Facility fence-line monitoring using passive samplers

J Air Waste Manag Assoc. 2011 Aug;61(8):834-42. doi: 10.3155/1047-3289.61.8.834.

Abstract

In 2009, the U.S. Environmental Protection Agency (EPA) executed a year-long field study at a refinery in Corpus Christi, TX, to evaluate the use of passive diffusive sampling technology for assessing time-averaged benzene concentrations at the facility fence line. The purpose of the study was to investigate the implementation viability and performance of this type of monitoring in a real-world setting as part of EPA's fence-line measurement research program. The study utilized 14-day, time-integrated Carbopack X samplers deployed at 18 locations on the fence line and at two nearby air monitoring sites equipped with automated gas chromatographs. The average fence-line benzene concentration during the study was 1075 parts per trillion by volume (pptv) with a standard deviation of 1935 pptv. For a 6-month period during which wind direction was uniform, the mean concentration value for a group of downwind sites exceeded the mean value of a similar upwind group by 1710 pptv. Mean value differences for these groups were not statistically significant for the remaining 6-month time period when wind directions were mixed. The passive sampling approach exhibited acceptable performance with a data completeness value of 97.1% (n = 579). Benzene concentration comparisons with automated gas chromatographs yielded an r2 value of 0.86 and a slope of 0.90 (n = 50). A linear regression of duplicate pairs yielded an r2 of 0.97, unity slope, and zero intercept (n = 56). In addition to descriptions of technique performance and general results, time-series analyses are described, providing insight into the utility of 2-week sampling for source apportionment under differing meteorological conditions. The limitations of the approach and recommendations for future measurement method development work are also discussed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Air Pollutants / analysis
  • Air Pollutants, Occupational / analysis*
  • Benzene / analysis
  • Environmental Monitoring / instrumentation*
  • Environmental Monitoring / methods
  • Industry
  • Petroleum
  • Reproducibility of Results
  • United States
  • United States Environmental Protection Agency

Substances

  • Air Pollutants
  • Air Pollutants, Occupational
  • Petroleum
  • Benzene