in reclaimed waters with concentrations reaching up to 18 µg/L. High frequency of detection (> 80%) in drinking waters indicate contamination of ground waters in South Florida by anthropogenic activity.

In recent years, new classes of aquatic pollutants have received growing concerns from the environmentalists due to their unclear effects and increasing release into the water environment. Generally, before entering the aquatic ecosystem, many of these emerging contaminants are deemed safe active ingredients in the commercial products. This may lead to the underestimation of their potential impacts to the environment, once these substances were drained into the natural waters. So far, a wide range of emerging contaminants are still not well studied. In this thesis work, the environmental behaviors for two typical groups of emerging contaminants, which are frequently used in personal care products, are systematically probed in the aquatic ecosystem. One is the hydrophilic compounds - artificial sweeteners and the other one is the moderate hydrophobic compounds - ultraviolet (UV) filters. Acesulfame and sucralose are two of the most commonly used artificial sweeteners, which are a newly recognized class of emerging contaminants due to their widespread occurrence and extreme persistence in water environment. To date, however, their environmental behaviors, fates as well as long term ecotoxicological contributions in our water resources still remain largely unknown. In this work, a photodegradation investigation with UV/TiO2 was performed on these two artificial sweeteners, which projected their potential impacts under prolonged exposure to intensive solar irradiation. Real-time observation of the degradation profiles in both sweeteners illustrated that formation of new photo by-products under prolonged UV irradiation is highly viable. For the first time, acute toxicity for the degradates of these two sweeteners were measured and the enhancement in their ecotoxicity has been observed during the irradiation. In an attempt to neutralize this prolonged environmental threat, the feasibility of UV/TiO2 as an effective mineralization process in wastewater treatment was evaluated for both sweeteners. As a result, relatively higher removal efficiencies for acesulfame and sucralose were achieved in this study. For UV filters, a comprehensive investigation on their environmental behaviors and impacts was described in this thesis, covering the occurrence study in surface water and biota, environmental fate and their ecological risks. In the first step, an analytical method based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of twelve UV filters in the environmental waters, which achieved good sensitivity to sub-ng/L levels. To monitoring their occurrence in local marine environment, the regional distribution of these sunscreen compounds was monitored along the coastline of Hong Kong. At the same time, considering the intensive consumption of sunscreen products in hot weathers, seasonal variation of UV filters between summer and winter was taken into consideration in our occurrence study. Additionally, we also monitored their occurrence in the drinking water supply system of Hong Kong, including the source water in Dongjiang, raw water in local reservoirs and tap water collected from urban communities, to support a good management on the reliable water supply. Furthermore, the distribution results indicated that the incomplete removal of UV filters in the effluents could be a major source for their release into the environmental waters. Aiming to achieve the complete removal of such compounds, a powerful technique of ozonation was employed in this study and the preliminary operational conditions were further provided. Secondly, in order to gain a better understanding of their environmental fate in surface water, a simulative catalytic photodegradation study with UV/TiO2 were performed to investigate the photostability, phototoxicity and the transformation pathways of seven selected UV filters. During the photodegradation, several transformation products were primarily identified. Thirdly, since lipophilic sunscreens were easily accumulated in the biota, we also made efforts to monitor their occurrence in marine organisms of different species, including farmed fish, wild mussels, prawns and sea urchin, which were collected from local offshore areas. Last but not the least, according to the measured concentrations of UV filters in Hong Kong marine environment, we further performed the ecological risk assessment with the approach specific to the marine aquatic compartment, so as to provide the overall understanding on the environmental impacts of these UV filters.

Railway vehicles require a certain level of adhesion between wheel and rail to operate efficiently, reliably, and economically. Different levels of adhesion are needed depending on the vehicle running conditions. In the wheel tread–railhead contact, the dominant problem is low adhesion, as low adhesion on the railhead negatively affects railway operation: on one hand, the vehicle will lose traction resulting in delay when driving on low-adhesion tracks; on the other hand, low adhesion during deceleration will extend the braking distance, which is a safety issue. This thesis examines the influence of several contaminants, i.e., water, oil, and leaves, on the adhesion in the wheel tread–railhead contact. This study will improve our knowledge of the low-adhesion mechanism and of how various contaminants influence adhesion. The thesis consists of a summary overview of the topic and three appended papers (A–C). Papers A and B focus mainly on water and oil contamination examined using two methods, numerical simulation and lab testing. In paper A, real measured wheel and rail surfaces, low- and high-roughness surfaces, along with generated smooth surfaces are used as input to the numerical model for predicting the adhesion coefficient. Water-lubricated, oil-lubricated, and dry contacts are simulated in the model. In the research reported in paper B, scaled testing using a mini traction machine (MTM) was carried out to simulate the wheel–rail contact under lubricated conditions. Two types of disc surfaces of different roughnesses were run at different contact pressures and temperatures. A stylus machine and atomic force microscopy (AFM) were used to measure the surface topography. A study of leaf contamination on the railhead surface, based on field testing, is presented in paper C. Railhead surface samples were cut and the friction coefficient was measured on five occasions over the course of a year. Electron spectroscopy for chemical analysis (ESCA) and glow discharge optical emission spectrometry (GD-OES) were used to detect the chemical composition of the leaf-contamination layer on the railhead surface. The main conclusion of the thesis is that different contaminants reduce the adhesion coefficient in different ways. Oil reduces the adhesion coefficient by carrying the normal force due to its high viscosity. Water can reduce the adhesion coefficient to different degrees depending on the surface topography and water temperature. The mixture of an oxide layer and water contamination may have an essential impact. A leaf-formed blackish layer causes low adhesion by means of a chemical reaction between the leaves and bulk material. The thickness of the friction-reducing oxide layer predicts the friction coefficient and the extent of leaf contamination. / QC 20111123

Thesis (M.Sc. (Chemistry)) -- University of Limpopo, 2021 / The present research work deals with the study of some of the important physicochemical parameters of restaurant wastewater effluents collected from Mankweng business centre along the University of Limpopo road. Studies revealed that restaurants, food preparation facilities, engineering, paper mill, fine chemical, dyes, paint, pharmaceutical, petrochemical and textile industries are some of the major industries responsible for polluting the aquatic environments. This research attempts to review the physical, chemical, and microbial analysis of wastewater from food service establishments (FSEs) and extraction of fats, oil, and grease (FOG) and its characterization using different analytical techniques. The elemental analysis revealed that the concentration of elements such as zinc, lead and manganese were 6.44 mg/L, 0.02 mg/L and 0.53 mg/L, respectively. The concentration of these elements was above the required South African National Standards 241 (SANS241) limit, that is, ≤5mg/L, ≤0.01mg/L and ≤0.4mg/L for Zn, Pb and Mn, respectively. The elevated concentrations may be due to corrosion, acidic pH found in some samples and high organic load. High organic content in wastewater influenced the production of oxygen by microorganisms in-order to degrade the amount of waste in the wastewater and this has led to high chemical oxygen demand (COD) level ranging from 1784-7196 mg/L and biochemical oxygen demand (BOD5) from 1101.32 to 3222.32 mg/L. The study has demonstrated that the wastewater samples are contaminated with faecal coliforms because the concentration of microbes Escherichia Coli (E.coli) with a Most Probable Number (MPN) >200.5 in most samples, P. aeruginosa, Pseudomonas spp. were too numerous to count (TNC) and total coliforms at the highest concentration of 9.1x103 CFU/ml which was influenced by change in pH of the wastewater, the FOG content consists of both triglycerides and acrolein. The overall results highlight the discharge of highly polluted wastewater effluent, these FSE have resulted in pollution of nearby rivers thereby affecting the growth of vegetation and aquatic life. The results of the present investigation point out the need to implement common objectives, compatible policies, and programmes for improvement in the FSEs wastewater treatment methods. / National Research Foundation and Sasol-Inzalo Foundation

Les PCB (polychlorobiphényles), PBDE (éthers de biphényles polybromés) et OCP (pesticides organochlorés) sont des composés d’origine anthropique classés comme POP (polluants organiques persistants) dont l’usage a progressivement été restreint ou interdit. Ces composés, de par leur caractère ubiquiste, persistant et bioaccumulable, sont néanmoins toujours présents dans l’environnement, d’où l’importance de continuer à étudier leur présence, leur dynamique et leur impact. Du fait de la restriction de leurs usages, d’autres composés sont maintenant utilisés pour les remplacer, tels que les retardateurs de flamme alternatifs (RFA). Ces composés bromés et chlorés ont des propriétés physico-chimiques comparables à celles des POP précités et peuvent potentiellement constituer un danger chimique pour l’environnement. Par ailleurs, les RFA sont attendus à des niveaux de concentration plus faibles que les PCB et les PBDE que ce soit dans les compartiments biotiques et abiotiques. Ainsi, l’un des enjeux de ce travail de thèse était de développer une méthode multi-résidus, associant chromatographie en phase gazeuse et spectrométrie de masse à temps de vol, permettant d’analyser simultanément 17 RFA à des niveaux inférieurs au ng.g-1. Les niveaux et profils de contamination en POP et RFA ont ensuite été renseignés dans les compartiments biotiques et abiotiques de différents systèmes aquatiques contrastés. Le caractère bioamplifiable de ces composés a été étudié grâce à la détermination de facteurs d’amplification trophique (TMF) dans l’estuaire de la Gironde et dans le bassin du Rhône, à l’aide d’outils statistiques innovants. Dans l’estuaire de la Gironde il a été mis en évidence que certains RFA étaient autant voire plus bioamplifiables que certains POP historiques. Par ailleurs, dans le bassin du Rhône, l’utilisation des TMF comme outil prédictif, pour le BDE-47 ou la ΣPBDE-DCE par exemple, a été discutée et parait envisageable dans un cadre réglementaire. / PCBs (polychlorinated biphenyls), PBDEs (polybrominated biphenyl ethers) and OCPs (organochlorine pesticides) are anthropogenic compounds classified as POPs (Persistent Organic Pollutants), their use was restricted or prohibited. These compounds are ubiquitous, persistent and bioaccumulative and they are still present in the environment; this is the reason why it is important to continue the study of the fate and impact in the environment. Due to their usage restriction, other compounds are now used to replace them, such as alternative flame retardants (RFAs). These brominated and chlorinated compounds have physicochemical properties comparable to those of POPs and can thus be potentially hazardous to the environment. In addition, RFAs are expected to occur at lower concentrations than PCBs and PBDEs, whether in the biotic and abiotic compartments. Thus, one of the challenges of the present work was to develop a multiresidue method, based on gas chromatography coupled with a time-of-flight mass spectrometer, allowing for the simultaneous analysis of 17 RFAs at levels below ng.g-1. The levels and patterns of POP and RFA contamination were reported in the biotic and abiotic compartments of selected hydrosystems. The biomagnification potential of these compounds was also studied by determining trophic magnification factors (TMF) in the Gironde estuary and in the Rhône basin. In the Gironde estuary, it was shown that some RFA biomagnify as much or more than some historical POPs. Furthermore, in the Rhône basin, the use of TMF for predictive purpose, for BDE-47 or ΣPBDEs-WFD for example, was discussed and found possible.