Indoor and ambient influences on PM_2.5 exposure and well-being for a rail impacted community and implications for personal protections

Abstract Higher air pollution concentrations can be observed near rail networks, local and highway automobile corridors, and shipyards. Communities adjacent to such sources are disproportionately exposed to air pollution from these stationary and mobile sources. One such community is West San Bernardino in California, where households are feet away from the Burlington Northern Santa Fe intermodal facility and are impacted by activities that are estimated to continuously emit air pollutants due to 24/7 operation. This study aimed to (1) quantify the impact of personal mobility and housing characteristics on daily PM 2.5 exposures and well-being for West San Bernardino community members, and (2) develop individualized resilience plans for community collaborators to support future PM 2.5 exposure reduction. Personal PM 2.5 exposures were measured for community collaborators for seven consecutive days during three deployment periods: October 2021, January 2022, and March 2022. Indoor and ambient PM 2.5 levels were also continuously measured for five households over six months using PurpleAir Classic monitors. Demographic and well-being data were collected upon recruitment and after each week of engagement, respectively. Personal exposures in home microenvironments were highest near the railyard and lower farthest away from the railyard. Home exposures were 40% higher on average compared to non-home microenvironments. Household PM 2.5 had a higher-than-expected average infiltration factor of 0.55, and indoor 98th percentiles across the households far exceeded a healthy level at an average of 165 μ g m 3 . Resilience plans featured summaries of personal data and recommendations for mitigating exposures. Results suggest that surrounding land use and residential building characteristics compound to worsen air pollution exposures beyond what is expected for exposures in non-industrialized areas. Findings prompt a call for stronger regulation, not only for emissions, but also for indoor air quality and zoning standards that specifically protect disproportionately impacted communities.