Air Pollution in the Puget Sound: Environmental Health Disparities and Brain Health

Thesis (Ph.D.)--University of Washington, 2023Ambient air pollution such as fine particulate matter (PM2.5) has been demonstrated to have respiratory and cardiovascular effects and is hypothesized to be associated with the Alzheimer’s disease processes. Community-engaged research provides an opportunity for the public to learn about their neighborhood level exposures to ambient air pollution, health effects, and mitigation strategies. Cumulative impact mapping tools have been used to inform state and local environmental policy, funding priorities, environmental justice advocacy and regulation enforcement to reduce health inequities across communities. However, it is not clear how much work has been done to evaluate the sensitivity of the mapping tools using different data sets. Furthermore, as new methods improve our ability to map and estimate exposures to ambient air pollution there are opportunities to improve health effects research, such as environmental epidemiological studies of PM2.5 and brain health in older adults. The goal of the following studies were to advance our understanding of air pollution health effects through an environmental justice lens as well a deeper understanding of the relationship between air pollution and cognitive function. In the first aim, I evaluated the importance of fit-for-purpose communication strategies for community-engaged research and identified elements of an overarching framework for tailoring communications for target public audiences. I present examples from two case studies of community-engaged air pollution research in the Puget Sound region. CAMPS was a community air monitoring study in the Puget Sound investigating neighborhood level ambient air pollution. Healthy Air, Healthy Schools was a collaborative study with the cities of Burien, Des Moines, Normandy Park, SeaTac and five schools in the Puget Sound region investigating infiltration of ambient air pollution into classrooms and the intervention of portable air cleaners in the classroom environment. Our case studies provide a framework that prioritizes developing partnerships, determining community needs, developing culturally relevant content, developing accessible educational materials, disseminating results in multiple approaches, and evaluation. In the second aim, I conducted a sensitivity analysis approach to illustrate the influence that different air pollution data sources have on Environmental Health Disparities (EHD) ranking. In addition, I developed novel NAAQS based ranking methodology to develop a new health informed map layer. The sensitivity analyses illuminated that overburdened communities could be at risk of not being prioritized for pivotal funding if alternate PM2.5 datasets are used in cumulative impact tools. The new health informed map layers can educate the public on the potential health risk from exposure to ambient air pollution in their communities. In the third aim, I tested the hypothesis that higher individual-level mid- to late-life long-term average exposure to fine particulate matter is associated with lower cognitive ability in later life. Cognitive Abilities Screening Instrument (CASI) data from ACT study was paired with individual-level exposure estimates of PM2.5 to determine the association between PM2.5 exposure and cognitive ability. We found that each additional 1 μg/m3 (5-year average) PM2.5 exposure at baseline was comparable to cognition of cohort members who were 0.62 (95% Confidence Interval (CI): -0.15, 1.28) years older. Similarly, we found that for every additional 1900 pt/cm3 of UFP at baseline was comparable to cognition of cohort members who were 0.73 (95% CI: 0.26, 1.13) years older. This broad innovative work developed a framework for communicating environmental health data and capitalized on novel air pollution data and ACT cohort data to investigate the effect of PM2.5 and UFP on cognitive function. Overall, these studies present novel findings in the areas of report-back and risk communication, environmental health disparities mapping and brain health