Semicontinuous PM_2.5and PM₁₀Mass and Composition Measurements in Lindon, Utah, during Winter 2007

Abstract

The U.S. Environmental Protection Agency is promoting the development and application of sampling methods for the semicontinuous determination of fine particulate matter (PM 2.5 , particles with an aerodynamic diameter Ͻ2.5 m) mass and chemical composition. Data obtained with these methods will significantly improve the understanding of the primary sources, chemical conversion processes, and meteorological atmospheric processes that lead to observed PM 2.5 concentrations and will aid in the understanding of the etiology of PM 2.5 -related health effects. During January and February 2007, several semicontinuous particulate matter (PM) monitoring systems were compared at the Utah State Lindon Air Quality Sampling site. Semicontinuous monitors included instruments to measure total PM 2.5 mass (filter dynamic measurement system [FDMS] tapered element oscillating microbalance [TEOM], GRIMM), nonvolatile PM 2.5 mass (TEOM), sulfate and nitrate (two PM 2.5 and one PM 10 [PM with an aerodynamic diameter Ͻ10 m] ionchromatographic-based samplers), and black carbon (aethalometer). PM 10 semicontinuous mass measurements were made with GRIMM and TEOM instruments. These measurements were all made on a 1-hr average basis. Source apportionment analysis indicated that sources impacting the site were mainly urban sources and included mobile sources (gasoline and diesel) and residential burning of wood, with some elevated concentrations because of the effect of winter inversions. The FDMS TEOM and GRIMM instruments were in good agreement, but TEOM monitor measurements were low because of the presence of significant semi-volatile material. Semi-volatile mass was present dominantly in the PM 2.5 mass.

Receptor model source attributions for Utah's Salt Lake City airshed and the impacts of wintertime secondary ammonium nitrate and ammonium chloride aerosol

“…Source apportionment is performed using two receptor models, PMF and Unmix, and model results are compared to each other as well as to emissions inventories. Analysis of chemically speciated PM 2.5 in this work and in previous studies (Hansen et al, 2010, Mangelson et al, 1997 indicates that the largest contribution to PM 2.5 on winter days that exceed the National Ambient Air Quality Standard comes from secondary ammonium nitrate aerosol. However, the source apportionment and monitoring data analyses presented in this work also demonstrate that secondary ammonium chloride aerosol is a significant source of wintertime PM 2.5 at all three monitoring locations.…”

“…The presence of significant concentrations of ammonium chloride aerosol in the Wasatch Front airshed has not previously been identified. The study by Hansen et al (2010) did identify elevated aerosol chlorine in their winter 2007 measurements, but lacking cation measurements, they made the assumption that the chlorine was associated with aerosolized sodium chloride from entrained road salt. In the work presented here, we determine that the majority of the chlorine is associated with secondary ammonium chloride rather than primary sodium chloride.…”

“…Several previous studies have examined the sources of fine particulate matter along the Wasatch Front; however, compared to this work these studies used data that spanned a brief time period, on the order of weeks. Hansen et al (2010) collected speciated hourly PM 2.5 data at the Utah Division of Air Quality (UDAQ) Lindon air monitoring station for 10 days during the winter of 2007 and performed a source apportionment study using the positive matrix factorization (PMF) model. Their model results identified the following four primary sources, mobile diesel, mobile gasoline, wood smoke, and road dust, and the following secondary sources: sulfate, nitrate, organic matter, and aged wood smoke.…”

Comparisons of PM10, PM2.5, Particle Number, and CO2 Levels inside Metro Trains between Traveling in Underground Tunnels and on Elevated Tracks

“…However, the Grimm OPC provides good temporal resolution of particle mass size distribution. In previous studies, PM measurement results obtained by a Grimm OPC approximated (± 15%) those of a reference sampler at urban sites (Chan et al, 2004;Giugliano et al, 2005;Grimm and Eatough, 2009;Cheng and Li, 2010;Hansen et al 2010;. In this study, the measured particle mass size distribution was determined using DistFit software (Chimera Tech., Inc., Forest Lake, MN, USA), and the PM 10 and PM 2.5 levels were calculated as fractions of particle mass size distribution (Cheng and Lin, 2010).…”

Spatial and temporal variations of the concentrations of PM<sub>10</sub>, PM<sub>2.5</sub> and PM<sub>1</sub> in China

“…The PM concentration results from the GRIMM instruments were compared to those from tapered element oscillating microbalance (TEOM) instruments reported in a number of other studies (Grimm and Eatough, 2009;Hansen et al, 2010). The instruments were in good agreement; linear regression with TEOM data from Rubidoux (California, USA) yielded a slope of 1.10 ± 0.05, with an intercept of −3.9 ± 4.2 µg m −3 and an uncertainty of 9.9 % (Grimm and Eatough, 2009).…”