A Decade of Progress: Quantifying Air Pollution Reductions in West Oakland, CA with Hyperlocal Monitoring
Year: 2026
Type: preprint
Abstract: West Oakland is a disadvantaged community in California that has historically experienced a high and disproportionate exposure to diesel air pollution due to its proximity to major transportation infrastructure, including the Port of Oakland and several interstate freeways. However, years of community activism, statewide regulation and targeted local emissions mitigation have altered these conditions. In 2025/26, we replicated a 2015/16 mobile monitoring campaign that characterized hyperlocal spatial gradients in diesel air pollution by repeatedly sampling every road within the community. By comparing how concentrations changed in both magnitude and location, we study the impact of the different mitigation strategies across the last decade. Community wide, weekday daytime black carbon (BC) and NO x concentrations fell by 59.5% [54.2-64.6] (-0.51 μg m -3 ) and 60.0% [54.0-65.7] (-22.0 ppb) respectively, with near uniform fractional declines across seven community identified high impact residential zones (57-62% for BC, 52-64% NO x ). This reduction is consistent with California’s aggressive statewide diesel truck regulations, a phased transition completed in 2023, under which every truck operating within the state must use diesel particulate filter and selective catalytic reduction exhaust treatment technologies. Concentration reductions on individual roads scaled linearly with measured truck traffic (R 2 ~ 0.9), while roads in and around the Port show BC reductions beyond those expected from truck traffic alone, consistent with local investment in cleaner off road equipment. Overall, the decade’s changes avoided an estimated excess lifetime cancer risk from diesel particulate matter of 269 [209-328] per million for those who grow up in the community, and cut absolute disparity in exposure between the most and least polluted zones by 70% for BC and 58% for NOx. These results demonstrate the measurable air quality benefits associated with sustained emissions control and provide quantitative evidence of progress towards goals identified through decades of community-led monitoring and advocacy.
Source: ChemRxiv
Institution: University of California, Berkeley
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7221623516