Trends in PM 2.5 composition at the Department of Energy OST NETL fine particle characterization site in Pittsburgh, PA, USA

Abstract

This paper reports on the results from the first 6 months (from November 1999 to April 2000) of an ongoing monitoring study of fine particulate air pollutants at the Department of Energy's Office of Science and Technology (OST) NETL sampling site, 30 km southwest of Pittsburgh city center, Pennsylvania. This study is part of a 2-year sampling program for PM characterization, under the auspices of The University Coal Research Program of the National Energy Technology Laboratory (NETL), US Department of Energy in Pittsburgh, PA, USA. Samples were collected daily with a Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS) to determine PM 2.3 composition, including the semi-volatile organic compounds (SVOC) and ammonium nitrate lost from particles during sampling. Average fine particulate composition during the 6-month period was: constructed PM 2.3, 19.4 μg m −3; ammonium sulfate 4.3 μg m −3; non-volatile organic material, 6.9 μg m −3; elemental carbon, 0.4 μg m −3; SVOC lost from particles during sampling, 6.1 μg m −3; retained ammonium nitrate, 1.4 μg m −3; lost ammonium nitrate, 0.3 μg m −3. Results from the PC-BOSS sampler are also compared with those obtained from a Federal Reference Method PM 2.5 sampler, and a Tapered Element Oscillating Microbalance monitor, both of which tended to not measure the semi-volatile particulate matter. SVOC concentrations were highest in the spring. Episodes of fine particulate non-volatile organic material occurred throughout the 6-month period. Average ammonium sulfate concentrations were higher in November and January than the other months for the study period.