Pittsburgh air quality study overview

Abstract

Ambient sampling for the Pittsburgh Air Quality Study (PAQS) was conducted from July 2001 to September 2002. The study was designed (1) to characterize particulate matter (PM) by examination of size, surface area, and volume distribution, chemical composition as a function of size and on a single particle basis, morphology, and temporal and spatial variability in the Pittsburgh region; (2) to quantify the impact of the various sources (transportation, power plants, biogenic sources, etc.) on the aerosol concentrations in the area; and (3) to develop and evaluate the next generation of atmospheric aerosol monitoring and modeling techniques. The PAQS objectives, study design, site descriptions and routine and intensive measurements are presented. Special study days are highlighted, including those associated with elevated concentrations of daily average PM 2.5 mass. Monthly average and diurnal patterns in aerosol number concentration, and aerosol nitrate, sulfate, elemental carbon, and organic carbon concentrations, light scattering as well as gas-phase ozone, nitrogen oxides, and carbon monoxide are discussed with emphasis on the processes affecting them. Preliminary findings reveal day-to-day variability in aerosol mass and composition, but consistencies in seasonal average diurnal profiles and concentrations. For example, the seasonal average variations in the diurnal PM 2.5 mass were predominately driven by the sulfate component. r

Mass balance closure and the Federal Reference Method for PM2.5 in Pittsburgh, Pennsylvania

“…The main PAQS ambient monitoring station was located in Schenley Park within the city of Pittsburgh (Wittig et al, 2004b). This location was not significantly impacted by local sources.…”

Organic nitrogen in PM<sub>2.5</sub> aerosol at a forest site in the Southeast US

“…Ambient PM 2.5 aerosol (i.e. particles smaller than 2.5 µm in aerodynamic diameter) contains numerous inorganic and organic nitrogen compounds, which cumulatively can contribute significantly to total atmospheric nitrogen deposition (Erisman et al, 1997;Garstang et al, 1998;Seinfeld and Pandis, 1998;Tolocka et al, 2001;Wittig et al, 2004). The majority of aerosol deposition studies concentrate on quantifying only the inorganic fraction (i.e., NH + 4 and NO − 3 ) (Garstang et al, 1998;Yeatman et al, 2001;Morselli et al, 2008;Rojas and Venegas, 2009).…”

The U.S. Environmental Protection Agency’s Particulate Matter Supersites Program: An Integrated Synthesis of Scientific Findings and Policy- and Health-Relevant Insights

“…77 At eastern U.S. locations, the aerosol was characterized by higher sulfate and significant amounts of SOA in the summer, when photochemical activity peaks, with higher overall OC (mostly primary), nitrate, and EC in the winter months because of lower mixing heights and cooler temperatures. 90,163,170,[173][174][175][176][177][178][179][180] In Atlanta, the highest concentrations were observed in the summer, with sulfate typically being the largest contributor, although OC was typically the second most abundant species with a relatively flat seasonal trend. 163,173 OC consisted of primary and SOA with up to 46% of the OC being SOA.…”