Global, Environmental, and Occupational Health Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/10071
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Item EXPLORING ENVIRONMENTAL INJUSTICE AND AIR POLLUTION-RELATED HEALTH EFFECTS IN PRINCE GEORGE'S COUNTY, MARYLAND(2024) Ravichandran, Vivek; Wilson, Sacoby M; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Polluting facilities have been historically sited in disadvantaged communities of color, known as environmental justice (EJ) communities, due to limited perceived community resistance and mobilization. There is a plethora of air quality disparity research but a gap persists in ascertaining the health inequities associated with community exposure to air pollutants, such as particulate matter (PM) and black carbon (BC), at the neighborhood resolution. To address this gap in EJ science, this dissertation has four specific aims: (1) Implement the community-based participatory research (CBPR) framework to expand and enhance the community-engaged infrastructure to ensure the success of Aims 2-4; (2) Identify spatiotemporal pollution patterns across the Route 50-Sheriff Road-Kenilworth Ave Quadrant; (3) Determine short-term health impacts associated with community exposure to PM and BC via a panel study involving pulse oximeters to correlate elevated PM and BC levels to blood oxygen saturation (SpO2 levels); and (4) Conduct semi-structured interviews and use NVivo to perform thematic analysis on barriers and motivating factors towards passing EJ legislation. My findings demonstrated that a more diverse and representative community advisory board (CAB) allowed us to successfully conduct research while maintaining trust within the community, and bringing in voices from various demographic groups, including different ethnicities, ages, income levels, and geographic locations. This led to a more comprehensive understanding of the community's concerns, priorities, and needs related to air quality. Additionally, my findings revealed that both PM and BC levels were elevated during morning rush periods. PM levels did not exceed the Environmental Protection Agency (EPA) annual standards, but did exceed the more protective World Health Organization (WHO) guidelines. Robert Gray Elementary School exhibited higher PM levels than the other Quadrant sites. Furthermore, BC levels at Fairmount Heights High School were above the threshold defined in the literature above which cognitive inhibition and poor respiratory outcomes have been observed, highlighting the effect of air pollution exposure on vulnerable life stages in the Quadrant. BC peaks were also observed 10-15x these unofficial health-based thresholds. Using a pulse oximetry panel study, we found previous and concurrent day lagged fine particulate matter (PM2.5) was weakly associated with reductions in SpO2. Using NVivo, we identified 18 parent codes and 27 subcategories from our semi-structured interviews with Maryland policymakers/agency staff. Key barriers were: (1) the lack of strategic EJ plans; (2) limited community engagement particularly from those living in communities impacted by environmental injustice; and (3) interagency and policymaker collaboration exacerbated by a clear partisan divide. These findings provide evidence of previous misclassified exposure assessments from sparse existing regulatory monitors, present strategies for overcoming EJ barriers in the state, and underscore the importance of collaboration, community engagement, and policy reform to address environmental disparities and promote environmental justice.Item Unmasking risk variability in a changing climate: acute effects from exposure to outdoor heat and air pollution among patients with end-stage renal disease(2021) Remigio, Richard V; Sapkota, Amir; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)End-stage renal disease (ESRD) is a chronic condition that disproportionately affects communities of color and diabetics. Hallmark burdens include the lack of essential renal functions and routine life-saving dialysis treatments to filter and remove toxic wastes from the body. Given their compromised survival advantage, the ESRD population is vulnerable to adverse complications associated with acute environmental exposures. However, little is known about the effect of extreme heat events (EHE), air pollution, and ambient temperature on this targeted population. This dissertation focused on ESRD patients receiving hemodialysis treatments at Fresenius Medical Care facilities within the Northeastern United States region (n=60,717). Using longitudinal study design methods, we investigated the association between acute environmental exposures and the risk of all-cause mortality (ACM) and all-cause hospital admissions (ACHA).We applied case-crossover methods to estimate acute EHE effects on mortality and hospital admissions stratified by latitude, race/ethnicity, and comorbidities. Overall, risks varied, but same-day ACM and ACHA risks were most pronounced. ESRD patients with cardiovascular disease (rate ratio [RR], 2.14; 95% CI:1.91-2.40) and cerebrovascular disease (RR, 1.47; 95% CI:1.26-1.71) had notably increased risks of same-day EHE-related mortality. We furthered our investigation by studying PM2.5 and O3 effects using a similar study design but considered the role of EHE as a modifier and incorporated distributed lag nonlinear modeling to account for cumulative lag structures. Pooled same-day EHE-adjusted models estimated an 8% ACM rate increase when O3 concentrations exceeded air quality standards during warmer months. Our data suggest that EHE can act as a modifier between O3 and ACM. Though, no effect modification by EHE was observed for acute air pollutant exposures and ACHA. Lastly, this dissertation explored the mediating role of selected thermoregulatory responses to increased temperature on ACM or ACHA outcomes using traditional mediation analyses. Systolic blood pressure before dialysis treatment (preSBP) and interdialytic weight gain change (IDWG) were identified as significant pathways. However, we observed inconsistent mediation in the IDWG pathway for ACM (-6.26%) and ACHA (-2.67%). Concomitant physiological changes in preSBP and IDWG may have little intermediary effect in combined pathway models. Overall, this research provided additional lines of evidence for enhancing patient response protocols and early warning systems to improve healthcare delivery in an era of a changing climate specific to subpopulations living with ESRD.