541 |
Micro-scale variability of atmospheric particle concentration in the urban boundary layerPaas, Bastian 08 January 2018 (has links)
Für die Luftqualitätsbewertung in Städten sind Informationen zur raumzeitlichen Variabilität luftgetragener Feinstäube auf kleiner Skala von wichtiger Bedeutung. Standardisierte Messverfahren, zur Bestimmung von Partikelkonzentrationen, sind mit hohem Aufwand verbunden, weshalb dichte Messnetze fehlen. Partikelausbreitungsmodelle sind kompliziert in der Anwendung und/oder benötigen hohe Computerrechenleistung. Infolgedessen gibt es bezüglich örtlicher Partikelkonzentrationen große Informationslücken.
Diese Arbeit untersucht die mikroskalige Variabilität von Aerosolen in Raum und Zeit mit unterschiedlichen Methoden. Es wurden Erhebungen mit mobilen Sensoren und eine Passantenbefragung durchgeführt. Weiterhin wurden in dieser Arbeit die physikalischen Partikeltransportmodelle ENVI-met und Austal2000 in ihrer Leistung bewertet und in angewandten Studien eingesetzt. Weiterhin wurde ein neuronales Netzwerk zur Vorhersage von Partikelkonzentrationen entwickelt. Die Untersuchungen erfolgten in den Städten Aachen und Münster.
Es konnten unerwartete Verteilungsmuster hinsichtlich der Massekonzentration von Partikeln beobachtet werden. In einem innerstädtischen Park wurden diffuse Partikelquellen identifiziert, mit einem deutlichen Hinweis darauf, dass feuchtgelagerte Wegedecken einen maßgeblichen Anteil an lokalen Partikelimmissionen hatten. Weiterhin wurde Straßenverkehr als wichtiger Beitrag zum städtischen Aerosol identifiziert. Passanten, die verschiedenen Partikelkonzentrationen ausgesetzt waren, konnten diese perzeptiv nicht unterscheiden. Simulationsergebnisse von Austal2000 und ENVI-met wiesen Unterschätzungen im Vergleich zu Messwerten auf. Das entwickelte neuronale Netzwerk prognostizierte Partikelkonzentrationen teilweise mit hoher Genauigkeit. Das große Potenzial von neuronalen Netzen für die Vorhersage von Partikelkonzentrationen in räumlicher und zeitlicher Ausdehnung, auch für den Bereich der Luftqualitätsüberwachung, wurde aufgezeigt. / Knowledge about the micro-scale variability of airborne particles is a crucial criterion for air quality assessment within complex terrains such as urban areas. Due to the significant costs and time consumption related to the work required for standardized measurements of particle concentrations, dense monitoring networks are regularly missing. Models that simulate the transmission of particles are often difficult to use and/or computationally expensive. As a result, information regarding on-site particle concentrations at small scales is still limited.
This thesis explores the micro-scale variability of aerosol concentrations in space and time using different methods. Experimental fieldwork, including measurements with mobile sensor equipment alongside a survey, and modeling approaches were conducted. Applied simulation studies, a performance assessment of two popular particle dispersion models, namely Austal2000 and ENVI-met, as well as the development of an ANN model are presented. The cities of Aachen and Münster were chosen as case studies for this research.
Unexpected patterns of particle mass concentrations could be observed, including the identification of diffuse particle sources inside a park area with strong evidence that unpaved surfaces contributed to local aerosol concentration. In addition, vehicle traffic was proved to be a major contributor of particles, particularly close to traffic lanes. Results of the survey reveal that people were not able to distinguish between different aerosol concentration levels. Austal2000 and ENVI-met turned out to have room for improvement in terms of the reproduction of observed particle concentration levels, with both models having a tendency toward underestimation. The newly developed ANN model was confirmed to be a fairly accurate tool for predicting aerosol concentrations in both space and time, and demonstrates the principal ability of the approach also in the domain of air quality monitoring.
|
542 |
Influência da poluição do ar na inflamação das vias aéreas e na atividade de doença de pacientes com lúpus eritematoso sistêmico juvenil / Influence of air pollution on airway inflammation and disease activity in childhood-systemic lupus erythematosusAlves, Andressa Guariento Ferreira 28 August 2018 (has links)
Lúpus eritematoso sistêmico juvenil é uma doença inflamatória autoimune multifatorial com elevação de citocinas inflamatórias e com gravidade variável. Estudos observaram associação entre exposição a poluição do ar e aumento do número de internações hospitalares devido à exacerbação das doenças reumáticas pediátricas e aumento no risco de crianças portadoras de lúpus eritematoso sistêmico juvenil apresentarem atividade de doença moderada /grave após exposição a material particulado e dióxido de nitrogênio. Exposição à poluição do ar pode acarretar agravo agudo em doenças reumatológicas pediátricas, incluindo lúpus eritematoso sistêmico juvenil. Objetivos: Avaliar o efeito da exposição real a poluentes atmosféricos sobre biomarcadores inflamatórios em condensado do ar exalado e sobre a fração de monóxido de nitrogênio em ar exalado em pacientes com lúpus eritematoso sistêmico juvenil. Avaliar ainda, a correlação entre os biomarcadores inflamatórios no ar exalado e atividade da doença. Métodos: Estudo longitudinal de painel de medidas repetidas realizado em 108 visitas consecutivas de pacientes com diagnóstico de lúpus eritematoso sistêmico juvenil sem doenças respiratórias. Por 4 semanas consecutivas, medidas diárias individuais de dióxido de nitrogênio, material particulado fino, temperatura ambiental e humidade relativa do ar foram obtidos. Este ciclo foi repetido a cada 2,5 meses ao longo de um ano, além disso, citocinas do condensado do ar exalado (interleucinas 6, 8, 17 e fator de necrose tumoral-alfa), fração exalada de monóxido de nitrogênio e parâmetros de atividade de doença foram coletados semanalmente. Modelos específicos de equação estimada generalizada foram usadas para avaliar o impacto destes poluentes no risco de Systemic Lupus Erythematosus Disease Activity Index 2000 >= 8, citocinas no condensado do ar exalado e fração exalada de monóxido de nitrogênio, considerando o efeito fixo para medidas repetidas. Os modelos foram ajustados para provas de fase aguda, índice de massa corpórea, infecções, medicações e variáveis meteorológicas. Resultados: Efeito positivo nas medidas de desfechos foi observado para um aumento do intervalo interquartil do material particulado fino (18.12 ?g/m3). Um aumento do intervalo interquartil na média móvel de 7 dias no material particulado fino (lag0 to lag6) foi associado a um aumento de 0.1pg/ml (95%IC:0.01;0.19) e 0.9pg/ml (95%IC:0.05;0,12) nos níveis de interleucina 17 e fator de necrose tumoral-? do condensado do ar exalado, respectivamente. Também foi observado um aumento no risco de Systemic Lupus Erythematosus Disease Activity Index 2000 >= 8 de 1.47(95%CI:1.10;1.84) associado ao aumento da média móvel de material particulado fino. Em adição, um efeito a curto prazo na fração exalada de monóxido de nitrogênio foi evidenciado, medida móvel de 3 dias do material particulado fino foi associada com um aumento de 0.75ppb (95%IC:0.38;1.29) na fração exalada de monóxido de nitrogênio. Conclusão: Exposição a partículas finas inaláveis pode aumentar a inflamação das vias aéreas e posterior inflamação sistêmica nos pacientes com lúpus eritematoso sistêmico juvenil / Systemic lupus erythematosus is an inflammatory multisystem, autoimmune disease with elevated inflammatory interleukins levels. Exposure to air pollution may trigger pulmonary inflammation/systemic inflammation. Objective: The objective of this study was to investigate the association between daily individual exposure to air pollutants and airway inflammation and disease activity in childhood-onset systemic lupus erythematosus patients. A longitudinal panel study was carried out in 108 consecutive appointments with childhood-onset systemic lupus erythematosus patients without respiratory diseases. Methods: Over four consecutive weeks, daily individual measures of nitrogen dioxide, fine particulate matter, ambient temperature, and humidity were obtained. This cycle was repeated every 2.5 months along 1 year, and cytokines of exhaled breath condensate (interleukins 6, 8, 17 and tumoral necrose factor-alpha), fractional exhaled nitrogen monoxide, and disease activity parameters were collected weekly. Specific generalized estimation equation models were used to assess the impact of these pollutants on the risk of Systemic Lupus Erythematous Disease Activity Index 2000 >= 8, exhaled breath condensate cytokines, and fractional exhaled nitrogen monoxide, considering the fixed effects for repetitive measurements. The models were adjusted for inflammatory indicators, body mass index, infections, medication, and weather variables. Results: An interquartile range increase in fine particulate matter 4-day moving average (18.12ug/m3) was associated with an increase of 0.05 pg/ml (95% CI 0.01; 0.09, p = 0.03) and 0.04 pg/ml (95% CI 0.02; 0.06, p = 0.01) in interleukin 17 and tumoral necrosis factor-alpha exhaled breath condensate levels, respectively. Additionally, a short-term effect on fractional exhaled nitrogen monoxide was observed: the fine particulate matter 3-day moving average was associated with a 0.75 ppb increase (95% CI 0.38; 1.29, p = 0.03) in fractional exhaled nitrogen monoxide. Also, an increase of 1.47 (95% CI 1.10; 1.84) in the risk of Systemic Lupus Erythematous Disease Activity Index 2000 >= 8 was associated with fine particulate matter 7-day moving average. Conclusion: Exposure to inhalable fine particles increases airway inflammation/pulmonary and then systemic inflammation in childhood-onset systemic lupus erythematosus patients
|
543 |
Influência da poluição do ar na inflamação das vias aéreas e na atividade de doença de pacientes com lúpus eritematoso sistêmico juvenil / Influence of air pollution on airway inflammation and disease activity in childhood-systemic lupus erythematosusAndressa Guariento Ferreira Alves 28 August 2018 (has links)
Lúpus eritematoso sistêmico juvenil é uma doença inflamatória autoimune multifatorial com elevação de citocinas inflamatórias e com gravidade variável. Estudos observaram associação entre exposição a poluição do ar e aumento do número de internações hospitalares devido à exacerbação das doenças reumáticas pediátricas e aumento no risco de crianças portadoras de lúpus eritematoso sistêmico juvenil apresentarem atividade de doença moderada /grave após exposição a material particulado e dióxido de nitrogênio. Exposição à poluição do ar pode acarretar agravo agudo em doenças reumatológicas pediátricas, incluindo lúpus eritematoso sistêmico juvenil. Objetivos: Avaliar o efeito da exposição real a poluentes atmosféricos sobre biomarcadores inflamatórios em condensado do ar exalado e sobre a fração de monóxido de nitrogênio em ar exalado em pacientes com lúpus eritematoso sistêmico juvenil. Avaliar ainda, a correlação entre os biomarcadores inflamatórios no ar exalado e atividade da doença. Métodos: Estudo longitudinal de painel de medidas repetidas realizado em 108 visitas consecutivas de pacientes com diagnóstico de lúpus eritematoso sistêmico juvenil sem doenças respiratórias. Por 4 semanas consecutivas, medidas diárias individuais de dióxido de nitrogênio, material particulado fino, temperatura ambiental e humidade relativa do ar foram obtidos. Este ciclo foi repetido a cada 2,5 meses ao longo de um ano, além disso, citocinas do condensado do ar exalado (interleucinas 6, 8, 17 e fator de necrose tumoral-alfa), fração exalada de monóxido de nitrogênio e parâmetros de atividade de doença foram coletados semanalmente. Modelos específicos de equação estimada generalizada foram usadas para avaliar o impacto destes poluentes no risco de Systemic Lupus Erythematosus Disease Activity Index 2000 >= 8, citocinas no condensado do ar exalado e fração exalada de monóxido de nitrogênio, considerando o efeito fixo para medidas repetidas. Os modelos foram ajustados para provas de fase aguda, índice de massa corpórea, infecções, medicações e variáveis meteorológicas. Resultados: Efeito positivo nas medidas de desfechos foi observado para um aumento do intervalo interquartil do material particulado fino (18.12 ?g/m3). Um aumento do intervalo interquartil na média móvel de 7 dias no material particulado fino (lag0 to lag6) foi associado a um aumento de 0.1pg/ml (95%IC:0.01;0.19) e 0.9pg/ml (95%IC:0.05;0,12) nos níveis de interleucina 17 e fator de necrose tumoral-? do condensado do ar exalado, respectivamente. Também foi observado um aumento no risco de Systemic Lupus Erythematosus Disease Activity Index 2000 >= 8 de 1.47(95%CI:1.10;1.84) associado ao aumento da média móvel de material particulado fino. Em adição, um efeito a curto prazo na fração exalada de monóxido de nitrogênio foi evidenciado, medida móvel de 3 dias do material particulado fino foi associada com um aumento de 0.75ppb (95%IC:0.38;1.29) na fração exalada de monóxido de nitrogênio. Conclusão: Exposição a partículas finas inaláveis pode aumentar a inflamação das vias aéreas e posterior inflamação sistêmica nos pacientes com lúpus eritematoso sistêmico juvenil / Systemic lupus erythematosus is an inflammatory multisystem, autoimmune disease with elevated inflammatory interleukins levels. Exposure to air pollution may trigger pulmonary inflammation/systemic inflammation. Objective: The objective of this study was to investigate the association between daily individual exposure to air pollutants and airway inflammation and disease activity in childhood-onset systemic lupus erythematosus patients. A longitudinal panel study was carried out in 108 consecutive appointments with childhood-onset systemic lupus erythematosus patients without respiratory diseases. Methods: Over four consecutive weeks, daily individual measures of nitrogen dioxide, fine particulate matter, ambient temperature, and humidity were obtained. This cycle was repeated every 2.5 months along 1 year, and cytokines of exhaled breath condensate (interleukins 6, 8, 17 and tumoral necrose factor-alpha), fractional exhaled nitrogen monoxide, and disease activity parameters were collected weekly. Specific generalized estimation equation models were used to assess the impact of these pollutants on the risk of Systemic Lupus Erythematous Disease Activity Index 2000 >= 8, exhaled breath condensate cytokines, and fractional exhaled nitrogen monoxide, considering the fixed effects for repetitive measurements. The models were adjusted for inflammatory indicators, body mass index, infections, medication, and weather variables. Results: An interquartile range increase in fine particulate matter 4-day moving average (18.12ug/m3) was associated with an increase of 0.05 pg/ml (95% CI 0.01; 0.09, p = 0.03) and 0.04 pg/ml (95% CI 0.02; 0.06, p = 0.01) in interleukin 17 and tumoral necrosis factor-alpha exhaled breath condensate levels, respectively. Additionally, a short-term effect on fractional exhaled nitrogen monoxide was observed: the fine particulate matter 3-day moving average was associated with a 0.75 ppb increase (95% CI 0.38; 1.29, p = 0.03) in fractional exhaled nitrogen monoxide. Also, an increase of 1.47 (95% CI 1.10; 1.84) in the risk of Systemic Lupus Erythematous Disease Activity Index 2000 >= 8 was associated with fine particulate matter 7-day moving average. Conclusion: Exposure to inhalable fine particles increases airway inflammation/pulmonary and then systemic inflammation in childhood-onset systemic lupus erythematosus patients
|
544 |
Evaluation of Dust Suppressants for Gravel Roads : Methods Development and Efficiency StudiesEdvardsson, Karin January 2010 (has links)
Approximately 75 percent (300 000 km) of the total Swedish road network and 20 percent(20 000 km) of the national road network consists of gravel roads. One of the most significantproblems associated with gravel roads is traffic-generated dust emission, which contributes tothe deterioration of the road surface and acts as a major source of particulate matter releasedinto the atmosphere, thereby involving public economics, road safety, human health, andenvironmental quality. In order to bind the fine granular material, which is prone to rise into theair, dust suppressants are applied on roads on a yearly basis. Methods for evaluating the efficiency of dust suppressants will facilitate in the selection of themost appropriate product and its optimal application rate. For example, methods forsupervision of residual dust suppressant concentration are valuable tools for estimatinglongevity and optimal application rates, and, consequently, effectiveness of different products. Application of the proper dust suppressant to a gravel road ensures road safety and ridingcomfort as well as creating a cleaner and healthier environment for residents in buildingsadjacent to the road. It also reduces the need and cost for vehicle repair, road maintenanceactivities, and aggregate supplementation. Both field-based and laboratory research were performed to evaluate the efficiency of varioussuppressants and the influence such factors as product concentration, leaching, and fine materialcontent have on the efficiency of different products. Within the field-based research, a newlydeveloped mobile methodology was used to measure dust emission on numerous test sectionstreated with various dust suppressants. In general, all dust suppressants tested, except apolysaccharide (sugar) and products, which form a brittle surface crust, i.e. lignosulphonate andbitumen emulsion, showed acceptable dust reduction. Test sections treated with a magnesium- or calcium chloride solution were the most effectivelydust suppressed. The application of solutions instead of a solid salts achieves a more uniformproduct distribution and, therefore, probably a more efficient performance. By applying acalcium- or magnesium chloride solution instead of traditionally used solids, the cost for annualdust control, as well as the environmental impact from the release of these chemicals in theenvironment, can be reduced by 50 percent. A significant problem when using dust suppressants is their tendency to leach during rainfalldue to their soluble properties. Residual chloride could be detected in the gravel wearing courseover a longer period of time than lignosulphonate and, therefore, showed more effective longtermperformance. Optimal percentages of fine material for minimal lignosulphonate andchloride leaching were found to be 15 percent by weight and 10-16 percent by weight,respectively. Ions of calcium chloride seemed to initiate flocculation of clay particles, therebypreventing them from leaching. Still, the fine material in gravel wearing courses has to be replenished regularly as indicated by studies of the longevity of fine material. Loss up to80 percent was found after two years. Toxicity tests show that dust suppressant application for dust control purposes, at traditionallyused application rates, does not constitute a threat to sensitive aquatic life. Tests on subsoilwater samples indicated elevated chloride levels, which possibly could cause corrosion to pipes,but not high enough to flavour drinking water. / QC20100616
|
545 |
Measurements of Water-soluble Composition of Fine Atmospheric Particulate Matter (PM2.5) and Associated Precursor Gases via Ambient Ion Monitor-ion Chromatography (AIM-IC)Markovic, Milos 30 August 2012 (has links)
Atmospheric fine particulate matter (PM2.5), which is mostly formed in the atmosphere from precursor gases, contributes to numerous environmental and health concerns. Quantifying the ambient concentrations of PM2.5 and precursor gases can be challenging. Hence, many scientific questions about the formation, chemical composition, and gas/particle partitioning of PM2.5 remain unanswered. Ambient Ion Monitor - Ion Chromatography (AIM-IC) was characterized and utilized to measure the water-soluble composition of PM2.5 (dominated by pNH4+, pSO42-, and pNO3-) and associated precursor gases (dominated by NH3(g), SO2(g), and HNO3(g)) during two field campaigns. The AIM-IC detection limits for hourly sampling were determined to be 3 - 45 ng m-3. The response time for “sticky” gases was significantly improved with a nylon denuder membrane. A novel inlet configuration for the AIM-IC, which minimizes sampling inlet losses and carryover in sample analyses, was implemented. Measurements from the BAQS-Met 2007 campaign were utilized to assess the accuracy of the AURAMS model and investigate gas/particle partitioning in SW Ontario. Due to high sulphate levels, NH3(g) was the limiting chemical factor in the formation and gas/particle partitioning of PM2.5. The errors in the predictions of relative humidity and free ammonia were responsible for the poor agreement
iii
between modelled and measured pNO3- values. The AIM-IC measurements from the CalNex 2010 study were compared to the CMAQ model and utilized to investigate the gas/particle partitioning in Bakersfield, CA. Very high NH3(g) concentrations were observed, and the formation and partitioning of PM2.5 was limited by HNO3(g) and H2SO4. Evidence of rapid removal of HNO3(g) by interactions with super-micron dust particles, and possibly with the alkaline surface was found. CMAQ exhibited significant biases in the predicted concentrations of pSO42-, NH3(g) and HNO3(g).
|
546 |
Measurements of Water-soluble Composition of Fine Atmospheric Particulate Matter (PM2.5) and Associated Precursor Gases via Ambient Ion Monitor-ion Chromatography (AIM-IC)Markovic, Milos 30 August 2012 (has links)
Atmospheric fine particulate matter (PM2.5), which is mostly formed in the atmosphere from precursor gases, contributes to numerous environmental and health concerns. Quantifying the ambient concentrations of PM2.5 and precursor gases can be challenging. Hence, many scientific questions about the formation, chemical composition, and gas/particle partitioning of PM2.5 remain unanswered. Ambient Ion Monitor - Ion Chromatography (AIM-IC) was characterized and utilized to measure the water-soluble composition of PM2.5 (dominated by pNH4+, pSO42-, and pNO3-) and associated precursor gases (dominated by NH3(g), SO2(g), and HNO3(g)) during two field campaigns. The AIM-IC detection limits for hourly sampling were determined to be 3 - 45 ng m-3. The response time for “sticky” gases was significantly improved with a nylon denuder membrane. A novel inlet configuration for the AIM-IC, which minimizes sampling inlet losses and carryover in sample analyses, was implemented. Measurements from the BAQS-Met 2007 campaign were utilized to assess the accuracy of the AURAMS model and investigate gas/particle partitioning in SW Ontario. Due to high sulphate levels, NH3(g) was the limiting chemical factor in the formation and gas/particle partitioning of PM2.5. The errors in the predictions of relative humidity and free ammonia were responsible for the poor agreement
iii
between modelled and measured pNO3- values. The AIM-IC measurements from the CalNex 2010 study were compared to the CMAQ model and utilized to investigate the gas/particle partitioning in Bakersfield, CA. Very high NH3(g) concentrations were observed, and the formation and partitioning of PM2.5 was limited by HNO3(g) and H2SO4. Evidence of rapid removal of HNO3(g) by interactions with super-micron dust particles, and possibly with the alkaline surface was found. CMAQ exhibited significant biases in the predicted concentrations of pSO42-, NH3(g) and HNO3(g).
|
547 |
Estudo das alterações no desenvolvimento, no comportamento e na bioquímica cerebral de ratos machos adultos expostos à poluição atmosférica ambiental durante a fase intra-uterina e o período de lactação / Study of the alterations in the development, behavior and cerebral biochemistry of male rats exposed to the environmental atmospheric pollution in the intra-uterine phaseAna Claudia Tedesco Zanchi 16 April 2010 (has links)
Estudos experimentais feitos em nosso laboratório comprovaram que a inalação de material particulado proveniente da queima de combustíveis fósseis utilizados em siderurgia pelos ratos adultos diminuiu a atividade motora dos animais no campo aberto. Além disso, provamos que os ratos habituaram ao ambiente desse teste, o que significa que a inalação desse tipo de material não provocou variação em termos de aprendizado simples. Uma das causas da alteração no comportamento em relação à motricidade seria o estresse oxidativo causado pelo material particulado no estriado e cerebelo desses animais. Entretanto, em nossa cidade não existem estudos que demonstrem a estreita associação entre inalação de poluentes, estresse oxidativo e alterações comportamentais. Baseados nos nossos trabalhos anteriores e na literatura, nosso objetivo foi investigar se a poluição atmosférica a nível ambiental durante as fases pré e pós-natal alteraria a memória discriminativa de curta-duração e a memória espacial. Além disso, avaliamos o papel do estresse oxidativo como o mecanismo propulsor dessas mudanças de comportamento. Para tal, ratas prenhas foram expostas ao ar filtrado e ao ar não filtrado durante os 21 dias de gestação. Ao final do período de amamentação, os machos foram separados e subdividos em 4 grupos experimentais (n=24): 1) Filtrado: nasceu e viveu em ambiente cujo ar era filtrado, 2) NFF: nasceu em ambiente cujo ar era não filtrado e viveu a partir do 21o dia do pós-natal no ambiente com ar filtrado, 3) FNF: nasceu sob ar filtrado e viveu a partir do 21o dia do pós-natal sob ar não filtrado, 4)NF: nasceu e viveu em ambiente cujo ar era não filtrado. Os animais ficaram expostos a poluição por 150 dias. Os animais foram divididos em 3 lotes: lote 1: n=6 animais por grupo; após anestesia profunda, os animais foram perfundidos com soro fisiológico seguido de paraformaldeído 4%, o encéfalo foi retirado e dissecado em córtex, hipocampo e estriado para análises histológicas por técnicas estereológicas; lote 2: n=12 ratos por grupo; aplicação dos testes comportamentais; um dia após os testes, esses animais foram eutanasiados por decapitação, o encéfalo retirado e dissecado da mesma forma citada anteriormente para análise de estresse oxidativo; lote 3: n=6 animais por grupo; os animais foram decapitados e o sangue troncular coletado para análises de elementos traço tóxicos e essenciais no sangue total. O córtex apresentou lipoperoxidação no grupo NF quando comparado aos outros grupos, assim como uma alta concentração de Cd no sangue. O grupo NFF apresentou uma maior concentração de Cu, Se e Zn no sangue em relação aos demais. Em relação à memória discriminativa de curta-duração, houve uma diminuição no grupo NF em relação aos demais grupos. No hipocampo e estriado, foi observado aumento da lipoperoxidação nos grupos FNF e NF, respectivamente, quando comparado aos outros grupos. Quanto à memória espacial, não houve diferença estatisticamente significativa entre os grupos. Primeiramente, como pudemos observar, o cada estrutura encefálica apresenta uma resposta ao estresse oxidativo. O córtex do grupo NF apresentou aumento de lipoperoxidação. Como se sabe, o Cd é feto tóxico e passa via transplacentária adsorvido ao material particulado inalado pela mãe. No caso do grupo NF, o Cd possivelmente deslocou o Zn do sítio ativo da enzima CuZn superóxido dismutase formando forma inativada da mesma. O Cd, também, forma conjugado com duas moléculas de glutationa reduzida a fim de ser excretado pela bile. Isso reduz a sua capacidade antioxidante. Esse elemento traço desloca o Fe e o Cu dos sítios ativos das suas proteínas de armazenamento, a ferritina e a ceruplasmina, respectivamente. Esses dois elementos ficam livres para catalisar a reação de Fenton cujo produto é o radical hidroxil, extremamente tóxico para o organismo. O grupo NF apresentou uma diminuição na capacidade de discriminar dois objetos diferentes. Provavelmente, o Cd agiu de forma indireta diminuindo a capacidade antioxidante da CuZn superóxido dismutase e da glutationa, além de liberar Fe e Cu e aumentar a produção de radical hidroxil. O aumento da lipoperoxidação causado pelo Cd pode ser o mecanismo responsável pela perda desse tipo de memória. Entretanto, o grupo NFF, cuja exposição à poluição foi na fase pré-natal, não apresentou aumento na lipoperoxidação. Possivelmente, a alta concentração dos elementos traço essenciais, Cu, Zn e Se aumentou a atividade das enzimas CuZn superóxidodismutase e glutationa peroxidase, respectivamente, o que evitou danos oxidativos durante o período intra-uterino. O grupo FNF apresentou aumento de lipoperoxidação no hipocampo, mas não houve diferença na memória espacial testada com o labirinto de Morris modificado. Portanto, considerando todos os achados, concluímos que, possivelmente, o aumento da lipoperoxidação causado indiretamente pelo Cd pode ser um dos mecanismos responsáveis pela perda da capacidade da memória discriminativa de curta-duração. Além disso, os elementos traço essenciais exercem uma proteção via aumento das defesas antioxidantes dos animais que nasceram em ambiente poluído e, após 21 dias de vida, foram transferidos para o ambiente com o ar filtrado, o que demonstra, provavelmente, a existência de mecanismos antioxidantes de adaptação em ambientes inóspitos como forma de proteção contra o agente agressor durante o desenvolvimento do embrião. / Experimental studies done at our laboratory demonstrated that the inhalation of residual oil fly ash by the adult rats decreased motor activity of the animals in the open-field test. Additionaly, we showed that rats which inhalated residual oil fly ash preserved its habituation capacity. In this study, oxidative stress in striatum and cerebellum might be the cause of motor activity alterations. However, there were any studies about air pollution and behavioral alterations in Porto Alegre. Based on our previous works and in the literature, our objective was to investigate if the exposure to air pollution during intrauterine and lactation periods would damage the short term discriminative and spatial memories and if the mechanisms would be dependent of oxidants. For such, female pregnant rats were exposed to the filtered air and to the non filtered air during the 21 days of gestation. At the end of the breast-feeding period, the males were separate and divided in 4 experimental groups (n =24): 1) Filtered (F): - pre and post-natal exposure until adulthood in filtered air; 2) non filtered/filtered air (NFF): pre-natal period in non-filtered air until PND21 and post-natal in filtered air until adulthood; 3) filtered air/non-filtered air (FNF): pre-natal period in filtered air until PND 21 and post-natal period in non-filtered air until adulthood; 4) non filtered air (NF): pre and post-natal periods in non-filtered air.The animals were exposed the pollution for 150 days. The animals were divided in 3 lots: lot 1: n=6 animals per group; after anesthesia, the animals were perfused with saline solution following by paraformaldehyde 4%, the brain was removed and dissected in cortex, hippocampus and striatum for histological analyses by stereological techniques; lot 2: n=12 rats per group; submitted to behavioral tests; one day after the tests, those animals were euthanized by decapitation, the brain was removed and dissected in the same way mentioned previously for oxidative stress analysis; lot 3: 6 animals per group; the animals were decapitated and the troncular blood was collected to analyze the toxic and the essential trace elements. The cortex presented lipoperoxidation in NF group when compared to other groups, as well as a high concentration of Cd in the blood. The group NFF presented higher blood concentration of Cu, Se and Zn when compared to other groups. There was a decrease in the discriminative capacity in the group NF when compared to other groups. In the hippocampus and striatum, increases of lipidperoxidation were observed in the groups FNF and NF, respectively, when compared to other groups. Spatial memory of all groups was preserved. We observed the each brain structure reacts in a different way to oxidative stress. The NF cortex group presented an increased of lipidperoxidation. In this group, there was higher Cd blood concentration, which passes through placenta and it is fetotoxic. It might be possible that Cd dislocated Zn of the active site of CuZn superóxido dismutase resulting in inactive forms of this enzyme. The Cd also depletes reduced glutathione. Moreover, Cd may dislocate the Fe and Cu from its storage proteins to react with oxygen peroxide increasing the hydroxyl radical production by Fenton reaction. The group NF presented a decrease in the capacity to discriminate two different objects. Cd may act in an indirect way reducing the antioxidant capacity of CuZn superxidodismutase and of the glutathione and increasing the hydroxyl radical production. Lipoperoxidation in NF cortex caused by the Cd may be one of the mechanisms which explain the loss of discriminative capacity. However, the group NFF, whose air pollution exposure was in the pre-natal period, did not present increase of lipidperoxidation. The higher concentrations of essential trace elements (Cu, Se and Zn) may protect this group against oxidative stress. These elements are cofactor of antioxidants enzymes, superoxidodismutase and glutathione peroxidase and increased its activities during the intra-uterine exposure to air pollution. The group FNF presented lipidperoxidation increase in the hippocampus, but there was no difference in the spatial memory tested with Morris\' maze. Therefore, considering our data, we suggested that the increase of lipidperoxidation caused indirectly by Cd, which was adsorbed in particulate matter surface, may be one of the mechanisms which explain the loss of short-term discriminative memory
|
548 |
Pollution atmosphérique et déclenchement de poussées de sclérose en plaques, investigation au niveau individuel / Air pollution and triggering of multiple sclerosis relapses, individual level investigationJeanjean, Maxime 30 January 2018 (has links)
La sclérose en plaques (SEP) est une maladie neuro-inflammatoire du système nerveux central. Les causes sont multifactorielles impliquant à la fois une prédisposition génétique et l'influence de facteurs environnementaux. Dans environ 85% des cas, les patients sont atteints de poussées correspondants à la survenue de signes neurologiques, suivis d'une phase de rémission partielle ou totale. De nombreux travaux avancent l'hypothèse selon laquelle le taux de poussées varie au gré des saisons, survenant plus fréquemment au printemps et en été. Cette fluctuation temporelle a soulevé la question de l'influence de paramètres dépendants de la saison tels que l'ensoleillement et le statut en vitamine D, le niveau de mélatonine ou encore la pollution atmosphérique. Etant donné cette variation de la pollution de l'air, nous avons cherché à explorer l'impact à court terme des particules fines (PM10), benzène (C6H6), dioxyde d'azote (NO2), monoxyde de carbone (CO) et de l'ozone troposphérique (O3), sur le risque de déclenchement de poussée, indépendamment des saisons "chaude" (1er avril au 30 septembre) et "froide" (1er octobre au 31 mars). Ce travail s'est appuyé sur les données de patients issus du réseau ville-hôpital alSacEP. Nous avons sélectionné 424 patients atteints de SEP à début rémittent et ayant connu un total de 1 783 poussées (2000-2009). Les niveaux journaliers de pollution, produits grâce au modèle physique déterministe ADMS-Urban, ont été modélisés sur une base horaire pour chaque IRIS de la communauté urbaine de Strasbourg par l'actuelle AASQUA ATMO Grand Est. De plus, une enquête individuelle menée dans le cadre de cette étude auprès de l'ensemble des patients (PT) a permis de collecter (par questionnaire téléphonique ou auto-questionnaire sur internet) des informations personnelles socio-économiques (SES) et du mode de vie pour 188 d'entre eux (PS). Enfin, le niveau SES des IRIS a été estimé à l’aide d’un indice de défaveur social - construit à partir des données du recensement de l’INSEE. Nous avons observé une influence saisonnière délétère à court terme de la pollution (3 jours précédant la poussée) sur le risque de poussée en PT, notamment de l'O3 en saison "chaude" et des PM10 et NO2 en saison "froide". Nos résultats suggèrent également que le contexte SES puisse exacerber ces associations, notamment chez les patients résidant dans les quartiers défavorisés lors d'exposition aux PM10, NO2, C6H6 et CO ("froide") et ceux résidant dans les quartiers favorisés et défavorisés lors de l'exposition à l'O3 ("chaude"). Enfin, nous avons observé chez la PS que le niveau d'éducation faible, le revenu familial moyen, la consommation de cigarette et le manque d'activité physique régulière sont les catégories SES et du mode de vie les plus associées avec le risque de poussée lors de l'exposition à la pollution de l'air. Ce travail montre la nécessité d'étudier les expositions environnementales au cours de la SEP selon une approche holistique intégrant des facteurs individuels et contextuels. / Multiple sclerosis (MS) is a neuro-inflammatory disease of the central nervous system (CNS). Causes are multifactorial enrolling both genetic predisposition and influence of environmental factors. In 85% of cases, patients experience relapse corresponding to the occurrence of neurologic signs, followed by a phase of partial or total remission. Several studies put forth the hypothesis that relapses rate varies across season, mainly occurring during spring and summer. This temporal fluctuation raised the question of season-dependent parameters influence such as sunlight exposure and vitamin D, melatonin level or ambient air pollution. Considering this variation of air pollution, we explored the short-term impact of fine particles (PM10), benzene (C6H6), nitrogen dioxide (NO2), carbon monoxide (CO) and ground-level ozone (O3), on the risk of relapse triggering, separately for "cold" (i.e., October-March) and "hot" (April-September) season. This work has drawn from data of patients provided by the alSacEP network. We included 424 patients affected with remitting MS onset who experienced 1,783 relapses over the 2000-2009 period. Daily level of air pollution was modeled through ADMS-Urban software at the census block scale of the Strasbourg metropolitan area (AASQA ATMO Grand Est). Furthermore, an individual survey was conducted among all the patients (PT) in order to collect individual socioeconomic (SES) and lifestyle features. Finally, the census block SES position was estimated using a composite deprivation index - created from the INSEE census data. A short-term (3 days preceding the relapse) seasonal adverse effect was observed in PT, in particular during exposure to O3 in "hot" season and PM10 and NO2 in "cold" season. Results also suggest that the SES context might exacerbate these associations, in particular among patients who were living in deprived neighborhood with exposure to PM10, NO2, C6H6 and CO ("cold) and those who were living in most well-of and deprived places with exposure to O3 ("hot"). Finally, we observed among Ps that low education level, average family income, smoking and lack of physical activity are more associated with the risk of relapse triggering when patients were exposed to air pollution. This work shows the need to investigate environmental exposure such as air pollution along the SEP course using a holistic approach integrating individual and contextual factors.
|
549 |
Critical perspectives: North Sea offshore wind farms. : Oral histories, aesthetics and selected legal frameworks relating to the North Sea. / Kritiska perspektiv: vindkraftparker i Nordsjön : Muntlig historia, estetik och utvalda rättsliga ramar relaterade till NordsjönMoss, Joanne January 2021 (has links)
The study is developed from five in-depth interviews with individuals from different walks of life who have interacted significantly with the North Sea. The study discusses change in the North Sea specifically in the development of fixed turbine wind farms and their physical and aesthetic effects. Observations speakers make as to changes in the North Sea and as to its beauty are contextualised and discussed using NASA satellite images, photographs and review of available academic literature, UK policy documents and law. This context includes a study of the industrialised North Sea with reference to the sediment sea plumes behind monopile turbines. The United Kingdom was selected for particular study of its wind farm development permissions process, including evaluations of seascape and the requirement of independence for expert evidence. Decline of trawler access to the North Sea is referenced to wind farm growth, and to adverse changes in public opinion leading to closure of the UK Dogger Bank to trawlers. Finality of wind farm development decisions is considered against the prospect of overturn by the courts. This aspect covers the application and development of principles relating to appeal by way of judicial review in the UK jurisdictions of Scotland, England and Wales, and Northern Ireland. The study identifies, and explains the English aesthetic evaluation of wind farms. It concludes that sea plumes are the result of a legal choice to allow permit applications to succeed without testing by reference to detailed in-sea turbine dimensions. In the permissions process (a) sea plumes are not evaluated by the seascape criteria applicable to coastal or off-coastal wind farms (b) deep offshore wind farms are instead evaluated by possible changes to character of the sea. The study further concludes that (i) the open horizon of the North Sea has been lost in significant part (ii) the combined aesthetic of transience, decay, and nostalgia underlies the aesthetic of the North Sea Maunsell forts (contrasted to Sealand), and also underlies attitudes to decommissioning wind farms, and (iii) concepts of sea beauty may be based on appearance or health, being regulated by different legal regimes in each eventuality (respectively the European Landscape Convention, or the OSPAR/ biodiversity/ habitat initiatives)
|
550 |
Evaluation of Indoor Air Quality in Four Nursing Home Facilities in Northwest OhioTebbe, Hope M. 18 October 2017 (has links)
No description available.
|
Page generated in 0.1108 seconds