Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007. / Dr. Michael E. Chang, Committee Member ; Dr. Michael H. Bergin, Committee Member ; Dr. Paige E. Tolbert, Committee Member ; Dr. James A. Mulholland, Committee Member ; Dr. Armistead G. Russell, Committee Chair.

Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007. / Dr. Armistead Russell, Committee Chair ; Dr. James Mulholland, Committee Member ; Dr. Michael Bergin, Committee Member.

Identification of airborne pollutant sources and estimation of source contributions to air quality ‘hot spots’ are very important in ambient air quality management. Social, economical, political and legal constraints on air quality management demand a convenient and accurate method for attributing air pollution sources to the ‘hot spots’. In this PhD research degree project, an automatic air pollution monitoring station was set up on the library roof at the University of Abertay Dundee to monitor urban background air quality in Dundee. Concentrations of the particulate with aerodynamic diameter less than 10 pm (PMio), the total suspended particulate (TSP), nitric oxide (NO), nitrogen dioxide (NO2) and nitrogen oxides (NOx) as well as wind speed, wind direction, ambient temperature and total rainfall were measured continuously for one year. The chemical components of PM10 and TSP, calcium (Ca2+), magnesium (Mg2+), copper (Cu), lead (Pb), nickel (Ni), zinc (Zn), sulphate (SO42'), nitrate (NO3'), chloride (C1‘), ammonium (NH/), sodium (Na+) and potassium (K+) were analysed in the laboratory. Additionally, the inventories of atmospheric emission sources in Dundee were investigated in detail in order to satisfy the needs of air dispersion model. A new software package for the atmospheric dispersion models was also developed by the author using Microsoft Visual C++. In contrast to other available software packages, this package offers a choice of different atmospheric models. The user may select a model according to the situation prevailing and the available parameters. The package for the atmospheric dispersion models was used to simulate transport of airborne pollutants in Dundee. Performance of the models was evaluated using the data gathered at the monitoring station and atmospheric emission inventories. The contributions of various air pollution sources of NOx and PM10 measured at the station were estimated. The receptor model was used to discriminate airborne pollutant emission sources and quantitatively apportion PM10 measured at the station to these sources. The results from the atmospheric dispersion model and the receptor model were compared and used in a complementary manner. A new methodology that combines the features of the receptor oriented and source oriented models, and supplements and corrects the two modelling approaches has been developed. The applicability of the methodology has been tested against the gathered air quality and source emission data in Dundee. The following outputs from the research work are completely novel: • A comprehensive database that consists of concentrations of gaseous pollutants and particulates, chemical compositions of particulates, weather conditions and atmospheric emission inventories. • A new software package for modelling atmospheric dispersion. This was programmed using Microsoft Visual C++. In contrast to other available commercial packages, the models embedded in the package include a modified hybrid plume dispersion model and a ground level release dispersion model that incorporate recent advances in the understanding of planetary boundary layer and atmospheric dispersion. They also include the conventional Gaussian plume dispersion model that is still generally used. The user may select different models according to the prevailing situation and the available parameters when applying the package. • The use of error estimate in ‘weighting’ the data of element matrix and complementary use of subjective information in receptor model trials. • A new methodology that complements atmospheric dispersion and receptor models to attribute sources of airborne pollutants to their receptors.

Ph.D. / Fossil fuel burning within residential, industrial and power generation sectors represents a persistent source of air pollution within many parts of South Africa, with the contribution of road transport emissions becoming increasingly important. Additionally, biomass burning, including agricultural burning and wild fires, represents an intermittent but seasonally significant source of atmospheric emissions. Effective air pollution control was historically hindered by the absence of enabling legislation and cooperative governance. The promulgation of the National Environmental Management: Air Quality Act, Act 39 of 2004 represented a major step forward in the evolution of air quality management within South Africa. The historical debate regarding the practicability of effective air quality management is however ongoing. South Africa‟s continued dependence on coal to support its energy-intensive industrial and mining sectors, continued household fuel burning for space heating and cooking purposes within a number of areas, and the dire need for employment creation and focus on rapid development continue to challenge the realisation of air quality improvements. This study investigates the multiple factors contributing to the degradation of air quality in South Africa, and the consequent human health, environmental and economic effects of this pollution. The study critically examines legal, technical and social measures implementable within a tailored system of air quality management which is compatible with socio-economic growth. This thesis integrates and expands on pertinent components of several individual research projects completed by the author during her tenure as a doctoral candidate. The research projects were completed during the period (2002 – 2009) on behalf of various parties including national and local government, standards setting bodies and private organisations. Quantification of health risks associated with significant anthropogenic sources within several South African conurbations, covering 40% of the national population, and the establishment of cost-optimised air pollution interventions, forms a key component of the thesis. In this externalities study, emissions were estimated and effects and associated costs quantified for household fuel burning, power generation, industrial and commercial fuel burning and road transport. Total direct health costs related to inhalation exposures to fuel burning emissions were estimated to be of the order of 3.5 billion 2002 Rands per annum across health effects, conurbations and source groupings assessed. Household fuel burning was estimated to be responsible for about 68% of the total health costs estimated across all conurbations, vehicle emissions for 13%, industrial and commercial fuel burning for 13%, and power generation for about 6%. Emission reduction opportunities were identified and assessed for residential fuel burning, coalfired power generation, road transport, coal-fired industrial boilers and specific individual industries. It was concluded that significant health effect reductions could cost-effectively be achieved through addressing residential fuel burning as a priority. Lower benefit-cost ratios associated with industrial and vehicular interventions are due, in part, to these fuel burning sources having been more effectively regulated historically. The need for effective management of industrial and vehicle emissions is however supported. Based on international experience and local trends in vehicle activity, the contribution of transport emissions will become increasingly ix significant if not adequately addressed. Industrial process emissions unrelated to fuel burning may include significant emissions of criteria pollutants, in addition to trace releases of a wide range of hazardous air pollutants. Internationally, actions taken to address air pollution problems have met with mixed results. Failure to integrate economic considerations into air quality management planning, and to integrate air quality considerations into development planning represent key weaknesses in the strategies implemented. A contribution is made in this thesis by highlighting such lessons and proposing legal, technical and social measures which, when implemented within a rational system of air quality management, are suited to addressing complex air pollution sources without negatively affecting socio-economic prosperity and equity. Components of an effective, affordable and equitable emissions control policy proposed for adoption within South Africa include phased national standards setting, compliance promotion and self-monitoring, market-based instruments, and the implementation of risk-based enforcement and compliance monitoring strategies.

A mini-lidar system, Vaisala's CL31 ceilometer, was installed within a suburban area of Vancouver, BC, for the purpose of making continuous observations of the boundary layer over a period of 11 months. Initial validation of the ceilometer for use in boundary layer observations was undertaken. This involved the comparison of ceilometer data with eight months of ground-level particulate matter measurements, as well as with 16 vertical profiles of particulate matter and meteorological data. Once a variety of persistent noise structures within the data were accounted for, it was found that the ceilometer data showed good agreement with the particulate matter data, suggesting its usefulness for assessing air-quality throughout the bottom 1km of the atmosphere. Additionally, two algorithms were developed in order to estimate the height of the convective boundary layer, or the mixed-layer height, from the ceilometer data. One involved the fitting of an ideal-profile to the measured data, while the other involved the location of a minimum-gradient in the backscatter profile. The performance of these two techniques were assessed and compared, and it was found that the ideal-profile method was the more robust of the two. Finally, mixed-layer heights were estimated for fair weather, convectively active days. In order to isolate such conditions, an automatic flagging algorithm was developed. However, additional manual assessment was needed to avoided unsuitable conditions. Mixed-layer heights were estimated for 19 days over an 11 month period. the estimates presented here were found to agree with previous observations. Daily maximum mixed-layer heights ranged from 650m in July to 350m in December, indicating that the height of the convective boundary layer within Vancouver is significantly suppressed due to the city's coastal location. / Arts, Faculty of / Geography, Department of / Graduate

Air pollution caused by ambient fine particulate matter (PM 2.5 ) is a significant global environmental problem. Pollutants that adhere to PM 2.5 may be transported into human respiratory system and perturb the redox equilibrium through the generation of reactive oxygen species (ROS), thus leading to myriad health effects. This mechanism has been proposed to be related with the high redox-active components in PM 2.5, such as transition metals, quinones, and humic-like substances (HULIS). This thesis aims to improve the scientific understanding on the sources and health impacts of PM 2.5 especially its HULIS fraction. Thus, both chemical characterization and redox activity measurement of ambient PM 2.5 samples were conducted. Positive matrix factorization (PMF) was then performed to apportion the source-specific contributions to PM 2.5 and its oxidative potential. The HULIS fraction of PM 2.5 was also quantified and source apportioned regarding their mass concentration and oxidative potential. The main findings are summarized below: (1) In Chapter 2, 66 PM 2.5 samples collected in Hong Kong during 2016-2017 were analyzed, including carbonaceous components, major ions, metals, and some source markers. The oxidative potential of PM 2.5 were measured using dithiothreitol (DTT) assay. Results showed clear temporal trends for both PM 2.5 mass concentration and its major fraction, with higher levels observed on days under regional pollution than on days under long range transport (LRT) pollution and local emissions. The DTT consumption of PM 2.5 on the contrary, only showed slightly higher activity on regional and LRT days than on local days, possibly due to the comprehensive effects of different sources and species concentrations under different sampling days. We then conducted source apportionment using PMF model. Five primary sources (i.e. marine vessels, Cu-related source, Fe-Mn-Zn-related source, vehicle emissions, biomass burning) and one secondary source were resolved for both PM 2.5 mass concentration and DTT activity. Secondary formation was found to be the most significant source responsible for PM 2.5 mass concentration (30.3%), followed by Cu- related source (24.8%), marine vessels (17.9%) and vehicle emissions (14.5%). Biomass burning (6.8%) and Fe-Mn-Zn-related source (5.8%) were two minor sources contributing to PM 2.5 mass concentration. For oxidative potential of PM 2.5, Cu- related source was the predominant contributor (39.1%). Secondary formation (23.7%) and marine vessels (20.1%) were also two significant sources responsible for the DTT consumption of PM 2.5 . For intrinsic oxidative potential, PM 2.5 emitted from marine vessels and Cu-related source showed highest value, indicating more toxic feature of PM 2.5 derived from those sources regarding DTT activity. (2) In Chapter 3 and 4, the mass concentration, optical properties, and ROS- generation potential of HULIS were investigated in PM 2.5 samples collected in Hong Kong during 2011-2012. They all showed higher levels on regional days than on LRT days and local days. PMF analysis was conducted regarding the mass concentration and ROS activity of HUILS. Six sources were determined, including four primary sources (i.e. marine vessels, vehicle emissions, industrial exhaust, and biomass burning) and two secondary sources (i.e. secondary organic aerosol formation and secondary sulfate). Most sources showed higher contributions to both mass concentrations and DTT activity of HULIS on regional days than on LRT and local days, except that marine vessels had a higher contribution on local days than the other two synoptic conditions. Secondary processes were the major contributor to HULIS (54.9%) throughout the year, followed by biomass burning (27.4%) and industrial exhaust (14.7%). As or the DTT activity of HULIS, biomass burning (62.9%) and secondary processes (25.4%) were found to be the top two contributors. Intrinsic ROS-generation potential of HULIS was also investigated by normalizing the DTT activity by HULIS mass in each source. HULIS from biomass burning were the most DTT-active, followed by marine vessels; while HULIS formed through secondary processes were the least DTT-active. For the optical properties of HULIS, multiple linear regression model was adopted to evaluate the contributions of various sources to the light absorbing ability of HULIS. Biomass burning was found to be the only source significantly associated with the light absorbing property of HULIS. In Chapter 5 and 6, the predominant species of water-soluble fraction of PM 2.5, HULIS, were measured in samples collected in Beijing from 2011 to 2012. Various HULIS species, and the redox activity of HULIS were quantified together with certain source markers of PM 2.5. HULIS and their redox activity showed similar temporal trend, with higher levels measured during the heating season (November to March) than during the non-heating season (April to October). Source apportionment of both HULIS and their redox activity was performed using PMF. Four combustion-related primary sources, namely coal combustion, biomass burning, waste incineration, and vehicle exhaust, and one secondary factor were resolved. In particular, waste incineration was identified as a source of HULIS for the first time. Biomass burning and secondary aerosol formation were the major contributors (>59%) to both HULIS and associated DTT activity throughout the year. During the non-heating season, secondary aerosol formation was the most important source, whereas during the heating season, the predominant contributor was biomass burning. The four combustion-related sources accounted for about 70% of HULIS and their ROS activity, implying that future reduction in PM 2.5 emissions from combustion activities can substantially reduce the HULIS burden and their potential health impact in Beijing.

Air pollution caused by ambient fine particulate matter (PM 2.5 ) is a significant global environmental problem. Pollutants that adhere to PM 2.5 may be transported into human respiratory system and perturb the redox equilibrium through the generation of reactive oxygen species (ROS), thus leading to myriad health effects. This mechanism has been proposed to be related with the high redox-active components in PM 2.5, such as transition metals, quinones, and humic-like substances (HULIS). This thesis aims to improve the scientific understanding on the sources and health impacts of PM 2.5 especially its HULIS fraction. Thus, both chemical characterization and redox activity measurement of ambient PM 2.5 samples were conducted. Positive matrix factorization (PMF) was then performed to apportion the source-specific contributions to PM 2.5 and its oxidative potential. The HULIS fraction of PM 2.5 was also quantified and source apportioned regarding their mass concentration and oxidative potential. The main findings are summarized below: (1) In Chapter 2, 66 PM 2.5 samples collected in Hong Kong during 2016-2017 were analyzed, including carbonaceous components, major ions, metals, and some source markers. The oxidative potential of PM 2.5 were measured using dithiothreitol (DTT) assay. Results showed clear temporal trends for both PM 2.5 mass concentration and its major fraction, with higher levels observed on days under regional pollution than on days under long range transport (LRT) pollution and local emissions. The DTT consumption of PM 2.5 on the contrary, only showed slightly higher activity on regional and LRT days than on local days, possibly due to the comprehensive effects of different sources and species concentrations under different sampling days. We then conducted source apportionment using PMF model. Five primary sources (i.e. marine vessels, Cu-related source, Fe-Mn-Zn-related source, vehicle emissions, biomass burning) and one secondary source were resolved for both PM 2.5 mass concentration and DTT activity. Secondary formation was found to be the most significant source responsible for PM 2.5 mass concentration (30.3%), followed by Cu- related source (24.8%), marine vessels (17.9%) and vehicle emissions (14.5%). Biomass burning (6.8%) and Fe-Mn-Zn-related source (5.8%) were two minor sources contributing to PM 2.5 mass concentration. For oxidative potential of PM 2.5, Cu- related source was the predominant contributor (39.1%). Secondary formation (23.7%) and marine vessels (20.1%) were also two significant sources responsible for the DTT consumption of PM 2.5 . For intrinsic oxidative potential, PM 2.5 emitted from marine vessels and Cu-related source showed highest value, indicating more toxic feature of PM 2.5 derived from those sources regarding DTT activity. (2) In Chapter 3 and 4, the mass concentration, optical properties, and ROS- generation potential of HULIS were investigated in PM 2.5 samples collected in Hong Kong during 2011-2012. They all showed higher levels on regional days than on LRT days and local days. PMF analysis was conducted regarding the mass concentration and ROS activity of HUILS. Six sources were determined, including four primary sources (i.e. marine vessels, vehicle emissions, industrial exhaust, and biomass burning) and two secondary sources (i.e. secondary organic aerosol formation and secondary sulfate). Most sources showed higher contributions to both mass concentrations and DTT activity of HULIS on regional days than on LRT and local days, except that marine vessels had a higher contribution on local days than the other two synoptic conditions. Secondary processes were the major contributor to HULIS (54.9%) throughout the year, followed by biomass burning (27.4%) and industrial exhaust (14.7%). As or the DTT activity of HULIS, biomass burning (62.9%) and secondary processes (25.4%) were found to be the top two contributors. Intrinsic ROS-generation potential of HULIS was also investigated by normalizing the DTT activity by HULIS mass in each source. HULIS from biomass burning were the most DTT-active, followed by marine vessels; while HULIS formed through secondary processes were the least DTT-active. For the optical properties of HULIS, multiple linear regression model was adopted to evaluate the contributions of various sources to the light absorbing ability of HULIS. Biomass burning was found to be the only source significantly associated with the light absorbing property of HULIS. In Chapter 5 and 6, the predominant species of water-soluble fraction of PM 2.5, HULIS, were measured in samples collected in Beijing from 2011 to 2012. Various HULIS species, and the redox activity of HULIS were quantified together with certain source markers of PM 2.5. HULIS and their redox activity showed similar temporal trend, with higher levels measured during the heating season (November to March) than during the non-heating season (April to October). Source apportionment of both HULIS and their redox activity was performed using PMF. Four combustion-related primary sources, namely coal combustion, biomass burning, waste incineration, and vehicle exhaust, and one secondary factor were resolved. In particular, waste incineration was identified as a source of HULIS for the first time. Biomass burning and secondary aerosol formation were the major contributors (>59%) to both HULIS and associated DTT activity throughout the year. During the non-heating season, secondary aerosol formation was the most important source, whereas during the heating season, the predominant contributor was biomass burning. The four combustion-related sources accounted for about 70% of HULIS and their ROS activity, implying that future reduction in PM 2.5 emissions from combustion activities can substantially reduce the HULIS burden and their potential health impact in Beijing.

Thesis (Ph.D.)--McMaster University, 2002. / Advisor: Susan Elliott. Includes bibliographical references. Also available on World Wide Web.

Thesis (Ph.D.)--McMaster University, 2002. / Advisor: Susan Elliott. Includes bibliographical references. Also available on World Wide Web.

Thesis (M. Sc.)--University of Hong Kong, 1999. / Includes bibliographical references.