The California Air Resources Board (CARB) has launched of the monitoring phase of the Statewide Mobile Monitoring Initiative (SMMI), a first-of-its-kind program delivering hyper-local air pollution data to guide efforts to improve air quality in California.

The pilot project will deploy mobile air monitoring equipment to communities throughout the state beginning in June 2025. It is designed to collect comprehensive air quality information and support actions to protect public health with a focus on communities that have long faced environmental disparities. CARB will use sensor-equipped vehicles from Aclima and mobile laboratories operated by researchers from the University of California, Berkeley, University of California, Riverside, and Aerodyne to gather pollution data across 64 communities statewide.

The initiative is part of California Climate Investments. A fleet of Aclima mobile monitoring vehicles will collect air quality data with a focus on criteria pollutants, black carbon and methane. Three mobile laboratories operated by SMMI partners will supplement air monitoring vehicles by providing comprehensive analysis of toxic air contaminants.

More than 60% of the mobile monitoring will serve priority populations including low-income communities and households. The 64 communities were consistently nominated for focused action under the Community Air Protection Program.

The mobile monitoring phase will begin this June, following the finalization of draft Community Air Monitoring Plans that were recently released for public comment. Monitoring will take place in the 64 communities over the next year. The project is expected to end in June 2026, when the collected data will become publicly available, along with visualization tools. Final results will be shared with the 64 communities, the general public and the Board. The data collected will be used by CARB, local air districts, stakeholders and community advocates to address existing and emerging pollution concerns. The data is also expected to inform future regulatory programs, academic research, and applications for grants such as the Community Air Grants Program.