title: South Philadelphia passive sampler and sensor study.
abstract: From June 2013 to March 2015, in total 41 passive sampler deployments of 2 wk duration each were conducted at 17 sites in South Philadelphia, PA, with results for benzene discussed here. Complementary time-resolved measurements with lower cost prototype fenceline sensors and an open-path ultraviolet differential optical absorption spectrometer were also conducted. Minimum passive sampler benzene concentrations for each sampling period ranged from 0.08 ppbv to 0.65 ppbv, with a mean of 0.25 ppbv, and were negatively correlated with ambient temperature (-0.01 ppbv/°C, R(2) = 0.68). Co-deployed duplicate passive sampler pairs (N = 609) demonstrated good precision with an average and maximum percent difference of 1.5% and 34%, respectively. A group of passive samplers located within 50 m of a refinery fenceline had a study mean benzene concentration of 1.22 ppbv, whereas a group of samplers located in communities >1 km distant from facilities had a mean of 0.29 ppbv. The difference in the means of these groups was statistically significant at the 95% confidence level (p < 0.001). A decreasing gradient in benzene concentrations moving away from the facilities was observed, as was a significant period-to-period variation. The highest recorded 2-wk average benzene concentration for the fenceline group was 3.11 ppbv. During this period, time-resolved data from the prototype sensors and the open-path spectrometer detected a benzene signal from the west on one day in particular, with the highest 5-min path-averaged benzene concentration measured at 24 ppbv.
  
  
  
  Using a variation of EPA's passive sampler refinery fenceline monitoring method, coupled with time-resolved measurements, a multiyear study in South Philadelphia informed benzene concentrations near facilities and in communities. The combination of measurement strategies can assist facilities in identification and mitigation of emissions from fugitive sources and improve information on air quality complex air sheds.
authors.affiliation: a U.S. EPA, Office of Research and Development , National Risk Managment Research Laboratory , Durham , NC , USA.
authors.forename: Eben D
authors.initials: ED
authors.lastname: Thoma
authors.affiliation: a U.S. EPA, Office of Research and Development , National Risk Managment Research Laboratory , Durham , NC , USA.|b Oak Ridge Institute for Science and Engineering Fellow , Durham , NC , USA.
authors.forename: Halley L
authors.initials: HL
authors.lastname: Brantley
authors.affiliation: c U.S. EPA, Office of Research and Development , National Exposure Research Laboratory , Durham , NC , USA.
authors.forename: Karen D
authors.initials: KD
authors.lastname: Oliver
authors.affiliation: a U.S. EPA, Office of Research and Development , National Risk Managment Research Laboratory , Durham , NC , USA.
authors.forename: Donald A
authors.initials: DA
authors.lastname: Whitaker
authors.affiliation: a U.S. EPA, Office of Research and Development , National Risk Managment Research Laboratory , Durham , NC , USA.
authors.forename: Shaibal
authors.initials: S
authors.lastname: Mukerjee
authors.affiliation: a U.S. EPA, Office of Research and Development , National Risk Managment Research Laboratory , Durham , NC , USA.
authors.forename: Bill
authors.initials: B
authors.lastname: Mitchell
authors.affiliation: a U.S. EPA, Office of Research and Development , National Risk Managment Research Laboratory , Durham , NC , USA.
authors.forename: Tai
authors.initials: T
authors.lastname: Wu
authors.affiliation: d U.S. EPA, Office of Enforcement and Compliance Assurance , National Environmental Investigations Center , Denver , CO , USA.
authors.forename: Bill
authors.initials: B
authors.lastname: Squier
authors.affiliation: e Arcadis U.S., Inc. , Philadelphia , PA , USA.
authors.forename: Elsy
authors.initials: E
authors.lastname: Escobar
authors.affiliation: f Jacobs Technology Inc. , Durham , NC , USA.
authors.forename: Tamira A
authors.initials: TA
authors.lastname: Cousett
authors.affiliation: g U.S. EPA, Region 3 , Philadelphia , PA , USA.
authors.forename: Carol Ann
authors.initials: CA
authors.lastname: Gross-Davis
authors.affiliation: g U.S. EPA, Region 3 , Philadelphia , PA , USA.
authors.forename: Howard
authors.initials: H
authors.lastname: Schmidt
authors.affiliation: h City of Philadelphia, Department of Public Health , Air Management Services Laboratory , Philadelphia , PA , USA.
authors.forename: Dennis
authors.initials: D
authors.lastname: Sosna
authors.affiliation: h City of Philadelphia, Department of Public Health , Air Management Services Laboratory , Philadelphia , PA , USA.
authors.forename: Hallie
authors.initials: H
authors.lastname: Weiss
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001554:Benzene / Q000032:analysis*; D004784:Environmental Monitoring; D015143:Philadelphia; D012621:Seasons; D014887:Weather
chemical_list: D000393:Air Pollutants; D001554:Benzene