The role of the spatial representation in the relation between chronic exposure to NO2 and respiratory health outcomes is studied through a spatial approach encompassing three conceptual components: the geography of susceptibility, the geography of exposure and the geography of risk. A spatially explicit methodology that defined natural neighbourhoods for the city of Ottawa is presented; it became the geography of analysis in this research. A LUR model for Ottawa is developed to study the geography of exposure. Model sensitivity to the spatial representation of population showed that dasymetric population mapping did not provide significant improvements to the LUR model over population at the dissemination block level. However, both the former were significantly better than population represented at the dissemination area. Spatial representation in the geography of exposure was also evaluated by comparing four kriging and cokriging interpolation models to the LUR. Geostatistically derived NO2 concentration maps were weakly correlated with LUR model results. The relationship between mean NO2 concentrations and respiratory health outcomes was assessed within the natural neighbourhoods. We find a statistically significant association between NO2 concentrations and respiratory health outcomes as measured by global bivariate Moran’s I. However, for regression model building, NO2 had to be forced into the model, demonstrating that NO2 is not one of the main contributing variables to respiratory health outcomes in Ottawa. The results point toward the importance of the socioeconomic status on the health condition of individuals. Finally, the role of spatial representation was assessed using three different spatial structures, which also permitted to better understand the role of the modifiable areal unit problem (MAUP) in the study of the relationship between exposure to NO2 and health. The results confirm that NO2 concentration is not a major contributing factor to the respiratory health in Ottawa but clearly demonstrate the implications that the use of opportunistic administrative boundaries can have on results of exposure studies. The effects of the MAUP, the scale effect and the zoning effect, were observed indicating that a spatial structure that embodies the scale of major social processes behind the health condition of individuals should be used when possible.

The role of the spatial representation in the relation between chronic exposure to NO2 and respiratory health outcomes is studied through a spatial approach encompassing three conceptual components: the geography of susceptibility, the geography of exposure and the geography of risk. A spatially explicit methodology that defined natural neighbourhoods for the city of Ottawa is presented; it became the geography of analysis in this research. A LUR model for Ottawa is developed to study the geography of exposure. Model sensitivity to the spatial representation of population showed that dasymetric population mapping did not provide significant improvements to the LUR model over population at the dissemination block level. However, both the former were significantly better than population represented at the dissemination area. Spatial representation in the geography of exposure was also evaluated by comparing four kriging and cokriging interpolation models to the LUR. Geostatistically derived NO2 concentration maps were weakly correlated with LUR model results. The relationship between mean NO2 concentrations and respiratory health outcomes was assessed within the natural neighbourhoods. We find a statistically significant association between NO2 concentrations and respiratory health outcomes as measured by global bivariate Moran’s I. However, for regression model building, NO2 had to be forced into the model, demonstrating that NO2 is not one of the main contributing variables to respiratory health outcomes in Ottawa. The results point toward the importance of the socioeconomic status on the health condition of individuals. Finally, the role of spatial representation was assessed using three different spatial structures, which also permitted to better understand the role of the modifiable areal unit problem (MAUP) in the study of the relationship between exposure to NO2 and health. The results confirm that NO2 concentration is not a major contributing factor to the respiratory health in Ottawa but clearly demonstrate the implications that the use of opportunistic administrative boundaries can have on results of exposure studies. The effects of the MAUP, the scale effect and the zoning effect, were observed indicating that a spatial structure that embodies the scale of major social processes behind the health condition of individuals should be used when possible.

Viena svarbiausių daugelio didesnių miestų ekologinių problemų - vis didėjanti oro tarša azoto dioksidu. Pagal taršą azoto oksidais, galima spręsti apie bendrą miesto oro užterštumą, todėl labai svarbu kontroliuoti šio teršalo koncentraciją ore. 2005 - 2007 metais Mažeikių mieste buvo atliktas tyrimas, kurio pagrindinis tikslas - ištirti azoto dioksido koncentraciją Mažeikių mieste skirtingais sezonais bei aptarti meteorologinių sąlygų įtaką azoto dioksido koncentracijos sklaidai. Azoto dioksido koncentracijai nustatyti buvo naudotas pasyvaus kaupimo metodas. Atlikus tyrimus paaiškėjo, kad didžiausia koncentracija buvo nustatyta 2005 metų vasaros sezono metu (14,2 μg/m3). Tam įtakos turėjo mažas kritulių kiekis, aukšta temperatūra, bei vyravusi vėjo kryptis, nešusi teršalus nuo AB „Mažeikių naftos“. Panašūs rezultatai gauti ir 2006 metų žiemos sezono metu (14,0 μg/m3). Žiemos metu dažnai stebimos didesnės teršalų koncentracijos, kurios išsiskiria iš nuosavų namų šildymo sistemų. Mažiausia koncentracija buvo nustatyta 2007 metų rudens sezono metu (7,2 μg/m3) . Panaši koncentracija nustatyta ir 2007 metų vasarą (7,9 μg/m3). Tai lėmė palankios teršalų sklaidai meteorologinės sąlygos: didesnis kritulių kiekis, didesnė santykinė drėgmė. Nagrinėjant meteorologinių sąlygų įtaką azoto dioksido koncentracijos pasiskirstymui, statistiškai reikšmingi ryšiai gauti tarp vidutinio vėjo greičio ir azoto dioksido koncentracijos rudens sezono metu (r = -0,8729; p = 0,0533), kritulių... [toliau žr. visą tekstą] / The most important problem of biggest towns is air pollution of nitric dioxide. By pollution of nitric dioxide we can decide about general towns polltution. In the Mažeikiai town was explore distribution of nitric dioxide concentration. Nitric dioxide concentrations were gauge in the different seasons. We used a passive sampling method and triethanolamine as an absorbent. After analysis we get such rezults: the maximum concentration was fixed in the summer (14,2 μg/m3). It could impact low rainfall, high temperature and dominant wind which pollution drived from AB „Mažeikių nafta“. A similar results were assessed in the winter (2006 year) (14,0 μg/m3). Minimum value was fixed in the autumn (2007 year) (7,2 μg/m3). Similar concentration was fixed in the summer too (7,9 μg/m3). It impacted atmospheric conditions: high humidity. Reliable results were get between wind rate and nitric dioxide concentrations in the autumn season (r = -0,8729; p = 0,0533), precipitation and nitric dioxide concentrations in the spring (r = -0,9983; p = 0,0374) also precipitation and nitric dioxide concentrations in all seasons r = -0,7897; p = 0,0066). But in the neither season was not exceed the quotas of concentration (40 μg/m3).

The role of the spatial representation in the relation between chronic exposure to NO2 and respiratory health outcomes is studied through a spatial approach encompassing three conceptual components: the geography of susceptibility, the geography of exposure and the geography of risk. A spatially explicit methodology that defined natural neighbourhoods for the city of Ottawa is presented; it became the geography of analysis in this research. A LUR model for Ottawa is developed to study the geography of exposure. Model sensitivity to the spatial representation of population showed that dasymetric population mapping did not provide significant improvements to the LUR model over population at the dissemination block level. However, both the former were significantly better than population represented at the dissemination area. Spatial representation in the geography of exposure was also evaluated by comparing four kriging and cokriging interpolation models to the LUR. Geostatistically derived NO2 concentration maps were weakly correlated with LUR model results. The relationship between mean NO2 concentrations and respiratory health outcomes was assessed within the natural neighbourhoods. We find a statistically significant association between NO2 concentrations and respiratory health outcomes as measured by global bivariate Moran’s I. However, for regression model building, NO2 had to be forced into the model, demonstrating that NO2 is not one of the main contributing variables to respiratory health outcomes in Ottawa. The results point toward the importance of the socioeconomic status on the health condition of individuals. Finally, the role of spatial representation was assessed using three different spatial structures, which also permitted to better understand the role of the modifiable areal unit problem (MAUP) in the study of the relationship between exposure to NO2 and health. The results confirm that NO2 concentration is not a major contributing factor to the respiratory health in Ottawa but clearly demonstrate the implications that the use of opportunistic administrative boundaries can have on results of exposure studies. The effects of the MAUP, the scale effect and the zoning effect, were observed indicating that a spatial structure that embodies the scale of major social processes behind the health condition of individuals should be used when possible.

Die Veröffentlichung analysiert die Ursachen der NO2-Belastung in Sachsen und prognostiziert deren Entwicklung. Die aktualisierte Version des Handbuchs der Emissionsfaktoren des Straßenverkehrs (HBEFA 3.1) ist eine der Datengrundlagen. Hauptverursacher von NO2-Grenzwertüberschreitungen in sächsischen Städten ist der Kfz-Verkehr. Die sächsischen Daten von Verkehrsstationen im Zeitraum von 1995 bis 2009 bestätigen den bundesweit abnehmenden Trend. An hoch belasteten Straßen sind weitere dauerhafte und/oder temporäre Maßnahmen erforderlich, um den NO2-Grenzwert bis spätestens 2015 einzuhalten. Die Erneuerung der Kfz-Flotte reicht dafür nicht aus. Als sofort wirkende Maßnahme hat auch unter Berücksichtigung des neuen HBEFA 3.1 die Umweltzone ihre Berechtigung. Die Festlegung von wirksamen Maßnahmen erfordert eine individuelle Planung.

Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains ix, 105 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 92-93).

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references. Issued in print and online. Available via ProQuest Digital Dissertations.

This thesis examines the spatial and temporal variation in nitrogen dioxide (NO2) levels in Guernsey and the impacts on pre-existing asthmatics. Whilst air quality in Guernsey is generally good, the levels of NO2 exceed UK standards in several locations. The evidence indicates that people suffering from asthma have exacerbation of their symptoms if exposed to elevated levels of air pollutants including NO2, although this research has never been carried out in Guernsey before. In addition, exposure assessment of individuals is rarely carried out and research in this area is limited due to the complexity of undertaking such a study, which will include a combination of exposures in the home, the workplace and ambient exposures, which vary depending on the individual daily experience. For the first time in Guernsey, this research has examined NO2 levels in correlation with asthma patient admissions to hospital, assessment of NO2 exposures in typical homes and typical workplaces in Guernsey. The data showed a temporal correlation between NO2 levels and the number of hospital admissions and the trend from 2008-2012 was upwards. Statistical analysis of the data did not show a significant linear correlation due to the small size of the data sets. Exposure assessment of individuals showed a spatial variation in exposures in Guernsey and assessment in indoor environments showed that real-time analysis of NO2 levels needs to be undertaken if indoor micro environments for NO2 are the be assessed adequately. There was temporal and spatial variation in NO2 concentrations measured using diffusion tubes, which provide a monthly mean value, and analysers measuring NO2 concentrations in real time. The research shows that building layout and design are important factors for good air flow and ventilation and the dispersion of NO2 indoors. Environmental Health Officers have statutory responsibilities for ambient air quality, hygiene of buildings and workplace environments and this role needs to be co-ordinated with healthcare professionals to improve health outcomes for asthmatics. The outcome of the thesis was the development of a risk management framework for pre-existing asthmatics at work for use by regulators of workplaces and an information leaflet to assist in improving health outcomes for asthmatics in Guernsey.

Made available in DSpace on 2015-05-14T13:21:28Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1522052 bytes, checksum: 728654c924983b2f081ae014dd6883a7 (MD5) Previous issue date: 2011-12-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / NO2 is a gas found in trace amounts in the atmosphere. Its main natural source of emissions is the rapid oxidation of NO by O3 in the upper troposphere. For this reaction to occur, first it is necessary for stable N2 molecule to be broken by natural or man-made phenomena that requires high energy. These phenomena consist of rays, lightning, combustion processes such as fires, the industrial combustions and those by vehicles. In metropolitan areas it has been observed an increase in the concentrations of NO2 relating them to diseases of the respiratory and cardiovascular causes of death. NO2 is a precursor to other strong oxidants such as tropospheric ozone, nitric acid and peroxyacetyl nitrate (PAN) therefore it is an indicator of a mixture of pollutants. This work aims to analyze the NO2 in the city of João Pessoa, get the time profile of their concentration and to identify pollution peaks. The method used was modified Griess-Saltzman with active sampling and pre-concentration of the sample in SPE cartridge, silica C-18. The determination of NO2 was made by molecular absorption spectrophotometer, UV-Vis. There were two sampling sites in the two seasons, in downtown during summer (January and February 2011) and in UFPB during autumn (April and May 2011). From the results, the samples from downtown had the highest concentrations of NO2, as 15 μg/m³, after 17h and 8 μg/m³, between 12/14 h, probably due to heavy traffic of diesel vehicles. The air collected in the UFPB showed lowest concentrations, ranged from 7 μg/m³ (at night) to 0.9 μg/m³, at 12 to 14 h. The data from PCA showed that the moisture influences the NO2 concentration in the morning while solar radiation and the radiation and the temperature affect NO2 concentrations in the afternoon. / O NO2 é um gás encontrado em quantidades traço na atmosfera. Sua principal fonte de emissão natural é a rápida oxidação do NO pelo O3 na alta troposfera. O NO é produzido através de fenômenos naturais ou antrópicos que demandam alta energia. Tais fenômenos consistem nos raios, relâmpagos, processos de combustão como as queimadas, as combustões industriais e as veiculares. O NO2 é precursor de outros oxidantes fortes como o ozônio troposférico, o ácido nítrico e o nitrato de peroxiacetila (PAN), e por isto pode ser indicador de uma mistura de poluentes. Este trabalho tem o objetivo de avaliar a concentração de NO2 na cidade de João Pessoa, obter o perfil horário de suas concentrações e identificar picos de poluição. O método utilizado foi o de Griess-Saltzman modificado, com amostragem ativa e pré-concentração da amostra em cartucho SPE, de sílica C-18. As amostras foram coletadas em dois locais, no centro da cidade, durante janeiro e fevereiro de 2011 e nas dependências da UFPB, entre abril e maio de 2011. Os resultados mostram o comportamento esperado para o NO2, com máximas no período da manhã, decaindo por das 12h e aumentando no final do dia. Devido ao tráfego intenso de veículos automotores, as amostras coletadas no centro da cidade apresentaram as maiores concentrações de NO2, com pico de 15 μg/m³ no horário da noite (após as 17 horas), e mínima de 8 μg/m³, no período das 12 às 14 horas. Já nas amostras coletadas na UFPB, a maior concentração de NO2 foi de 7 μg/m³ no horário da noite, e a menor de 0,9 μg/m³, no período das 12 às 14 horas. Após o tratamento dos dados, a PCA mostrou que das variáveis climáticas, a umidade influencia a concentração no turno da manhã e as outras variáveis climáticas (radiação, temperatura) influenciam no turno da tarde.

The role of the spatial representation in the relation between chronic exposure to NO2 and respiratory health outcomes is studied through a spatial approach encompassing three conceptual components: the geography of susceptibility, the geography of exposure and the geography of risk. A spatially explicit methodology that defined natural neighbourhoods for the city of Ottawa is presented; it became the geography of analysis in this research. A LUR model for Ottawa is developed to study the geography of exposure. Model sensitivity to the spatial representation of population showed that dasymetric population mapping did not provide significant improvements to the LUR model over population at the dissemination block level. However, both the former were significantly better than population represented at the dissemination area. Spatial representation in the geography of exposure was also evaluated by comparing four kriging and cokriging interpolation models to the LUR. Geostatistically derived NO2 concentration maps were weakly correlated with LUR model results. The relationship between mean NO2 concentrations and respiratory health outcomes was assessed within the natural neighbourhoods. We find a statistically significant association between NO2 concentrations and respiratory health outcomes as measured by global bivariate Moran’s I. However, for regression model building, NO2 had to be forced into the model, demonstrating that NO2 is not one of the main contributing variables to respiratory health outcomes in Ottawa. The results point toward the importance of the socioeconomic status on the health condition of individuals. Finally, the role of spatial representation was assessed using three different spatial structures, which also permitted to better understand the role of the modifiable areal unit problem (MAUP) in the study of the relationship between exposure to NO2 and health. The results confirm that NO2 concentration is not a major contributing factor to the respiratory health in Ottawa but clearly demonstrate the implications that the use of opportunistic administrative boundaries can have on results of exposure studies. The effects of the MAUP, the scale effect and the zoning effect, were observed indicating that a spatial structure that embodies the scale of major social processes behind the health condition of individuals should be used when possible.