My research is motivated by a desire to alleviate environmental health disparities in a world that is rapidly urbanizing. A question we frequently ask in public health is: Why does place matter? In an effort to answer this question, my work aims to identify the specific aspects of housing, communities, and neighborhoods that shape an individual's health. Home environments are particularly important microenvironments yet largely overlooked when discussing approaches to reduce disease burden and disparities. My work strives to understand the specific causal pathways that lead to health-relevant exposures so that we can ultimately intervene to mitigate them. How do these mechanisms lead to exposure and health disparities which burden low-income communities in the U.S. and globally? Both theoretical models and empirical evidence reveal that disparities in environmental exposures are significant. Understanding key determinants of multiple exposures can aid in developing policies to reduce these disparities. In the years ahead, urban health challenges will present significant stresses locally and globally. According to a recent estimate by the United Nations, 68% of the world’s population is projected to live in urban areas by 2050. This rapid urbanization puts substantial pressures on key sectors such as housing, transportation, sanitation, and employment, especially for the nearly 1 billion urban poor who live in informal settlements. All of these sectors connect to health, with city leaders playing a key role in addressing these problems, especially as climate change stresses continue to accrue. My work ultimately aims to provide evidence-based approaches to meet these urban health challenges for the decades ahead.