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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
671

Vulnerabilidade e perigo de contaminação dos aquíferos nas sub-bacias do Alto Aguapeí e Alto Peixe - SP /

Montero, Rafael Carrion. January 2012 (has links)
Orientador: Anna Silvia Palcheco Peixoto / Co-orientador: Emília Carlos Prandi / Banca: Rodrigo Lilla Manzione / Banca: Ilza Machado Kaiser / Resumo: A crescente demanda por recursos subterrâneos nas Bacias Hidrográficas dos Rios Aguapaí e Peixe, localizadas no oeste do Estado de São Paulo e a presença cada vez maior de substâncias em condições de acesso e contaminação das águas em subsuperfície têm pressionado de forma negativa a disponibilidade hídrica nessas bacias. Neste contexto de degradação, esta Dissertação objetiva a caracterização e avaliação da vulnerabilidade natural e dos perigos de contanimação das unidades aquíferas aflorantes nas subunidades de gestão de recursos hídricos denominados Alto Aguapeí e Alto Peixe. A caracterização da Vulnerabilidade foi realizada com aplicação do método GOD (Foster & Hirata, 1988). O perigo de contaminação dos aquíferos foi avaliado mediante a interpolação da vulnerabilidade natural com as fontes potencias de contaminação, identificadas e classificadas quanto o seu potencial de gerar carga contaminante, a partir da aplicação do método POSH (FOSTER et al, 2006). Os procedimentos de geoprocessamento foram realizados com auxílio do SIG ArcMap TM 9.3. Os resultados demonstraram que vulnerabilidades de classificação Extrema estão restritas as planícies fluviais dos rios Aguapeí e Tibiriça, ocupando cerca de 2% da área de estudos, as classes de vulnerabilidade Alta e Alta Baixa ocupam 41,5% e 23,7% respectivamente, enquanto 28,4% da área correspondem à vulnerabilidade Média. Para o restante da área obteve-se a classificação Média e Média Baixa Vulnerabilidade. A correlação das vulnerabilidades com as fontes potenciais de contaminação demonstraram que independente da localização, os postos de combustível e os locais de disposição de resíduos sólidos apresentam Alto perigo de contaminação. As atividades da indústria, por sua vez, apresentam Alto perigo de contaminação para os distritos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The increasing demand for groundwater resources in the Watersheds of Aguapeí and Peixe Rivers, located in the western part of São Paulo province, and also the increasing presence of substances in access condition and water contamination in the subsurface have been pressuring negatively the water availability in both basins. In this degradation context, this dissertation aims to characterize and evaluate the natural vulnerability and contamination risks of aquifers outcropping units in the sub water resources management units called. Alto Aguapeí and Alto Peixe. The vulnerability characterization was made applying the GOD method (Foster & Hirata, 1988). The aquifers contamination risk was estimated by interpolation of the natural vulnerability and the potential contamination sources that was identified and classified by their potential to generate contaminant load, using the POSH method (Foster et al, 2006). The geoprocessing producers were performed with assisting of some tools from the GLS ArcMap TM 9.3. The results evidenced that extreme classification vulnerability are restricted just for river plaints of Aguapeí and Tibiriça rivers, occupying around 2% of the studied area. The High and High Low vulnerability classes occupy 41.5% and 23.7% respectively and average vulnerability 28.4%. For the rest of the area was obtained medium and low vulnerability classification. The correlation of vulnerabilities and potential sources of contamination demonstrated that regardless of location, gas stations and solid waste disposal spots have high risks of contamination. The industrial activities have a high risk of contamination due the industrial district of Garça and Marilia and moderate for units in the food sector, located outside these districts. Furthermore, it is evident the importance of introducing the territory management policies... (Complete abstract click electronic access below) / Mestre
672

Emprego de filtro de fibras flexíveis constituído de fibras de algodão mercerizado e poliéster na clarificação de água para abastecimento / Employment of flexible fiber filter made of mercerized cotton and polyester fibers in the clarification of drinking water

Fagundes, Thalita Salgado 01 June 2015 (has links)
Os filtros de fibras flexíveis são módulos de filtração direta cujo leito filtrante é formado por micro fibras de poliamida, permitindo altas eficiências de remoção de sólidos suspensos, e aplicação de altas taxas de filtração. O presente estudo avaliou tal configuração de filtro utilizando fibras de algodão mercerizado e poliéster na forma de fios. Foram realizados testes de resistência dos fios a meios com características químicas distintas - alcalino, ácido e com cloro residual. Foi realizada caracterização das fibras estudadas através de Microscopia Óptica e Microscopia Eletrônica de Varredura. Foram construídos 4 filtros com diâmetro interno de 28 mm, e porosidade 67% (algodão), e 75% (poliéster), sendo 2 filtros constituídos de fibras de algodão mercerizado - comprimento de leito 60 e 100 cm; e 2 filtros constituídos de fibras de poliéster - comprimento de leito 60 e 100 cm. Foi utilizada para alimentação dos filtros água sintética de turbidez 7,7 ± 0,3 uT, e cor aparente 97 ± 5,0 uC, e realizada coagulação in-line com 22,5mg/L e 15 mg/L (este último valor somente para os filtros de 100 cm) de sulfato de alumínio. Foram avaliadas taxas de filtração de 40, 60, 80, 100 e 120 m/h. Os limites de turbidez estabelecidos para o filtrado foram de 1 e 2 uT. Os filtros de fibras flexíveis de algodão mercerizado e poliéster de leito 60 cm só conseguiram atingir os limites de turbidez até taxa de 80 m/h. Os filtros de leito 100 cm atingiram os limites satisfatoriamente em todas as taxas de filtração. Os filtros de poliéster obtiveram carreiras de filtração mais longas do que as obtidas pelos filtros de algodão, além de apresentarem perdas de carga menores. Exceto para taxa 40 e 60 m/h para o filtro de algodão mercerizado, todas as outras taxas em ambos os filtros obtiveram desempenhos melhores (carreiras de filtração longas, e filtrado de melhor qualidade) com dosagem menor de coagulante. Esse estudo mostrou potencial no uso das fibras de algodão mercerizado e poliéster nos filtros de fibras flexíveis aplicados em tratamento de água para abastecimento. Sugere-se estudos avançados para aplicação no Brasil de tal tecnologia. / The flexible fiber filters are direct filtration modules which filter media is made of polyamide micro fibers, obtaining high solids removal efficiency, and high filtration rates. This study evaluated the performance of the filter using mercerized cotton and polyester fibers. Tests of fibers resistance due to alkaline, acid and chlorinated environments were realized at the present research. The fibers were also analyzed by means of Optic and Scanning Electronic Microscopy. Four field-scale filters with an internal diameter of 28mm, porosity of 67% (cotton), and 75% (polyester) were installed; two of them made of mercerized cotton fiber- high of 60 and 100 cm; and two made of polyester fiber - high of 60 and 100 cm. A synthetic water was used as influent - turbidity 7,7 ± 0,3 uT, and color 97 ± 5,0 uC. In-line coagulation was used with 22,5 mg/L and 15 mg/L (this last value was only applied on 100cm length filters) of aluminium sulfate. The filtration rates studied were 40, 60, 80, 100 e 120 m/h. The turbidity limits were 1 e 2 uT. The 60 cm high flexible fiber filter made of mercerized cotton and polyester only could work under the established turbidity limits until 80 m/h. The 100 cm high flexible fiber filter could work well in all the filtration rates. The flexible fiber filter made of polyester obtained longer filtration times, and lower pressure drop comparing to the flexible fiber filter made of mercerized cotton. Except for filtration rates of 40 e 60 m/h which mercerized cotton filter, in all the rates for both fiber filters, the lower coagulant dosage demonstrated better results - longer filtration times, and better quality in the effluent. This study indicated the potential of using flexible fiber filter made of mercerized cotton and polyester in water treatment. It is suggested advanced studies for this technology application in Brazil.
673

Jodversorgung deutscher Wehrpflichtiger imAlter von 17,5 bis 21 Jahren

Bittermann, Heike 22 October 1999 (has links)
Daten der WHO belegen fast weltweit eine Jodmangelversorgung der Bevölkerung. Auch Deutschland wird zu den Jodmangelgebieten gezählt. Um repräsentative Daten zur Jod-versorgung verschiedener Bevölkerungsgruppen in Deutschland nach der Wieder-ver-einigung zu erheben, wurde ein Jod-Monitoring durchgeführt. Das Jod-Monitoring besteht aus 4 Teilstudien. In dieser Arbeit wird die Teilstudie, in der die Jodversorgung junger Männer, in diesem Fall Wehrpflichtige einer bestimmten Alters-gruppe, untersucht wurde, detailliert dargestellt. Dazu wurde die Jodausscheidung und die Jod-zu-fuhr der Probanden ermittelt. Die Jodaus-scheidung wurde in Spontanurinproben gemes-sen. Die Jodzufuhr wurde nach den Angaben eines Fragebogen berechnet. Ergänzend wurde in den Regionen, in denen das Jod-Monitoring durchgeführt wurde, der Jodgehalt in Trinkwasserproben analysiert. Die statistische Auswertung erfolgte im Hinblick auf regionale Unterschiede (Vergleich Nord/Süd und neue/alte Bundesländer). Die Arbeit enthält eine systematische Analyse der erhobenen großen Datenmenge. Daraus lassen sich Erkenntnisse über das Ernährungsverhalten, den Wissensstand zum Thema Jod und über die regionale Ausprägung der Jodversorgung der Probanden gewinnen. Sie bildet somit eine geeignete Basis für spätere prospektive Erhebungen zur Jodversorgung der Bevölkerung in Deutschland. / Data published by WHO prove a world-wide lack of iodine intake by the population. Even Germany is known as area of nutritional iodine deficiency. An iodine monitoring study has recently been undertaken with the aim of collecting representative data from different sections of the German population following reunification. The iodine monitoring project comprised four partial studies. The present paper represents such a partial study, giving details of iodine intake of young men, in this particular case of persons liable to military service of a specific age group. Iodine excetion and iodine intake of the tested persons were determined. Iodine excretion was measured on the basis of spontaneous urinanalyses. Data on iodine supply were determined in accordance with a questionnaire. In addition, the iodine content of drinking water in the areas covered by the study was determined. Statistical evaluation of the data was performed in respect to regional variations (comparing nothern and southern areas and new/old Lands of the Federal Republic of Germany). The study includes a systematic analysis of the voluminous data set. It allows insights into the eating habits, the status of knowledge about the significance of iodine and on the regional state of iodine supply available for the tested persons. Summing up, this study offers itself as a basis for future prospective studies with respect to the iodine supply of the German population.
674

Multistage solar still desalination system

Mkhize, Mfanafuthi Mthandeni January 2018 (has links)
Thesis (Master of Engineering in Mechanical Engineering)--Cape Peninsula University of Technology, 2018. / The present study was centred on the design of a thermal multistage solar still desalination system. The design is a multistage with new configurations such as direct vapour input into each stage using vapour make-up tubes and the integration of a multistage with a basin type solar still. The incorporation of float a valve in the secondary seawater tank to regulate the seawater in the assembly eliminated the need of pumps to the system. The circulation of seawater between the evaporator and the evacuated tube solar collector (ETC) was through the pressure difference and the flow back was controlled through the incorporation of oneway flow valve. The ETC was used as a heat source to supply the thermal energy into the multistage system. The system had no electrical connections and therefore, no forced circulation as no pumps or any electrical components were used. The system consisted of six stages in total, the evaporator supplied the vapour to five of the six stages of the system. The system was tested on the roof of Mechanical Engineering Department and this location was chosen because of less sun’s intensity obstructions. The system was tested for nine (9) days but the distillate collection was not performed for the whole each day. This was due to the controlled access to the roof and the minor repairs that had to occur before the tests were conducted. The duration on which the tests were conducted varied in each day. The data was supposed to be logged from 08h00 am to 18h00 pm but this was not so due to the controlled access to where the tests were conducted. This data logging period was chosen based on the assumptions that the sun’s intensity would be at maximum within this period. The longest period of test was approximately 7 hours and the system managed to produce about 1500 ml and the maximum temperature for the day was 28oC. The system produced a minimum of 225 ml in the space of 3 hours and the temperature of the day was 26oC. The total amount of distillate produced was about 7600 ml and this amount was produced within the period of 49 hours. The 49 hours is equivalent to two days and 1 hour. It is anticipated that the system would have produced more should there be no repairs involved during the tests. The system produced a maximum of 48 ml at night and a minimum of 8ml in some nights. The night tests were not controlled and monitored due to limited access. It was noticed that the system was empty in each morning of the first few days of the tests. This emptiness contributed to the leakage occurred to the evaporator. The leakage of the evaporator was caused by unmonitored heat supplied by the ETC. The evaporator was constructed using unsuitable material and this was another factor which contributed towards the failure of the evaporator.
675

Delivery of environmental health services to Ducats informal settlement

Sompani, Thozamile Matthews January 2003 (has links)
Thesis (MTech (Environmental Health))--Cape Technikon, 2003 / This study provides information on the provision of environmental health services to informal housing settlements by local authorities. A standard for Environmental Health Service delivery according to Government policies and legislation has been provided. Actual environmental health services delivered to Ducats informal settlement at the time (1992), have been compared to the services that should have been delivered by law. Baseline data have been compiled by means of questionnaires, in order to assist the different levels of government in addressing the housing and environmental health needs of the Ducat community. The nature of Environmental Health and the history of informal housing, more specific that of the Ducat informal housing settlement, have been determined. Limited environmental health services were rendered to informal housing settlements occupying land illegally during 1992. These environmental health services were limited to basic sanitation, water supply and refuse removal. Only pit latrines or bucket latrines were required as a means of sanitation, tanks for water supply and skips for the disposal of waste. Amatola Regional Services Council however rendered all the environmental health services required. Other environmental health aspects such as pest control, communicable disease control, air pollution control, radiation, occupational health issues, temperature extremes, lighting, ventilation, noise, social environment, food and meat hygiene were not required. This study has provided a set of Government policies and legislation, which should be considered in rendering environmental health services for housing in future. Uncertainty of the past decade, about rendering of Environmental Health services to people occupying land illegally, still persists. The Municipal Structures Act, 117 of 1998 requires the rendering of Environmental Health services by local authorities, but it does not state whether these services should be rendered to people occupying land illegally as well. Since this has been the biggest restriction in providing environmental health services in the past, it is recommended that Government address this uncertainty.
676

Águas subterrâneas / Subterranean water

Carvalho, Maria Serina Areias de 03 June 2013 (has links)
A água doce e potável representa um dos maiores desafios da humanidade. A tendência é reconhecer a água como um elemento natural de valor econômico, jurídico e social, cuja ameaça de escassez começa a ser debatida com maior interesse pela Organização das Nações Unidas. E os reservatórios de água doce e potável demandam uma proteção ambiental complexa, por conjugar o uso racional e a necessidade de desenvolvimento econômico e social. Por isso, nesse trabalho, propomos discutir sobre as formas de assegurar a continuidade do abastecimento das águas subterrâneas, para que possam servir às gerações futuras. / The sweet and drinking water represent one of the greatest challenges of humankind. The trend is to acknowledge water as a natural element with economic, legal and social values, which threat of scarcity commences to debate with larger interest for the United Nations Organization. And the reservoirs of sweet and drinking water demand a complex environmental protection, for conjugating the rational use and the necessity of economical and social development. Therefore, in that paper, we propose to discuss the means to legally ensure the continuity of subterranean water supply, so that they can attend the future generations.
677

Ocorrência e caracterização de Giardia e Cryptosporidium em águas captadas para abastecimento público no município de Cajamar-SP e avaliação do risco / Occurrence and characterization of Giardia and Cryptosporidium in water collected for public supply in the municipality of Cajamar-SP and risk assessment

Bataiero, Marcel Oliveira 18 April 2016 (has links)
Introdução: O risco à saúde humana ocasionado pela contaminação biológica de águas captadas para abastecimento público é realçado pela ocorrência de surtos de doenças associadas aos protozoários Giardia e Cryptosporidium, que possuem baixas doses infecciosas e alta capacidade de sobrevivência no ambiente, além de serem capazes de resistir ao processo tradicional de desinfecção da água (cloração). Partindo-se da hipótese de que há um risco elevado de infecção por estes protozoários pela ingestão de água tratada por métodos convencionais e que fazem uso de mananciais superficiais impactados por contaminação biológica, resultando num possível incremento da incidência de diarréias, este estudo se propôs a verificar a ocorrência destes protozoários em águas captadas para abastecimento público no município de Cajamar-SP, caracterizar sua patogenicidade e avaliar o risco associado ao seu consumo através da água tratada. Métodos: Foram coletadas 48 amostras do ribeirão dos Cristais no ponto de captação da estação de tratamento de água, semanalmente, durante 12 meses (de 16/05/2013 a 21/05/2014). A detecção e a análise da concentração dos protozoários foram realizadas de acordo com Método 1623.1 da United States Environmental Protection Agency e a extração e caracterização dos espécies/genótipos de Giardia e Cryptosporidium foi realizada através metodologias moleculares e seqüenciamento. O risco de infecção pela ingestão de cistos de Giardia e oocistos de Cryptosporidium presentes na água tratada foi calculado usando a ferramenta da Avaliação Quantitativa do Risco Microbiológico, a partir dos dados de concentração dos patógenos obtidos pelo Método 1623.1, eficiência de remoção dos (oo)cistos durante o processo convencional de tratamento da água, modelo dose-resposta e taxa de ingestão diária de água para indivíduos menores de 5 anos e maiores de 21 anos. Resultados: Cistos de Giardia foram detectados em 83,3% das amostras (40/48), com concentrações variando desde o limite de detecção (<0,1) até 8,6 cistos/L. Oocistos de Cryptosporidium foram etectados em 37,5% das amostras (18/48), com concentrações variando desde o limite de detecção (<0,1) até 2 oocistos/L. As espécies/genótipos encontrados (Giardia intestinalis A e B e Cryptosporidium parvum e hominis) são característicos de contaminação antrópica e são frequentemente identificados em estudos epidemiológicos como responsáveis por surtos. A estimativa do risco anual de infecção por Giardia foi de 3,3x10-3 (IC95% 4,6x10-3) para crianças e de 11,5x10-3 (IC95% 13,3x10-3) para adultos, enquanto o risco por Cryptosporidium foi de 1,1x10-3 (IC95% 1,7x10-3) para crianças e de 3,9x10-3 (IC95% 5,0x10-3) para adultos. O incremento da incidência de diarréias foi observado no cenário de estudo após um acidente que resultou em transbordamento de esgotos não tratados no manancial, coincidindo com o aumento na detecção de (oo)cistos. Conclusão: Os resultados evidenciaram que a vulnerabilidade do ribeirão dos Cristais a contaminações biológicas pode culminar em um risco elevado de infecção e adoecimento por Giardia e Cryptosporidium através da ingestão de água tratada. Portanto, o caso é preocupante, tanto do ponto de vista do tratamento e abastecimento de água potável, quanto da degradação e contaminação do manancial, evidenciando a necessidade de se estabelecer medidas de intervenção direcionadas a promover a qualidade da água e garantir sua segurança / Introduction: The risk to human health caused by biological contamination of source water from public water supply is highlighted by the occurrence of outbreaks associated with the protozoa Giardia and Cryptosporidium, which have low infectious doses and high capacity of survival in the environment, besides being capable of withstanding traditional process for water disinfection (chlorination). Considering that there is a high risk of infection by these protozoa through drinking water treated with conventional methods uptaked from surface waters impacted by biological contamination, resulting in a possible increase in the incidence of diarrhea, this study aimed to verify the occurrence of these protozoa in waters collected for public supply in Cajamar-SP, characterize their pathogenicity and evaluate the risk associated with its consumption. Methods: Forty eight samples were collected in ribeirão dos Cristais, at uptake point of the water treatment plant, weekly, for 12 months (from 05/16/2013 to 05/21/2014). The detection and quantification of protozoa were carried out according to the United States Environmental Protection Agency Method 1623.1, and the extraction and characterization of species/genotypes of iardia and Cryptosporidium were performed through molecular methods and sequencing. The risk of infection by ingestion of Giardia and Cryptosporidium (oo)cysts present in the treated water were calculated using the Quantitative Microbial Risk Assessment tool, based on the concentration data of pathogens obtained by the Method 1623.1, removal efficiency of (oo) cysts in the conventional process of water treatment, dose-response model and rate of daily water intake for individuals under the age of 5 years and over 21 years. Results: Giardia cysts were detected in 83.3% of the samples (40/48), with concentrations ranging rom the detection limit (<0.1) to 8.6 cysts/L. Cryptosporidium oocysts were detected in 7.5% of the samples (18/48), with concentrations ranging from the detection limit (<0.1) to 2 oocysts/L. The species/genotypes found (Giardia intestinalis A and B and Cryptosporidium parvum and hominis) are characteristic of anthropogenic contamination and are often identified in epidemiological studies as being responsible for outbreaks. The estimated annual risk of infection by Giardia was 3,3x10-3 (95% CI 4,6x10-3) for children and 11,5x10-3 (95% CI 13,3x10-3) for adults, while the risk for Cryptosporidium was 1,1x10-3 (95% CI 1,7x10-3) for children and 3,9x10-3 (95% CI 5,0x10-3) for adults. The increase in the incidence of diarrhea was observed in the study scenario after an accident that resulted in an overflow of untreated sewage that reached the reservoir, coinciding with an increase in the detection of the (oo)cysts. Conclusion: The results showed that the vulnerability of the ribeirão dos Cristais to biological contamination may result in a high risk of infection and illness by Giardia and Cryptosporidium through the drinking water consumption. Therefore, the case is of concern, both from the point of view of the treatment and supply of drinking water, as well as to the degradation and contamination of the water source, highlighting the need to establish intervention measures aimed at promoting water quality and ensure its safety
678

Solar Disinfection of Drinking Water

Rojko, Christine 23 April 2003 (has links)
Over 30% of the population in developing countries is in need of access to safe drinking water. The 875 million cases of diarrhea and 4.6 million deaths that occur each year due to a lack of a safe water supply occur primarily in these countries. It is estimated that these countries will need over $150 billion to establish full drinking water supply system coverage. Conventional methods of drinking water disinfection, such as chemical treatment, heat pasteurization, and filtration, require facilities, materials, and fuel that may not be readily available or feasible to attain. An alternative treatment option is to utilize solar energy, which has been shown to inactivate pathogens through pasteurization and radiation effects. This research was conducted to determine the effectiveness of solar disinfection for the inactivation of E. coli. Turbidity, sample volume, exposure time, and bottle size were varied. Experiments were conducted by adding E. coli to water samples (phosphate buffered saline with or without added montmorillonite clay or pond water) in clear drinking water test bottles. The bottles were then placed in full, direct sunlight. Samples were taken at predetermined intervals and solar intensity, weather conditions, and water temperatures were recorded during each sampling session. The viable bacterial count was enumerated using the pour plate method to determine log inactivation achieved. Laboratory experiments were also conducted to determine the effects of heating only on the inactivation of E. coli. Sample volumes from 1 to 2 L and turbidity values ranging from <1 ntu to approximately 100 ntu did not significantly affect inactivation levels when samples were exposed to sunlight for at least 4 hours. In samples with 0 ntu turbidity, a minimum cumulative intensity of 20.8 J/cm2 of wavelengths below 400 nm was required for a 7-log inactivation of E. coli. In samples with up to 100 ntu, a maximum fluence of 99.8 J/cm2 was required. Temperatures up to 46.0°C did not significantly inactivate E. coli, therefore radiation or the synergistic effects of radiation and heating accounted for the inactivation in samples exposed to sunlight.
679

Understanding inorganic arsenic exposure in Bangladesh and respiratory health consequences using a life course approach

Sanchez, Tiffany Renee January 2016 (has links)
Inorganic arsenic exposure is a well-known toxicant of which we are still discovering harmful effects. People are exposed to inorganic arsenic in the environment through either drinking arsenic-contaminated groundwater or consuming arsenic-contaminated food. Regarding global public health, drinking water is still the most important source of inorganic arsenic exposure and is the main focus of this work. The overall goal of this dissertation is to answer some pointing epidemiological questions about exposure to inorganic arsenic: How much do we know about inorganic arsenic and non-malignant lung disease in the general population? To what extent are adolescents with lifetime arsenic exposure susceptible to the respiratory consequences seen in adults? And what actions can be taken to effectively reduce exposure from arsenic-contaminated drinking water? First, we conducted a systematic review of 29 peer-reviewed articles from various populations around the world. The review focused on the different ways in which arsenic is associated with respiratory health to help inform policy makers and public health researchers on the existing evidence. In short, associations between arsenic and respiratory health were noted throughout the lifespan: in infancy, there was growing evidence that in utero arsenic exposure was associated with increased frequency and severity of respiratory tract infections; in childhood, evidence of respiratory symptoms also began to appear; and in adulthood, there was consistent evidence that arsenic exposure was associated with deficits in lung function and increased reports of coughing and breathing problems. The review also uncovered some research gaps, including few studies with strong exposure history from early life and few studies examining respiratory effects during adolescence. Next, we used a life course epidemiological approach to create a more precise understanding of arsenic exposure and respiratory health during the teenage years. This study examined the relationship between lifetime arsenic exposure and lung function in 14-17 year olds, thus studying the period of maximal lung function before natural decline. Overall, higher arsenic exposure was associated with lower lung function levels; however, these associations were only observed in males. This study used a sensitive marker of lung function to investigate early signs of small airway disease. Incorporating this common marker of small airway disease and airflow limitation in future studies on arsenic and respiratory health may help clarify how inorganic arsenic contributes to the development of chronic respiratory disease. Lastly, we evaluated the effectiveness of arsenic removal filters at the household-level in rural Bangladesh. Identifying sustainable ways of reducing exposure to arsenic from naturally contaminated groundwater has been a major environmental health challenge. Although lab-approved arsenic removal water filters exist, there was limited evidence of their prolonged efficacy in the field. To our knowledge, this was the largest and longest deployment of filters accompanied by monitoring of urinary arsenic. Our results demonstrated that filters can temporarily reduce arsenic exposure for weeks to a few months, but should not be considered as a long-term arsenic mitigation option. This failed attempt to reduce exposure confirmed that alternative mitigation strategies need to be employed in Bangladesh, particularly among more vulnerable populations, including pregnant women and young children. This dissertation has important policy implications for future arsenic research and mitigation efforts and should be effectively communicated to policy makers, public health officials, and the general population. Given the pervasive nature of arsenic exposure and the growing evidence of health consequences at different stages throughout the life course, the continued integration of information on inorganic arsenic and research collaborations across disciplines is critical for the prevention and mitigation of arsenic-induced health consequences.
680

La qualité de l'eau de la ressource au robinet : proposition d'une méthodologie pour l'identification de situations à risque à l'échelle du bassin versant / The water quality from the resource to the tap : proposal for a methodology for the identification of at risk situations at river basin scale

Piel, Stéphanie 10 April 2013 (has links)
Cette thèse se propose de contribuer aux connaissances relatives à l’impact des facteurs spatiaux (occupation du sol) et temporels (saisons, étiages, pluies) sur la qualité des eaux de ressource à l’échelle du bassin versant. Ainsi les zones et conditions à risque pourront être identifiées à l’aide de l’exploitation et de l’interprétation de bases de données historiques et expérimentales de qualité d’eau à l’échelle du bassin versant de la Vilaine en Bretagne. Cette étude se focalise principalement sur les micropolluants, avec notamment les pesticides et les produits pharmaceutiques vétérinaires pour le contexte agricole, mais également les produits pharmaceutiques humains compte tenu de l’intérêt grandissant qui leur est porté dans le domaine de l’évaluation des risques sanitaires et environnementaux. De plus, cette thèse se propose également de contribuer à l’amélioration et à l’adaptation des traitements des produits pharmaceutiques humains en usine de production d’eau potable compte tenu de l’évolution de la règlementation et de la protection du consommateur. / This thesis aims at contributing to knowledge about the impact of spatial (land use) and temporal (seasonal, low water levels, rainfall) factors on the resource quality at river basin scale. Thus at risk conditions and areas risk could be identified with the exploitation and interpretation of historical and experimental databases on water quality of the Vilaine’s river basin in Brittany. This study focuses mainly on micropollutants, including pesticides and veterinary pharmaceutical products for the agricultural context, but also on human pharmaceutical products considering the growing interest which is carried in the field of health and environmental risk assessment. In addition, this thesis also proposes to contribute to the improvement and adaptation of human pharmaceuticals treatment in drinking water treatment plant according to regulation evolution and to consumer protection.

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