Despite the growing need for mobility, the anthropogenic byproducts of transportation, construction, and other human activity within our built environments, such as air pollution and noise, are detrimental to human health. In the United States (US), environmental noise is a ubiquitous yet overlooked pollutant and source of physiological and psychological stress. Several studies have examined associations between environmental noise and health outcomes, particularly in Europe; however, an insufficient number of longitudinal studies have been conducted. Additionally, much of the research lacks individual-level data, sufficient adjustment for confounding, and the ability to establish temporality. With an increasing demographic shift of the US population to an older age profile, there is heightened imperative to examine new interventions to reduce chronic disease risk, specifically upstream factors associated with risk factors for cardiovascular disease (CVD) and dementia, at the population level.
The objective of this dissertation was to investigate the potential effects of long-term environmental noise exposure on CVD and dementia-related outcomes in the US by leveraging data from nationwide (Nurses’ Health Studies, Chapter Two) and local (Chicago Health and Aging Project [CHAP], Chapters Three and Four) cohorts. In both cohorts, annual aircraft noise estimates obtained from the Aviation Environmental Design Tool were generated every five years from 1995 to 2015 and linked to participants’ geocoded addresses. In CHAP, annual community and road noise estimates were generated within the Chicago city boundaries from separate land-use regression and CadnaA noise propagation models, respectively, for the same period as our aircraft noise estimates (1995 to 2015).
In Chapter Two, we examined associations of aircraft noise with CVD incidence, CVD mortality, and all-cause mortality in the nationwide Nurses’ Health Studies, consisting of two prospective cohorts of 121,700 (Nurses’ Health Study, NHS) and 116,686 (Nurses’ Health Study II, NHSII) female nurses followed over the past 40 years. Overall, we did not find associations of aircraft noise with our outcomes of interest, which may reflect the lack of variability estimated exposure, as only approximately 7% of individuals experiencing a CVD-related event or death were exposed to aircraft noise above 50 A-weighted decibels.
In Chapter Three, we assessed the relations of various types of environmental noise (community, road, aircraft) with three blood biomarkers of neurodegeneration (total tau, t-tau; neurofilament light chain, Nf-L; and glial fibrillary acidic protein, GFAP) in CHAP, a local prospective cohort of older adults living in Chicago, Illinois. We observed weak adverse associations of community, road, and aircraft noise with t-tau and Nf-L, which suggest that noise may work directly through neuronal damage. With GFAP, we observed weak and imprecise protective relations with GFAP, which may indicate that astrocyte activation may not be a pathway in which noise impacts health.
Lastly, in Chapter Four, we continued to use data from CHAP to quantify associations of each noise measure (community, road, aircraft) with baseline cognitive performance, cognitive decline, and Alzheimer’s dementia (AD) incidence. In this study, we operationalized cognitive level and decline using assessments of perceptual speed, episodic memory, and a global cognitive performance score. With community and road noise, we found associations between increasing noise level and worse performance on each cognitive domain at baseline; however, we did not observe any associations with cognitive decline. With aircraft noise, we found mixed associations with cognitive performance at baseline, in which we unexpectedly observed some increasing aircraft noise categories with better cognitive performance, particularly with episodic memory. Yet, higher exposure to aircraft noise corresponded to faster rate of cognitive decline over time, most notably among the highest (versus the lowest) exposure category. When examining each noise source with cumulative odds of AD, we found suggestive yet imprecise associations, indicating greater odds with increasing exposure. Overall, our results should be interpreted cautiously, as the confidence intervals for the estimates were wide, and estimates were not necessarily consistent across sources of noise exposure.
Although many of the results consistent with no association, this dissertation adds to the sparse literature on noise and health in aging populations and establishes a foundation for developing research on these questions that is more robust. / 2026-05-10T00:00:00Z
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/48739 |
| Date | 11 May 2024 |
| Creators | Grady, Stephanie Theresa |
| Contributors | Peters, Junenette L |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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