Date of Award
Summer 8-4-2023
Degree Name
Doctor of Philosophy (PhD)
Degree Type
Dissertation
Abstract
The urban environment contains both air pollution and noise pollution from various sources. For noise pollution, sources include biogenic emissions such as insect chorus and anthropogenic emissions such as highway traffic and airplane flyovers. Numerous studies link exposure to noise with increased health risks through mechanisms such as disruption of sleep and introduction of external stress factors. It is not clear whether biogenic and anthropogenic noise have differential impacts. Ultrafine particulate matter (UFP) contribute to adverse health outcomes such as asthma, obstructive pulmonary disease, cardiovascular disease, and lung cancer. Ambient UFP is currently not regulated in the United States with one challenge being its often-high urban-scale spatial variability that complicates exposure estimates and health outcomes assessments. Recent research draws attention to elevated UFP number concentrations near airports and highways. While reported noise studies typically focused on the urban spatial scale, this work focuses on small-scale spatial variations within largely residential neighborhoods impacted by highways, aircraft flight paths, and a mix of land uses. In addition, I assessed UFP concentrations near an interstate highway with a noise wall and near an international airport that has some of the highest cargo operations in the world. A Class II noise monitor was thoroughly characterized to assess its suitability in a planned high-density low-cost sensor network to elucidate spatiotemporal noise patterns. The monitor did not meet my performance criteria for accuracy, precision, and functional usage; therefore, I conducted four short-term (two-to-three week) studies using a low-density network of Class I monitors. These measurements revealed considerable seasonal and spatial variation in both total noise and the underlying frequency patterns. Anthropogenic and biogenic source contributions were separated using non-negative matrix factorization. An instrumented vehicle was used to measure UFP near an interstate highway bisecting a residential neighborhood and near an international airport during nighttime cargo operations. In contrast to most near-highway UFP studies, this highway features a noise wall that influences ground-level downwind concentration gradients. The noise wall’s spatial zone of impact on UFP concentrations was evaluated including comparisons to a Gaussian dispersion model for an infinite line source. UFP measurements were also conducted during nighttime cargo plane operations at an international airport. Despite the numerous complexities to interpret these data, such as superposed aircraft plumes from the high flight activity level and the coupling between aircraft flight patterns (a moving point source) and meteorology, insights were gained into the ground-level impacts from individual aircraft.
Language
English (en)
Chair
Jay Turner