Our findings highlight the importance of identifying both highly localized patterns and intraurban disparity for addressing environmental injustice. We performed a set of stylized sensitivity analyses, described in SI, to characterize the degree to which hyperlocal, local, and regional air pollution control interventions might help reduce racial/ethnic exposure disparities within the San Francisco Bay Area. Consistent with our findings that between-neighborhood patterns are the principal driver of racial/ethnic disparities, interventions that only eliminate within-neighborhood hotspots may not substantially reduce systematic disparity, although such interventions address the concentration extremes often experienced disproportionately by people of color. In contrast, interventions that reduce the differences in background concentrations among neighborhoods have higher potential to address population-wide racial/ethnic exposure disparities (see SI Appendix). Higher-pollution areas often contain a variety of features that individually cause hyperlocal peaks and as a group contribute to elevated local background concentrations. Some examples of these features include greater heavy-duty vehicle traffic, adjacent high-emissions areas like ports and railyards, a high density of industrial operations, and a lack of green space. A community-centered approach to policymaking can account for issues at both hyperlocal and local scales by first identifying a suite of neighborhood features that contribute to higher pollution, and then seeking local, regional, or state support for targeted interventions. Such interventions may include incentives and infrastructure to support zero-emission vehicles, accelerated emission control retrofits for point sources, and city planning to restrict new industrial facilities and infrastructure in disproportionately burdened communities. The differences in disparity patterns among pollutants further underscores the importance of multi-source control policies. This community-centered approach is exemplified by the West Oakland "Owning Our Air" plan co-authored by the Bay Area Air Quality Management District, the West Oakland Environmental Indicators project, and a community-based steering committee and the broader Community Air Protection Program (AB617) in California, which includes West Oakland among fifteen areas chosen for targeted interventions . Continued monitoring is necessary for evaluating policy effectiveness. Regional monitoring strategies may benefit from the multiscale approach of this study, as we identified some areas for which a single "background" monitor would represent neighborhood exposure within reasonable bounds, especially for secondary pollutants. Further investigation of the association of peaks and regional variation with specific emission sources and land uses is a useful direction for future research. We hypothesize that expanding this approach to other urban or rural settings would likely reveal different but similarly complex patterns and advance our understanding of the interaction between demographic patterns, pollution sources, and the built environment. Environmental policy efforts in the coming years will increase the emphasis on addressing systemic racial/ethnic disparities in air pollution exposure. We illustrate here how environmental justice concerns arise from the confluence of multi-scale patterns of emissions, concentrations, and populations within urban landscapes. Future efforts to address disparities will benefit from recent advances in both extensive fine-scale measurement -as we have demonstrated here -as well source-oriented models that identify the specific causes and drivers of exposure disparities. Broader solutions to environmental injustice will also involve greater partnership between scientists and community organizations, new approaches to synthesizing and communicating high-resolution data, and innovations in inclusive policymaking.