Advancing Air Quality Monitoring in Environmental Justice Communities of the South Coast Air Basin, CA: Design and Development of a Novel Multi-Metal Mobile Platform

Abstract:

Ambient particulate metals are an important category of Hazardous Air Pollutants (HAPs) with known detrimental impacts on human health. Given the large spatio-temporal variability in ambient concentrations of particulate metals, information from sparsely distributed fixed air monitoring networks may not adequately reflect their levels and trends, especially in disproportionately impacted (i.e., Environmental Justice (EJ)) communities. Mobile monitoring techniques are a potential solution, as they enable us to capture data in a short enough time period that can represent the spatial variations of the target pollutant. In this study, we developed a novel platform for mobile monitoring of multiple ambient particulate metals using an optimized X-Ray Fluorescence- (XRF) based instrument. The instrumentation aboard the platform also enables the measurement of aerosol characteristics, including particulate matter (PM) mass (PMx), particle number (PN), particle number size distribution, and black carbon (BC); trace gases, including NO₂ and CO₂; and meteorological parameters, including wind speed and direction; all in fine time resolutions (seconds to minutes). It is noteworthy that the mobile platform has been developed as a modular system able to switch and host other monitors as well. Since most pollutants of interest for this platform are in particulate phase, an inlet system was designed that is appropriate for both mobile and stationary measurements with minimum losses for relevant particle sizes (< 10 µm). The efficiency of the designed inlet system was fully characterized using laboratory-generated polystyrene latex (PSL) particles. Here, we will provide an overview of the design criteria, features, and characterization of the platform, and discuss examples and challenges in the application of the platform for both mobile and stationary monitoring. In a companion presentation, we will present preliminary results of the full-blown application of the developed platform, and demonstrate a complex approach for concentration mapping, source identification, and source characterization.