The problem of disparate exposures to environmental pollution has become the focus of renewed policy interest in the United States. Full-coverage mobile monitoring of air pollution can support policy advances in several ways. High-intensity mobile monitoring can reveal sources of localized hotspots (e.g., warehouses, metals processing, or restaurant clusters) that may be the subject of community concern but are not always detected by conventional monitoring . More broadly, the range and spatial variability of exposures revealed by mobile monitoring-not generally provided by conventional modeling and regulatory measurement networks-support the development of community-focused plans to improve air quality.