UCSF

Asthma is the most common chronic disease among children. Despite the high prevalence of asthma, there is no cure and its etiology is poorly understood. Of all racial/ethnic groups, African Americans and Puerto Ricans have the highest rates of asthma in the US. Asthma is a multifaceted disease, with genetic, social and environmental risk factors. Outdoor air pollution is a known risk factor, associated with asthma exacerbations and emergency room hospitalizations. US minorities often live in neighborhoods that are disproportionately exposed to higher levels of air pollution, yet few studies are conducted in minority groups. The objective of this dissertation was to evaluate the effects of air pollution on asthma in Latinos and African Americans.

This work utilized data from two parallel case-control studies: the Genes-environments and Admixture in Latino Americans (GALA II) and the Study of African Americans, Asthma, Genes and Environments (SAGE II). Children were recruited from five urban regions in the US, and were assigned estimates of air pollution exposure to five common pollutants for each year of their lives.

The first chapter describes the associations between early-life air pollution exposures and the subsequent risk for developing childhood asthma. Early-life exposure to NO2, a traffic-related pollutant, was associated with an increased risk for subsequent asthma. The second chapter describes the association between recent air pollution exposures and lung function in children with asthma. Exposure to SO2 and coarse particulate matter, both industrial-related pollutants, were associated with poorer lung function. Significant effect modification by race/ethnicity was also detected. The third chapter describes the variation in total IgE and atopy prevalence and outlines the associations between early-life air pollution exposures and the risk for developing non-atopic asthma. Ozone exposure in the first year of life was found to be associated with an increased risk for developing non-atopic asthma.

In summary, our findings suggest that air pollution impacts numerous aspects of asthma risk and morbidity. Gaining a better understanding of these associations could potentially prevent a substantial proportion of current and future asthma disparities. Replication of these findings is needed in addition populations and regions.