"Breathing the Burden: Assessing the Human Health Risks and Impact of Air Pollution on Respiratory Health in Southwestern Pennsylvania", Department of Environmental and Occupational Health, School of Public Health. 

Committee: 

• Travis Knuckles (chair)
• Tina Ndoh
• Melissa Bilec
• Neta Bortey-Sam
• Linda Wigington, ROCIS team leader

Abstract: 
Air pollution in Allegheny County, Pennsylvania — driven by active industrial sources and river valley topography — poses persistent respiratory health risks, yet the pathways linking ambient pollution to personal exposure and respiratory harm remain poorly characterized. This dissertation traces that pathway from outdoor air to indoor environments to the lungs of individuals living closest to emission sources. Outdoor and indoor PM2.5 was simultaneously characterized across 290 homes in 12 municipalities (2016–2021) using Dylos particle counters from the Reducing Outdoor Contaminants in Indoor Spaces (ROCIS) Low Cost Monitoring Project, applying generalized estimating equations and hazard quotient estimation. Using paired indoor-outdoor monitors at the same households, indoor-to-outdoor ratios and household predictors of indoor PM₂.₅ were then examined. Narrowing to the individual level, ten asthma patients from the Asthma and Environmental Health Lung Institute (AEHLI) living upwind and downwind of the U.S. Steel Edgar Thomson Plant were recruited and monitored across five separate two-week monitoring periods (2022–2024). AQMesh multi-pollutant pods and twice-daily spirometry were used to link pollutant exposure directly to lung function.

Across the county, 66.5% of outdoor sites and 10.5% of indoor exceeded the 2024 EPA annual PM₂.₅ standard. Outdoor hazard quotients exceeded 1.0 in 42% of municipalities; indoor HQ values were uniformly lower but approached the concern threshold in communities nearest to industrial sources. Inside the home, outdoor pollution dominated 87.5% of paired monitoring periods (median I/O = 0.318). However, household-level factors — such as air conditioning, frying frequency, candle burning, and pet ownership — significantly modified indoor concentrations. Closer to the source, indoor concentrations near the Edgar Thomson Plant exceeded outdoor levels for PM2.5, CO, and SO2, with significant associations observed between indoor SO2, indoor O3,
outdoor NO2, and reduced FEV1/FVC%. Wall-to-wall carpet emerged as the strongest predictor of uncontrolled asthma (OR = 117.0, 95% CI: 1.94–7,061). Together, these findings reveal the indoor microenvironment as a critical, modifiable link between ambient pollution and respiratory health, supporting expanded hyperlocal monitoring and housing-level interventions in industrially burdened communities.