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1
Jackson, Paul P. "Removal of cadmium from polluted water by immobilized algae." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/6184/.
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A feasibility study was planned to determine the efficiency of immobilized algal cells growing in a packed bed for removing Cd from commercial effluents. To select appropriate material for an immobilized cell system, twenty-five strains of algae isolated from heavy-metal contaminated environments of known water chemistry were tested for their ability to accumulate Cd. Before accumulation experiments were initiated, ion exchange resin was employed to demonstrate that EDTA in the medium did not complex Cd to a significant degree. Svnechococcus D562 cells subcultured in Cd accumulated the most metal; little was bound to the cell wall. A continuous culture of steady- state Svnechococcus D562 cells tolerated a lower maximum concentration of metal (3.4 mg 1(^-1) Cd) than batch- cultured cells (5 mg 1(^-1) Cd), indicating that metabolic status influences the toxicity of Cd. When flasks of calcium-alginate beads were challenged with Cd, up to 60 % of the added metal was bound within 16 h; however, further incubation did not reduce the pollutant concentration. Two axenic strains which accumulated the metal to a high concentration were then immobilized and tested for their capacity to remove Cd from the circulating medium. A packed-bed reactor containing Mougeotia D536 cells proved more effective at metal removal than Svnechococcus D562, but both species grew to a lower cell density at the effluent end of the column. The medium was then aerated to overcome such growth-limiting conditions, but this treatment inhibited Cd accumulation. Column-immobilized cells reduced Cd levels more effectively than inoculated, alginate beads in stationary flasks or free cells. Energy dispersive X-ray microanalysis located Cd only in particular Svnechococcus D562 polyphosphate bodies (those with a high Ca to K ratio); peaks for Zn, Pb, Fe, Mn and Ba were also detected in algae isolated from the field. Scanning proton microanalysis provided information on the distribution of macro- and micro-elements throughout the two strains of cyanobacteria and two strains of algae selected from the Durham Culture Collection and demonstrated the presence of Cd in Klebsormidium rivulare D537.Detergent-sensitive spheroplasts of Svnechococcus D562 were produced by lysozyme and protease digestion, but were not viable for growth. To observe the extracellular mucilage of this strain by EM, lysozyme digestion proved imperative for effective ruthenium red staining to convert the material into an electron opaque material. From cultures of Svnechococcus D562 grown with or without Cd a 14 kD plasmid was isolated, which contained two Eco RI, two Bam HI and five Hind III restriction sites. A radiolabelled oligonucleotide probe based on part of the nucleotide sequence of a metallothionein from Svnechococcus FCC 6301 did not bind to a genomic and plasmid blot of Svnechococcus D562 DNA. The putative Cd-binding peptides ((yEC)(_n)G's) that were discovered only bound significant quantities of the metal when cells were exposed to 6.17 mg 1(^-1) Cd for 2 days at the end of their log-growth phase. Indigenous peptides failed to bind substantial amounts of the metal and the presence of Cd throughout growth did not influence the quantity of chelated Cd, except for Mougeotia D536. The pH of half displacement for (yEQjp's from this strain is comparable with that of other species. Reversed-phase HPLC of the peptides from Mougeotia D536 generated a thiol profile similar to that recorded for the Cd-binding peptides of Datura innoxia. The Cd-induced ultrastructural distortions that were recorded include potential Ca / P / Cd precipitates in Mougeotia D536, the loss of polyglucoside granules from Calothrix D184 together with a relaxation of its thylakoid packing and a lack of plastoglobuli in Cd-exposed Klebsormidium D537. The space between an immobilized cell and the matrix either represents shrinkage of the matrix during dehydration or mucilage which does not bind electron dense stains. Release of alkaline phosphatase into the medium by Svnechococcus D562, provided suitable material to study the inhibitory effects of Cd upon P hydrolysis. Ultrafiltration membranes proved effective as initial step towards enzyme purification and for the determination of activity under sub-optimal pH conditions. At pH 7.0, the activity of an enzyme concentrate was inhibited when 1 and 10 mg 1(^-1) Cd were added to the assay medium, but the presence of this metal in the growth medium did not reduce activity. One-dimensional SDS PAGE revealed only one protein difference between strains grown with or without Cd; a reduction in the staining intensity of a 17 kD band of Calothrix D184.
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Gerst, Thierry. "Etat, devenir et toxicité du cadmium en hydrologie." Paris 5, 1988. http://www.theses.fr/1988PA05P154.
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Mackay, Elaine A. "Polymorphism of cadmium-induced mussel metallothioneins." Thesis, University of Aberdeen, 1990. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU024434.
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Metallothioneins are ubiquitous sulphur-rich heavy metal binding proteins whose biosynthesis is induced in response to a variety of agents, including heavy metals. A number of isoforms of metallothionein are known to be induced by heavy metals in the common mussel Mytilus edulis, and recently interest has centred on the nature of these proteins and their possible utility as pollution indicator agents. Cadmium-induced metallotheioneins were isolated from mussels by procedures which included gel permeation and anion-exchange chromatography. They were shown to comprise two molecular mass classes of 10 and 20KDa. The 10kDa class was resolved by anion-exchange into four components designated 10-I, 10-II, 1--III and 10-IV. The 20kDa class was similarly resolved into three components designated 20-I, 20-II and 20-III. The amino acid sequences of each of the components in both of the classes were determined. This involved digestion with a variety of proteinases and separation of the resulting peptides. The abundance of crysteines in these mussel metallotheioneins necessitated their derivatisation with methyl-p-nitrobenzenesulphonate to generate the S-methyl derivative of cysteine which has been found to be suitable for peptide mapping by HPLC and sequence analysis by automated methods. The components of the 20kDa class were shown to possess linked peptides consisting of 71 amino acids, which were distinct from the 72 amino acid peptides of the 10kDa class. It is suggested that the two monomers in the 20kDa proteins are linked via S-Cd-S bonding, i.e. a bridging cadmium ion. The various components within both classes exhibited homology, particularly with regard to the location of the cysteine residues, to metallothioneins from other species, including mammals. On the basis of this homology these proteins were classified as class I metallothioneins.
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El-Rais, Mahmoud Abdussamad. "Determination of cadmium and lead in the ppb range by atomic absorption." Thesis, University of Salford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360479.
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Fadil, Abdelmajid. "Contribution à l'étude de la pollution par le cadmium : méthodes d'avaluation de cette contamination chez l'homme." Strasbourg 1, 1985. http://www.theses.fr/1985STR10473.
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Kaigate, Boonsong. "Epuration des eaux chargées en cadmium et en nickel." Chambéry, 1987. http://www.theses.fr/1987CHAMS008.
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Bidston, Caroline. "The effects of metal pollution on the spectral reflectance of plants." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314319.
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Hamidian, Amir Hossein, and n/a. "Cadmium in the marine environment." University of Otago. Department of Chemistry, 2008. http://adt.otago.ac.nz./public/adt-NZDU20090728.100026.
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Cadmium in the ocean has a nutrient-like cycling pattern: with biological uptake at the surface, subsequent sinking in particulate form and then regeneration as dissolved species in deeper waters. Many measurements have been made over time of the ratio of the concentrations of dissolved Cd to those of PO₄ (Cd/PO₄) in the world ocean and this has become one of the best relationships documented between a trace metal and a nutrient. Combined with the measurements of the Cd/Ca ratio in foraminifera, the Cd/PO₄ ratio has been used to reconstruct the oceanographic circulation patterns that existed during past glacial periods and hence provides information on past climate changes.
In the present study Cd/PO₄ ratios of the Southern Indian Ocean in surface and deep waters were investigated. The slopes of the relationships between Cd and PO₄ concentrations in waters of this region are high compared to the global correlations, and lie between those reported for other parts of the Southern Ocean and the Pacific Ocean. In surface waters of the Southern Indian Ocean, Cd/PO₄ ratios decrease from regions exhibiting high nutrient-low chlorophyll (HNLC) characteristic in the south to oligotrophic waters further north. It is also found that particulate Cd plays an important role in regulating the high Cd/PO₄ ratios reported in waters south of the Polar Front.
Very low Cd/PO₄ ratios were measured in waters associated with the Subtropical Front southeast of New Zealand compared to other Southern Ocean and global oceanic waters. Seasonal variations in the Cd/PO₄ ratios measured for these waters strongly suggest they are associated with a significant biological uptake of dissolved Cd particularly during the phytoplankton growth season in summer.
Dissolved Fe concentrations in the Southern Indian Ocean and seasonal variations of Fe in waters off the Otago Coast (southeast of New Zealand) suggest that Fe may stimulate phytoplankton growth and this might result in lower Cd/PO₄ ratios in surface waters through enhanced Cd uptake relative to PO₄ by the phytoplankton. However there is no distinct relationship between dissolved Fe concentrations and the dissolved Cd/PO₄ ratios measured in these surface waters. This finding is in disagreement with the recent 2006 hypothesis put forward by J.T. Cullen, which proposed that waters exhibiting low dissolved Cd/PO₄ ratios were associated with the HNLC regions. From a consideration of the potential Zn concentrations calculated from Si concentration measurements reported for these waters, it would appear that Zn may play a more important role than Fe in regulating Cd/PO₄ ratios in these waters.
Measurements of dissolved and total Cd concentrations relative to those of PO₄ were also undertaken in the Otago Harbour and immediate surrounding coastal waters. These exhibited higher Cd concentrations and higher Cd/PO₄ ratios than open ocean waters further off the Otago Coast. The particulate Cd concentrations showed a negative correlation with Cd concentrations measured in cockle species (Austrovenus stuchburyi) collected in the harbour, suggesting that particulate Cd is not the source of Cd measured in the tissue of this species.
The concentrations of Cd and other trace metals were also measured in samples of green mussel (Perna canaliculus), ribbed mussel (Aulacomya atra maoriana) and oyster (Saccostrea cucullata) collected from Otago Harbour and possible correlations explored between these concentrations and other parameters such as the shellfish condition indices and environmental gradients in the harbour.
In summary, measurements of dissolved and particulate Cd concentrations in the water column can provide unique information on a number of processes occurring in the global marine environment.
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Paris, Benoît. "Modelisation du fonctionnement d'une barriere anti-pollution. Application au plomb, cadmium et zinc." Paris 6, 1996. http://www.theses.fr/1996PA066316.
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L'objectif de cette etude est de determiner, et de quantifier, les mecanismes intervenant des melanges d'argile et de ciments, appeles coulis, lors de la retention de plomb, de cadmium et de zinc. La diversite et la complexite des phenomenes mis en jeu a conduit a l'elaboration d'un modele global couplant transport et geochimie. Le module de transport est base sur le concept des differences finies en une dimension. Celui de geochimie sur la methode des composantes de base a partir de constantes thermodynamiques. Le couplage s'effectue sur deux pas, les inconnues principales du calcul etant les concentrations totales par defaut. La prise en compte des solides, difficulte majeure pour la methode des composantes de base, est resolue par changement de base automatique. La partie experimentale est axee sur deux types d'essais: - essais de retention sur des granules de coulis durcis (melange argile-ciment-gravier) des polluants seuls ou ensembles (tests d'equilibre) ; - essais de percolation de solutions complexes sur des eprouvettes contenant differents melanges argile-ciment durcis. L'interpretation des tests d'equilibre est effectuee a l'aide du module de calcul d'equilibre geochimique seul. Il apparait que les mecanismes de retention des metaux lourds etudies sont essentiellement domines par la precipitation (hydroxydes, carbonates, chlorures ou sulfates) et par l'adsorption. Celle-ci est attribuee aux silicates de chaux hydrates (csh), constituants majeurs des coulis durcis. La fixation, particulierement intense, s'effectue par le biais d'un echange entre une fraction du calcium, sans doute adsorbee sur les csh, et les metaux. Ces reactions chimiques, tres dependantes du ph, ont ete etablies et leur constante intrinseque d'adsorption estimees d'apres la theorie de la double couche generalisee. Les essais de percolation se sont poursuivis pendant une annee a l'issue de laquelle aucune concentration notable de polluant n'a ete detectee en sortie de colonne. La comparaison du positionnement des differents fronts de polluant dans la colonne entre le calcul et le resultat experimental est satisfaisante et permet de valider le modele mis en place lors des tests d'equilibre
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Valori, Federico. "Effects of root exudates on cadmium bioavailability in the rhizosphere : assessment of cadmium toxicity to plants and microorganisms, and soil remediation." Bordeaux 1, 2006. http://www.theses.fr/2006BOR13151.
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Des sols contaminés uniquement en Cd, depuis une longue période, ont d'abord été utilisés pour évaluer les effets d'exsudats racinaires de faible masse moléculaire, libérés dans un système modèle par un filtre placé à la surface du sol, sur les biomasses microbiennes carbonées et azotées, la respiration microbienne, le pool inorganique d'N et la biodisponibilité de Cd dans la rhizosphère (BIOMET®). L'utilisation d'une espèce végétale, Holcus lanatus L. , pour la phytoremédiation aidée de sols contaminés en Cd a été étudiée de façon préliminaire en solution hydroponique sur 4 semaines. Les plantes, dont le système racinaire a été lavé, ont été placées dans une solution nutritive simulant la concentration en Cd extrait et le pH des parcelles d'origine. La concentration et la quantité de Cd ont été quantifiées dans les parties aériennes, les feuilles et les racines. On a mesuré les activités enzymatiques Guaiacol peroxidase dans les feuilles, ainsi que leur densité en chlorophylle et caroténoïdes totaux. L'assainissement des sols contaminés en Cd a été étudié en utilisant une technique de stabilisation in situ basée sur l'apport au sol de l'un des 3 composés inorganiques suivants: beringite + grenailles d'acier, sépiolite, et bentonite. La concentration en Cd a été mesurée dans la solution du sol (Rhizon) au cours des premiers jours suivants l'amendement du sol et après 6 mois. L'efficacité de la remédiation des sols contaminés en Cd par stabilisation in situ a été évaluée en vase de végétation placés sous serre, avec 3 végétaux de sensibilité différente à l'exposition au Cd (sensible: Phaseolus vulgaris, moyennement tolérante: Holcus lanatus, tolérante: Lactuca sativa).
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White, Jessica C. "Comparative Bioavailability of Dietary and Dissolved Cadmium to Freshwater Aquatic Snails." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4351/.
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Heavy metal bioaccumulation in aquatic organisms may occur through direct or indirect uptake routes. Research indicates that the significance of uptake route varies with contaminant and organism exposed. The relative importance of different metal sources in aquatic systems was investigated by exposing freshwater snails to dietary or dissolved sources of cadmium. Snails were exposed to control, contaminated food only, contaminated water only, and contaminated food and water treatments. During the 15-day exposure, samples were taken to determine Cd concentration in snail soft tissue, snail shell, algal food, and overlying water. Analyses of snail soft tissue and shells indicate that exposure route significantly affects Cd concentrations in the tissues. In both cases, dissolved Cd is the primary contributor to metal body burden.
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Lindén, Anna. "Biomonitoring of cadmium in pig production /." Uppsala : Dept. of Pharmacology and Toxicology, Swedish Univ. of Agricultural Sciences ([Institutionen för farmakologioch toxikologi], Sveriges lantbruksuniv.), 2002. http://projkat.slu.se/SafariDokument/222.htm.
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Shirley, Mark David Foster. "The effect of metapopulation structure on evolutionary responses to cadmium pollution in Drosophila melanogaster." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320087.
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Hee, Calvin K. "Field scale phytoremediation trials of lead and cadmium-contaminated soil." Virtual Press, 2005. http://liblink.bsu.edu/uhtbin/catkey/1314328.
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There is an ever-increasing need to address problems associated with the creation and disposal of wastes which result from human activities. Pb and Cd contamination is a common problem at many abandoned and uncontrolled commercial and industrial sites. Phytoremediation is one technology that can be employed to remove metals such as Pb from the soil. This study investigated the effectiveness of several plant and soil treatments on the uptake and retention of Pb and Cd by vegetation from contaminated soil at a Superfund site. Field plots were established and plant treatments included a mixture of grasses including Festuca, Poa. and Phleum; red clover (Trifolium Pratense); and sunflower (Helianthus annuus). Soil treatments included a common NPK fertilizer, ethylenediaminetetraacetic acid (EDTA), dilute sulfuric acid (H2SO4), and a mixture of EDTA and H2SO4 (EDTA+H2SO4). Trifolium tissue contained a greater quantity of Pb (182 mg Pb/kg tissue) than that of Poa (65 mg Pb/kg tissue). Cadmium concentration was similar in Poa and Trifolium tissue. ranging from 7.2 to 10.6 mg/kg tissue. Different soil treatments affected Pb levels found in plant tissue in order of effectiveness: H2SO4>EDTA>NPK>EDTA+H2SO4 The effects of soil treatments on Cd levels were similar to those for Pb with a difference of 0.1 mg Cd/kg tissue between EDTA and NPK treatments. Soil amendments differentially influenced Pb bioavailability and uptake, with H2SO4 exhibiting the greatest positive influence on Pb and Cd concentration in tissue. There was no correlation between the quantity of Pb and Cd up taken by vegetation at the site. The current study demonstrated the capability of common native plant species to grow on toxic and infertile soils, and the ability to uptake Pb and Cd to a limited degree. Regardless of tissue concentrations of Pb or Cd, Poa coverage at the site was generally dense. demonstrating the ability of Poa to become established on toxic soils and prevent soil erosion.Department of Natural Resources and Environmental Management
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Bernard, Hélène. "Bioindication des métaux lourds (Plomb, mercure, cadmium et thallium) par les basidiomycètes sauvages." Bordeaux 2, 1996. http://www.theses.fr/1996BOR2P026.
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Cossa, Daniel. "Le cadmium et le mercure en milieu cotier : biogéochimie et utilisation du genre mytilus comme indicateur quantitatif." Paris 6, 1987. http://www.theses.fr/1987PA066317.
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Contribution a la connaissance du comportement et des flux de ces deux metaux dans le systeme cotier du saint laurent. Etude des niveaux de concentration et surveillance de la contamination par optimisation de l'outil de "moule-temoin
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Laurent, Nathalie, and XAVIER JOUGLEUX. "Ecotoxicologie du cadmium et du mercure : problemes poses sur le littoral de la region nord - pas-de-calais." Lille 2, 1997. http://www.theses.fr/1997LIL2P021.
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Pan, Ke. "Application of biokinetic model in studying the bioaccumulation of cadmium, zinc, and copper in the scallop chlamys nobilis /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202009%20PAN.
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Abedi, Shafa Eddin. "The effect of cadmium pollution on apoptosis in the immune system of carp (Cyprinus carpio)." Thesis, Keele University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397508.
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Resende, Luis Manuel Vieira Soares de. "Solid <-> solution equilibria of cadmium and zinc in a contaminated Derbyshire woodland." Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286246.
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Ciliberti, Alexandre. "Le Varan du Nil (Varanus niloticus), indicateur de la pollution des zones humides d’Afrique Sub-Saharienne." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10241/document.
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En Afrique, la contamination des zones humides par les métaux et les pesticides va se poursuivre durablement. Pour autant, le statut toxicologique de ces milieux reste trop peu documente. Le but du présent travail est d’estimer la valeur du varan du Nil (Varanus niloticus) en tant qu’espèce sentinelle pour la contamination des zones humides continentales d’Afrique sub-Saharienne. Plomb, cadmium, et pesticides organochlorés et organophosphorés ont été quantifies, par spectrométrie d’absorption atomique et chromatographie gazeuse (respectivement), dans plusieurs tissus provenant de 71 spécimens issus de quatre sites (au Mali et au Niger) juges a priori inégalement contamines. Bien que des différences claires apparaissent, la contamination environnementale s’avère modérée sur les quatre sites, et ne semble pas constituer un risque notable pour les varans ni pour les humains qui s’en nourrissent occasionnellement. Toutefois la variabilité interindividuelle est importante. Les organotropismes des polluants détectés sont cohérents avec ceux préalablement décrits. Si l’on n’a pu mettre en évidence de différence liée au sexe en ce qui concerne les pesticides, les femelles présentaient des charges en métaux supérieures. La relation entre d’autres facteurs (taille, proportion de graisse) et les concentrations tissulaires a également été considérée. Les varans sont susceptibles de révéler des différences subtiles de contamination environnementale entre sites, et la résolution spatiale de l’outil semble très fine. La possibilité pratique d’utiliser cet indicateur se trouve donc validée. Un travail expérimental sur des varans captifs a par ailleurs été mené pour approfondir l’étudeIn Africa, metal and pesticide contamination of wetlands is supposed to continue on a permanent basis. However, the ecotoxicological status of these ecosystems remains poorly documented. The aim of the present work is to assess the value of the Nile monitor (Varanus niloticus) as a sentinel species for the environmental contamination of continental wetlands in sub-Saharan Africa. Lead and cadmium on the one hand, and organochlorine and organophosphate pesticides on the other, have been quantified in several tissues by atomic absorption spectrophotometry and gas chromatography, respectively. Samples come from 71 specimens originating from four sites considered unequally contaminated (in Mali and Niger). Although clear differences appear between sites, the environmental contamination turns out to be moderate at the four sites, and does not seem to represent a significant risk neither for the monitors themselves, nor for occasional human consumers. However, the interindividual variability is important. The organotropisms relative to the detected pollutants are consistent with those described in previous studies. Concerning the pesticides, no gender effect has been found, whereas females were more contaminated by metals. The relation between other factors (size, proportion of fat) and tissue concentrations has been considered too. Nile monitors can reveal subtle differences in local pollution and the spatial resolution of this tool seems to be very sharp. Its practical relevance is thus validated. Additionally, an experimental work has been carried out on captive monitors to go into the subject in greater depth
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Dhahiyat, Yayat. "The effect of chromium (CR VI) and cadmium (CD'2'+) on the life history Daphnia magna straus." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360076.
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Andres, Sandrine. "Etude écotoxicologique des transferts de cadmium et zinc entre la colonne d'eau et les sédiments du Lot (France) et les organismes aquatiques. Approches in situ et expérimentale." Toulouse 3, 1997. http://www.theses.fr/1997TOU30258.
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Les recherches sont consacrees a l'etude de la contamination des organismes aquatiques par le cadmium et le zinc presents dans la riviere lot. Afin de preciser les mecanismes ecotoxicologiques mis en jeu dans ces systemes complexes, les etudes in situ sont completees par une approche experimentale de laboratoire. Les travaux realises sur le terrain portent sur la contamination de 4 especes de poissons d'eau douce (chevaine : leuscicus cephalus, gardon : rutilus rutilus, breme : abramis brama et perche : perca fluviatilis). Des prelevements, realises dans 4 stations reparties selon un gradient de pollution sur la partie moyenne du lot, permettent de dresser un premier bilan des niveaux de contamination des poissons. Parallelement a ces travaux, des mollusques bivalves non contamines (c. Fluminea), sont implantes dans cinq stations (technique de caging). Les mesures de la bioaccumulation des deux metaux par ces mollusques revelent des cinetiques de contamination rapides a partir du cadmium et du zinc presents dans les sediments et la colonne d'eau. La seconde partie des recherches, effectuee en laboratoire, repose sur l'utilisation de microcosmes, permettant d'etudier les transferts du cadmium entre les sediments du lot et trois types d'organismes : c. Fluminea, une macrophyte enracinee elodea densa et une larve d'ephemere fouisseuse : h. Rigida. Afin de completer l'etude des transferts de metaux entre les sediments du lot et c. Fluminea, tant au laboratoire qu'in situ, une analyse des principaux vecteurs de contamination des mollusques par voie trophique est conduite.
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Fevrier, Laureline. "Transfert d'un mélange Zn-Cd-Pb dans un dépôt fluvio-glaciaire carbonate : approche en colonnes de laboratoire." Lyon, INSA, 2001. http://theses.insa-lyon.fr/publication/2001ISAL0071/these.pdf.
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En milieu périurbain, l'emploi de techniques d'infiltration pour l'évacuation des eaux pluviales entraîne des risques de contamination des sols et des nappes phréatiques. L'étude vise à améliorer la compréhension des mécanismes hydrauliques et chimiques impliqués dans le devenir des polluants au cours de leur transfert dans un dépôt fluvio-glaciaire carbonaté de l'est lyonnais utilisé en fond de bassin d'infiltration. Le travail a été réalisé à l'échelle du laboratoire sur des colonnes de dépôt fluvio-glaciaire tamisé à 1 cm. La source de pollution est un mélange équimolaire artificiel Zn-Cd-Pb à 1 o-3 mol. -1. Des expériences de traçage, associées à des phases de modélisation (modèle MIM), ont mis en évidence le fonctionnement hydrodynamique du dépôt en fonction de sa teneur en eau et de la vitesse d'écoulement. A saturation, l'écoulement est fortement régionalisé (50 % de régions mobiles). En conditions non saturées, l'écoulement se fait de façon plus homogène. Cette particularité semble être un conséquence de la distribution granulométrique du dépôt étudié. Les interactions entre les métaux et le dépôt ont été étudiées par des expériences en conditions statiques et en conditions dynamiques, associées à des phases de modélisation (modèle PHREEQC). D'un point de vue qualitatif, les réactions prépondérantes sont la dissolution de la calcite du dépôt fluvio-glaciaire, la précipitation des métaux sous forme carbonatée (cérusite ou hydrocérussite pour Pb, espèce mixte non identifiée pour Cd et Zn), et les réactions d'échange cationique. La rétention des métaux au cours de leur transfert apparaît fortement influencée par la cinétique chimique de dissolution de la calcite et la cinétique physique d'échange entre régions mobile et immobile. Elle est maximale pour des écoulements en conditions non saturées et à faibles vitessesThe use of stormwater infiltration basins in urban area can generate a risk of contamination for soils and groundwater. The aim of this work is ta increase the knowledge of the hydraulic and the chemical mechanisms implied in the transfer of pollutants. The porous matrix studied is a carbonated fluvio-glacial deposit usually found in the infiltration basins of the Lyon area. Some columns were designed at the laboratory scale, with the fluvio-glacial deposit sieved at 1 cm. The pollution studied was a mixture of Zn-Cd-Pb - 1 o•3 mol. -1. Some flow tracer. Experiments coupled with modeling (MIM model) were used to characterize the hydrodynamic behaviour of the columns, as a function of water content and flow rate. At saturation, the flow is divided in mobile (50 %) and immobile regions whereas for unsaturated conditions, the flow is more homogeneous. This property seems to be a consequence of the particle size distribution of the fluvio-glacial deposit. The interactions between the metals and the fluvio-glacial deposit were studied thanks to batch and transfer experiments, coupled with modeling (PHREEQC model). From a qualitative point of view, the main reactions are the dissolution of the fluvio-glacial deposit's calcite, the metals precipitation in a carbonated form (cerusite and hydrocerussite for Pb, an unknown mixed specie for Cd and Zn) and the cationic exchange reactions. During the transfer, the metals retention is governed by the chemical kinetic dissolution of the calcite and by the physical kinetic exchange between the mobile and the immobile regions. The retention is maximized for transfer in unsaturated conditions and law flow rates
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Adams, Kim Marie. "The inorganic pollution of the Franschhoek River : sources and solutions." Thesis, University of the Western Cape, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3321_1351864435.
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The aim of the study was to quantify the extent of inorganic chemical pollution of the Franschhoek River and draw relationships between contaminants in water, sediment and plants. The invasive Acacia mearnsii and Salix babylonica and indigenous Brabejum stellatifolium species were chosen as biomonitors due to their wide spread distribution along the river and their apparent ability to accumulate heavy metals. The sites chosen allowed for comparison of the river quality upstream with that of the river further down stream as it meandered through residential, agricultural and recreational areas, until it joined with the Berg River further downstream. The general aim of the study was to assess the degree of inorganic pollution in the Franschhoek River to evaluate its contribution to pollution of the Berg River, of which it is an important tributary. Also understanding the sources of the pollution would contribute to the ability to reduce pollution.
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Férard, Jean-François. "Aspects de la toxicité et de la biosorption du cadmium chez l'algue Chlorella vulgaris." Metz, 1986. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1986/Ferard.Jean_Francois.SMZ8606.pdf.
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Redon, Paul-Olivier. "Rôle de champignons mycorhiziens à arbuscules dans le transfert du cadmium (Cd) du sol à la luzerne (Medicago truncatula)." Thesis, Nancy 1, 2009. http://www.theses.fr/2009NAN10015/document.
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L’accumulation d’éléments en traces métalliques (ETM), dont le cadmium (Cd), dans les sols et leur transfert aux plantes sont problématiques à cause de leur toxicité. Les champignons mycorhiziens à arbuscules (MA), symbiontes des plantes, peuvent influencer le transfert des ETM de manière directe en les transportant jusqu’aux racines et de manière indirecte en favorisant la croissance de la plante. Des résultats divergents ont néanmoins été reportés et leur rôle global doit donc être éclairci. En prenant comme plante modèle la luzerne Medicago truncatula, l’effet d’un champignon MA (Glomus intraradices) sur le bilan de Cd dans la plante, le sol et les percolats a été étudié. La contribution du champignon au transfert de Cd a été évaluée dans des cultures en pot et des dispositifs à compartiment. Le champignon a principalement influencé la dynamique de Cd dans le système sol-plante de manière indirecte en améliorant fortement la croissance de la plante sur sol contaminé, conduisant à une quantité plus importante de Cd exporté dans les parties aériennes de la plante, bien que leur concentration en Cd soit plus faible que dans les plantes non mycorhizées. Cette forte augmentation de croissance de la luzerne par ce champignon est associée à la stimulation de bactéries formant des nodules. Cette influence mycorhizienne est néanmoins complexe, elle est variable selon les conditions édaphiques et selon l’isolat du champignon étudié. Le champignon MA contribue aussi directement au transfert de Cd en sorbant et en transportant le Cd soluble-échangeable par son mycélium extraracinaire, mais cette contribution directe semble être faible en comparaison de l’effet des racinesAccumulation of trace metals, such as cadmium (Cd), in soils and their transfer to plants are serious environmental problems because of their acute toxicity. Metal mobility in soil depends on various abiotic and biotic factors. Among them, arbuscular mycorrhizal (AM) fungi are known to influence metal transfer by transporting metals to roots and also by improving plant growth. However, diverging results were reported and the global role of AM fungi thus needed more investigation. The influence of an AM fungus (Glomus intraradices) on Cd uptake and transfer to leachates was studied with Medicago truncatula as a host plant. Experiments were performed in pot cultures and in compartmented devices. The dynamic of Cd in the soil-plant system was indirectly influenced by the fungus via a strong increase of plant biomass, in interaction with nodulating rhizobacteria, leading to a higher total quantity of Cd transferred to shoots although Cd plant concentration was lower than in non mycorrhizal plants. This fungal influence was complex, and was variable according to soil conditions and to the fungal isolate studied. The AM fungus also contributed directly to Cd transfer thanks to its sorption capacity and its ability to transport soluble-exchangeable Cd via the extraradical mycelium, but this direct contribution seemed to be low as compared to the influence of roots
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Baliardini, Cecilia. "Genetic analysis of cadmium tolerance in Arabidopsis halleri: contribution of CAX1." Doctoral thesis, Universite Libre de Bruxelles, 2015. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/218852.
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Analyse génétique de la tolérance au cadmium dans l'espèce Arabidopsis halleri: contribution du CAX1Résumé de la thèseDans les milieux contaminés par les excès en éléments traces métalliques, de rares plantes peuvent accumuler ces éléments a de très fortes concentrations sans symptômes de toxicité. Parmi elles, Arabidopsis halleri, proche parente d' A. thaliana, hyperaccumule le Zn et le Cd. C’est une espèce modèle pour étudier l'homéostasie métallique et l'adaptation aux environnements extrêmes. Alors qu’un ensemble de mécanismes moléculaires permettent d’expliquer l’hyperaccumulation de Zn, la compréhension de la tolérance et de l’accumulation du Cd est bien moins connue. Une analyse de liaison génétique dans A. halleri a permis d'identifier un locus de caractère quantitatif (QTL) majeur co-localisant avec HMA4 et deux autres QTL. HMA4 codant pour une pompe a métaux, impliquée dans la translocation du Cd des racines a la partie aérienne et dans la distribution de ce métal dans les feuilles, a pu être validé par ARN interférence.L'objectif de ce projet est de contribuer a la compréhension de la tolérance au Cd dans A. halleri en identifiant de nouveaux déterminants génétiques.Par cartographie fine, CAX1, codant pour un antiport calcium/proton, a été identifié comme gène candidat pour le second QTL majeur impliqué dans la tolérance au Cd dans A. halleri.Les analyses d’expression de CAX1 dans trois espèces d’Arabidopsis, tolérantes ou sensibles au Cd, et dans la descendance de croisements entre A. halleri et l’espèce sensible A. lyrata, l’étude d’un mutant «knock-out» dans Arabidopsis et des analyses biochimiques ont confirmé l’implication de CAX1 dans la tolérance au cadmium. En séquestrant le calcium dans la vacuole, CAX1 participe a limiter l’accumulation des espèces réactives de l’oxygène (ROS) induite par un excès de Cd et a limiter la toxicité du Cd. Ce rôle est observable lorsque les plantes sont cultivées a basse concentration de calcium. A plus hautes concentrations de calcium, l’expression de CAX1 est induite dans les trois espèces étudiées et ne présente plus de difference entre A. halleri et A. lyrata. En accord avec ce résultat, la detection du locus de caractère quantitatif co-localisant avec CAX1 disparaît lorsque la concentration de calcium augmente dans le milieu. Néanmoins, le rôle de CAX1 dans la tolérance aux stress oxydatifs est observable quelle que soit la concentration en calcium utilisée.L’ensemble des résultats soutiennent un rôle encore inexploré de CAX1 dans les plantes.Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Ramakrishnan, Rema. "Ambient Ozone and Cadmium as Risk Factors For Congenital Diaphragmatic Hernia." Scholar Commons, 2017. https://scholarcommons.usf.edu/etd/7439.
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Congenital diaphragmatic hernia (CDH) results from a defect in the diaphragm through which abdominal contents enter the thorax displacing the heart and the lungs. This causes lung hypoplasia and varying degrees of pulmonary hypertension resulting in high rates of morbidity and mortality. Though CDH has a prevalence rate of 2.61 per 10,000 live births it is an expensive birth defect with an estimated annual cost of nearly $250 million for all CDH survivors. Maternal exposure to air pollutants have not been studied as risk factors for CDH in humans. Ambient ozone has been found to be risk factors for certain birth defects including congenital heart defects, chromosomal anomalies, and limb reduction defects. Cadmium, however, has been found to be a risk factor for diaphragmatic hernia, cleft palate, renal defects, anopthalmia, microphthalmia, anal atresia, undescended testes, and dysplastic ears in animal studies only. The objectives of this study were to: 1) examine the prevalence, temporal trends, and correlates of CDH among live-born infants during 1998–2012; 2) investigate the association between sociodemographic and perinatal characteristics and neonatal and one-year survival among infants with CDH and its subtypes, isolated and complex; 3) examine the role of ambient ozone as a risk factor for CDH; and 4) determine the association between maternal exposure to ambient cadmium in air and CDH and assess if maternal smoking during pregnancy is an effect modifier of the cadmium-CDH association. To answer these questions we used a population-based, retrospective cohort study using data from the 1998–2012 Florida Birth Defects Registry. We classified CDH cases into isolated and complex. A case that was associated with other anomalies listed on the National Birth Defects Prevention Network list of major structural reportable defects was classified as complex CDH. We used Poisson and joinpoint regression models to compute prevalence ratios and assess temporal trends, respectively. Kaplan-Meier survival curves and Cox proportional hazards regression were used to describe neonatal and one-year survival and estimate hazard ratios of neonatal and one-year mortality. We then used multilevel Poisson regression models to examine the association between maternal exposure to ambient ozone and CDH as well as cadmium and CDH. We conducted stratified analyses to test for effect measure modification by maternal smoking status. The study population to answer the first two questions consisted of 3,209,775 live-born infants (including 1,025 cases). To answer the third and fourth questions, the study population consisted of 3,039,685 and 2,591,395 live-born infants (including 981 and 840 cases), respectively. We found a 4% increase in the annual prevalence of CDH among complex cases, but no trend for isolated cases. We observed higher prevalence of CDH among infants born to mothers with high school or less maternal education and for multiple births. Female sex and maternal obesity were found to be associated with decreased risk for CDH. The most important predictor of neonatal and one-year mortality was gestational age
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Chandurvelan, Rathishri. "Investigation of waterborne cadmium toxicity in the green-lipped mussel, Perna canaliculus using biomarkers – a potential bioindicator of coastal metal pollution in New Zealand." Thesis, University of Canterbury. School of Biological Sciences, 2013. http://hdl.handle.net/10092/8486.
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Coastal metal pollution is a major concern to the health and well-being of aquatic organisms. Bioindicator organisms such as mussels have the potential to monitor coastal metal pollution. In New Zealand, the feasibility of employing green-lipped mussels, Perna canaliculus as a bioindicator species is yet to be investigated. This thesis focuses on applying a suite of biomarkers on green-lipped mussels exposed to cadmium (Cd) to evaluate the utility of the biomarkers and investigate the utility of the mussels in assessment of metal pollution.
Cd is a non-essential metal and is known to be highly toxic to many aquatic organisms. This research consisted of a laboratory study to understand the mechanistic effects of Cd toxicity in green-lipped mussels. Physiological, biochemical, immunocytotoxic and cytogenotoxic biomarker responses were measured in mussels exposed to acute (96 h; 2000 µg L⁻¹ and 4000 µg L⁻¹) and subchronic (28 d; 200 µg L⁻¹ and 2000 µg L⁻¹) Cd treatments. The 96 h LC₅₀ value for P. canaliculus was 8160 µg L⁻¹, indicating that the green-lipped mussels were relatively tolerant to Cd exposure.
Results from the Cd exposures, indicated that Cd had a negative impact on physiological processes such as feeding and oxygen consumption. Cd-induced physiological impairments caused an imbalance between energy gain and energy loss in the mussels that led to negative scope for growth. Detoxification (metallothionein-like protein) and defence mechanisms (catalase) were induced in the mussels to provide protection against the toxic effects of Cd. However, the defence mechanisms were not sufficient to protect the mussels from damage due to lipid peroxidation. DNA damage was also observed in the haemocytes of mussels as a result of Cd exposure. Cellular homeostasis (alkaline phosphatase) mechanisms were also perturbed. The immunocytotoxic endpoints reflected differences in haemocyte proportions in the haemolymph of Cd-exposed mussels. Exposure to Cd also led to the formation of several nuclear aberrations in the gill cells of mussels. Overall the laboratory study highlighted toxic effects of Cd on green-lipped mussels that were dependent on the dose and/or the duration of exposure to Cd. Among the biomarkers tested, clearance rate, metallothionein-like protein induction and the formation of nuclear aberrations in mussel gill cells correlated strongly to Cd accumulation levels and reflected Cd exposure effects.
The feasibility of employing green-lipped mussels as bioindicators was tested during the field study. Green-lipped mussels were collected from different coastal sites along the South Island in NZ. Metal concentrations in the sediment and in four different mussel tissues were analysed. The findings indicated a significant geographical difference in metal concentration in the environment and in the metal accumulation levels in the mussels. Overall, the field study indicated that the green-lipped mussel, Perna canaliculus has the potential to be used as a bioindicator species for assessment of coastal metal pollution levels in NZ.
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Mohan, C. V. "Modulatory effects of cadmium and copper on the susceptibility and immune response of common carp, Cyprinus carpio (L) to selected pathogens." Thesis, University of Stirling, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280056.
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Carrier, Roxie. "Temperature Tolerance of Freshwater Fish Exposed to Water-Borne Cadmium." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc504077/.
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Lethal toxicity values (96 h LC50; mg Cd/L) for the test species were similar: Lepomis cyanellus, 11.52; Notropis lutrensis, 6.62; Pimephales promelus, 3.58. However the effects of cadmium concentration and exposure time on temperature tolerance varied between species. Neither cadmium concentration nor exposure time had a significant effect on the CTM of green sunfish. Both cadmium concentration and exposure time had a significant effect on the CTMs of red shiners and fathead minnows. By day 10 mean CTMs were 2.3 t- 4.5 C (red shiners) and 4.2 to 5.7 C (fathead minnows) lower than control CTM. These results suggest a potential problem in cadmium contaminated systems for high environmental temperatures to stress or kill fish.
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Briones-Gallardo, Roberto. "Caractérisation des propriétés de surface des champignons mycorhiziens à arbuscules (MA) en relation avec l'adsorption du cadmium et du cuivre." Nancy 1, 2002. http://www.theses.fr/2002NAN10023.
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Les champignons mycorhiziens à arbuscules (MA) améliorent la survie et la croissance des plantes dans de sols pollués par des métaux. Pour préciser le rôle des cette symbioses dans le devenir des métaux dans la rhizosphère, les propriétés physico-chimique et le caractère acido-basique pariétal du mycélium des différents champignons ont été étudiés par une description fonctionnelle chimique et l'évolution de charge de surface. La complexation et la fixation de cadmium et de cuivre ont été étudiées en analysant les modifications chimiques par spectroscopie infrarouge. La cinétique et les isothermes de fixation ont été suivies en continu par une électrode à ion sélective (Cd2+) afin de déterminer les mécanismes de fixation impliqués. Les résultats obtenus montrent que la composition pariétale et la distribution de l'acidité organique sur la paroi fongique (liée à la teneur chitineuse ou à l'abondance de sites carboxyliques) jouent un rôle prépondérant dans la réactivité chimique des parois fongiques vis-à-vis de la séquestration des métaux. Elles déterminent les mécanismes impliqués: complexes de sphère interne (complexation) ou de sphère externe (précipitation)Arbuscular mycorrhizal fungi (AM) improved plant survival and growth in heavy metal polluted soils. To understand the contribution symbiosis in the fate of metals in soil-plant systems, the physico-chemical and parietal acido-basic properties of the mycelium of different AM fungi were characterized from their chemical functional description and evolution of surface charge. Metallic ion sorption experiment with cadmium and copper, were performed and the complexation verified by infrared spectroscopy. Sorption kinetics and isotherms were studied in a continuous reactor by an ion selective electrode (Cd2+), in order to establish the sorption mechanisms involved. Results showed that the parietal composition and the distribution of the organic acidity on the fungal wall (related to chitin content and abundance of carboxylic sites) play an key role in the fungal wall reactivity and sequestration of metal. They also determine the mechanisms involved such as the formation of internal sphere complex (complexation) or external sphere complex (precipitation) according to the surface charge developed on the fungal wall
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Hoang, Trung Kien. "Ingénierie écologique pour la biorémédiation des systèmes aquatiques : effets du couplage de la bioturbation avec la phytoremediation sur le cadmium et l'atrazine." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30348/document.
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Ce sujet de recherche vise mieux comprendre les processus de bio remédiation qui participent à la réduction des charges en polluants dans les écosystèmes aquatiques du type zones humides, en tant que question d'actualité en ingénierie écologique. L'efficacité des processus de phytoremédiation a été largement démontrée par des applications individuelles sur le sol et les sédiments. Cette thèse a pour objectif de démontrer la participation d'une population d'invertébrés dans l'efficacité de la réduction de polluants des sédiments aquatiques en combinant le processus de bioturbation avec la phytoremédiation. Les hypotheses de recherche ont été testée expérimentalement en conditions de laboratoire à l'aide d'une série de microcosmes reproduisant chacun une portion d'interface eau/ sédiments similaire aux conditions en zones humides. Dans nos expériences, la bioturbation est réalisée par une population d'oligochètes Tubificidae bien connue comme un ingénieur écologique. La phytoremédiation associée est effectuée par une plante aquatique Typha latifolia connue pour sa capacité à extraire les polluants organiques et inorganiques des sédiments par l'accumulation dans leur biomasse. L'influence de cette biodiversité sur les flux et bilan de masse de polluants modèles, a été démontré à l'aide de 2 expériences de laboratoire mettant en oeuvre des séries de microcosmes contaminées avec du Cadmium en tant que métal trace avec une concentration initiale de 20 µg.L-1, dans l'eau surnageante, et de l'atrazine marquée avec une concentration de 5 µg.g-1 de sédiment frais en tant que micropolluant organique persistant et herbicide. Les résultats de ces expériences démontrent que le bio-transport créé par la population de tubificidae ainsi que la bioremédiation sont toujours actifs en présence de contamination ce qui confirme le potentiel de dévelopement de ces organismes en ingénierie écologique. La bioadvection du sédiment et des contaminants par les tubificidae est quantifiée grâce à l'utilisation de luminophores (traceurs particulaires). [...]The development of efficient bioremediation techniques to reduce pollutant loads in aquatic ecosystems is a challenging research question for ecological engineering. The accuracy of phytoremediation processes has been primarily demonstrated by individual applications on soils or water sediments. The present Ph.D. aims to demonstrate the interest of additional bioturbation combined to phytoremediation processes for the improvement bioremediation efficiency of aquatic sediments. This strategy benefits are tested experimentally in controlled laboratory conditions with a serie of microcosms reproducing each a portion of water/sediment interface such as in wetland areas. In our experiments, bioturbation was carried out by a conveyor-belt invertebrate population, the tubificidae oligochaetes Tubifex tubifex, well known as an active ecological engineer. The phytoremediation was conducted by the riparian plant Typha latifolia known for its ability to remove organic and inorganic pollutants from sediments by accumulation into its biomass. The experiments were managed to demonstrate the effects of this biological influence (plant and inveterbrate) on the mass balances and fluxes of one metal and one pesticide as models of pollutants. Cadmium as a heavy, inorganic and conservative metal pollutant was introduced as a pulse input in the overlying water of the contaminated microcosms, with a cadmium concentration of 20 µg.L-1 in at the initial time of the experiment that lasted one month. In a second experiment, atrazine was mixed in the whole sediment column at the initial time in order to reach a concentration of 5 µg.g-1 of fresh sediment as a source of organic micropollutant and herbicide in the microcosms. The pesticide was radiolabeled with 14C. Fluxes from water to sediment, and from sediment to plants were assessed in experimental conditions with several treatments (+/- plants, +/- bioturbation, +/- pollutants) allowing to demonstrate the effects of the biological influence. Our results indicated that the tubificids and the related bioremediation influences are still efficient under cadmium and atrazine contaminations in aquatic systems. Biotransport due to tubificids changed the distribution of cadmium across the sediment column and enhanced the pumping of cadmium from the water to surface sediment and then to the anoxic underlying sediment surrounding the plant roots. [...]
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Etien, N'Dah. "Contribution à l'étude des effets d'un polluant métallique (le Cadmium) sur la physiologie respiratoire des communautés mino et meiobenthiques de microcosmes sédimentaires expérimentaux." Bordeaux 1, 1985. http://www.theses.fr/1985BOR10537.
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L'action d'un polluant metallique, le chlorure de cadmium, sur les communautes vivantes de microcosmes sedimentaires experimentaux est analysee ; le test biologique de l'intoxication consiste en une modification de la physiologie respiratoire (respiration et activite ets) mesuree par l'intermediaire d'aliquotes prelevees dans les compartiments sedimentaires etudies (sediments entier et lyophilise, meiofaune seule). Les etudes preliminaires portant sur des microcosmes non intoxiques, ont permis de situer la place de chaque fraction sedimentaire dans le systeme microcosmique. Il apparait que le sediment entier a un metabolisme respiratoire en general superieur a celui du sediment lyophilise et toujours tres superieur a celui de la meiofaune seule. D'autre part, l'action du chlorure de cadmium sur les differents maillons du systeme doit etre definie plus en terme de sensibilite que de doses. C'est ainsi que la meiofaune extraite du sediment est plus sensible au cadmium que les sediments entier et lyophilise ; ce phenomene pourrait etre lie au haut degre de complexite de ces deux compartiments sedimentaires
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Paul, Jenny Sueanna. "ECOLOGICAL AND SOCIOLOGICAL IMPLICATIONS OF TISZA RIVER MINE TAILINGS POLLUTION AND EFFECT OF CHRONIC CADMIUM EXPOSURE ON FISH PHYSIOLOGY." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/dissertations/1450.
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Metals are ubiquitous and naturally occurring; however, anthropogenic activities have elevated metal concentrations in river sediments above what would be expected naturally. One of the primary anthropogenic sources of metals in freshwater is contamination by mine tailings, a toxic slurry of waste rock and chemicals left over after ore minerals or coal extraction. Mining waste is most often stored in retention ponds, which sometimes leak or fail. One of the worst mine tailings disasters on record occurred on the Tisza River of Central Europe in the winter of 2000, releasing over 240,000 tons of mine tailings laced with metals into the natural environment. Elevated metals in freshwater can negatively affect fish and other aquatic organisms, raising concerns as to the long-term ecological consequences of the spill. Therefore, the objectives of this dissertation were to describe the ecological implications of metals pollution from mining on freshwater systems through an empirical case study of the Tisza River combined with controlled laboratory experiments of chronic cadmium exposure on a model species, channel catfish (Ictalurus punctatus). Specific research questions discussed in the following chapters include: (1.) What is the current distribution of metals in the lower Tisza River Basin and are metals transported from the main channel to floodplain habitats?; (2.) Is there evidence for bioaccumulation and/or trophic transfer of metals to fish in the Tisza?; (3.) What are angler’s perceptions and fish consumption risks in the lower Tisza river basin?; and (4.) What are the effects of sub-lethal exposure to cadmium on growth, development, metabolism, and stress response in a model fish species? The case study of the Tisza River Basin was conducted during early summer in 2013 and 2014. Water, sediment, and fish were collected from the Tisza River as well oxbow lakes along the lower basin. Samples were screened for metals via GF-AAS following standard methods. Additionally, we conducted interviews at each sampling location to determine fish consumption habits. Controlled laboratory exposures were conducted during summer of 2015. Eggs of channel catfish (Ictalurus punctatus) were fertilized in treatment water and raised to 6 month old fingerlings. Treatments of cadmium included concentrations of 0.5 µg L-1 (control), 2 L-1 (low) and 6 L-1 (high), with endpoints of growth, development, cellular stress, metabolism, and general stress response. Results indicate that lakes with the greatest connectivity trended toward elevated metals; however, chlorophyll a concentrations decreased suggesting dilution of nutrients from surrounding agriculture. River connectivity therefore increases ecosystem health of floodplain lakes by ameliorating eutrophication, but as a trade-off with potential contamination of metals. This may have implications for management strategies in the basin as fish from the oxbow lakes also trended toward higher concentrations of metals compared to the river main stem. Although we did not detect any indication that metals are biomagnifying through the fish community, fish are clearly taking up contaminants from the water and sediment. Additionally, although fish fillets generally fell below human consumption guidelines, surveys collected at field sites indicate disparities between health risks and perceptions of those risks. For example, many people believe that fish from the oxbow lakes present a lower risk for metals than the river main stem, converse to our findings. Exposure of channel catfish to cadmium concentrations similar to those observed in the Tisza Basin indicate that negative physiological effects, such as altered carbohydrate metabolism and subsequently growth, can occur in fish at muscle concentrations below consumption guidelines. Although cadmium in Tisza fish fillets were lower than expected, metals may still be problematic for the basin as they may disproportionately affect early life stages of fish. This could skew life histories of exposed populations compared to unaffected fish, potentially reducing growth rates, size at maturity, reproductive output, and lifespan; indicating the need for more paired field and laboratory assessments of chronic metals exposure.
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Willems, Glenda. "Characterisation of zinc and cadmium tolerance in Arabidopsis halleri." Lille 1, 2006. https://ori-nuxeo.univ-lille1.fr/nuxeo/site/esupversions/481f2da5-d398-40e2-b36f-2796fb68be85.
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Dans cette étude, nous avons développé une approche de type Quantitative Trait Loci (QTL) afin d'étudier le déterminisme génétique de la tolérance au zinc (Zn) et au cadmium (Cd) dans l'espèce Arabidopsis halleri A. Halleri (n = 8) est une espèce métallophyte distribuée sur des sites pollués et non pollués. La tolérance au Zn et au Cd étant constitutivement présentes dans l'espèce étudiée, nous avons développé une population de type backcross (BC 1) à partir d'un croisement interspécifique entre un individu A. Halleri, et un individu de l'espèce proche non tolérante A. Lyrata ssp. Petraea (n = 8). Une carte génétique constituée de 8 groupes de liaison, équivalents au nombre de chromosomes des deux espèces parentales a été construite. Nous avons identifié 3 QTLs pour la tolérance au Zn, ainsi que pour la tolérance au Cd. Le QTL majeur de la tolérance au Cd est également impliqué dans la tolérance au Zn. Nous proposons 3 gènes candidats pour la tolérance au Zn HMA4 (pompe à métaux), MTP1-A et MTP1-B (des transporteurs de Zn). HMA4 co-localise aussi avec le QTL majeur de la tolérance au Cd. Nous n'avons identifié aucun gène candidat potentiel pour les deux autres régions QTL de la tolérance au Cd. Vu la taille des intervalles de confiance associés aux régions QTLs (> 4 cM), nous ne pouvons actuellement pas confirmer avec certitude l'implication des gènes proposés ci-dessus dans la tolérance au Zn ou au Cd. Cependant, la localisation dans les zones QTL de ces gènes actifs dans l'homéostasie des métaux justifie aujourd'hui qu'ils fassent l'objet d'une étude plus approfondie en génomique fonctionnelle afin de déceler leur contribution exacte à la tolérance aux métaux lourds dans A. Halleri ainsi qu'en évolution moléculaire afin de rechercher par analyse du polymorphisme nucléaire d'éventuelles signatures de sélection. En vue de l'identification d'autres gènes potentiellement impliqués dans la tolérance au Zn, nous avons appliqué une deuxième stratégie consistant dans l'intégration des résultats obtenus dans une analyse transcriptomique et dans l'analyse QTL de la tolérance au Zn.
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Gérard, Émilie. "Caractérisation du cadmium phytodisponible des sols par méthodes isotopiques." Vandoeuvre-les-Nancy, INPL, 2000. http://docnum.univ-lorraine.fr/public/INPL_T_2000_GERARD_E.pdf.
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La quantification du cadmium (Cd) phytodisponible des sols est essentielle à l'évaluation du risque de transfert de ce métal toxique vers les plantes. Des méthodes isotopiques (cinétiques d'échange isotopique (CEI), marquage isotopique) couplées à la culture de végétaux, ont été mises en œuvre dans le but d'identifier l'origine du Cd prélevé par la plante et, sur le plan pratique, de définir des méthodes chimiques d'évaluation du Cd phytodisponible. Le ray grass (Lolium perenne L. ), la laitue (Lactuca sativa L. ) et l'hyperaccumulatrice de Cd Thlaspi caerulescens Presl. & C. Presl. Ont été choisis pour leurs prélèvements variés en Cd. Les terres retenues sont polluées par du Cd d'origine industrielle, elles ont des pH différents et représentent une gamme de concentration en Cd total. Les résultats montrent que, dans une tette à tendance acide, toutes les plantes ont accès à un même compartiment, le Cd2+ isotopiquement échangeable. C'est aussi le cas dans des terres carbonatées pour le ray grass mais la laitue et T. Caerulescens ont alors accès à une fraction plus importante et non isotopiquement échangeable du Cd représentant 16 à 52 % des quantités phytodisponibles. La majorité du Cd dans une terre à tendance acide est rapidement isotopiquement échangeable (87 % en 21 jours). Dans les terres carbonatées, le Cd se répartit en deux fractions, l'une très rapidement échangeable et l'autre non échangeable après 21 jours (21 à 70 % du Cd total), en relation avec les faibles quantités de Cd labile dans les poussières à l'origine de la contamination. La mesure en solution de la composition isotopique du Cd2+ et les CEI permettent de quantifier le Cd phytodisponible dans les sols, mais restent peu utilisables en routine. La plupart des réactifs chimiques courants testés (CaCl2, DTPA etc. ) rendent compte du Cd phytodisponible des sols. Cependant, pour les terres carbonatées, le réactif doit parfois être choisi en fonction de la plante.
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Marie, Véronique. "Etude de la réponse des métallothionéines chez les bivalves, Corbicula fluminea, Dreissena polymorpha et Crassostrea gigas, après exposition au cadmium et au zinc : approches in situ et expérimentales." Bordeaux 1, 2005. http://www.theses.fr/2005BOR12989.
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Le potentiel de réponse des métallothionéines (MTs) à l'égard de la bioaccumulation du cadmium (Cd) et du zinc (Zn) a été étudié pour trois espèces de mollusques bivalves, Corbicula fluminea, Dreissena polymorpha et Crassostrea gigas, dans un contexte environnemental de pollution polymétallique, en amont et en aval du continuum fluvio-estuarien "Lot / Garonne / estuaire de la Gironde". Ces travaux de recherche ont reposé sur des études menées conjointement sur le terrain, à partir de transplantations in situ, et en conditions contrôlées de laboratoire, après exposition au Cd et au Zn, isolément et en mélange. Les objectifs étaient (i) de caractériser la réponse protéique des MTs chez les trois espèces de bivalves en fonction des facteurs abiotiques et de contamination rencontrés en milieu naturel ; (ii) d'explorer l'influence de la présence d'un troisième jeu de chromosomes chez C. Gigas (triploïdie) d'un point de vue physiologique (cycle de reproduction) et génétique ; (iii) de définir la capacité de biosynthèse protéique et d'expression des gènes de MTs disponibles chez D. Polymorpha et C. Gigas, en fonction de chaque métal. Les résultats ont mis en évidence des différences interspécifiques majeures en termes de sensibilité de la réponse MTs face à la contamination métallique, notamment vis-à-vis du Zn. Des interactions métalliques ont été observées sur la bioaccumulation uniquement chez les deux bivalves d'eau douce, avec néanmoins la même induction des MTs pour les métaux considérés isolément et en mélange, et ceci pour les trois espèces. Chez C. Gigas, la triploïdie a montré n'exercer aucune influence sur la bioaccumulation du Cd et du Zn et sur la production de MTs. Seuls les facteurs liés à la reproduction se sont révélés être une source de variation des concentrations de MTs chez les individus diploïdes. L'analyse de l'expression des trois gènes de MTs clonés chez C. Gigas a permis de révéler une induction différentielle de chacun d'eux en fonction du métal considéré.
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Pham, Thi Thao Trang, Thi Phuong Phan, Khanh Linh Nguyen, Thi Kim Oanh Nguyen, Thi Thu Thuy Ha, Thi Oanh Ho, Kieu Bang Tam Nguyen, et al. "Status of heavy metal (Pb, Cd) pollution in agricultural soil in Dong Mai lead recycling craft village in Hung Yen, Vietnam." Technische Universität Dresden, 2016. https://tud.qucosa.de/id/qucosa%3A32639.
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The newly planned lead recycling zone in Dong Mai village has been operating with primary treatment systems using lime to neutralize acid in wastewater is a good sign for the local environment, yet the real problem that needs further attention and proper solutions is the accumulation of heavy metals typically lead (Pb) and cadmium (Cd) in agricultural land near the old Pb recycling area. In
this context, 27 soil samples were collected and analyzed by AAS method to assess the situation and the quality of the agricultural soil. The results showed that the levels of Cd in the soil were still in acceptable level according to National Regulation. However, the lead contents in all of the soil samples exceeded National Regulation. The level of Pb pollution in soil was inversely proportional to
the distance with old lead melting zone. The lead content in the soil sample collected at the distance of 50 m radius to the old melting zone reached 7070 ppm, which was 100 times higher than the allowable value of National Regulation.Khu tái chế chì mới tại thôn Đông Mai đã được quy hoạch và đi vào hoạt động cùng hệ thống xử lý sơ bộ với vôi bột là một tín hiệu đáng mừng cho môi trường nơi đây, nhưng vấn đề cần quan tâm và giải quyết triệt để là sự tích lũy một lượng lớn kim loại nặng điển hình là chì (Pb) và cađimi (Cd) trong đất nông nghiệp gần những khu tái chế chì cũ. 27 mẫu đất đã được thu thập và phân tích bằng phương pháp AAS để đánh giá tình trạng, chất lượng đất nông nghiệp tại đây. Kết quả cho thấy hàm lượng Cd trong đất vẫn trong mức độ cho phép theo Quy chuẩn quốc gia. Tuy nhiên, 100% các mẫu đất đều có hàm lượng chì vượt quá mức cho phép theo Quy chuẩn quốc gia. Mức độ ô nhiễm Pb trong đất tỷ lệ nghịch với khoảng cách tới khu lò nấu chì cũ. Mẫu đất cách 50 m so với khu vực lò cũ có hàm lượng chì lên tới 7070 ppm, gấp hơn 100 lần so với Quy chuẩn quốc gia.
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Stanley, Jacob K. "Laboratory and field studies of cadmium effects on Hyalella azteca in effluent dominated systems." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4291/.
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Laboratory single-species toxicity tests are used to assess the effects of contaminants on aquatic biota. Questions remain as to how accurately these controlled toxicity tests predict sitespecific bioavailability and effects of metals. Concurrent 42-day Hyalella azteca exposures were performed with cadmium and final treated municipal effluent in the laboratory and at the University of North Texas Stream Research Facility. Further laboratory testing in reconstituted hard water was also conducted. Endpoints evaluated include survival, growth, reproduction, and Cd body burden. My results demonstrate that laboratory toxicity tests may overestimate toxicity responses to cadmium when compared to effluent dominated stream exposures. Discrepancies between endpoints in the three tests likely resulted from increased food sources and decreased cadmium bioavailability in stream mesocosms
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Smith, David P. (David Paul) 1956. "Responses of Pristina leidyi Smith 1896 (Naididae: Oligochaeta) to Cadmium, Vanadium, and Some Environmental Factors." Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc500695/.
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Concern over sediment toxicity has increased the need for toxicity test information with organisms that inhabit sediments. Oligochaetes are exposed to toxicants through feeding and direct body contact with aquatic sediments. Chronic testing with oligochaetes has historically focused on tubificids with test lengths of one year or more to encompass several generations. Most naidid oligochaetes have generation times of three to seven days and could provide chronic information in a matter of weeks. The cosmopolitan distributed naidid, Pristina leidyi, was evaluated for use as a toxicity test organism. Results of research conducted includes culture methods, effects of temperature on reproduction, growth rates in a reference sediment, acute toxicity tests, and chronic toxicity tests.
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Chaabouni, Rim. "Utilisation et mise au point au niveau moléculaire de biomarqueurs pour étudier la répartition spatiale de la contamination au voisinage d’une source de pollution." Le Mans, 2009. http://cyberdoc.univ-lemans.fr/theses/2009/2009LEMA1016.pdf.
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La répartition spatiale du Cd et son impact écotoxicologique ont été évalués à l'aide des biomarqueurs métallothionéines (MT), malonedialdéhyde (MDA) et acétylcholinéstérase (AChE). Les résultats montrent que la contamination migre vers le sud par les courants de direction nordsud. Les teneurs en biomarqueurs reflètent l'état alarmant de cet écosystème. La palourde Rudifapes decussatus et la coque Cerastoderma glaucum ont pu développer des systèmes adaptatifs particuliers pour survivre dans de telles conditions. Deux séquences partielles d'ADNc MT ont été clonées et utilisées comme sonde pour mesurer le taux d'ARN MT. L'analyse en dot blot a confirmé l'induction de l'expression du gène MT dans les branchies des animaux contaminés. Une différentiation génétique entre différentes populations de C. Glaucum (Méditerranée, Atlantique, Mer du Nord) et C. Edule (Atlantique et Mer du Nord) a été réalisée à l'aide des séquences 28S, ITSI et COIThe spatial distribution of Cd was studied and its toxicological impact was evaluated using metallothionein (MT), malonedialdehyde (MDA) and acetylcholinesterase (AChE) as biomarkers. Results showed that Cd contamination migrates southward the polluted site by the NS currents. The biomarkers concentrations reflect the alarming state of this ecosystem. The clam Ruditapes decussatus and the cockle Cerastoderma glaucum may have settled up sorne peculiar adaptive strategies to survive in such conditions. Two partial MT cDNAs were cloned from R. Decussatus and C. Glaucum and used as probes to quantify the MT mRNA levels. Dot blot analysis confirmed the induction of MT gene expression in gills of the contaminated animaIs. A genetic discrimination between different populations of C. Glaucum from the Mediterranean sea, Atlantic and the North sea, and C. Edule from Atlantic and the North sea were performed using the 28S, ITSI and COI sequences
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Ciliberti, Alexandre. "Le Varan du Nil (Varanus niloticus), indicateur de la pollution des zones humides d'Afrique Sub-Saharienne." Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00861862.
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En Afrique, la contamination des zones humides par les métaux et les pesticides va se poursuivre durablement. Pour autant, le statut toxicologique de ces milieux reste trop peu documente. Le but du présent travail est d'estimer la valeur du varan du Nil (Varanus niloticus) en tant qu'espèce sentinelle pour la contamination des zones humides continentales d'Afrique sub-Saharienne. Plomb, cadmium, et pesticides organochlorés et organophosphorés ont été quantifies, par spectrométrie d'absorption atomique et chromatographie gazeuse (respectivement), dans plusieurs tissus provenant de 71 spécimens issus de quatre sites (au Mali et au Niger) juges a priori inégalement contamines. Bien que des différences claires apparaissent, la contamination environnementale s'avère modérée sur les quatre sites, et ne semble pas constituer un risque notable pour les varans ni pour les humains qui s'en nourrissent occasionnellement. Toutefois la variabilité interindividuelle est importante. Les organotropismes des polluants détectés sont cohérents avec ceux préalablement décrits. Si l'on n'a pu mettre en évidence de différence liée au sexe en ce qui concerne les pesticides, les femelles présentaient des charges en métaux supérieures. La relation entre d'autres facteurs (taille, proportion de graisse) et les concentrations tissulaires a également été considérée. Les varans sont susceptibles de révéler des différences subtiles de contamination environnementale entre sites, et la résolution spatiale de l'outil semble très fine. La possibilité pratique d'utiliser cet indicateur se trouve donc validée. Un travail expérimental sur des varans captifs a par ailleurs été mené pour approfondir l'étude
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Melo, Leônidas Carrijo Azevedo. "Phytotoxicity of cadmium and barium and derivation of critical limits in soils." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-17032011-155912/.
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Soil pollution by heavy metals caused by anthropogenic activities is a problem in many countries. Cadmium (Cd) is one of the most hazardous elements due to its relatively high mobility in soils and transfer to plants. The main human exposure pathway to Cd is through the vegetable consumption and depends on the exposure scenario. Thus, defining a critical limit of Cd in soil is necessary. Barium is an earth alkaline element that can be toxic to humans and plants when it is present in the free form (Ba2+). However, only few studies have focused on Ba in soil. Soil characteristics influence Cd and Ba availability for plant uptake. Both metals may affect plant growth and metabolism and cause oxidative stress. The aims of this study were: (i) to compare tropical and temperate datasets to establish critical soil Cd concentrations for the State of São Paulo, Brazil; (ii) to evaluate the influence of liming on Cd availability and accumulation in lettuce in order to calculate site specific critical soil Cd concentrations for two typical tropical soils from the State of São Paulo; (iii) to evaluate the effects of Cd and Ba concentrations on plant growth, lipid peroxidation and activities of antioxidant enzymes in leaves of soybean, grown in tropical soils with contrasting properties. The Cd uptake from the tropical dataset was higher as compared to the temperate dataset. Critical soil Cd concentrations were from 1.7 to 3.2- fold lower when tropical soil data were used. It is suggested that only literature data, regarding Cd in soils and vegetables, from tropical regions should be used for the State of São Paulo to derive critical soil Cd concentrations. Cadmium accumulated linearly in lettuce at soil concentrations up to 12 mg kg-1. In both soils, a slight reduction on Cd uptake was observed as a response to liming. The calculated critical soil Cd concentrations were lower in the Ultisol because of the differences in soil characteristics. Besides, there was a positive correlation with the vegetable consumption rates. Cadmium strongly reduced soybean growth at concentrations from 5.2 mg kg-1, while Ba only slightly reduced at 600 mg kg-1 in the sandy Entisol. The activities of superoxide dismutase, catalase and glutathione reductase were dependent mainly on the soil type: soybean plants grown in the Entisol suffered higher oxidative stress than those grown in the clayey Oxisol and, consequently, responded less to the increase of metal concentrations.A poluição do solo por metais pesados causada principalmente por atividades antrópicas é um problema em muitos países. Cádmio (Cd) é um dos elementos mais perigosos devido à sua mobilidade relativamente alta em solos e transferência para as plantas. A principal via de exposição humana ao Cd é por meio do consumo de vegetais e depende do cenário de exposição. Assim, a definição de um limite crítico de Cd no solo é necessária. O bário (Ba) é um elemento alcalino-terroso que pode ser tóxico aos seres humanos e às plantas, quando absorvido na sua forma livre (Ba2+). No entanto, há poucos estudos sobre Ba em solos. As características do solo influenciam na disponibilidade de Cd e Ba para absorção pelas plantas. Ambos os metais podem afetar o crescimento e metabolismo das plantas e causar estresse oxidativo. Os objetivos deste estudo foram: (i) comparar resultados oriundos de regiões tropicais e temperadas para determinar concentrações críticas de Cd em solos para o Estado de São Paulo; (ii) avaliar a influência da calagem na disponibilidade e no acúmulo de Cd em plantas de alface, a fim de calcular as concentrações críticas de Cd específicas para solos do Estado de São Paulo; e (iii) avaliar os efeitos das concentrações de Cd e Ba no crescimento das plantas, na peroxidação lipídica e na atividade de enzimas antioxidantes em folhas de soja, cultivada em solos tropicais com propriedades contrastantes. A absorção de Cd a partir do conjunto de dados de solos tropicais foi maior em relação ao de dados de clima temperado. As concentrações críticas de Cd no solo foram de 1,7 a 3,2 vezes menores quando os dados de solos tropicais foram utilizados. Sugere-se que apenas resultados de literatura de regiões tropicais, em relação a Cd em solos e vegetais, sejam utilizados para o Estado de São Paulo para derivação de concentrações críticas de Cd em solo. O Cd acumulou linearmente em alface em concentrações de até 12 mg kg-1 no solo. Apenas uma leve redução na absorção de Cd em resposta à calagem foi observada tanto no Latossolo quanto no Argissolo. As concentrações críticas de Cd foram menores no Argissolo do que no Latossolo, devido às diferenças nas características dos mesmos. Tais concentrações críticas tiveram correlação positiva com o consumo de hortaliças. O Cd reduziu fortemente o crescimento da soja em concentrações a partir de 5,2 mg kg-1, enquanto Ba causou apenas ligeira redução na dose de 600 mg kg-1 no Neossolo Quartzarênico. As atividades das enzimas superóxido dismutase, catalase e glutationa redutase dependeram, principalmente, do tipo de solo. Assim, as plantas de soja cultivadas no Neossolo sofreram mais estresse oxidativo do que as cultivadas no Latossolo. Conseqüentemente, a resposta das enzimas ao aumento das concentrações de metais foi pequena.
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Schoeman, Werner. "Cellular stress responses to cadmium contamination as measure of sensitivity in intertidal molluscan species." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/460.
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Conto, Cinier Christine de. "Analyse de la bioaccumulation des métaux chez les poissons : complexation du cadmium par des protéines de détoxication : les métallothionéines." Lyon 1, 1997. http://www.theses.fr/1997LYO10357.
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Les elements metalliques introduits a l'etat de traces, dans le milieu aquatique, se repartissent dans trois compartiments interactifs : l'eau, les matieres en suspension et les organismes vivants. Par exemple, dans les milieux pollues par le cadmium, les poissons constituent une cible potentielle d'accumulation de ce metal. L'importance des poissons dans les chaines trophiques, ainsi que l'aspect toxicologique pour les poissons eux-memes, conferent un grand interet a l'etude de la bioaccumulation de tels micropolluants. En laboratoire, des experiences de longues durees ont ete conduites pour contaminer des carpes par voie directe dans une eau dont la teneur en cadmium etait soit de 500 g. L#-#1 soit de 50 g. L#-#1. A differents temps d'intoxication, plusieurs individus ont ete preleves et disseques. Le cadmium a ete dose par icp-ms dans le rein, le foie et le muscle afin de comprendre les mecanismes de bioaccumulation et de bioelimination du polluant. La realisation de plusieurs experiences a permis d'etudier l'influence de l'age, du sexe et du niveau de contamination sur les cinetiques d'accumulation et de detoxication. Les metallothioneines, proteines de faibles masses moleculaires cytosolubles qui fixent le cadmium, le cuivre et le zinc, ont ete recherchees dans le rein et le foie de carpes intoxiquees. Apres ultracentrifugation des tissus, les fractions cytoplasmiques recuperees ont ete deposees sur une colonne d'exclusion-diffusion. Le dosage du cadmium, du cuivre et du zinc dans les fractions eluees ainsi que l'analyse des spectres uv de ces fractions ont permis de mettre en evidence la presence de metallothioneines dans le rein et le foie des poissons. Enfin, le dosage des metallothioneines par polarographie impulsionnelle differentielle dans les fractions cytoplasmiques issues du rein et du foie preleves a differents temps d'intoxication a conduit a mettre clairement en evidence une correlation lineaire entre la biosynthese des metallothioneines et le taux de cadmium fixe dans les organes. Une investigation en milieu naturel a ete realisee afin de detecter une eventuelle pollution metallique d'une riviere de la region lyonnaise, l'ardieres, a partir du dosage du cadmium, du plomb, du cuivre et du zinc dans differents milieux : l'eau, les sediments, les mousses aquatiques et les poissons (chevesne et blageon). Une etude statistique, notamment par analyse en composantes principales, a montre une correlation entre differents parametres concernant, d'une part les poissons et, d'autre part les sites de prelevements.
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Sornom, Pascal. "Indicateurs populationnels de pollution : marqueurs comportementaux chez des crustacés d'eau douce face à un stress métallique." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0324/document.
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Les réponses des organismes exposés à des perturbations environnementales sont couramment utilisées comme biomarqueurs pour l'évaluation de la qualité des milieux. Ces réponses sont modulées par de nombreux facteurs et apportent des informations différentes selon leur précocité, leur pertinence, leur spécificité ou leur complexité. Dans ce contexte, nous avons étudié une batterie de réponses comportementales de diverses espèces de crustacés d'eau douce d'intérêt écotoxicologique. Nous nous sommes intéressés aux effets d'un stress biotique (i.e. risque de prédation) et/ou d'un stress abiotique (i.e. contamination métallique) sur des comportements à haute pertinence écologique, avec la prise en compte de certains facteurs confondants (i.e. le sexe et la taille des individus). En laboratoire, nous avons étudié les effets : (i) d'une contamination des sédiments sur l'évitement au substrat du décapode A. Astacus, de l'isopode A. Aquaticus et des amphipodes G. Pulex, G.roeseli et D. Villosus, (ii) d'un risque de prédation sur les stratégies d'anti-prédation de G. Pulex, G. Roeseli et D. Villosus, (iii) d'un risque de prédation et d'une contamination de l'eau au cadmium sur les stratégies d'anti-prédation, les dommages cellulaires et les réserves énergétiques de g. Roeseli et d. Villosus, et (iv) d'une contamination de l'eau au cadmium sur l'appariement sexuel de d. Villosus. Nous avons mis en évidence des variabilités inter-espèces fortes, peu de différences inter-sexes et un impact significatif du cadmium sur les réponses testées. Cette étude montre la précocité et la cohérence des comportements et souligne leur importanceOrganisms responses to various environmental disturbances are commonly used as biomarkers in the assessment of environmental quality. However, these responses are modulated by many factors and provide different information depending on their precocity, their relevance, specificity and complexity. In this context, we chose to study a set of behavioural responses in various species of freshwater crustaceans of ecotoxicological interest. To achieve this goal, we investigated the effects of biotic (i.e. predation risk) and/or abiotic stress (i.e. metal contamination) on behaviours of high ecological relevance, including some confounding factors (i.e. gender and individual length). In laboratory experiments, we studied the effects of: (i) a sediment contamination on the substrate avoidance in the decapod Astacus Astacus, the isopod Asellus Aquaticus and the amphipods gammarus pulex, gammarus roeseli and dikerogammarus villosus, (ii) a high predation risk on antipredator strategies in G. Pulex, G. Roeseli and D. Villosus, (iii) a high predation risk and a contamination of water by cadmium on antipredator strategies, cell damages and energy reserves in G. Roeseli and D. Villosus, and (iv) a contamination of water by cadmium on the precopulatory behaviour in D. Villosus. We have highlighted a strong interspecies variability and small differences depending on gender. The impact of cadmium was significant on the tested responses. Overall, this study emphasizes the importance of behaviours, which can be considered as early warning signals and as relevant tools with high ecological relevance, in the assessment of stress effects and environmental quality
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Falgayrac, Guillaume Brémard Claude Sobanska Sophie. "Physico-chimie de micro particules pour la prévision de la spéciation du plomb, du zinc et du cadmium dans des aérosols de pollution atmosphérique." Villeneuve d'Ascq : Université des sciences et technologies de Lille, 2007. https://iris.univ-lille1.fr/dspace/handle/1908/1031.
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Reproduction de : Thèse de doctorat : Structure et dynamique des systèmes réactifs : Lille 1 : 2006.N° d'ordre (Lille 1) :3894. Résumé en français et en anglais. Titre provenant de la page de titre du document numérisé. Bibliogr. à la suite de chaque chapitre.
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Smaoui-Damak, Wafa. "Effets de la contamination in situ (golfe de Gabès) par le cadmium sur la synthèse des métallothionéines et sur le potentiel reproducteur de la palourde Ruditapes decussatus." Nantes, 2005. http://www.theses.fr/2005NANT25VS.
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Notre étude a porté sur la bioaccumulation in situ du Cd chez la palourde, et ses effets sur leur potentiel reproducteur, dans deux sites du golfe de Gabès: " El Hofra " fortement contaminé et " Bordj d'Ungha " moins impacté. Les palourdes d'El Hofra présentent les concentrations en Cd les plus fortes, avec des fluctuations saisonnières reflétant le phénomène de dilution biologique, essentiellement lié au stade de développement des gonades. Les concentrations en Cd et en métallothionéines (MTs) sont plus élevées dans la glande digestive que dans les branchies. Elles y sont significativement corrélées pour les palourdes des deux sexes d'El Hofra, et pour les mâles de Bordj d'Ungha. L'étude des cycles reproducteurs a révélé un retard de la maturité des gamètes chez les femelles du site contaminé. Cd pourrait perturber l'activité des gonades en créant un déséquilibre hormonal. Le décalage avec la période de maturité des mâles pourrait influer sur le potentiel reproducteur de l'espèceOur study related to the in situ bioaccumulation of Cd in the clam, and its effects on their reproductive potential, in two sites of the gulf of Gabès: "El Hofra" strongly contaminated and "Bordj d'Ungha" less impacted. The clams from El Hofra present the strongest Cd concentrations, with seasonal fluctuations reflecting the phenomenon of biological dilution, primarily related to the stage of development of gonads. The concentrations of Cd and metallothioneins (MTs) are higher in digestive gland than in the gills. They are significantly correlated in the digestive gland for the clams of the two sexes from El Hofra, and for the males from Bordj d'Ungha. The study of the reproductive cycles revealed a delay of the maturity of the gametes in the females of the contaminated site. Cd could disturb the activity of the gonads by creating an hormonal imbalance. The shift with the period of maturity of the males could influence the reproductive potential of this species