Assessing the Impact of Emission Control Measures on Air Quality and Human Health using Numerical Models, Statistical Analysis, and Machine Learning Approach

This dissertation examines the effects of past and prospective mitigation strategies on air quality from regional and health standpoints. In Chapter 1, we analyze in-situ measurement data to discern trends in surface ozone and NO₂ concentrations across major megacity clusters in China from 2015 to 2019. Our findings highlight a concerning increase in daily maximum 8-hour average (MDA8) ozone levels across most regions, with meteorology and precursor emissions being significant contributors to this rise. The study urges a reduction in NOx and VOCs to negate the adverse meteorological effects on ozone concentrations, aiding in the formulation of effective regional air pollution control policies. In Chapter 2, we deploy quantile regression to assess the impact of emission control measures across various climatic regions in the Contiguous United States between 1991 and 2020. Despite a nationwide decline in adjusted ozone concentrations, climate variability threatens to undermine these achievements. The machine learning (SHAP) analysis outlines the meteorological factors chiefly influencing ozone levels in different regions, guiding future emission reduction strategies. Chapter 3 investigates the repercussions of diverse electrification and emission mitigation scenarios on PM2.5 and ozone levels in major U.S. cities. We note a general reduction in PM2.5 with increased electrification but also pinpoint potential hikes in secondary organic aerosols (SOA) and ozone levels. The research proposes region-specific policies, emphasizing the need to curb VOC emissions to enhance the benefits of electrification. In the final chapter, we delve into the health implications of short-term exposure to ozone, spotlighting a notable decrease in premature deaths in the Northeast and Ohio Valley regions due to emission reduction policies. The study recognizes the health and economic gains from integrating EVs, yet warns of potential setbacks, thereby urging a continual reassessment of policies to accommodate dynamic urban scenarios and pollutant complexities. Our comprehensive analysis underscores the critical role of strategic emission controls in enhancing air quality and public health, advocating for adaptive, region-specific policies informed by detailed trend analyses and scenario evaluations. It offers pivotal insights for refining current approaches to air quality management, emphasizing the nuanced challenges posed by changing climatic conditions and urban dynamics.