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South Philadelphia Passive Sampler and Sensor Study
Citation:
Thoma, E., W. Jiao, T. Wu, B. Squier, Bill Mitchell, K. Oliver, D. Whitaker, S. Mukerjee, M. Colon, C. Gross-Davis, H. Schmidt, R. Landy, J. Dewees, R. Merrill, S. Amin, M. Modrak, AND T. Cousett. South Philadelphia Passive Sampler and Sensor Study. 108th Annual Conference of the Air & Waste Management Association, June 23-26, 2015, Raleigh, NC, June 23 - 25, 2015.
Impact/Purpose:
This the presentation associated with previously cleared conference paper # 2015-A-34-AWMA "South Philadelphia Passive Sampler and Sensor Study", to be presented at the Annual Conference of the A&WMA - June 24, 2015, Raleigh, NC.
Description:
Starting in June 2013, the United States Environmental Protection Agency (U.S. EPA) and the City of Philadelphia Air Measurements Services began collaborative research on the use of passive samplers (PSs) and stand-alone air measurement (SAM) systems to improve information on the spatial distributions of air pollutant concentrations in south Philadelphia. The study uses draft U.S. EPA Method 325 time-integrated PSs, deployed in novel ways near facilities and in communities, along with sensor-based SAM technologies to help identify the origin of emissions. Following an overview of project elements, this presentation examines preliminary PS benzene results and provides an example of supporting SAM data. Related presentations in this conference will further detail PS and prototype SAM network deployments and data analysis. Considering all 17 PS sites and 28 (two-week nominal) deployment periods, the median and maximum PS benzene concentrations for this interim set were 0.51 ppbv and 3.13 ppbv, respectively (N = 854). Good co-deployed PS duplicate precision performance was found with an average percent difference of 5.8% for pairs with concentrations over 0.2 ppbv (N = 362). Preliminary data suggests a negative correlation between the sampling period minimum benzene concentrations and average temperature. Although no definite source attribution is offered in this interim report, benzene concentrations for PSs located in close proximity to facility fence lines were found to be consistently elevated by 1 ppbv to 2 ppbv in comparison to distant, in-community sites. An examination of prevailing wind directions, spatial concentration gradients, and an example of time-resolved SAM data are also provided.