Date of Award
Doctor of Philosophy (PhD)
Hyperlocal air pollution exposure is driven by local emission sources, meteorology, and the built environment, with traffic-related emissions modulating primary and secondary pollutant concentrations against a variable background of similar contaminants from other sources. Recent studies show that intra-urban air quality has temporally persistent patterns that sharply vary 5-8 times within a city block; currently, regulatory ambient air quality monitoring (2-5 fixed-site monitors per 1000 km2 in U.S. census urban areas) cannot capture exposure at this spatial resolution. This dissertation aims to advance methods relying on fixed-site and mobile measurements using high-time resolution aerosol instruments as well as low-cost sensors to generate pollutant concentration surfaces with spatial resolutions required for robust health effect studies. Specific outcomes from this work include 1) assessment of the near-road pollution attenuation capability of an engineered vegetative buffer, 2) community-level air pollutant exposure estimation in neighborhoods of metropolitan Louisville, KY, and 3) evaluation of the association of biomarker metal abundances among residents of Meyerton, South Africa, and their proximity to a ferromanganese smelter. In the first study, I measured oxides of nitrogen using passive samplers and ultrafine particle number concentrations using high time-resolution instruments to quantify changes to pollutant levels due to the vegetative barrier. This work is distinct in its evaluation of a barrier designed to maximize pollutant removal using ecologically compatible flora. In the second study, I deployed passive samplers bimonthly for three years in a dense, fixed-site network in the domain of a health study, Green Heart Louisville, to measure mixing ratios of oxides of nitrogen and ozone. Additionally, I conducted mobile monitoring campaigns to measure ultrafine particle number concentrations in the study domain. Datasets from both the passive sampling—the most temporally extensive and spatially resolved of its kind to date—and mobile monitoring informed hyperlocal land-use regression models of air pollution. Lastly, I quantified metal content in hair and toenail of residents and fine particulate matter to determine biomarkers of inhalation exposure to urban air toxic metals; this project is notable for its focus on a heretofore understudied geography and demography. All projects informed clinical studies of health effects in area residents.
Jay R. Turner
Available for download on Saturday, January 07, 2023