A new air monitoring project is underway in Wilmington to take a closer look at fine particulate matter, also known as PM2.5. The three-year study includes one full year of measurements followed by data review and analysis. The air measurements officially began on October 1, 2025, and the project is funded through a U.S. EPA grant under the American Rescue Plan with some resources leveraged from the AB 617 program as part of the Community Emission Reduction Plans and Community Air Monitoring Plans for the Wilmington, Carson, West Long Beach (WCWLB) community. The goal is to better understand the composition and sources of PM2.5 in this community — home to major oil refineries, oil fields, heavy truck traffic, and the Ports of Los Angeles and Long Beach.

The new advanced air monitoring instruments installed at the Wilmington air monitoring site continuously measure the size and chemical makeup of PM2.5 particles. These high-resolution measurements will provide valuable insights into how local emission sources influence particulate pollution, particularly from port activities, refineries, and oil production operations.

This monitoring effort complements the Atmospheric Science and Chemistry mEasurement NeTwork (ASCENT), a nationwide 12-site research network (including two in the South Coast Air Basin) that characterizes aerosol composition and properties. By using the same suite of instruments as ASCENT sites, Wilmington’s data will be directly comparable to other regions, helping scientists better understand PM2.5 spatial patterns, secondary PM formation mechanisms, and atmospheric aging processes across the South Coast Air Basin.

This study will also support ongoing clean air efforts through California’s AB 617 Community Air Program in the WCWLB community. The enhanced PM2.5 data will help inform and/or support targeted, science-based strategies to reduce PM2.5 exposure and improve public health that were developed by the Community Steering Committee of the WCWLB community.

Ultimately, this project aims to increase community awareness of local air quality while strengthening the foundation for effective emission reduction policies. Lessons learned from this study may also benefit other coastal communities near major ports facing similar air quality challenges.