Advancing Air Quality Monitoring in Environmental Justice Communities of the South Coast Air Basin, CA: Community-scale monitoring of particulate metals and other air pollutants using a recently developed mobile platform

Abstract:

In this study, a recently developed mobile platform was deployed for near-source and community-scale monitoring of ambient particulate metals and other air pollutants (i.e., particle number and mass, black carbon (BC), CO₂, and NO₂) in two Environmental Justice (EJ) communities within the South Coast Air Basin (SCAB). The monitoring scheme consisted of sequential steps, including area-wide mobile monitoring to broadly identify the local hotspots; investigative mobile monitoring for identification of potential sources; and subsequent stationary monitoring downwind of the identified sources to characterize their emissions. As these measurements were typically conducted during the day and on weekdays, they lacked information on concentrations outside of these hours. They were also, by design, not collected at one location, complicating direct comparison between measurements while accounting for variations due to changes in emissions and meteorological conditions. Therefore, fixed sites were established for continuous monitoring of particulate metals and other air pollutants to account for those variations. In addition, to ensure data representativeness, sample size (i.e., number of data points in each location for stationary monitoring and number of passes for mobile monitoring) calculations were done using statistical techniques, taking into account the desired confidence limits, confidence intervals, and the standard deviations of air pollutant concentrations. In this presentation, we report the hyper-local, spatio-temporal variations of ambient particulate metals in the EJ communities of the SCAB and demonstrate how this approach has enhanced our capabilities to identify and characterize potential emission sources in the study area. Results from this study will be used for future community-scale source apportionment and source-specific exposure/risk assessment studies. Our findings can also be used to support development of strategies and policies to reduce the exposure to air pollutants in EJ communities.