Abstract View
Evaluating the Accuracy of Optical Particle Counters for Estimating Size-Resolved Particulate Matter Mass Concentrations in Occupied Homes
YICHENG ZENG, Insung Kang, Kari Abromitis, Parham Azimi, Brent Stephens, Illinois Institute of Technology
Abstract Number: 559
Working Group: Health-Related Aerosols
Abstract
Optical particle counters (OPCs) are commonly used to characterize particle number concentrations in indoor environments and to estimate size-resolved mass-based concentrations of particulate matter (e.g., PM1, PM2.5, or PM10) by assuming particle shape and density. To date, studies have compared the utility and accuracy of using research-grade aerosol instrumentation (such as scanning mobility particle sizers combined with aerodynamic particle sizers) as well as low-cost particle counters to estimate total and/or size-resolved PM mass concentrations, but there is limited data on the accuracy of mid-range OPCs (e.g. ~$2500 USD) for estimating mass-based PM concentrations. Here we present results from a sampling campaign in which time- and size-resolved indoor particle concentrations were measured using MetOne GT-526S OPCs in 41 occupied homes in Chicago, IL; co-located size-resolved gravimetric PM samples were also collected using Sioutas Personal Cascade Impactors deployed in a subset of home visits for comparison between instruments. Gravimetric samples have been collected in 21 home visits to date with a goal of 30 visits by 2020 (sampling is still ongoing). Preliminary results show reasonable correlations between the OPC estimates and actual size-resolved mass-based concentrations (e.g., PM0.5, PM1, and PM2.5), but that correlations vary highly between home visits likely because of (i) differences in indoor particle density and/or shapes and/or (ii) the vast majority of PM mass was observed in the size bin smaller than 0.25 µm (which is below the detection limit of ~0.3 µm of the OPCs). These data are expected to provide useful insights into how accuracy mid-cost OPCs can (or cannot) be used to estimate PM mass concentrations.