What is in the air: Air pollution variability in urban areas

Elevated levels of particulate pollution are a known environmental health risk, especially in urban areas. While substantial data exists to describe particulate levels on an averaged, city-wide basis, there is comparatively little known about levels of particulate concentrations within urban areas. This study investigates the variability of particulate pollution within cities, using an integrated approach and drawing from different health and pollutant data sets on different scales. In order to integrate these different and diverse elements, the study focuses on a single site—New Haven, Connecticut—a small post-industrial city in the northeastern United States.; Current air monitoring practices, mostly single site particulate monitoring in urban areas, provide much of the data used in air quality analyses. These measurements are the result of decades of research and regulatory work. They represent our best current practices. They are the best, but are they doing any good? What is the nature of urban air quality and do current regulatory practices capture the actual range of particulate matter concentrations in urban areas?; This is the central question that drives this thesis. There is no simple answer, nor single approach. The question requires analyses of human health, particulate matter patterns and human perceptions. The intent of this thesis is to explore and define the key issues and—where discrepancies are found—to suggest and test approaches to contribute to a fuller understanding of the spatial variability of particulate matter in urban areas. This thesis considers four inter-related aspects of urban air quality with a focus on particulate matter: aspects concerning health effects, exposure, monitoring and public perceptions.; The study concludes that current monitoring standards provide useful but severely limited information on general trends in spatial and temporal trends in particulate matter distribution. This data has been invaluable in epidemiological research such as the morbidity and mortality studies that revealed the health effects of fine particles. Yet at the same time, given what is known about pollution patterns, it is clear that current standards do not measure what is in the air where people live. There are no mechanisms in place to learn about local patterns that influence actual exposure. Without this critical data on the air people breathe, researchers cannot really understand the mechanisms of how air pollutants impact health. The thesis concludes with a series of specific recommendations for both further research and regulation.