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Gaseous and particulate pollutant concentrations associated with five samples per day collected during a July 2001 summer intensive study at the Pittsburgh Carnegie Mellon University (CMU) Supersite were used to apportion fine particulate matter (PM2.5) into primary and secondary contributions using PMF2. Input to the PMF2 analysis included the concentrations of PM2.5 nonvolatile and semivolatile organic material, elemental carbon (EC), ammonium sulfate, trace element components, gas-phase organic material, and NO(x), NO2, and O3 concentrations. A total of 10 factors were identified. These factors are associated with emissions from various sources and facilities including crustal material, gasoline combustion, diesel combustion, and three nearby sources high in trace metals. In addition, four secondary sources were identified, three of which were associated with secondary products of local emissions and were dominated by organic material and one of which was dominated by secondary ammonium sulfate transported to the CMU site from the west and southwest. The three largest contributors to PM2.5 were secondary transported material (dominated by ammonium sulfate) from the west and southwest (49%), secondary material formed during midday photochemical processes (24%), and gasoline combustion emissions (11%). The other seven sources accounted for the remaining 16% of the PM2.5. Results obtained at the CMU site were comparable to results previously reported at the National Energy Technology Laboratory (NETL), located approximately 18 km south of downtown Pittsburgh. The major contributor at both sites was material transported from the west and southwest. Some difference in nearby sources could be attributed to meteorology as evaluated by HYSPLIT model back-trajectory calculations. These findings are consistent with the majority of the secondary ammonium sulfate in the Pittsburgh area being the result of contributions from distant transport, and thus decoupled from local activity involving organic pollutants in the metropolitan area. In contrast, the major local secondary sources were dominated by organic material.

Apportionment of primary and secondary pollutants during a July 2001 intensive study at the National Energy Technology Laboratory is reported. PM2.5 was apportioned into primary and secondary contributions using PMF2, and results were compared with apportionment based on UNMIX 2.3. Input to PMF2 included PM2.5 mass data from four per 24 hour PC-BOSS filters and TEOM, NOx, NO2, O3, non-volatile, semi-volatile, and volatile organic material, elemental carbon, sulfate, and PIXE determined trace metals. Nine factors were identified in the PMF analysis. Six factors were associated with primary particles from crustal, mobile (gasoline and diesel), and three local sources high in trace metals. Three factors were associated with secondary sources. Two were associated with local emissions dominated by organic material, one was dominated by transported ammonium sulfate. UNMIX was able to identify the two major mobile sources, major local secondary source and transported secondary source. The three major sources of ...

The Salt Lake City EPA Environmental Monitoring for Public Access and Community Tracking (EMPACT) project, initiated in October 1999, is designed to evaluate the usefulness of a newly developed real-time continuous monitor (RAMS) for total (non-volatile plus semi-volatile) PM2.5 mass and the health relevance of PM2.5 measured by this method as compared to other measurements of PM2.5 parameters. Ammonium nitrate and semi-volatile organic compounds (SVOC) are significant components of fine particles in many urban atmospheres. These components however, are not properly measured by current EPA accepted methods, such as the PM2.5 FRM, due to loss of semi-volatile material (SVM) from the filter during sampling. Continuous PM2.5 mass measurements are attempted using methods such as the R&P TEOM monitor. This method however, heats the sample to remove particle-bound water. This results in evaporation of significant amounts of semi-volatile material. Similarly, continuous carbonaceous material monitors are expected to lose semi-volatile organic material during sample collection. Continuous RAMS and collocated TEOM monitor data have been obtained at the EMPACT sampling site in Salt lake City, Utah during a 2-year period. Results obtained for the continuous determination of total PM2.5 mass with the RAMS have been validated by comparison with results obtained from collocated PC-BOSS diffusion denuder integrated samples at the EMPACT sampling site in Salt Lake City, Utah during three intensive sampling periods (winter 1999–2000, summer 2000, and winter 2000–2001). While the RAMS is shown to measure total PM2.5, including semi-volatile nitrate and organic material, commercially available semi-continuous TEOM and C monitors do not reliably measure these species.

Lichens are known to accumulate airborne elements. This characteristic makes them useful as biomonitors of air quality. However, direct correlations of element concentrations in the air with element concentrations in lichen thalli are generally unavailable. The purpose of this study was to quantitatively examine the relationship between concentrations of copper in ambient air samples and thalli of foliose and fruticose lichens. Lichen samples from four sites along an air copper gradient were collected and analyzed. Foliose specimens consistently accumulated more than twice as much copper as fruticose specimens at all four sites. The relationship between copper concentrations in foliose and fruticose lichens and ambient air samples along an airborne copper gradient was examined using a stepwise regression model. An R2 value of (0.84) and an F-statistic of (182.5, p

PM2.5 mass was measured daily with three batch samplers, a PM2.5 R&P Partisol-Plus FRM, an Andersen RAAS, and a BYU PC-BOSS, and continuously with a TEOM monitor during July and August 2000. PM2.5 composition was also determined. These data are part of an ongoing PM2.5 characterization program centered around a sampling site at the National Energy Technology Laboratory Pittsburgh campus. The composition and concentrations of PM2.5 were both highly variable during this time period. Likely sources of PM2.5 during low concentration periods were transportation, coal-fired boiler, and other emissions generated in the local area. For these periods, the average concentration of PM2.5 was 13 μg/m3 and 70% of the PM2.5 mass was carbonaceous material, including semivolatile organic material that was lost in varying degrees from both the TEOM and FRM samplers. In contrast, much higher concentrations of PM2.5 were associated with transport of pollutants to the site. Analysis of meteorological and back-trajectory data...

The concentration and composition of PM2.5 has been measured with a variety of continuous and integrated samplers at the Hawthorne EPA Environmental Monitoring for Public Awareness and Community Tracking (EMPACT) sampling site in Salt Lake City, UT, and at an EPA Science to Achieve Results (STAR) sampling site in Bountiful, UT. Data are considered at both sites during a 10-day winter period with high PM2.5 concentrations due to winter inversions, and at the Hawthorne site only during a fourteen day summer period when the site was impacted by smoke from wildfires in the Wasatch Mountains. The PM2.5 was dominated by organic material and ammonium nitrate in the winter and by organic material in the summer. In both cases, substantial amounts of sem-volatile material, SVM, was present which was not measured by a Tapered Element Oscillating Microbalance (TEOM) monitor but was detected by a Real-Time Ambient Mass Sampler (RAMS). The PM2.5 data have been combined with concentrations of particulate soot and soil c...

Lichen samples were collected and observations about lichen communities were recorded at sites in the intermountain western United States. Specifically the states of Idaho, Montana, Wyoming, Nevada, Utah, Colorado, Arizona, and New Mexico were included in this study. The minor and trace-element concentrations in many of the lichens collected were determined by proton induced X-ray emission (PIXE). These data are part of a base line assessment of current air pollution conditions in this region. These data also provide an opportunity to study some aspects of lichen physiology. Using the data from 508 foliose and fruticose lichens, frequency distributions for concentrations of phosphorus and calcium are considered. Phosphorus has a closely-spaced, bimodal distribution: one mode for foliose lichens and one mode for fruticose lichens. This suggests that all lichen genera in this study have similar requirements and absorption mechanisms for phosphorus. Calcium has a complex frequency distribution and concentrations that range from 450 mg/kg to 14 % dry weight. Contributions to this complex distribution pattern can be understood if the data are resolved into growth form, genera within each growth form, and in some cases species within a given genus. This complex dependence on calcium is strong evidence that lichens develop specific calcium-related adaptations in order to accommodate various habitat conditions.

Total fluoride (gas plus fine particle), spherical aluminosilicate particles, particulate selenium, arsenic, lead, bromine, and absorption of light by fine particles have been used to characterize chemical profiles for sources of sulfur oxides impacting the Grand Canyon National Park Class I Visibility Region. During the Project MOHAVE (Measurement of Haze and Visual Effects) winter and summer intensive studies in 1992, these various species were determined at seven sampling sites in and around the Grand Canyon. Extensive upper air and surface-based meteorological measurements were examined to determine probable geographical origins of the air mass present during a given sampling period for each sampling site. Samples corresponding to air masses dominated by transport from a single major source region were used to determine a source profile for each region. Source regions which have been characterized by this analysis include the San Joaquin Valley area, the southern California coastal urban area, the Baja, California-Imperial Valley area, the Arizona and Mexico area (including major smelters) south of the Grand Canyon, the area southeast of the Grand Canyon, the Colorado Plateau area, the Wasatch Front in Utah, and the area in Nevada to the west and northwest of the Grand Canyon. Source profiles giving the ratio of each endemic marker to SO x for each identified regional source in these areas have been determined. The source profiles for the various regional sources are all statistically different and distinguishable from those for other geographically adjoining sources.

Thirty-six lichen samples that were collected from five wilderness areas and a national monument in the intermountain western United States have been analyzed by PIXE for the determination of 21 elements: P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Ba, and Pb. Samples were powdered and spiked with Y as an internal standard. The powder was analyzed directly as a sample of moderate thickness. Elemental concentration means and ranges were generally consistent with concentration ranges from other studies of unimpacted lichens. Some samples, however, had high concentrations of S, Cu, As, and a few other elements. There are interpretations of the data that imply some wilderness areas are being impacted to some degree by industrial-plant atmospheric emissions.

Fine particulate matter (PM2.5) concentrations associated with 202 24-hr samples collected at the National Energy Technology Laboratory (NETL) particulate matter (PM) characterization site in south Pittsburgh from October 1999 through September 2001 were used to apportion PM2.5 into primary and secondary contributions using Positive Matrix Factorization (PMF2). Input included the concentrations of PM2.5 mass determined with a Federal Reference Method (FRM) sampler, semi-volatile PM2.5 organic material, elemental carbon (EC), and trace element components of PM2.5. A total of 11 factors were identified. The results of potential source contributions function (PSCF) analysis using PMF2 factors and HYSPLIT-calculated back-trajectories were used to identify those factors associated with specific meteorological transport conditions. The 11 factors were identified as being associated with emissions from various specific regions and facilities including crustal material, gasoline combustion, diesel combustion, and three nearby sources high in trace metals. Three sources associated with transport from coal-fired power plants to the southeast, a combination of point sources to the northwest, and a steel mill and associated sources to the west were identified. In addition, two secondary-material-dominated sources were identified, one was associated with secondary products of local emissions and one was dominated by secondary ammonium sulfate transported to the NETL site from the west and southwest. Of these 11 factors, the four largest contributors to PM2.5 were the secondary transported material (dominated by ammonium sulfate) (47%), local secondary material (19%), diesel combustion emissions (10%), and gasoline combustion emissions (8%). The other seven factors accounted for the remaining 16% of the PM2.5 mass. The findings are consistent with the major source of PM2.5 in the Pittsburgh area being dominated by ammonium sulfate from distant transport and so decoupled from local activity emitting organic pollutants in the metropolitan area. In contrast, the major local secondary sources are dominated by organic material.