This study characterizes 21 wastewater samples collected from Al-Amal hospital between the period of 12 April till 8 July 2020. Al Almal is a hospital that provides drug addiction and psychological treatment to patients. Using solid-phase extraction and liquid chromatography with tandem mass spectrometry (LC-MS/MS), chemical contaminants profiles in these wastewater samples were determined in a non-targeted manner. These chemicals were then individually analyzed in an in-silico manner by checking against databases and literature to determine if they were mutagenic. By determining the proportion of mutagenic chemicals against the non-mutagenic ones, we aim to determine if untreated hospital wastewater may potentially negatively impact the downstream municipal biological wastewater treatment process. It was determined that 64% of the identified chemicals were not tested for their mutagenic effect, and hence no prior information is available in the literature and databases. Instead, we further performed in-vitro mutagenicity tests using Ames test to determine if the wastewater sample, with all of its chemical constituents, would be mutagenic. Ames test results showed that majority of the samples were non-mutagenic except for 1 sample that imposed a mutagenic effect on Salmonella enterica serovar Typhimurium TA98 and 3 samples with mutagenic effect on TA100. In addition, 1 sample showed a toxic effect on TA100. However, in all 5 instances, these samples only imposed a mutagenic and toxic effect at high concentrations of > 10x. The findings in this study suggest that a specialty hospital like Al Amal does not contribute substantially to mutagenic wastewater streams to the municipal sewer, and hence unlikely to significantly perturb the downstream biological treatment processes. However, there may still be a need to consider ad-hoc contributions of mutagenic and/or toxic wastewater streams from the hospitals.

Ecotoxicology studies attempt to evaluate the consequences of exposure to environmental contaminants by defining exposure and effects parameters across multiple levels of biological organization. Genetic markers are well-suited for these studies as they can track both somatic and evolutionary effects. In the studies reported here, connections among contaminant levels in environmental media and biota, in vitro bioassay results, and changes in individual- and population-level biomarkers were explored. Sediment and/or wildlife samples were collected from each of three sites of documented environmental contamination, Sumgayit and Baku in the Republic of Azerbaijan and East Fork Poplar Creek in Tennessee. Sumgayit and Baku are heavily contaminated with petroleum and petrochemical wastes. Sediments from several areas and tissues from turtles inhabiting a contaminated wetland contained high levels of several compounds, including mercury, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides. Sediment extracts produced variable responses in the Salmonella/microsome mutagenicity assay and did not necessarily reflect contaminant burden. Micronucleus counts in European pond turtles were not statistically different from counts in the same species from an uncontaminated reference site. The counts were statistically correlated with tissue levels of mercury, heptachlor, DDD, hexachlorobenzene, and trans-nonachlor. These results confirmed that Sumgayit and Baku are heavily contaminated with a complex mixture of pollutants and demonstrated that genotoxic effects from exposure to contaminated sediments appear to be slight. East Fork Poplar Creek is a stream that receives contaminant influx from a former Department of Energy nuclear weapons production facility and several point and non-point sources around the city of Oak Ridge, Tennessee. In this study, coefficient of variation in cellular DNA content and randomly amplified polymorphic DNA markers were examined in central stonerollers and compared to previous studies in which the same markers were evaluated in red-breasted sunfish from the same sites. While assay responses were attenuated in stonerollers compared to the sunfish, there is some evidence of genetic damage in both species at the most contaminated sampling site. A common problem in the wildlife studies was high within sample variability combined with small sample size, which most likely masked potential contaminant-induced differences in markers used in these studies.

Ecotoxicology studies attempt to evaluate the consequences of exposure to environmental contaminants by defining exposure and effects parameters across multiple levels of biological organization. Genetic markers are well-suited for these studies as they can track both somatic and evolutionary effects. In the studies reported here, connections among contaminant levels in environmental media and biota, in vitro bioassay results, and changes in individual- and population-level biomarkers were explored. Sediment and/or wildlife samples were collected from each of three sites of documented environmental contamination, Sumgayit and Baku in the Republic of Azerbaijan and East Fork Poplar Creek in Tennessee. Sumgayit and Baku are heavily contaminated with petroleum and petrochemical wastes. Sediments from several areas and tissues from turtles inhabiting a contaminated wetland contained high levels of several compounds, including mercury, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides. Sediment extracts produced variable responses in the Salmonella/microsome mutagenicity assay and did not necessarily reflect contaminant burden. Micronucleus counts in European pond turtles were not statistically different from counts in the same species from an uncontaminated reference site. The counts were statistically correlated with tissue levels of mercury, heptachlor, DDD, hexachlorobenzene, and trans-nonachlor. These results confirmed that Sumgayit and Baku are heavily contaminated with a complex mixture of pollutants and demonstrated that genotoxic effects from exposure to contaminated sediments appear to be slight. East Fork Poplar Creek is a stream that receives contaminant influx from a former Department of Energy nuclear weapons production facility and several point and non-point sources around the city of Oak Ridge, Tennessee. In this study, coefficient of variation in cellular DNA content and randomly amplified polymorphic DNA markers were examined in central stonerollers and compared to previous studies in which the same markers were evaluated in red-breasted sunfish from the same sites. While assay responses were attenuated in stonerollers compared to the sunfish, there is some evidence of genetic damage in both species at the most contaminated sampling site. A common problem in the wildlife studies was high within sample variability combined with small sample size, which most likely masked potential contaminant-induced differences in markers used in these studies.

Sarotherodon melanotheron est un poisson euryhalin endémique d'Afrique de l'ouest, qui vit et se reproduit dans tous les milieux aquatiques. Dans cette région où le changement climatique a provoqué l'apparition d'estuaires hypersalés, cette espèce est la seule à survivre en milieu hyperhalin, et constitue donc un excellent modèle biologique. Les milieux aquatiques côtiers sont aussi impactés par de nombreux contaminants issus de l'activité humaine. L'objectif de cette thèse était d'évaluer l'impact des effets croisés de la salinité et des contaminants chez S. melanotheron dans des milieux très contrastés au Sénégal en utilisant une approche multi-multiparamétrique. Des indicateurs physiologiques (taux de croissance, facteur de condition) et une batterie de biomarqueurs en lien avec l'osmorégulation (pompe NKA), le métabolisme des xénobiotiques (EROD et GST), la protection vis-à-vis du stress (TBARS), la transmission de l'influx nerveux (AChE) et la reproduction (vitellogénine et histopathologie gonadique) ont été mesurés. Ils ont été complétés par une étude de la diversité génétique et de la forme des otolithes pour différencier les populations. Un dosage préalable de la contamination des sédiments a permis de caractériser précisément les sites échantillonnés. L'induction de l'activité EROD sur le site le plus impacté en HAP et celle de la NKA sur les sites de salinité plus élevée ont montré la sensibilité de ces biomarqueurs. Des expérimentations sur S. melanotheron en milieu contrôlé ont permis d'appréhender l'impact des effets combinés de la salinité et du DDT, et de caractériser l'activité NKA et les transporteurs protéiques (NKA et CFTR) mis en jeu lors de l'osmorégulation. L'immunofluorescence prononcée des transporteurs et leur abondance au niveau des branchies suggèrent leur implication fonctionnelle dans l'osmorégulation. L'analyse de la forme des otolithes et de la génétique des populations de S. melanotheron échantillonnées ont montré que la distance géographique semble être discriminante pour les variations morphométriques des otolithes, alors que la variabilité génétique observée traduisait l'histoire de la colonisation postglaciaire et les évènements démographiques affectant les populations les plus isolées. Tous les résultats montrent l'intérêt de l'utilisation d'une approche multi-paramétrique pour caractériser l'impact de perturbateurs environnementaux multiples. Des travaux complémentaires permettraient d'affirmer que ce tilapia est un très bon indicateur utilisable dans l'évaluation de la qualité des écosystèmes côtiers en milieu tropical. / The euryhaline black-chinned tilapia Sarotherodon melanotheron heudelotii is endemic in West Africa and able to adapt to changes of salinity, to survive and to reproduce in different natural conditions. It is one of rare species to survive in hyperhaline area. Increased of the salinity levels is one of the consequences of climate change in West Africa coastal environments. However coastal zones are also the ultimate sink of chemical contaminants. The aim of this study was to assess the impact of the combined effects of salinity and pollutants in the black-chinned tilapia for evaluate the Senegalese aquatic habitat quality. In accord to this objective physiological marker (condition factor and growth rate) and several biochemical biomarkers to link with osmoregulatory (NKA), xenobiotic metabolisation (EROD, GST), oxidative stress (TBARS), neurotoxicity (AChE) and reproduction (VTG and gonad histopathology) were assessed. Field studies revealed that EROD and NKA can discriminate different sampling site and could be used as biomarkers on pollutants and salinity exposure respectively. The combined effects of salinity and DDT on osmoregulatory were characterized in laboratory conditions. Results showed that influenced the osmoregulatory mechanisms with differential abundance of transport proteins (NKA and CFTR) in gill and induction of NKA. The results showed that a set of biomarkers to assess effects of multiple stressors can be useful in S. melanotheron. In addition, the S. melanotheron population structure using morphologic and genetic analysis revealed that otolith shape analysis provides a geographical discrimination and microsatellites analysis allow genetic pool discrimination. Results show the absence of correspondence between the morphologic and genetic patterns. The present study demonstrated that importance of use multi-parametric approach to assess impact of multiple stressors, such as salinity and contaminants on black-chinned tilapia. Further studies should be realized for a better characterize this set of biomarker responses.

Les intégrons sont des plateformes génétiques bactériennes de capture et d'expression de gènes. Les intégrons cliniques sont les principaux responsables de la forte augmentation récente des bactéries multirésistantes aux antibiotiques. Cependant, dans l’environnement, ils ne représentent qu’une part minime de l’importante diversité des intégrons. Ainsi, les objectifs de cette thèse étaient (i) d’évaluer l’étendue de la diversité des intégrons dans l’environnement, (ii) de comprendre les phénomènes responsables de la structuration du pool d’intégrons dans le compartiment sédimentaire d’un milieu estuarien anthropisé et (iii) de rechercher l’existence potentielle d’intégrons indicateurs du niveau de contamination chimique.Le suivi des intégrons de classes 1, 2 et 3 et des populations d’E. coli dans des sédiments du bassin versant de la Risle impactés par des sources de contamination fécale bien caractérisées ont montré qu’en étiage, les souches d’E. coli d’origine humaine se disséminaient sur de courtes distances. Les intégrons de classe 1 se disséminent sur des distances un peu plus importantes et se maintiennent dans les 12 premiers centimètres du compartiment sédimentaire au moins.Une méthode a été développée permettant, pour la première fois, l’analyse de la diversité des intégrons via séquençage haut-débit. L’application de cette méthode sur une carotte sédimentaire de 4,8 m de profondeur prélevée dans l’estuaire fluvial de la Seine a permis de mettre en évidence plusieurs milliers de classes d’intégrons dont de nombreuses intégrases encore jamais répertoriées. La diversité des intégrons chute fortement avec la profondeur. Les intégrons de classe 1, majoritaires dans les sédiments de surface, ont une abondance qui chute fortement avec la profondeur cependant ils répondent plutôt positivement à la contamination chimique renforçant l’idée de leur utilisation comme proxy de pollutions anthropiques récentes. Trois classes d’intégrons dominent dans la vase consolidée représentant 38% des séquences obtenues dans la carotte sédimentaire mais répondant plutôt négativement à la contamination chimique. Enfin, la structure du pool d’intégrons est fortement corrélée à celle de la communauté bactérienne mais semble en partie indépendante de la communauté bactérienne dans deux des fractions sédimentaires profondes avec la dominance d’une nouvelle classe d’intégrons qui semble sélectionnée par les HAP. / Integrons are bacterial genetic platforms allowing acquisition and expression of genes. Clinical integrons play a major role in the strong increase of antibiotic multi-resistant bacteria recently observed. However, in the environment, they represent only a tiny fraction of the large integron diversity. Therefore, the aims of this thesis were (i) estimating the extent of the integron diversity in the environment, (ii) understanding phenomena responsible for integron pool structure in anthropized estuarine sediments and (iii) looking for integrons potentially proxy of chemical pollution level. The research of class 1, 2 and 3 integrons and the analysis of E. coli populations in sediments from the Risle drainage basin impacted by well-characterized fecal contamination sources show that E. coli strains with human origins were spread on short distances during low water level periods. However, class 1 integrons are spread on slightly longer distances and remain present in the 12 first centimeters of sediments at least. A methodology was developed allowing, for the first time, the analysis of integron diversity by high-throughput sequencing. In this way, the analysis of a 4.8 meter core sediment from the fluvial Seine estuary highlighted several thousands integron classes including many new integrases absent from data bases. Integron diversity decreases along with depth. Class 1 integrons are the majority integrons in surface sediments but their abundance strongly decreases in deep sediments. Class 1 integron abundance rather responds positively to chemical pollutions accentuating the idea that class 1 integrons could be used as proxy of recent anthropogenic pollutions. In the sediment core, three integron classes outshine the whole dataset: they represent 38% of all the sequences from the sediment core. However, abundances of these three majority integron classes rather respond negatively to chemical pollution levels. Integron pool structure is highly correlated to bacterial community diversity but seems to be partially independent to bacterial community diversity within two deep fractions from the sediment core: in these two sediment fractions, a new integron class outshines the rest of integron classes and seems to be specific to these two sediment fractions. Furthermore, this new integron class seems to be selected by PAH.

No description available.

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.

Au cours de leur élevage, les animaux sont exposés à divers contaminants chimiques, qui peuvent s’accumuler au niveau des tissus animaux et être retrouvés in fine dans les produits carnés consommés par l’Homme, représentant alors un risque pour la santé des consommateurs. L’évaluation de ce risque repose classiquement sur la mesure de teneur en contaminants de la viande fraîche alors que plusieurs travaux suggèrent que seule une fraction de ces contaminants est effectivement assimilée par le consommateur du fait des transformations technologiques comme la cuisson et physiologiques comme la digestion. L’objectif de cette thèse est d’étudier ces effets modulateurs de la cuisson et de la digestion sur les contaminants chimiques de la viande et leur bioaccessibilité. En s’appuyant sur le développement d’une méthode multirésidus GC×GC-TOF/MS pour le suivi de 206 polluants environnementaux et sur des collaborations avec des Laboratoires Nationaux de Référence, le premier objectif de ce travail était d’étudier l’impact de la cuisson sur un large spectre de contaminants chimiques d’une viande intentionnellement contaminée. Les résultats montrent que la cuisson n’a pas d’impact significatif sur la teneur en PCDD/F et en métaux lourds de la viande alors que des pertes significatives (d’autant plus importantes que l’intensité de cuisson est élevée) en PCB, antibiotiques et pesticides ont pu être détectées. Ces pertes ont pour origine soit une libération dans le jus de cuisson des contaminants thermorésistants, soit une dégradation sous l’effet de la cuisson des contaminants thermosensibles, comme cela a été observé pour un antibiotique, le sulfaméthoxazole, pour lequel un schéma de dégradation thermique est proposé. Le second objectif de ce travail était d’évaluer la bioaccessibilité des contaminants chimiques de la viande en s’appuyant sur un protocole standardisé de digestion in vitro statique. Dans le cas des PCB, les résultats obtenus indiquent que la bioaccessibilité dans la viande est relativement faible (26%). La teneur initiale de la viande en matière grasse et les variations physiologiques liées à l’âge du consommateur influencent significativement ces valeurs de bioaccessibilité alors que la cuisson de la viande a moins d’influence sur la bioaccessibilité. A terme, les résultats obtenus durant ce travail devraient conduire à proposer de nouvelles procédures d’évaluation des risques liés aux contaminants chimiques de la viande, prenant en compte les modulations induites par la cuisson et la digestion. / Livestock animals are exposed to various chemical contaminants during breeding. These contaminants are rapidly transferred from the environment to animal edible tissues, thus representing a public health risk. This risk is classically assessed based on the level of contaminants in raw meat. However, due to technological processes such as cooking or physiological transformations such as digestion, only a fraction of meat contaminants can be absorbed by the body. The purpose of this PhD thesis is to investigate the modulating effect of cooking and digestion on chemical contaminants in meat and on their bioaccessibility. Thanks to a GC×GC-TOF/MS multiresidue method developed in this study for the analysis of 206 environmental pollutants and to collaborations with French National Reference Laboratories, the first aim of this work was to assess the effects of pan cooking on a broad range of chemical contaminants in spiked meat. Cooking did not impact the level of PCDD/Fs and heavy metals in meat whereas significant losses (more important as cooking conditions were more intense) of PCBs, antibiotics and pesticides were observed. These losses may originate from juice expelling of heat-resistant compounds or from degradation by breakdown of thermolabile compounds such as the sulfamethoxazole antibiotic. The second aim was to assess the bioaccessibility of chemical contaminants in meat based on a standardized in vitro static digestion. For PCBs, results showed that their bioaccessibility was low (26%). Both the meat fat content and the age of consumer significantly affect this bioaccessibility value. In contrast, meat cooking was shown to have less influence on PCB bioaccessibility. The ultimate goal of the project will be to improve chemical risk assessment procedures taking into account the changes induced by cooking and digestion on micropollutants in meat.

Doctor of Philosophy / Food Science / Justin Kastner / Many Chinese aquaculture farmers use unapproved chemicals to treat their fish, many of which are diseased as a result of the country’s poor waste management and environmental practices. During 2006-2007, the United States (U.S.), the European Union, and Japan rejected large amounts of Chinese seafood imports due to the presence of unapproved chemicals or the presence of approved chemicals at concentrations that exceeded permitted levels. This dissertation examines the sources of environmental health and food safety problems in China; it also examines how effective the U.S. and Chinese governments’ regulations are in protecting consumers from hazards in Chinese aquaculture products. The study looks at specific chemical contaminants found in Chinese aquaculture imports, explores their potential toxicity or carcinogenicity, and examines the reasons for their prohibition from human food. The study exploits the available U.S. seafood consumption patterns (courtesy of the National Health and Nutrition Examination Survey—NHANES—database) and then uses probabilistic modeling (courtesy of CREMe Software Limited) to determine the extent to which specific sensitive U.S. consumer subpopulations were exposed to aquaculture chemical contaminants in the food supply in a contrived scenario using real consumption data (from NHANES) and actual contamination data (from the FDA). The study compares exposure between children and adult consumers, and also looks at exposure among women aged 18 years and older and the elderly aged 60 years and older. This study suggests a strong likelihood that NHANES children, as well as female consumers aged 18 years and older and elderly consumers aged 60 years and older, were (in the contrived scenario) all exposed to violative intake levels of chemical contaminants from Chinese aquaculture imports. Children forming the 99.5th and 99.9th percentiles of NHANES seafood consumers were exposed to higher levels of nitrofuran, gentian violet, and malachite green contaminants per kilogram of body weight than were their adult counterparts. Conversely, children were exposed to lower levels of fluoroquinolone contaminants per kilogram of body weight than were their adult counterparts. The 50th, 95th, and 99.9th percentiles of female consumers aged 18 and older and elderly consumers aged 60 years and older were exposed to violative daily intake levels of contaminants in Chinese aquaculture. The study concludes by examining what the U.S. and Chinese governments should do to address aquaculture safety.