Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic air pollutants formed during incomplete combustion and are ubiquitously distributed in the environment. To determine particle-bound PAHs in archived PM2.5 samples taken with low flow rate in Atlanta, a sensitive and robust method was developed for measuring 28 PAHs and methyl PAHs in PM samples using isotope dilution gas chromatography/high resolution mass spectrometry (GC/HRMS). The method was then used to analyze PM2.5 samples collected at three sites (rural, urban, suburban-highway) from the Assessment of Spatial Aerosol Composition in Atlanta (ASACA) network. Distinct seasonal and spatial variations were observed in PAH concentration. Particle-bound PAH levels were significantly higher in winter than in summer. The suburban-highway site had higher PM2.5-bound PAH concentration than did the urban site, and the rural site had the lowest PAH levels. Retene, a proposed biomass burning tracer, captured both the high leaves-grasses-bushes-branches burning season and the high wood burning months, suggesting that it might be a better marker for all biomass burning, while potassium ion might be a more specific tracer for wood burning. Human exposure to PAHs can be assessed by characterizing their hydroxy PAH (OH-PAH) metabolites in urine samples. A method was developed to measure 24 urinary OH-PAHs, metabolites of 8 parent PAHs, using enzymatic de-conjugation, automatic liquid-liquid extraction, and GC/HRMS. A study was then carried out to evaluating the variability of the urinary biomarker levels in a non-occupationally exposed non-smoking reference group. Levels of urinary PAH metabolites varied widely both within-subject and between-subjects and the within-day variance far exceeded the between-day variance. There were also considerable temporal correlations for these biomarkers. Sample size calculations were conducted and taking 24-hour voids would require the least number of subjects, which should be considered during epidemiological study design. Finally, a study was conducted to evaluate exposure to ambient PAHs in an urban setting among 8 non-occupationally exposed non-smoking volunteers employing both personal air sampling and urine biomonitoring. PAH levels varied largely in air samples taken at home, at work, and while driving or jogging. Monitoring urinary OH-PAH levels can capture both inhalation and dietary exposures. Total inhaled PAH was correlated with total excreted OH-PAHs, suggesting that by combining personal air sampling and biomonitoring, exposure to environmental PAHs can be well characterized even for low-level exposure.

The research described in the thesis details the investigation of build-up and wash-off process kinetics of Polycyclic Aromatic Hydrocarbons (PAHs) and heavy metals in urban areas. It also discusses the design and development of a rainfall simulator as an important research tool to ensure homogeneity and reduce the large number of variables that are usually inherent to urban water quality research. The rainfall simulator was used to collect runoff samples from three study areas, each with different land uses. The study areas consisted of sites with typical residential, industrial and commercial characteristics in the region. Build-up and wash-off samples were collected at each of the three sites. The collected samples were analysed for a number of chemical and physico-chemical parameters. In addition to this, eight heavy metal elements and 16 priority listed PAHs were analysed in five different particle size fractions of the build-up and wash-off samples. The data generated from the testing of the samples were evaluated using multivariate analysis, which reduced the complexity involved in determining the relative importance of a single parameter in urban water quality. Consequently, variables and processes influencing loadings and concentrations of PAHs and heavy metals in urban stormwater runoff from paved surfaces at any given time were identified and quantified using Principal Component Analysis (PCA). Furthermore, the process kinetics found were validated using a multivariate modelling approach and Partial Least Square (PLS) regression, which confirmed the transferability of chemical processes in urban water quality. Fine particles were dominant in both the build-up and wash-off samples from the three sites. This was mirrored in the heavy metal and PAH concentrations at the three sites, which were significantly higher in particles between 0.45-75μm than in any other fraction. Thus, the larger surface area and electrostatic charge of fine particles were favourable in sorbing PAHs and heavy metals. However, factors such as soil composition, total organic carbon (TOC), the presence of Fe and Mn-oxides and pH of the stormwater were all found to be important in partitioning of the metals and PAHs into different fractions. Additionally, PAHs were consistently found in concentrations above their aqueous solubility, which was attributed to colloidal organic particles being able to increase the dissolved fraction of PAHs. Hence, chemical and physico-chemical parameters played a significant role in the distribution of PAHs and heavy metals in urban stormwater. More importantly, the research showed the wide range of factors that distribute metals and PAHs in an urban environment. Furthermore, it indicated the need for monitoring these parameters in urban areas to ensure that urban stormwater management measures are effective in improving water quality. The build-up and wash-off process kinetics identified using PCA at the respective land uses were predicted using PLS and it was found that the transferability of the governing processes were high even though the PAHs and metal concentrations and loads were highly influenced by the source strength at each site. The increased transferability of fundamental concepts in urban water quality could have significant implications in urban stormwater management. This is primarily attributed to common urban water quality mitigation strategies relying on studies based on physical concepts and processes derived from water quantity studies, which are difficult to transfer between catchments. Hence, a more holistic approach incorporating chemical processes compared to the current piecemeal solutions could significantly improve the protection of key environmental values in a region. Furthermore, urban water quantity mitigation measures are generally designed to reduce the impacts of high-flow events. This research suggests that fairly frequent occurring rainfall events, such as 1-year design rainfall events, could carry significant heavy metal and PAH concentrations in both particulate and dissolved fractions. Hence, structural measures, designed to decrease quantity and quality impact on receiving waters during 10 or 20-year Average Recurrence Interval (ARI) events could be inefficient in removing the majority of PAHs and heavy metals being washed off during more frequent events. The understanding of physical and chemical processes in urban stormwater management could potentially lead to significant improvements in pollutant removal techniques which in turn could lead to significant socio-economic advantages. This project can serve as a baseline study for urban water quality investigations in terms of adopting new methodology and data analysis.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 4 uppsatser.

Thesis (Ph.D.)--McMaster University (Canada), 1996. / Source: Dissertation Abstracts International, Volume: 58-06, Section: B, page: 3006. Adviser: B. E. McCarry.

Thesis (Ph. D.)--Carleton University, 2004. / Includes bibliographical references (p. 193-221). Also available in electronic format on the Internet.

Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 148-160). Also available in electronic format on the Internet.

Thesis (Ph.D.) - Simon Fraser University, 2004. / Theses (Dept. of Biological Sciences) / Simon Fraser University.

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 95-104). Also available on the World Wide Web.

Maîtrise (M.Eng.)--Université du Québec à Chicoutimi, 1998. / Document électronique également accessible en format PDF. CaQCU

Thesis (Ph.D.)--University of Ottawa, 2008. / Includes bibliographies. Also available via the World Wide Web.