Mobile Monitoring of PM2.5 - Insights from On-road Comparisons with MetOne BAM 1020 and Teledyne T640 FEMs

ANDREW WHITEHILL, Melissa Lunden, Brian LaFranchi, Paul Solomon, Surender Kaushik, United States Environmental Protection Agency

     Abstract Number: 283
     Working Group: Instrumentation and Methods

Abstract
Spatially and temporally resolved fine particulate matter (PM_2.5) measurements can provide insight into population exposure to PM_2.5 in different communities and neighborhoods, including in environmental justice regions. Aclima, Inc. has performed ongoing mobile monitoring in the San Francisco Bay Area of California for over 3 years, including measuring size-binned particle number counts in the 0.3 μm to 2.5 μm diameter range using an optical particle counter (OPC). During this period, there have been periods of driving with or near various continuous PM_2.5 federal equivalent methods (FEMs), including MetOne BAM 1020 and Teledyne T640 monitors. We demonstrate comparisons between OPC estimates of PM_2.5 and continuous FEM measurements of PM_2.5 in both low (background) and high (wildfire-impacted) regimes. The OPC had stronger correlations with the Teledyne T640, especially in lower concentration regimes, than with the BAM 1020. However, correlations between the OPC and BAM 1020 improved during wildfire events with higher PM_2.5 loading. The high limit of detection (and higher noise) for the BAM 1020 versus the Teledyne T640 makes comparisons with the T640 easier for calibrating lower-cost sensors and mid-range PM monitors at typical ambient PM_2.5 concentrations. We will conclude with a case study demonstrating preliminary results of mobile PM_2.5 measurements using OPCs in the San Francisco area.

Disclaimer:
The views expressed in this abstract are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency. Any mention of trade names, products, or services does not imply an endorsement by the U.S. Government or the U.S. Environmental Protection Agency. The EPA does not endorse any commercial products, services, or enterprises.