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1
MacDougall, Kenneth Alasdair. "Groundwater contamination : a risk based approach." Thesis, University of Strathclyde, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366814.
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Kortbaoui, Ziad S. "The sea shore contamination of the Lebanese coast /." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27537.
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Sea water samples were collected from different sampling stations along the Lebanese coast in the summer of 1994. Chemical, biological and physical analysis were conducted to assess the recreational water quality in Lebanon.Some 125 samples were then analyzed for the presence of Cadmium and Mercury by atomic absorption spectrophotometry. Cadmium content, holding a mean 0.77 $ mu$g/L, was generally low for most areas with only a few elevated readings in Tripoli (1.89 $ mu$g/L), Checca (1.83 $ mu$g/L), Kaslik (0.79 $ mu$g/L), Beirut (1.19 $ mu$g/L) and Ramlet Al-Bayda (1.77 $ mu$g/L). Mercury content, holding a mean value of 0.06 mg/Kg (wet weight), was below the accepted tolerance limit of 0.5 mg/Kg for all sampling sites.
Some 128 samples were then analyzed for fecal coliforms (Escherichia coli and Streptococcus feacalis). Approximately, 50% of the sampling stations showed satisfactory results (less than 100 colonies/100 ml). High counts of fecal coliforms, over 500 colonies/100 ml, collected at Dora, Ramlet Al-Bayda and Antelias, reveal poor sea water quality and a public health hazards to swimmers and fishermen.
Some 36 samples were collected and analyzed for dissolved oxygen (DO), pH, salinity and temperature. For all sites sampled, DO averaged 4.03 mg/L, pH averaged 7.97, salinity averaged 38.77 ppt and temperature averaged 27.9$ sp circ$C.
The degree of pollution was found to be related to population density, industrial and human activity, continental runoffs and hydrological and meteorological conditions.
3
Trowsdale, Sam A. "The depth of penetration of contamination in urban groundwater." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269320.
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Burton, Susan Mary. "Evaluation of stream meiofauna as a monitor of trace metal contamination." Thesis, University of Plymouth, 1998. http://hdl.handle.net/10026.1/2168.
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Members of the meiobenthos have been used extensively to determine the effects of anthropogenic perturbation in marine systems (Coull & Chandler, 1992). Despite this, the meiofauna has been virtually excluded from freshwater pollution monitoring. This thesis aimed to address this research caveat, by evaluating the potential of stream meiofauna for monitoring metal-contamination. Meiofaunal communities were sampled from streams in SW England representing a gradient in metal contamination. Environmental variables in these streams were also measured to identify the important forcing agents structuring the stream benthos. Multivariate techniques demonstrated Cu, either alone or in combination with other environmental variables was of most importance in correlations with the composition of meiofaunal communities. Comparison with the macrofaunal data demonstrated that both components of the benthos responded in a similar way to metal contamination, although the meiofauna also highlighted other differences in water chemistry. The combination of meiofauna, macrofauna and temporary meiofauna in a combined metazoan community analysis gave the best discrimination of sites. Detection of metal-contamination was retained in meiofaunal data aggregated to the family level. The abundances of the harpacticoid copepod Bryocamptus zschokkei were consistently important in contributing to between-site differences in community structure. The harpacticoid, therefore was selected as an ecologically-relevant freshwater toxicity test for Cu. Laboratory experiments demonstrated that Cu had toxic effects on the survival and reproduction of Bryocamptus zschokkei. Although acute toxicity tests gave more rapid results, these effects on survival occurred at a higher Cu concentration than those in the chronic tests. Sub-lethal concentrations of Cu led to a reduction in the numbers of offspring per brood Animals with pre-exposure to chronic concentrations of Cu exhibited greater tolerance to this metal. In conclusion, more information may be gained by including the meiofauna, alongside the macrofauna, when monitoring the impact of contaminants on freshwater systems. To reduce the effort of processing samples it appears family level data could be used to detect metal-contamination. The novel use of B. zschokkei in laboratory tests, where it showed lethal and sub-lethal responses to Cu, demonstrated that this species may have much potential as an ecologically-relevant freshwater bioassay organism for this metal. The advantages of using meiofaunal species such as B. zschokkei as toxicity test organisms are discussed.
5
Halstead, John Michael. "Managing ground water contamination from agricultural nitrates." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54787.
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Ground water contamination from agricultural nitrates poses potential adverse health effects to a large segment of the rural population of the United States. Contamination is especially prevalent in livestock intensive areas, which produce large quantities of animal waste with substantial nitrogen content.
In this study, potential management strategies for reducing nitrate contamination of ground water from agricultural sources were examined using an economic-physical model of a representative dairy farm in Rockingham County, Virginia. A mixed integer programming model with stochastic constraints on nitrate loading to ground water and silage production was used to simulate the impacts of various nitrate loading reduction strategies on estimated farm level net returns over variable costs. A survey of all dairy operations in the county was conducted to assist in specifying the mathematical programming model, identify current nutrient management and quality issues, and gauge farmers’ attitudes toward ground water quality and agricultural chemical use.
Results of the model indicate that substantial reductions in current nitrate loadings are possible with relatively minor impacts on farmers’ net returns through the use of currently practiced approaches of cost sharing for manure storage facility construction and nutrient management planning. Greater loading reductions are achievable through presently untried policies of land use restrictions, bans on purchase of commercial fertilizer, and imposition of standards on loadings to ground water. These reductions are achieved, however, at higher costs in terms of reduced net returns.
Study results indicate that a wide range of policy options exist for reducing nitrate loading to ground water; these reductions, while varying in cost, do not appear to come at the expense of eliminating the economic viability of the county dairy sector. Model results indicate that reductions in nitrate loading of 40 to 70 percent (on average) could be achieved with reductions in farmers’ net returns of one to 19 percent, respectively, when cost sharing for manure storage construction was provided. Explicit consideration was given to the annual variability in nitrate loading due to weather and other factors. The result was higher policy costs than when average loadings alone were considered.Ph. D.
6
Harrison, Adrian Briscoe. "Hydrocarbon pollution of soil : effects on microbial populations and biomediation methods." Thesis, University of York, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362025.
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Printes, Liane Biehl. "The value of acetylcholinesterase activity in Daphnia as a biomarker of environmental contamination." Thesis, University of Reading, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288746.
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Payne, Rosara Faith. "Investigation of radiological contamination of soil samples from Idaho National Laboratory." Diss., Online access for everyone, 2006. http://www.dissertations.wsu.edu/Dissertations/Summer2006/r%5Fpayne%5F053106.pdf.
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Choi, Chung-ming. "Land contamination and its remediation methods : a case study in Hong Kong /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14709156.
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Weemees, Ilmar Andrew. "Development of an electrical resistivity cone for groundwater contamination studies." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28730.
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The evaluation of groundwater quality has become increasingly important as more industrial waste and solid domestic refuse comes into contact with groundwater. Often the quantity and extent of contamination is determined by direct sampling of the groundwater and soil. An alternative method of detecting contaminated groundwater is by noting the electrical resistivity of the contaminated soil. The feasibility of logging resistivity while conducting cone penetrometer testing has been investigated in this research. To this end a two stage program was devised, consisting of lab testing and then field tests of a working tool.
Lab testing was carried out using a prototype probe designed to evaluate the feasibility of the project. The lab testing consisted of determining the resistivity of a number of different soil, electrolyte, and organic contaminant mixtures while varying the configuration of the probe. On the basis of lab testing the necessary requirements for the module dimensions and electronics were chosen and were fine tuned by field tests. The module itself consists of an insulated four electrode array and is mounted behind a standard 15 sq cm piezo-cone (CPTU). Upon completion of the development phase the instrument was tested at four different sites. From field testing it was determined that the resistivity cone (RCPTU) was able to accurately map changes in groundwater chemistry on the basis of resistivity measurements. The results of the resistivity testing were verified by groundwater sampling. It was also found that changes in lithological properties, as determined by the cone penetration test (CPT), could influence the resistivity. Basic guidelines for the use of the RCPTU in contaminant investigations are presented.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Tu, Wai-ki Alex. "Hong Kong marine sediment contamination with Tributyltin and its impacts /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22285180.
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Ott, Cindy Lee. "Groundwater and surface water contamination by fire retardants at Abbotsford Airport." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24893.
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The impact of fire retardant waste on the aquatic environment was investigated at Abbotsford Airport located in the Lower Fraser Valley, in Southwestern British Columbia. The cleaning of fire fighting aircraft results in significant quantities of fire retardant waste being washed into the airport drainage system with subsequent transport to a drainage ditch located in the southwest corner of the Airport Chemical components of the fire retardant likely to be of environmental concern were identified as ammonia, phosphate, and a corrosion inhibitor.
Glacial and outwash deposits consisting of sands and gravels comprise the surficial geology of the study area. Hence, the fire retardant waste would have the potential to impact both surface water and groundwater resources. Therefore there was concern due to the extensive use of groundwater in the local area for both drinking and irrigational purposes.
The major components of the research design were 1) assessment of the spatial and temporal distribution of fire retardant introduced into the aquatic environment, and 2) overall impact of fire retardant contamination on surface water and groundwater quality.
A long term and two short term monitoring programs were designed to determine the rate of transport and distribution of the fire retardant in the aquatic environment Results showed that although the fire retardant was observed to wash through the drainage system into the stream, no measurable impact on surface water quality was recorded during the study period. Fire retardant components which would cause surface water contamination are ammonia, phosphorus, iron and chromium. A significant rise in nitrate-nitrogen concentration was detected in groundwater samples less than a day after fire retardant waste was recorded in measurable quantities in the ditch water. Temporal distribution of fire retardant in the aquatic environment was correlated with the high hydraulic conductivity of the subsurface and specific hydrological events involving heavy precipitation. Results from the laboratory column experiments indicated that components of the Fire retardant were not retained in the soil and would therefore be rapidly leached into groundwater.
Surface water quality and groundwater quality results were compared with established water quality standards for drinking water and protection of freshwater aquatic life. On the basis of these standards the fire retardant waste was not found to contribute to degradation of the surface and groundwaters at Abbotsford Airport
Overall impact of the fire retardant waste on the aquatic environment at Abbotsford Airport during the study period was not found to be significant The low fire season combined with a change in washing policy resulted in a fewer number of planes being cleaned at Abbotsford Airport during 1983-84. Therefore, the impact on the aquatic environment recorded during this period cannot be considered typical.Graduate and Postdoctoral Studies
Graduate
13
Casper, Susan Theresa. "Contamination, bioavailability and speciation of metals from copper processing industry in the Churnet River valley, Staffordshire, UK." Thesis, University of Derby, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270033.
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O'Shea, Francis Timothy. "Assessment of diffuse pollution originating from estuarine historical landfills." Thesis, Queen Mary, University of London, 2016. http://qmro.qmul.ac.uk/xmlui/handle/123456789/12995.
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The UK contains 5000 unlined historical landfills in the coastal zone currently at risk of erosion within the next 50 years. These rely on natural attenuation in surrounding sediment to reduce the contaminant load to the environment. This thesis investigates the extent and magnitude of sediment metal contamination from historical estuarine landfills. An intensive investigation of Newlands historical landfill, Essex, indicated elevated metal concentrations in surface and sub-surface sediments. Surface sediment concentrations were similar to other industrially impacted estuaries, whilst peak metal concentrations at c. 50 cm depth were indicative of industrial activity in the mid-20th Century. Below this depth, sediments were enriched with Pb (EF > 2) and Zn (EF = 1.5) indicative of an historic leachate plume that extends c. 15 m from the landfill site boundary. These sediments present a secondary source of diffuse pollution and a site contamination load of c. 1200 kg Pb. In-situ XRF was demonstrated as a rapid contamination screening tool for Fe, Pb, Sr and Zn enabling a broad-scale investigation of historical landfills across SE England. Sediment cores from eight sites containing both hazardous and inert waste were screened. Concentrations and EFs of Pb and Zn at depth were significantly higher in hazardous sites compared to inert sites. Spatial distributions of Pb and Zn were comparable to Newlands historical landfill. This indicates that diffuse pollution from historical landfill sites with similar chemical and physical attributes to Newlands is likely to present a regional, if not national problem, with UK historical landfills presenting contaminated sediments, comprising a significant, previously unidentified and unquantified diffuse pollution source in the coastal zone.
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Ma, Kit-cheong James. "Hong Kong Government criteria for assessing contamination levels of dredged marine sediments /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22264474.
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Buco, Stéphanie. "Métrologie de la contamination des sols par les hydrocarbures aromatiques polycycliques." Aix-Marseille 3, 2001. http://www.theses.fr/2001AIX30098.
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Les Hydrocarbures Aromatiques Polycycliques (HAP), reconnus comme polluants prioritaires en raison de leurs propriétés mutagènes et cancérigènes, ont suscité le développement de nombreuses techniques analytiques de terrain ou de laboratoire. Les techniques in situ sont utilisées pour un criblage de la pollution et peuvent être complétées par des analyses de laboratoire qui apportent une connaissance précise de la contamination. Notre travail était de développer de nouvelles méthodes en minimisant les inconvénients de ces deux approches analytiques qui sont pour la première, une faible précision des résultats et pour la seconde un temps et un coût d'analyse élevés. L'étude réalisée en laboratoire montre que la pyrolyse à point de Curie couplée à la chromatographie gazeuse et spectrométrie de masse (Cpp-CG/SM) est une méthode alternative efficace pour l'analyse des HAP. Elle permet d'obtenir des résultats au moins similaires à ceux des techniques classiques dans un court intervalle de temps et sans consommation de solvant. .The Polycyclic Aromatic Hydrocarbons (PAHs) are proven to be major pollutants because of their mutagenic and carcinogenic properties. These compounds raised up many "on-site" or laboratory methods developments. The in situ methods are used for a rapid screening of contaminated soils and can be completed by laboratory analyses to give more accuracy. The aim of this study was to develop new methods with the minimization of the "on-site" and laboratory methods drawbacks which are respectively low accuracy, cost and analysis time. It appears from our laboratory study that the Curie-point pyrolysis-gas chromatography/mass spectrometry (Cpp-GC/MS) is an efficient alternative method for the PAHs determination. We obtained similar results compared to classical methods, with short operating time and without solvent consumption. The in situ methodology is based on a "on-site" extractor, developed during this work and UV spectrophotometric measurements (Pastel-UV). This methodology has proved to be a fast, quantitative and qualitative screening of contaminated soils by PAHs. The results show that our "on-site" extractor is more efficient than the usual "hand shaking" methods. A correlation was established between laboratory and "on-site" results to near to real PAHs concentration
17
Harries, Julie Elizabeth. "A study of the extent of estrogenic contamination of English inland waters." Thesis, Brunel University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336703.
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Montague, David Joel. "Managing agricultural contamination of ground water: the institutional framework." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43408.
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Paisse, Sandrine. "Etude de la réponse d’une communauté bactérienne de sédiments côtiers à une contamination pétrolière." Pau, 2009. http://www.theses.fr/2009PAUU3015.
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Les zones côtières constituent des environnements très productifs chroniquement exposés à des contaminations pétrolières. Dans ces écosystèmes, les communautés bactériennes, qui jouent un rôle majeur dans les cycles biogéochimiques, forment le plus souvent des tapis microbiens en surface des sédiments au sein desquels les relations entre microorganismes sont favorisées. Afin de mettre en évidence les mécanismes adaptatifs de ces communautés complexes lors d’une contamination par des hydrocarbures, la réponse des communautés bactériennes des sédiments côtiers de l’Etangde-Berre soumises à une contamination pétrolière a été étudiée. Cette étude repose sur l’analyse in situ des communautés naturelles et sur des expérimentations en microcosmes. Dans un premier temps, la structure des communautés bactériennes naturelles a été caractérisée in situ dans les sédiments où les concentrations en hydrocarbures formaient un gradient. Cette étude a mis en évidence une importante adaptation des communautés à la présence de pétrole. Nous avons alors étudié la réponse précoce d’une communauté bactérienne de ces sédiments à une contamination pétrolière. Les analyses au niveau des gènes codant pour les ARNr 16S et leurs transcrits ont montré des modifications structurales de la communauté bactérienne dans les premières heures et les premiers jours suivant la contamination. L’étude de la diversité et de l’expression des gènes impliqués dans la dégradation des hydrocarbures, alcane monoxygénase et naphtalène dioxygénase, a ensuite été entreprise. L’expression rapide des gènes fonctionnels en réponse à la contamination a pu être associée à une biodégradation importante des hydrocarbures. Cette étude confirme l’intérêt d’étudier les mécanismes adaptatifs de la communauté en réponse à la contamination dans les heures suivant la contamination. Ainsi, l’identification de gènes réprimés et/ou exprimés en réponse à la contamination a été envisagée afin de caractériser, de manière plus générale, la réponse à la contaminationCoastal zones are highly productive environments chronically exposed to hydrocarbon contamination. Bacterial communities inhabiting these ecosystems play key role in biogeochemical processes and often form microbial mats in which microorganisminteractions are enhanced. In order to characterize the modifications occurring in the bacterial community during oil spill, the bacterial community response of Etang-de-Berre coastal sediment to oil contamination was studied based on in situ analysis of natural bacterial communities as well as on microcosm experiments. First the investigation of the in situ natural bacterial communities inhabiting sediments in a gradient of hydrocarbon concentrations revealed an important adaptation of the bacterial community to the oil contamination. We then explored the early response of the bacterial community to cope with the oil contamination. Analyses based on 16S rRNA genes and their transcripts revealed structural modifications occurring in the first hours and the first days following the contamination. The diversity and the expression of functional genes involved in hydrocarbon degradation such as alkane monooxygenase and naphthalene dioxygenase were investigated. These genes were immediately expressed in response to the oil addition while concomitantly high rates of hydrocarbon biodegradation were observed. Thus these results indicated important adaptative mechanisms during the first two days following the contamination. In order to further characterize this mechanism at the whole bacterial community level, we then performed the identification of genes repressed and/or overexpressed in response to oil addition
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Svendsen, Claus. "Earthworm biomarkers in terrestrial ecosystems." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326956.
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Lucas, Jean-Paul. "Contamination des logements par le plomb : prévalence des logements à risque et identication des déterminants de la contamination." Nantes, 2013. http://archive.bu.univ-nantes.fr/pollux/show.action?id=ee1e7f1b-e1e9-455c-afa8-ea7f68143c8e.
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Les niveaux en plomb (Pb) en milieu résidentiel ont été estimés pour la 1ère fois en France métropolitaine. Pour cela les outils de la théorie des sondages ont été appliqués aux données de l'enquête Plomb-Habitat (2008-2009). Un échantillon de 484 logements a été construit afin d'étudier la population de résidences principales (N = 3 581 991) abritant au moins un enfant âgé de 6 mois à 6 ans. Environ 2,9% des logements possèdent une concentration en Pb dans l'eau du robinet supérieure au seuil réglementaire (SR) de 10 µg/L ; dans 0,21% des logements et 4,1% des parties communes le SR américain de 430 µg/m² de Pb est dépassé dans les poussières intérieures ; 1,4% des sols des aires de jeu extérieures dépassent le SR américain de 300 mg/kg de Pb ; 24,5% des logements ont encore des peintures au Pb. Le Pb des poussières est connu comme étant le principal prédicteur des plombémies infantiles. Un modèle multi-niveaux à 2 niveaux a été construit afin d'expliquer les charges en Pb des poussières des 1834 pièces (niveau 1) investiguées dans les logements (niveau 2). Aucune pondération n'a été introduite dans la méthode d'estimation (pseudo vraisemblance) utilisée pour ce type de modèle sur données d'enquête. La poussière du palier est le principal contributeur à la contamination des poussières. Une étude de simulation a été réalisée à partir de nos données afin de comparer les différentes pondérations pour le niveau 2 d'un modèle multi-niveaux. Son résultat a permis de valider l'utilisation d'un modèle à 2 niveaux non pondéré pour expliquer les charges en Pb de la poussière. Jusqu'alors dans la littérature, seule la pondération au niveau 1 avait été étudiée pour ce type de modèleResidential lead levels were estimated for the first time in mainland France. For this, tools of the theory of survey sampling were applied to the data of the Plomb-Habitat survey (2008-2009). A sample of 484 dwelling was drawn to study the population (N = 3 581 991) of the main residences (as opposed to second home) where at least one child aged 6 months to 6 years was present. Approximately 2. 9% of housing units have a lead concentration in tap water higher or equal than the regulatory threshold (RT) of 10 µg/L; in approximately 0. 21% of dwellings and in 4. 1% of common areas the American RT of 430 µg/m² (40 µg/ft²) was exceeded for interior floor dust lead; 1. 4% of exterior play area soils exceed the American RT of 300 mg/kg of lead; 24. 5% of housing units have still lead-based paint. Lead in floor dust was pointed out as the main predictor of blood lead level in children. A multilevel model with 2 levels was fitted to explain the floor dust lead loadings of the 1834 rooms as level-1 units investigated in the homes considered as level-2 units. No weights was used in the estimation method (pseudolikelihood) used for this kind of modeling on survey data. Dust of the landing of an apartment is the main contributor to the contamination of dust by lead. A simulation study was carried out from our data to compare the different weights for the level-2 units of a multilevel model. Its result enabled us to confirm the fitting of an unweighted model to explain the dust lead loadings. Until now, only the level-1 weights had been studied in the literature for this kind of model
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Leeming, Rhys, and n/a. "Coprostanol and related sterols as tracers for feacal contamination in Australian aquatic environments." University of Canberra. School of Resource, Environmental & Heritage Sciences, 1996. http://erl.canberra.edu.au./public/adt-AUC20060816.172519.
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Pollution from human and animal faecal waste is a major cause of deteriorating water
quality and increased nutrient loads in coastal and inland waterways. Management of
this problem depends on knowing which sources of faecal matter are the cause and
what is the degree and extent of the pollution. Bacterial indicator organisms have long
been the principal method used to test water samples for faecal contamination.
However, none of the currently used bacterial indicators on their own are source
specific enough to distinguish different sources of faecal matter. The use of faecal
sterol biomarkers in conjunction with existing bacterial indicators offers a new way to
distinguish sources of faecal contamination.
This study investigates the sources of faecal sterols, the relationship of coprostanol to
existing bacterial indicators of faecal pollution, the degradation of faecal sterols and the
problem of determining the sources of faecal contamination and the distribution of
faecal contamination using faecal sterol biomarkers. 5p-Stanols (i.e. faecal sterols)
were found to be significant constituents of human, herbivore (i.e. cows, sheep etc.)
and pig and cat faeces. Human faeces contained 73 ± 4% coprostanol in relation to
the sum of coprostanol and 24-ethylcoprostanol and primary treated effluent contained
86 ± 0.4% coprostanol. Herbivore faeces contained 38 ± 4% coprostanol and 62 ±
4% 24-ethylcoprostanol whereas pig faeces contained 50 � 5% of each compound.
Both birds and dogs faeces contained either trace amounts of 5B-stanols or they could
not be detected. Notable differences were observed in the abundance of Closthdium
perfringens spores between the faeces of birds and domestic pets such as cats and
dogs. The above differences were subsequently exploited to distinguish faecal
contamination in Lake Tuggerah. An examination of the relationships between
coprostanol and bacterial indicator concentrations from several environments revealed
that 60 and 400 ng L of coprostanol corresponded to currently defined primary and
secondary contact limits for bacteria measured as either thermotolerant coliforms or
enterococci in the environment.
Four degradation experiments showed faecal sterols and related sterols such as
cholesterol decay at similar rates. An induction period was observed in all
experiments which meant that simple exponential equations to describe the rate of
decay of coprostanol were inadequate; a complimentary log - log transformation of the
data was used and the equation:
Y = l-Exp(-Exp(time x -0.01 + temp x -0.158 + 3.33)) x 100
was derived where Y equals the predicted percentage of coprostanol remaining over
time at a given temperature. In terms of persistence in the environment, Clostridium
perfringens spores > coprostanol > enterococci > thermotolerant coliforms.
Two field studies were undertaken to highlight the use of faecal sterols. In the Lake
Tuggerah study, the results indicated that faecal contamination of receiving waters in
the Tuggerah Lakes during rain events was significant, but was not derived from
human faecal matter; rather it appears to be principally derived from native birds and,
to a lesser extent, domestic pets. In the Derwent Estuary study, based on the
distribution of the faecal biomarker coprostanol, the mid estuary and parts of the upper
estuary (from Newtown Bay to Taroona), were found to be severely contaminated by
sewage. In summary, the use of faecal sterols to trace faecal contamination were found
to be an invaluable addition to the tools water managers use to investigate faecal
pollution.
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Cosson, Richard P. "Influences des pratiques agricoles sur la contamination des écosystèmes aquatiques par les métaux lourds : approche écotoxicologique." Paris 11, 1987. http://www.theses.fr/1987PA112209.
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Suite aux précipitations et au lessivage des sols des sels métalliques (Cu, Zn, Pb, Cd, Hg) présents dans les produits phytosanitaires utilisés en agriculture intensive·sont susceptibles de s’accumuler dans les milieux limniques et représentent une menace pour la stabilité de ces écosystèmes. L'évalua ion des niveaux de contamination d’écosystèmes aquatiques situés en zone agricole, en région parisienne et en Camargue, a été menée par le dosage en absorption atomique des éléments traces : dans les sédiments et des organismes représentatifs des différents niveaux trophiques rencontrés dans ces écosystèmes. Les résultats obtenus mettent en évidence des teneurs anormalement élevées pour le cadium, le mercure et le plomb. D'autre part, des dosages de métallothionéines ont été effectués par polarographie sur des organismes prélevés in situ. La mise au point de cette technique analytique a été effectuée au laboratoire sur des organismes intoxiqués par voie directe. Elle a permis de suivre simultanément, la bioconcentration des métaux et leur métabolisation. Le dosage de métallothionéines par polarographie est une technique rapide, très sensible et, aisée à mettre en oeuvre. Il apporte des résultats complémentaires aux dosages bruts de métaux traces. Sur le plan·fondamental, les résultats acquis, tant au laboratoire que sur le terrain (complémentarité essentielle à l'approche écotoxicologique) confirment le rôle essentiel des métallothionéines dans l'homéostasie du zinc. Ils mettent aussi en évidence que la teneur en métallothionéine d’un tissu est corrélée à sa teneur en zinc. Le zinc apparaît comme un inducteur primaire pour la synthèse de cette protéine. Cadmium et mercure ne font que se substituer au zinc dans le processus de détoxication impliquant le métallothionéine. Il apparaît en conclusion, que les pesticides et les engrais utilisés en agriculture intensive représentent un danger pour les écosystèmes limniques avoisinants.
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Larno, Valérie. "Réponses génétiques et physiologiques de populations de Chevaine (Leuciscus cephalus) à la contamination chimique dans le bassin du Rhône." Lyon 1, 2004. http://www.theses.fr/2004LYO10241.
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L'élaboration de méthodes performantes permettant d'évaluer la qualité du milieu aquatique et de prédire les effets à long terme d'une pollution sur les populations constitue un défit majeur. Dans ce contexte, l'écotoxicologie génétique est d'un intérêt grandissant, l'objectif étant de rechercher des changements induits par les polluants sur le matériel génétique des populations naturelles. Ce travail vise à comparer la diversité génétique de populations de chevaine (Leuciscus cephalus) du Bassin du Rhône exposées in situ à différents niveaux de pollution, via l'étude du polymorphisme de marqueurs microsatellites et enzymatiques, et à évaluer la susceptibilité des individus vis-à-vis du stress contaminant en recherchant les relations possibles de types "génotypes-phénotypes". Les principaux résultats montrent un polymorphisme génétique aux loci microsatellites fortement structuré par la géographie, une augmentation de la fréquence de l'allèle PGM-90 dans les populations exposées, des relations entre certains allèles ou génotypes enzymatiques et la capacité des individus à maintenir l'intégrité de leur ADN. La variabilité génétique des microsatellites paraît par ailleurs associée à la capacité des individus à maintenir l'intégrité de leur ADN en situation de stress chimique. La comparaison du polymorphisme de marqueurs fonctionnellement distincts entre des populations de poissons exposées à différents niveaux de pollution peut être considérée comme une approche puissante permettant de suspecter la présence d'effets sélectifs liés au stress chimique
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Shuping, Likentso Sylvia. "Biomonitoring of metal contamination in the lower Diep River, Milnerton, Western Cape." Thesis, Cape Peninsula University of Technology, 2008. http://hdl.handle.net/20.500.11838/786.
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Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2008The lower Diep River is a major freshwater ecosystem in the Western Cape. The river is surrounded by many possible sources of metal pollution such as an oil refinery, industries, a sewage treatment plant and a landfill site. However, metal contamination levels have not been monitored in this river. The aim of the study was therefore to monitor the degree of metal pollution in the lower Diep River, over a period of one year, and to investigate the use of the sedge Bolboschoenus maritimus, as biomonitor species. Three sampling sites were used. Site I was located in the vicinity of landfill sites and farm areas. Site 2 was located I km upstream from a wetland reserve, surrounded by heavy industrial activity and continuous residential developments. Site 3 was located downstream of the wetland reserve, 2 km from the river mouth. The following metals were investigated: aluminium, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel and zinc. Water and sediment samples were collected every two months for a period of one year. Plant specimens (roots, leaves and stems) were collected seasonally from site I and site 3. Samples were acid digested and metal analysis was done using an ICP - AES (Inductively Coupled Plasma- Atomic Emission Spectrophotometer). Statistical analyses were done to investigate possible differences between the sites, sampling occasions and various plant components.
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Williams, Benjamin Deeter. "Uranium contamination of vadose zone sediments from the Hanford U single shell tank farm." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/B_Williams_112709.pdf.
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Thesis (M.S. in environmental science)--Washington State University, December 2009.Title from PDF title page (viewed on Jan. 26, 2010). "School of Earth and Environmental Sciences." Includes bibliographical references (p. 48-51).
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Korre, Anna. "A methodology for the statistical and spatial analysis of soil contamination in GIS." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266111.
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Lafabrie, Céline. "Utilisation de Posidonia oceanica (L. ) Delile comme bio-indicateur de la contamination métallique." Corte, 2007. http://www.theses.fr/2007CORT3098.
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La zone littorale du plateau continental renferme une grande richesse écologique. Or, cette zone présente une grande fragilité vis-à-vis des xénobiotiques ; la pollution de ce milieu peut porter atteinte à la structure des biocénoses et à la productivité des écosystèmes. Les métaux sont des constituants normaux de l'environnement à l'état de traces, contrairement à de nombreux contaminants, et sont tous toxiques au dessus d'un certain seuil. A la fin des années 1970, plusieurs chercheurs proposent l'utilisation d'organismes pour évaluer la qualité du milieu marin ; c'est dans ce contexte que naît le concept de bio-indicateur. La magnoliophyte marine Posidonia oceanica (L. ) Delile, endémique de Méditerranée, a fait l'objet de plusieurs travaux proposant d'utiliser cette espèce pour déterminer les concentrations métalliques du milieu. Toutefois, un certain nombre d'axes d'étude restait encore à explorer afin de qualifier cette espèce de bio-indicateur. Les résultats de ce travail valident l'utilisation de cette espèce en tant qu'outil fiable pour l'évaluation de la contamination métallique des écosystèmes littoraux. En effet, ce travail a permis : (i) de mieux comprendre les processus d'accumulation des métaux traces par Posidonia oceanica ( influence de l'âge et de la croissance des tissus foliaires dans l'accumulation métallique ) ; (ii) de confirmer la grande sensibilité de cette espèce comme traceur de la contamination métallique (identification des apports métalliques associés à l'ancienne mine d'amiante de Canari et évaluation de l'étendue de l'impact de cette ancienne exploitation) ; (iii) de confirmer sa fiabilité comme bio-indicateur de contamination métallique (mêmes tendances observées chez cette espèce et le bio-indicateur Mytilus galloprovincialis Lamark, 1819 ). Posidonia oceanica apparaît, par conséquent, comme un outil intéressant dans le cadre de la mise en oeuvre de réseaux de surveillance à l'échelle de la Méditerranée. Une technique, consistant à prélever uniquement les limbes des feuilles adultes, est proposée dans la mesure ou elle permettra de réaliser des analyses de métaux traces sans entraîner la mortalité de la plante (espèce protégée dans de nombreux pays méditerranéens) et tout en conservant son intégrité. Des grilles préliminaires d'interprétation de la contamination métallique du milieu ont également été proposées pour le cadmium, le mercure, le nickel et le plomb (substances prioritaires ; Décision N° 2455/2001/EC ; EC, 2001). Enfin, ce travail montre également l'utilisation possible de Posidonia oceanica comme "traceur" de la contamination mercurielle passée grâce à la technique de la lépidochronologieThe coastal zone of the continental shelf contains a high ecological richness. However, this zone is very fragile towards xenobiotics ; the pollution of this environment can be damaging to the structure of the biocenoses and to the productivity of the ecosystems. Metals, contrarily to numerous contaminants, are normal constituents of the environment at a trace level, but are all toxic above a certain threshold. At the end of the 1970s, several researchers proposed the use of organims to evaluate the quality of the marine environment ; it is in this context that the bio-indicator concep arises. The seagrass Posidonia oceanica (L. ) Delile, endemic of the Mediterranean Sea, has been the subject of several work proposing to use this species to determine the metal concentrations of the environment. However, most studies carried out explorative research in order to qualify this species as bio-indicator. The results of this work validate the use of Posidonia oceanica as a reliable tool for the evaluation of metal contamination of coastal ecosystems. Inded, this work allowed : ( i ) to better understand the trace metals accumulation processes by Posidonia oceanica (influence of age and growth of foliar tissues in the metal accumulation ); (ii) to confirm the high sensitivy of this species as a tracer of metal contamination (identification of metal inputs associated to the previous asbestos mine of Canari and evaluation of the extent of the impact of this previous exploitation) ; (iii) to confirm its reliability as bio-indicator of metal contamination (same trends observed for this species and the bio-indicator Mytilus galloprovincialis Lamark,1819). Therefore, Posidonia oceanica appears as an interesting tool in the frame of setting up biomonitoring networks at the scale of the Mediterranean Sea. A technique, which consists in collecting only the blades of the adult leaves is proposed insofar as it will allow to carry out trace metals analyses without inducing the mortality of the plant (protected species in numerous Mediterranean countries) and conserving its integrity. Preliminary scales to interpret the level of metal contamination in the environment have equally been proposed for cadmium, mercury, nickel and lead (priority subtances ; Decision N° 2455/2001/EC ; EC, 2001). Finally, this work shows equally the possible use of Posidonia oceanica as a "tracer" of the past mercurial contamination thanks to the lepidochronology technique
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Ginnever, Rhoda C. "Soil and plant contents of lead and other trace elements with special reference to the influences of parent rock and pollution." Thesis, Aberystwyth University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324309.
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Brostrom, Kathleen A. "Are Fecal Sterols a Possible Alternative Indicator of Human Waste Contamination in Hawaiian Recreational Waters?" Thesis, Water Resources Research Center, University of Hawaii at Manoa, 2005. http://hdl.handle.net/10125/22259.
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Many of Hawaii’s recreational streams and beaches contain high fecal indicator bacteria levels that are not indicative of sewage pollution. Instead, this pollution is due to environmental sources of fecal bacteria which reside and multiply in tropical soils. Current EPA fecal indicator bacteria are no longer representative of human fecal contamination in tropical waters. Fecal sterols have been used as chemical indicators of fecal pollution in many parts of the world. The primary sterol found in human feces is coprostanol. Detection and quantification of coprostanol and related sterols using GCMS analysis provides a fingerprint that can be used to characterize fecal contamination. The objective of this study was to assay for fecal sterols as an independent method to determine whether streams in Hawaii are contaminated with sewage. This method was applied to ambient streams, a stream recently contaminated by a sewage spill, and a stream suspected to be affected by a sewage line leak. The results of this study showed that some ambient streams in Hawaii contain high levels of fecal indicator bacteria, but low concentrations of coprostanol (<10 ng/L). A stream contaminated with sewage during a sewage spill event contained high concentrations of coprostanol (18,000 ng/L) in the first 24 hours after contamination, but this level dropped to ≤ 60 mg/L after 72 hours. A stream suspected to be contaminated with sewage contained significant levels of coprostanol (>1000 ng/L) when fecal indicators were also high, confirming a possible sewage line leak. This study demonstrated that coprostanol is a useful and independent measurement of sewage pollution. It is best used in conjunction with other fecal indicators and human fecal markers if confirmation of human fecal pollution is sought.
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Bensoussan, Hélène. "Effets d'une contamination à l'uranium sur le système cholinergique : approches in vivo et in vitro." Paris 11, 2009. http://www.theses.fr/2009PA11T073.
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Suvornmongkhol, Narumon. "Uptake of radionuclides by wheat roots with respect to location of contamination below the surface." Thesis, Online version, 1996. http://ethos.bl.uk/OrderDetails.do?did=2&uin=uk.bl.ethos.321557.
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Dubé, Jean-Sébastien. "Modifications hydrodynamiques du comportement des métaux lourds dans un sol hétérogène présentant une contamination résiduelle en NAPL : étude sur la contamination mixte des sols." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ65448.pdf.
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Lang, Cassandra C., and University of Lethbridge Faculty of Arts and Science. "Identification and metabolic characterization of host-specific enterococci for use in source-tracking faecal contamination." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2005, 2005. http://hdl.handle.net/10133/265.
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Metabolic were used to evaluate Enterococcus as an indicator of faecal pollution. Enterococci were isolated using m-Enterococcus agar and speciated using conventional biochemical tests. Forty percent of the isolates were identified and metabolically characterized by the automated Biolog system. The biochemical test scheme recognized 16 enterococcal species, while Biolog recognized nine. Both methods identified E. faecalis at the greatest frequency. Overall species frequencies varied between the two methods. Biolog was unable to identify 31% of the isolates; 7% of the isolates were unidentified by the biochemical test scheme. Of the identified isolates, metabolic profiling with Biolog achieved speciation with 60 substrates. Unique profiles were obtained for 89% of the isolates. Isolates also demonstrated inter-trial differntial metabolism of substrates. This and the large number of unidentified isolates suggest great diversity among enterococci. Diversity and inter-trial metabolic inconsistencies will complicate use of enterococcal metabolic profiles as a source-tracking tool.xxiii, 264 leaves ; 29 cm.
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Tayab, Muhammad Rehan. "Environmental impact of heavy metal pollution in natural aquatic systems." Thesis, Brunel University, 1991. http://bura.brunel.ac.uk/handle/2438/5503.
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The distribution of heavy metals between soil and soil solutions is a key issue in evaluating the environmental impact of long term applications of heavy metals to land. Contamination of soils by heavy metals has been reported by many workers. Metal adsorption is affected by many factors, including soil pH, clay mineralogy, abundance of oxides and organic matter, soil composition and solution ionic strength. The pH is one of the many factors affecting mobility of heavy metals in soils and it is likely to be the most easily managed and the most significant. To provide the appropriate level of protection for aquatic life and other uses of the resource, it is important to be able to predict the environmental distribution of important metals on spatial and temporal scales and to do so with particular emphasis on the water column concentrations. Regulatory levels reflected in water quality criteria or standards are based on water column concentrations. Predicting water column concentrations requires a consideration of the interactions of water column contaminants with both bed sediments and suspended particulates as critical components in the assessment. The adsorption behaviour of cadmium, copper, lead and zinc onto soils is studied under the various geo-environmental conditions of pH, concentration of adsorbate and adsorbent, and solution compositions. Experiments were conducted to determine the equilibrium contact time of various adsorbates for adsorbent in different systems. Experiments were also conducted to check the efficiency of various acid-mixtures to extract heavy metal from soils into the aqueous phase. The adsorption behaviour of heavy metals onto soils was also studied from sea-water system. Soils are characterized in terms of the role of clay minerals to remove the metals from the solution phase, back-ground levels of metals, maximum adsorption capacity to adsorb various heavy metals from different adsorption systems, and type of surface sites present. The experimental data of metal adsorption is described by Langmuir adsorption model. The adsorption data are also expressed in terms of surface loading, surface acidity, adsorption density, and affinity of soils for heavy metals in different adsorption systems. Ecological implications of changes in physical and chemical conditions in aquatic systems on heavy metals uptake by soils are also discussed. This research covers the following areas: the environmental impact of heavy metal discharge into the aquatic systems, the study of the mobility patterns of different heavy metals as function of geo-environmental conditions, and determination of the pathways and the ultimate fate of heavy metals in the environment.
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Dupuy, Alain. "Simulation de la contamination diffuse des eaux souterraines par les nitrates à l'échelle du bassin versant." Poitiers, 1997. http://www.theses.fr/1997POIT2306.
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La presente etude s'inscrit dans le cadre de recherches sur la gestion des pollutions diffuses agricole a l'echelle du bassin versant. Les sols et l'assolement observes sur un bassin versant pilote de poitou-charentes sont utilises dans un modele mecaniste stochastique agriflux pour simuler l'ecoulement de l'eau et le transport des nitrates dans la zone racinaire et dans la frange superieure de la zone non saturee sur une periode de 15 ans. Les resultats de cette sont utilises sous forme de flux saisonniers pour reconstituer les concentrations en nitrates rencontrees dans la nappe. Une approche basee sur un modele de melange a montre que l'on pouvait reconstituer les concentrations de nitrates dans la nappe en fonction des conditions hydrodynamiques et des flux d'eau et de nitrates percolant depuis la surface. Dans une seconde approche, le couplage hydrodynamique entre les differentes zones du milieu (racinaire, non saturee et saturee) est realise sur des modeles d'ecoulement et de transport adaptes a l'echelle du bassin versant. Les flux d'infiltration calcules par agriflux dans la zone non saturee sont utilises comme flux de recharge dans le modele hydrodynamique modflow qui est utilise pour simuler l'hydrodynamique transitoire sur l'ensemble du bassin. Les periodes de contraintes de 90 jours sont determinees a l'aide d'une analyse correlatoire sur les donnees pluviometrique et piezometrique, et permettent de reconstituer un pseudo-regime transitoire par une succession d'etats permanents. Le modele mt3d est utilise pour la simulation du transport des nitrates dans la nappe avec le meme decoupage temporel que celui de modflow. L'hydrodynamique et le transport sont reconstitues sur le bassin sur une periode de 15 ans avec un pas de temps saisonnier. La dynamique des teneurs en nitrates dans une nappe a l'echelle d'un bassin versant et l'impact de differentes pratiques culturales peuvent ainsi etre simules dans une optique de gestion des pollutions diffuses agricoles.
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Ghosn, Micheline. "Chemical contamination in different marine organisms along the Lebanese coast : Environmental implications and health risks." Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0552.
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La consommation mondiale des produits de la mer est en perpétuelle croissance et les produits de la pêche sont devenus parmi les produits les plus marchandés à travers le monde. Cependant, la qualité de ces derniers soulève une problématique au niveau de la santé humaine avec l’augmentation des pressions anthropiques menaçant les écosystèmes côtiers et les organismes marins. Par la suite, malgré les qualités nutritionnelles des produits de la pêche, leur consommation peut être une voie d’exposition de l’homme à différents types de contaminants chimiques dont les éléments traces métalliques (ETMs). Dans ce contexte, l’évaluation du niveau de contamination dans ces produits et les risques qu’ils peuvent engendrer s’avère être une nécessité surtout en l’absence de normes locales et de programmes de surveillance. Les objectifs de cette étude sont de deux ordres : i) l’évaluation la qualité environnementale du littoral Libanais à travers les organismes marins et, ii) l’estimation du niveau des risques sanitaires liés à la consommation d’une sélection des produits de la pêche. Le premier objectif, était d’évaluer les niveaux de contaminants métalliques (20 éléments traces) chez six espèces marines de différents niveaux du réseau trophique (algues, moules, crevettes et poissons) représentatif des eaux côtières libanaises. Les résultats ont révélé que les espèces accumulent les métaux différemment soulignant ainsi l’importance d’une approche multi-espèce pour mieux refléter le niveau de contamination du milieu. Des variations inter-sites ont été également trouvées surtout durant la période pluvieuse de l’année indiquant l’effet des apports des rivières vers la zone côtière. Les niveaux des ETMs obtenus dans les muscles et les tissus comestibles dans le cadre de notre étude étaient du même ordre de grandeur que ceux mesurés dans d’autres régions du bassin Levantin. Cependant, les foies ont montré des concentrations supérieures comparées à d’autres études, suggérant ainsi que la côte libanaise est soumise à des pressions environnementales importantes. Le deuxième objectif, concerne l’évaluation des risques sanitaires liés à la consommation de différents produits de la pêche échantillonnés le long du littoral Libanais. Pour cela, cinq espèces consommées localement (1 bivalve, 1 crustacé et 3 espèces de poisson) et échantillonnés le long du littoral Libanais au niveau de trois sites soumis à différents niveaux de pressions anthropiques ont été sélectionnés. Tous les échantillons ont été analysés pour leur contenu en éléments traces. Des métaux comme le mercure (Hg) se retrouvent sous plusieurs formes chimiques, sa forme la plus toxique étant le méthylmercure (MeHg). La voie principale de l’exposition humaine au MeHg est la consommation de produits de la pêche. Pour cela, une méthode de spéciation du Hg dans les produits de la pêche a été optimisée et validée par profil d’exactitude. Les résultats ont montré que les niveaux des ETMs et du MeHg dans les espèces concernées, étaient largement inférieurs aux limites maximales admissibles fixées par la Commission Européenne et que leur consommation ne présente pas de risques pour la santé humaineGlobal food fish consumption has been in continuous increase and fishery products have become some of the most traded items in the world. However, the quality of these products is becoming an issue of concern to human health with the increase of anthropogenic activities threatening marine coastal ecosystems. Therefore, despite the well-known health benefits of fishery products, their consumption may be a route of human exposure to different kinds of chemical contaminants including trace elements. In this context, evaluating the contamination levels in these products and the risks they may engender to human health proves to be a necessity in the absence of local guidelines and monitoring programs. Thus, the thesis has 2 main objectives: i) the evaluation of environmental quality through marine organisms and, ii) the assessment of health risks related to the consumption of a selection of fishery products.The first objective was to study the levels of metallic contaminants (20 trace elements) in six marine species from different trophic levels of a food web (algae, mussel, shrimp and fish), representative of Lebanese coastal waters. The results showed that species accumulated metals differently underlining the importance of a multi-specific approach to reflect the contamination level of a certain site. Inter-site variations have been found mainly during the rainy period of the year while they were less prominent during the dry season, highlighting the effect of land-based sources and riverine effluents on the marine coastal area. Levels of trace elements in the muscles and edible tissues in species from our study, were similar to the ones reported in the Eastern Mediterranean (Levantine Basin) whereas livers showed higher levels compared to other studies suggesting that the Lebanese coast is exposed to strong environmental pressure. The second objective was to evaluate the health risks related to the consumption of different fishery products sampled along the Lebanese coast. In this prospect, five commonly consumed local species belonging to different compartments of the food chain, (1 bivalve, 1 crustacean and 3 fish species) sampled from three sites with different levels of anthropogenic pressures were selected. The samples were all analyzed for their content of trace elements. Metals such as mercury (Hg) are found in several chemical forms, the most toxic form being methylmercury (MeHg). The main route of human exposure to MeHg is the consumption of fishery products. That’s why, a method for the speciation of mercury in fishery products by HPLC-ICP-MS was optimized and validated based on an accuracy profile. The results showed that the levels of trace elements and MeHg in the selected species were all below the allowed maximum levels set by the European commission and so their consumption is not likely to cause any adverse effects to human health
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Nigar, Meher. "Studies on the interaction between arsenic (As) and rice varieties which differ in arsenate (As(V)) tolerance." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=33413.
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Nordstrom, Jeanne McDonald 1957. "The utility of using matched weight PVC filters during air sampling for particulates." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276824.
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Matched weight polyvinyl chloride (PVC) filters are currently available for use in total dust air sampling. This paper studies the utility of employing two superimposed filters in a cassette. Cassettes containing "paired" PVC filters were employed, in the same way matched weight filters would be used, during side by side sampling studies with cassettes housing single PVC filters, to determine whether the presence of two filters in a cassette presented problems during sampling. The effects of dust type, particle breakthrough, moisture concentration, and increased pressure drop from the addition of a second filter were studied. The presence of static electricity between filter pairs was also noted. Under recommended loading conditions "paired" filters seemed to perform as well as single filters in all aspects studied. Due to large filter weight variations found within individual batches of PVC filters, randomly selected filter pairs should not be used as actual matched weight filters.
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Randima, Livhuwani Priscilla. "Rhizosphere microbial diversity in PAH's contaminated and uncontaminated soil." Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-11302009-195201/.
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Aponte, Carmen Alicia. "Process inventory and pollution prevention overview for the citrus industry." FIU Digital Commons, 2000. http://digitalcommons.fiu.edu/etd/1298.
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Florida citrus represents approximately 70 percent of the industry production in the United States; therefore, any associated agricultural and industrial contamination is of concern and a focus of attention. The use of synthetic organic chemicals has become a farmer's necessity in order to supply consumers with high quality products, free of pest damage. However, industrial citrus wastes and chemical residual levels worry not only government agencies but also consumers since they indicate a serious habitat risk.
This study assesses citrus industrial processes and the paths that chemical substances follow from the time the citrus seed is planted until consumers get a final product as either fresh fruit or processed product. The study is built on information from United States Environmental Protection Agency (US EPA) manuals, Dade County Environmental Resources Management (DERM) inspection records, United States Food and Drug Administration (US FDA) regulations, Florida standards, journal publications, and research reports. Pollution prevention (P2 or prevention-of-pollution) alternatives are identified; alternatives are proposed, evaluated, and included. Strategies are described and pollution prevention opportunities proposed to minimize citrus wastes generation, chemical residuals in products, their environmental impact and health risk aspects while maximizing product quality.
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Abella, Justine Marie. "Implication des intégrons dans l’adaptation des communautés bactériennes." Thesis, Pau, 2015. http://www.theses.fr/2015PAUU3051/document.
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Les intégrons sont des éléments génétiques bactériens. Découverts récemment dans le contexte clinique, ils sont présents dans le génome d’un certain nombre de bactéries provenant d’environnements très variés. Ils sont composés d’un gène codant une intégrase et d’une succession de cassettes de gènes. L’activité de l’intégrase permet l’acquisition, la perte ou le réarrangement des cassettes. Par ailleurs un promoteur permet l’expression des cadres de lecture contenus dans les cassettes de gène. Ainsi les intégrons sont à la fois des réservoirs de gènes et des systèmes d'expression de ces gènes. Dans le contexte clinique, ils sont connus pour être impliqués dans l'adaptation des bactéries pathogènes. Ils sont en effet capables d'acquérir et de diffuser des gènes conférant un avantage sélectif face à la pression exercée par l’usage des antibiotiques et des biocides, et par ailleurs d’être mobilisés afin d’être transférés horizontalement. Quelques études ont porté sur les intégrons en dehors des environnements cliniques. Elles ont permis de caractériser de nombreuses cassettes de gènes, sans toutefois en atteindre toute la diversité, à partir de bactéries ou de communautés bactériennes issues d’environnements soumis à différents niveaux de contaminations. Cependant, la diversité de l'intégrase a été peu étudiée, car le plus souvent les études se sont limitées aux séquences d’intégrons cliniques. Ainsi, les intégrons environnementaux sont encore mal connus et mal caractérisés. Les objectifs de ma thèse étaient de caractériser la diversité des intégrons environnementaux, avec un focus particulier sur les intégrases, à partir d’environnements soumis à des contaminations chimiques variables, dans le but d’évaluer le rôle possible des intégrons dans l'adaptation des bactéries face à des perturbations environnementales. Au cours de ces travaux, environ 800 séquences d’intégrases différentes, pour la plupart encore inconnues, ont été obtenues à partir de différents sédiments d’eau douce et côtiers. Des études in situ et en microcosmes, d’environnements d’eau douce ou de milieux côtiers, et avec différents types et niveaux de polluants, ont permis de mettre en évidence un impact des contaminations du milieu sur la diversité des intégrons, sur l’intégrase comme sur les cassettes de gène, de manière indépendante à la structure de la communauté bactérienne. Enfin, lors de cette thèse a été réalisée la caractérisation d’un intégron potentiellement adaptatif face à une pollution pétrolière, porteur de la séquence intIOPS mise en évidence et nommée par Lionel Huang lors de sa thèse. Finalement, les résultats obtenus lors de cette thèse ont apporté de nouveaux éléments qui viennent soutenir notre hypothèse principale que les intégrons environnementaux seraient impliqués dans l’adaptation des communautés bactériennes en réponse à la présence de contaminants dans les milieux non cliniquesIntegrons are bacterial genetic elements. Recently discovered in the clinical context, they are present in the genome of a number of bacteria from a variety of environments. They are composed of a gene encoding an integrase and a succession of gene cassettes. The activity of integrase allows the acquisition, loss or rearrangement of cassettes. Furthermore, a promoter allows expression reading frames contained in the gene cassettes. Thus, integrons are both reservoirs of genes and these gene expression systems. In the clinical context, they are known to be involved in the adaptation of pathogenic bacteria. They are able to acquire and disseminate genes conferring a selective advantage over the pressure exerted by the use of antibiotics and biocides, and also being mobilized to be transferred horizontally. Some studies have focused on integrons outside of clinical environments. They have characterized many gene cassettes, without however reaching the diversity, from bacteria or bacterial communities coming from environments with different levels of contamination. However, the diversity of integrase has been little studied, because the majority of studies are limited to clinical integron sequences. Thus, environmental integrons are still poorly characterized and their diversity are little understood. The objectives of my thesis were to characterize the diversity of environmental integrate with a particular focus on integrase, from environments with varying chemical contamination, to evaluate the possible role of integrating in adapting bacteria face environmental disturbances. In this work, approximately 800 different integrase sequences, mostly unknown, were obtained from various freshwater and coastal water sediments. Field studies and microcosms of freshwater or coastal environments, with different types and levels of pollutants allowed to demonstrate an impact of environmental contaminations on the integron diversity, whether on the integrase or the gene cassettes, independently to the bacterial community structure. Finally, in this thesis the characterization of a potentially adaptive integron facing an oil pollution were performed. This integron carrying the intIOPS sequence highlighted and named by Lionel Huang during his thesis. Finally, the results obtained in this thesis provide further elements which support our main hypothesis that environmental integrons would be involved in the adaptation of bacterial communities in response to the presence of contaminants in non- clinical settings
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Tapie, Nathalie. "Contamination des écosystèmes aquatiques par les PCB et PBDE : application à l'estuaire de la Gironde." Bordeaux 1, 2006. http://www.theses.fr/2006BOR13325.
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Parmi la multitude de composés d’origine anthropique qui terminent leur course dans les écosystèmes aquatiques, les Polychlorobiphényles (PCB) connaissent un regain d’intérêt dû à la réévaluation de leur toxicité (perturbateur endocrinien, neurotoxicité) et à l’identification dans de nombreux écosystèmes aquatiques de composés aux propriétés similaires, les Polybromodiphényles éthers (PBDE). Dans cette étude des protocoles d’analyse simples, rapides et efficaces, permettant de traiter un grand nombre d’échantillons, ont été mis en place pour la quantification des PCB et PBDE. Ces protocoles ont permis de réaliser des expérimentations en milieux contrôlés et un suivi environnemental de grande ampleur. Une étude en milieux contrôlés des phénomènes d’accumulation et de dépuration des PCB et des PBDE a été réalisée sur trois espèces sentinelles : une algue (Isochrysis galbana), un bivalve (Mytilus edulis) et un poisson (Sparus aurata). Les cinétiques d’accumulation ont été réalisées à deux concentrations sur des composés modèles (CB 77, CB 153, BDE 47, BDE 153, chrysène, benzo(a)pyrène, fluoranthène). Parallèlement à ces études en milieu contrôlé, un suivi environnemental des niveaux de contamination des organismes du réseau trophique pélagique de l’estuaire de la Gironde a été réalisé (phase dissoute, phase particulaire, copépodes, mysidacés, gammares, crevettes, anguilles, mulets, flets, soles, maigres). Afin de replacer les niveaux de contamination de l’estuaire de la Gironde dans un contexte plus global, une étude des niveaux de contamination de flets issus des différents estuaires français a également été réaliséeDue to the recent re-evaluation of their toxic properties, the study of environmental distribution of Polychlorobiphenyls (PCBs) has regained a great interest. At the same time, concentration of similar compounds with similar properties, such as Polybromodiphenyl-ethers (PBDEs), seems to increase in environment. In order to understand transfer phenomenon of PCBs and PBDEs in aquatic ecosystems, fast and reliable analytical methods using ASE (Accelerated Solvent Extraction) and MAE (Microwave Extraction) have been developed. These protocols allow handling a lot of samples per day and managing environmental study and field experiment at large scale. Field experiments on different trophic status (algae (Isochrysis galbana), mussels (Mytilus edulis) and fishes (Sparus aurata)) were realised in order to understand the mechanisms of bioaccumulation or depuration of organic compounds (PCB 77, PCB 153, PBDE 47, PBDE 153, Bap, Fluoranthene, Chrysene). At the same time, Gironde estuary has been selected as a specific study area to study transfer of PCBs and PBDEs in aquatic ecosystems. The contamination of pelagic food web was evaluated by analysing water, particles, crustaceans and fishes. To compare Gironde estuary contamination to other French Atlantic coast estuaries (Seine, Ster, Loire, Vilaine and Gironde), flounder was selected as a model specie and its levels of contamination were characterised. Results show a relatively low contamination of French estuaries by PBDEs, but PCB contamination is still important and could be problematic particularly if we consider level of contamination of eel in Gironde estuary
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Tlili, Ahmed. "Signification écologique de la tolérance acquise des communautés microbiennes des biofilms de rivières à une contamination d’origine anthropique." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10293/document.
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Les modifications de structure et de diversité des communautés biologiques au sein d’un écosystème soumis à une perturbation, se traduisent généralement par la raréfaction, la disparition d’espèces sensibles et/ou l’apparition de nouvelles espèces tolérantes ou par la prolifération d’autres espèces tolérantes déjà présentes mais à une faible densité. Dans le cas d’une perturbation d’origine toxique, ceci a pour conséquence une diminution de la sensibilité globale de la communauté par rapport à la (aux) substance(s) responsable(s) de cette modification de structure et de diversité. L’évaluation de la tolérance vis-à-vis d’un toxique peut donc nous permettre de révéler a posteriori l’exposition d’une communauté biologique à ce toxique, en mettant en évidence le lien entre pression et impact sur le compartiment biotique d’un écosystème. Malgré de nombreux travaux en ce domaine, il reste cependant de nombreuses lacunes scientifiques dans la compréhension de cette tolérance induite par les pollutions (PICT). Le modèle d’étude retenu est le biofilm aquatique (ou périphyton), dont les spécificités biologiques et écologiques en font un outil d’étude très intéressant. Ce travail a permis de montrer que l’intégration du concept PICT comme un outil complémentaire dans les systèmes d'évaluation environnementale donnerait plus de pertinence écologique et de spécificité écotoxicologique à la batterie actuelle des bioindicateurs utilisés. Par ailleurs, le PICT est aussi une approche conceptuelle, à l’échelle des communautés, très riche et qui confirme l’intérêt d’aborder l’écotoxicologie avec le regard de l’écologue plus holistique que celui du toxicologue. En effet, les mesures de tolérance-induite qui prennent en compte la diversité fonctionnelle du biofilm, ainsi que les analyses taxonomiques associées, nous ont permis une meilleure compréhension de la résistance et de la résilience de cet écosystème suite à des perturbations d’origine chimique. Nos travaux nous ont aussi permis d’aborder le concept des seuils de résistance et de résilience écologiques, et de mettre en évidence le fait qu’une acquisition de tolérance à un stress donné, pourrait se traduire par le déplacement des communautés d’un état initial vers un état « alternatif » stable, même après le retrait du stress. Ces seuils écologiques ainsi que cet état alternatif stable signifient que la disparition des espèces les plus sensibles (comme l'un des processus expliquant le PICT) n'affecte donc pas les fonctions de la communauté dans son ensemble au début et ce seulement jusqu’à un certain seuil de résistance. Le PICT pourrait ainsi se traduire par une réduction de la diversité ou avec des modifications dans la composition spécifique, sans pour autant qu’il y ait un effet négatif sur le fonctionnement de la communauté. Cependant, la capacité des communautés à devenir tolérantes à une perturbation peut avoir des conséquences négatives sur les capacités de résilience et de résistance des écosystèmes. Nous avons donc abordé dans nos travaux le concept de « co-tolérance négative entre espèces » et de coût de la toléranceChanges in structure and diversity of biological communities within ecosystems subjected to disturbances are generally synonymous of the scarcity, loss and/or the emergence of new tolerant species or by the proliferation of other species already present but at low density. This leads to a decrease in the overall sensitivity of the community toward the substance(s) responsible for this change of community structure and diversity. The evaluation (and if possible the quantification) of tolerance towards a toxicant may therefore enable us to reveal a posteriori the exposure of a biological community to this toxicant (its exposure history), and demonstrate the specific link between pressure and impact on the biotic compartment of an ecosystem and, more generally, on the ecosystem. Despite numerous studies in this area, there are still many gaps in scientific understanding of the pollution induced-tolerance. The biological model that we used is the lotic biofilm (or periphyton) whose biological and ecological characteristics make it a very interesting tool for study. This work has shown firstly that the integration of the acquired tolerance concept as a complementary tool in the environmental assessment systems would allow more ecological relevance and ecotoxicological specificity to the current set of used bio-indicators. Furthermore, the PICT is also a conceptual approach at the community level, which confirms the interest to address ecotoxicology from the viewpoint of the ecologist that is more holistic than the toxicologist one. Indeed, measures of pollution-induced tolerance, by taking into account the functional diversity of biofilms, and the associated taxonomic analysis, allowed to have a better understanding of resistance and resilience of the ecosystem submitted to chemical perturbations. Our works enabled us to tackle the concept of ecological thresholds of resistance and resilience, and to highlight the fact that enhanced tolerance to a given stress, could result in the displacement of communities from an initial state to an « alternative » stable state, even after the stress removal. These ecological thresholds and the alternative stable state mean that the disappearance of the most sensitive species (as a process explaining the PICT) does not affect the functions of the community until reaching a threshold of resistance. Thus the PICT could correspond to a reduction in diversity or changes in species composition, without having a negative effect on the functioning of the community. However, the ability of communities to be tolerant toward disturbance can have negative consequences on the resilience and resistance of ecosystems. Consequently, we addressed in our work the concept of "negative co-tolerance between species" and costs of tolerance
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Tu, Wai-ki Alex, and 杜偉麒. "Hong Kong marine sediment contamination with Tributyltin and its impacts." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31254780.
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Hamel, Hélène. "Étude de l’évolution du trichlorure d’azote et des trihalométhanes dans l’eau et l’air des piscines chlorées : exploration des voies de réduction de cette contamination." Rennes 1, 2007. http://www.theses.fr/2007REN1S066.
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Dans l’eau des piscines, le chlore utilisé comme désinfectant réagit avec la pollution apportée par les baigneurs (sueur, urine, …), pour former des sous-produits. Certains de ces composés, tels que la trichloramine et les trihalométhanes sont très volatils et se transfèrent dans l’air des piscines couvertes. Ce travail renseigne d’une part les niveaux et les facteurs déterminants de la contamination de l’eau et de l’air des piscines par les trihalométhanes, jusqu’ici mal connus. D’autre part, en raison des préoccupations sanitaires liées à la présence des sous-produits de désinfection dans les piscines, ce travail explore deux stratégies de réduction de cette contamination. Nous avons ainsi amélioré les connaissances relatives au traitement de l’eau des bassins par les UV et à leur impact sur la formation des trihalométhanes. Nous avons également développé au laboratoire un dispositif innovant permettant de réduire significativement les teneurs en trichloramine dans les bassinsChlorination of swimming pool water generates various disinfection by-products like trihalomethanes and nitrogen trichloride, arising from the reaction between organic compounds released by the swimmers and chlorine. These compounds are of great volatility and also contaminate indoor air of swimming pools. This work brings on the one hand useful information on trihalomethane levels in pool water and indoor air, which are poorly documented, and highlights the important contributors to this contamination. Given the great concern for public health authorities caused by exposure of the population to disinfection by-products, this work explores on the other hand two ways of reduction of this contamination. UV treatment of pool water was first studied and particularly its impact on trihalomethane levels. We also developed a promising lab-scale to remove nitrogen trichloride from water
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Choi, Chung-ming, and 蔡頌明. "Land contamination and its remediation methods: a case study in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B3125312X.
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Reese, Ronald S. "Characterization of organic contamination of groundwater in a mining area, Globe, Arizona." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277240.
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Organic contamination is associated with inorganic contamination in a plume resulting from acidic mine drainage water in an area of copper mining, Globe, Arizona. The level of dissolved organic carbon (DOC) is low, but is eight times the 0.5 mgC/l background. The source is probably organic reagents used in mineral processing. DOC fractionation using XAD-8 resin sorption chromatography gave a hydrophobic acid fraction (humic substances) of 1.0 mgC/l, and the hydrophobic neutral fraction was also anomalous, being as high as 49% of DOC. The fractionation data matched that for a waste-solution lake, believed to be a source of the aquifer contamination. Loss of DOC is occurring downgradient in the aquifer, based on comparison of DOC/chloride ratios. Loss occurs as the pH increases to over 4 or 5. Sorption onto metal precipitates being formed, particularly of the hydrophilic fraction, may be occurring.
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RAMBERT, ALECSANDRA. "Etude de l'interaction particules-ecoulement : applications a l'analyse de la contamination aerienne en bioclimatologie et en pollution urbaine." Paris 11, 1998. http://www.theses.fr/1998PA112412.
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Dans ce travail, l'etude de l'interaction particules-ecoulement apporte des reponses a la question de la contamination aerienne en bioclimatologie (dans ce processus, l'etape de la liberation des particules est centrale) et en pollution urbaine. Nous avons propose une nouvelle approche de modelisation de la liberation des particules situees dans la sous-couche laminaire d'une couche limite turbulente. L'effet perturbateur de la partie turbulente de la couche limite sur la partie visqueuse a ete simule par une interaction entre une structure tourbillonnaire et une couche limite laminaire. L'arrachement de particules se produit quand les forces du fluide induites a la paroi par ce mecanisme sont superieures aux forces d'adhesion entre les particules et la surface. Nous avons developpe un dispositif pour la caracterisation experimentale de la liberation. L'utilisation de la velocimetrie laser a effet doppler permet une mesure de la vitesse de spores qui est non intrusive et d'une precision elevee. La mesure simultanee de la vitesse et de la taille de particules a ete exploitee pour estimer le transport de particules dans un ecoulement donne. Nous avons egalement aborde l'etude d'un autre type d'interaction particules-ecoulement, concernant cette fois-ci la dispersion de polluants dans une rue canyon. L'etude du transport de polluants a l'echelle urbaine est modelisee dans un premier temps par une interaction entre une couche limite (caracteristique de la couche limite atmospherique) et une encoche (rue canyon). La dynamique spatio-temporelle a ete quantifiee par des mesures de vitesses locales et globales. Les mesures de velocimetrie laser a effet doppler fournissent les histogrammes des fluctuations de vitesse des points specifiques de l'ecoulement. Une nouvelle technique basee sur le flot optique a ete appliquee pour le calcul des champs de vitesses.
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El-Osmani, Racha. "Étude de la contamination des eaux et des sédiments par les pesticides." Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10165/document.
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Depuis l’explosion de l’industrie chimique au début du XXème siècle et l’utilisation de produits de synthèse, des quantités croissantes de substances chimiques, n’ont cessé d’être émises dans l’environnement. Toutefois, dans les dernières décennies, il y a eu une préoccupation croissante au sujet du sort de ces produits chimiques qui menacent la ressource en eau. L’accroissement des connaissances sur la performance analytiques et les données toxicologiques sur les produits actifs a conduit les autorités dans les pays industrialisés et en développement à imposer diverses restrictions. La surveillance des contaminants dans les milieux aquatiques a été mise en place pour atteindre le bon état écologique des milieux. Parmi les polluants organiques les plus dangereux et les plus couramment détectés dans les milieux aquatiques, on trouve les hydrocarbures aromatiques polycycliques, leurs dérives et les pesticides. Ces contaminants présents à l’état de trace dans les milieux aquatiques. Leurs analyses nécessitent des méthodes analytiques appropriées à la fois spécifiques et sensibles. Les travaux de cette thèse s’orientent ainsi dans une direction visant à développer des méthodes analytiques pour l’extraction de plusieurs familles de contaminants organiques (pesticides, hydrocarbures …) présents dans l’eau et dans les sédiments. Un modèle mathématique Umetrics a été employé pour étudier l’influence de chaque paramètre intérêt. Comparé à des méthodes classiques, ce modèle permet de réduire le nombre d’expériences, et d’avoir des rendements très satisfaisants. Les méthodes optimisées ont été ensuite appliquées à étudier des milieux naturels en France et au LibanSince the explosion of the chemical industry in the twentieth century and the use of synthetic products, increasing amounts of chemicals, have continued to be released into the environment. However, in recent decades, there has been a growing concern about the fate of these chemicals that threaten water resources. Increased knowledge on the analytical performance and toxicological data on active products has led authorities in industrialized and developing countries to impose various restrictions. Monitoring of contaminants in aquatic environments has been put in place to achieve good ecological state of the environment. Among the most dangerous and the most commonly detected in aquatic organic pollutants, polycyclic aromatic hydrocarbons, their derivatives and pesticides. These contaminants present in trace amounts in aquatic environments. Analyzes require appropriate analytical methods to be both specific and sensitive. The objective of this thesis is to develop analytical methods for the extraction of several families of organic contaminants (pesticides, hydrocarbons ...) in water and sediment. A mathematical model Umetrics was used to study the influence of each interest parameter. Compared to conventional methods, this model reduces the number of experiments, and have very good yields. The optimized methods were then applied to study the natural environment in France and Lebanon