AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
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Personal Exposure to Black Carbon and PM Oxidative Potential in Fresno, CA using an Automated Microenvironmental Aerosol Sampler (AMAS)
CASEY QUINN, Dan Miller-Lionberg, Kevin Klunder, Jaymin Kwon, Betsey Noth, John Mehaffy, Laurelle Turner, Sheryl Magzamen, S. Katharine Hammond, Charles Henry, John Volckens, Colorado State University
Abstract Number: 486 Working Group: Aerosol Exposure
Abstract Human exposure to particulate matter is a leading risk factor for disease and premature death. Current methods for assessing time-integrated personal exposure are cumbersome and relatively expensive, especially in the context of large-scale epidemiological studies. To address these limitations, we developed an automated microenvironmental aerosol sampler (AMAS). The AMAS is a low-cost, wearable device with a GPS-based algorithm that detects predetermined microenvironments (home, school, other) and collects PM2.5 particulate matter from each microenvironment on distinct 15mm filter channels. A pilot study in Fresno, CA enrolled 25 student participants to collect 42 microenvironment personal samples (139 filters) in November 2016. To measure reliability, 10 AMAS samples were paired with a reference instrument. Black carbon (BC) was quantified using optical transmissometry, and the oxidative potential (OP) on the AMAS filters was quantified with both the traditional dithiothreitol (DTT) assay and an electrochemical DTT assay. Participants spent an average of 31.5, 12.8, and 4.5 hours of the 48-hour sampling period in each microenvironment (home, school, other) based on the algorithm classification. The analytic techniques provided reliable, low-cost analyses, with method detection limits of: BC [0.485 µg LOD]; OP [0.252 µM*min-1 LOD]. The BC sum on the AMAS filters had a mean error of 14% as compared to the reference filter. The BC and OP cumulative exposures were greatest at home(1.48µg, 0.290µM*min-1) compared to the school(0.391µg, 0.159µM*min-1) and other microenvironments(0.591µg, 0.192µM*min-1). While a strong correlation between BC and OP (R=0.66) was found, the number of filters exceeding the LOD for each analysis (76 BC, 42 DTT) was low. Future work will modify the AMAS to increase the volume of sample collected on each filter to improve the filter analyses. The results from this pilot study indicate that the AMAS is a feasible approach for low-cost, personal exposure assessment of BC and OP within microenvironments.