No description available.

The presence of 'greenhouse gases' in the atmosphere has a warming effect on the biosphere, making the world habitable for life. Human activities, particularly energy use and deforestation, are increasing the concentration of these gases, and in particular carbon dioxide (CO₂). Many climatologists believe that the global temperature is beginning to rise as a result. The intergovernmental Panel on Climate Change (IPCC) has recommended that emissions of CO₂ be cut by 60 per cent in order to stabilise the atmospheric concenaation of this gas and to minimise the resulting disruption to the world's climate. Transport is currently Britain's fastest growing source of carbon dioxide, the principal anthropogenic greenhouse gas. An assessment is made of the relative contributions to CO2 emissions of different forms of travel, and trends in energy use are surveyed. Emissions of CO₂ from 'secondary' sources, such as vehicle production, are also examined. A computer model called SPACE is described, which was developed in order to assess CO₂ emissions under different policy scenarios up to the year 2025. A 'business as usual' scenario predicts that emissions will rise substantially, mainly as a result of an ongoing rise in road traffic. This contrasts with the Government's stated aim of stabilising emissions of CO₂ at the 1990 level by 2000. A modification of this scenario, in which technological improvements to vehicles are vigorously applied, shows a reduced growth in emissions. A third scenario then examines the effect of a combination of technological and demand management policies, and demonstrates a significant reduction in emissions. Scenario 3 adopts what are seen as fairly modest policy measures, making use of their synergistic effect. The main justification for this 'non-radical' approach is public and political acceptability. It is, however, recognised that most of the policy measures could be applied more vigorously if required If it is assumed that transport is allotted a less stringent target than other energy-consuming sectors, the reduction in emissions projected in Scenario 3 is consistent with the IPCC goal of atmospheric CO₂ stabilisation. Data sets compiled as part of the SPACE model can be made available on request.

No description available.

The hypothesis of this thesis is that the time-of-flight method of determining an estimate of the aerodynamic diameter of aerosol particles is fundamentally flawed when applied to non-spherical and/or non-unit density particles. Such a particle-sizing system, the TSI Aerodynamic Particle Sizer, is challenged with solid, non-spherical particles of known aerodynamic diameter to assess the influence of particle shape on instrument response. The aerodynamic diameter of the non-spherical particles is also determined under gravitational settling. Deposits that had been size-separated are resuspended for aerodynamic sizing by the APS. The experimental study is supplemented by a theoretical investigation of the relative effects of particle density and shape on APS-measured diameters. This is achieved through the development of a computational routine to calculate the trajectories of particles of various densities and shapes through the APS nozzle and sensing zone. The results of these calculations are compared with the experimentally-measured APS performance. The consequences for the traceability and accuracy of data measured using this technique are assessed in the light of the outcome of both aspects of the study.

No description available.

This thesis examined associations between ecological indicators of residential radon and fine particulate matter air pollution (PM2.5) and lung cancer mortality using data from the American Cancer Society Cancer Prevention Study-II (CPS-II) prospective cohort. Nearly 1.2 million CPS-II participants were recruited in 1982. Mean county-level residential radon concentrations were linked to study participants according to ZIP code information at enrollment (mean (SD) = 53.5 (38.0) Bq/m3). Cox proportional hazards regression models were used to obtain adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for lung cancer mortality associated with radon. After necessary exclusions, a total of 811,961 participants in 2,754 counties were retained for analysis. A significant positive linear trend was observed between categories of radon concentrations and lung cancer mortality (p = 0.02). A 15% (95% CI 1 - 31%) increase in the risk of lung cancer mortality was observed per each 100 Bq/m3 radon. Radon was also positively associated with chronic obstructive pulmonary disease mortality (HR per each 100 Bq/m3 = 1.13, 95% CI 1.05 - 1.21). No clear associations were observed between radon and non-respiratory mortality. In lifelong never smokers (n = 188,699), each 10 µg/m3 increase in mean metropolitan statistical area PM2.5 concentrations was associated with a 15-27% increase in the risk of lung cancer death which strengthened among individuals with a history of asthma or any prevalent chronic lung disease at enrollment (p for interaction < 0.05). There was no association between PM2.5 and mortality from non-malignant respiratory disease. In conclusion, this thesis observed significant positive associations between ecological indicators of residential radon and PM2.5 concentrations and lung cancer mortality. These findings further support efforts to reduce radon concentrations in homes to the lowest possible level and strengthens the evidence that ambient concentrations of PM2.5 measured in recent decades are associated with small but measurable increases in lung cancer mortality. Further research is needed to better understand possible complex inter-relationships between environmental risk factors, chronic lung disease, and lung cancer.

Using an innovative arrangement of instruments to obtain a comprehensive set of properties, we present a description of the submicron aerosol properties for two distinct regions. During the 2009 SHARP/SOOT campaign in Houston, TX, the average effective density was 1.54 ± 0.07 g cm^-3, consistent with a population comprised largely of sulfates and organics Even in low concentrations (0.31 ± 0.22 µg m^-3), black carbon concentration has a significant impact on the overall density and optical properties. Under prevailing northerly winds, the average black carbon concentration increases from 0.26 ± 0.18 µg m^-3 to 0.60 ± 0.21 µg m^-3. Throughout the campaign, aerosols are often internally mixed, with one peak in the effective density distribution located at 1.55 ± 0.07 g cm^-3. In addition, we conclude that in this region the meteorology has a discernible impact on the concentration and properties of aerosols. After a frontal passage, there is a significant shift in the size distribution as the concentration of <100 nm particles increase and the average effective density decreases to 1.43 ± 0.08 g cm^-3. In Tijuana, Mexico, the submicron aerosols are heavily influenced by vehicle emissions. We observe an average single scattering albedo of 0.75. This average SSA is lower than observed in many US urban environments, and indicates a high concentration of black carbon. The average black carbon concentration is 2.71 ± 2.65 g cm^-3. The aerosol size distributions reveal a high concentration of small particles (< 100 nm) during the day, which are frequently associated with vehicle emissions. Overall, 46 and 81 nm particles are hydrophobic, have an average effective near 1.30 g cm^-3, a higher volatile growth factors than the larger particles, and exhibit a distinct diurnal cycle, which, on average, ranges between 0.80 during the afternoon and 1.70 g cm^-3 overnight. 46 and 81 nm distributions indicate a uniform aerosol composition. 151 and 240 nm aerosols are less cyclical, and the hygroscopicity, volatility, and effect density distributions all exhibit a bimodal distribution, which indicates an external mixture of aerosols. Black carbon and vehicle and industrial organic emissions appear to be the main components of the external mixture.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1988. / Bibliography: leaves 520-551. / Photocopy. / Microfilm. / xxi, 551 leaves ill. 29 cm

"The aims of this research were to investigate the association between air pollution and respiratory health effects using a spatial approach, and to derive a composite indicator of ambient air pollution." / Master of Information Technology by Research

Since the beginning of the 20th century indoor air has produced distinctive pollution problems. The most critical pollutants in relation to indoor air quality (IAQ) are chemical contaminants which, in the form of volatile organic compounds (VOCs), have been identified as arising mainly from building materials. Conventional solutions such as ventilation systems and bake-out processes have been developed, but the IAQ problem, often reported as sick building syndrome (SBS), still persists. This study set out to establish to what extent VOCs may affect the health of occupants in a particular built environment, and how much architectural design factors, the use of particular building materials, and human activities may contribute to the problem of SBS. A further question was to establish to what extent current attempted solutions to IAQ problems, namely ventilation and bake-out, were in practice effective in a specific built environment. While previous research and attempted solutions have focused on work places as areas of concern for SBS, the problem is especially significant in residential housing and is particularly concentrated in post-disaster public housing (PDPH). For this reason the research was based on the case of a PDPH project in Abuta, Japan. To analyse the separate components of the problem, several distinct studies were undertaken. The level of pollutants in the air was analysed by means of chemical sampling of VOCs in two units of the PDPH, while the a SBS survey and assessment of the residents of the entire project, as well as interviews with the building professionals involved was designed to identify the human causes and effects of the situation. The effectiveness of the attempted solutions to the problem were considered by means of a study of the bake-out procedure, and finally an airflow simulation by computational fluid dynamics (CFD) was conducted to consider the design and ventilation features of the units in relation to IAQ. The study results have indicated that IAQ problems existed after the completion of construction. It was found that certain VOC levels were far above the guidelines, and the health hazard symptoms known for these VOCs matched the SBS symptoms found in participants??? health complaints. Interviews with building professionals involved in the project revealed that the lifestyles of the occupants were not seriously considered in the project design. The results of the airflow simulation also revealed problematic aspects of the planning design, exacerbating rather than limiting the pollution problem as intended. The study concludes with a number of recommendations for taking these inter-related aspects of the problem into consideration in future, so that the health of residents is not adversely affected.