Development and Evaluation of a Personal Particulate Organic and Mass Sampler

Abstract

Accurate measurement of personal exposure to particulate matter and its constituents requires samplers that are accurate, compact, lightweight, inexpensive, and convenient to use. The Personal Particulate Organic and Mass Sampler (PPOMS) has been developed to meet these criteria. The PPOMS uses activated carbon-impregnated foam as a combined 2.5-µm size-selective inlet and denuder for assessment of fine particle mass and organic carbon. Proof of the PPOMS concept has been established by comparing mass and organic carbon in particles collected with collocated samplers in Seattle, at a central outdoor site, and in residences. Daily particulate mass concentrations averaged 10.0±5.2, 12.0±5.3, and 11.2±5.1 µg m -3 for the Federal Reference Method, the Harvard Personal Exposure Monitor, and the PPOMS, respectively, for 10 24-h sampling periods. During a series of PM 2.5 indoor organic carbon (OC) measurements from single quartz filters, the apparent indoor OC averaged 7.7±0.8 µg of C m -3 , which was close to the indoor PM 2.5 mass from collocated Teflon filters (7.3±2.3 µg of C m -3 ), indicating the presence of a large positive OC artifact. In collocated measurements, the PPOMS eliminated this artifact just as well as the Integrated Gas and Particle Sampler that incorporated a macroreticular polystyrene-divinylbenzene (XAD-4) resin-coated denuder, yielding OC concentrations of 2.5 ± 0.4 and 2.4 ± 1.0 µg C m -3 , respectively. Thermal analysis for OC indicated that the indoor positive artifact was due to adsorption of gas-phase semivolatile organic compounds SVOC. This study shows that the PPOMS design provides a 2.5-µm size-selective inlet that also prevents the adsorption of gas-phase SVOC onto quartz filters, thus eliminating the filter positive artifact. The PPOMS meets a significant current challenge for indoor and personal sampling of particulate organic carbon. The PPOMS design can also simplify accurate ambient sampling for PM 2.5 .

Improved Measurement of Seasonal and Diurnal Differences in the Carbonaceous Components of Urban Particulate Matter Using a Denuder-Based Air Sampler

“…The average nighttime FP-OC1 was 1.15 µg C/m 3 , compared to an average IOGAPS-OC1 of 0.37 µg C/m 3 . Our findings are consistent with results reported by Pang et al (2002c). They used two denuder-based samplers and a FP sampler to collect indoor PM 2.5 samples in May 2001 in Seattle, WA.…”

“…These have included the Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS; Eatough et al 2001) and the integrated organic gas and particle sampler (IOGAPS; Gundel et al 1995;Lewtas et al 2001;Pang et al 2002c). The IOGAPS, which was used in this study, collects the particles (i.e., PM 2.5 ) by a quartz filter placed downstream of a XAD-resin-coated denuder that functions to remove gas-phase organics.…”

Sources of Personal Exposure to Fine Particles in Toronto, Ontario, Canada

“…19,55 It has been reported that the indoor proportion of outdoor particles can vary from 5% to Ͼ90% depending on the ventilation status of a building. 55 For residences likely to be similar to those in this study (i.e., continuous central air conditioning and a standard furnace filter), Riley et al 54 calculated indoor proportion of outdoor particles of 44% for sulfate and 38% for EC. This suggests that although there appears to be some difference between these two particle-bound constituents, which may be because of differences in their size, it is not large.…”

“…38 In the case of OC sampling for personal exposure measurements positive artifacts are also known to be problematic. 54 It was believed that these negative and/or positive artifacts would significantly bias personal exposure measurements, because the particle load on sampled filters was very low. However, in this study, these sources of sampling bias could not be investigated, because collocated, unbiased measurements were not available.…”

Source Apportionment of Indoor, Outdoor, and Personal PM2.5in Seattle, Washington, Using Positive Matrix Factorization

“…21 Additional fixed 4-L/min HI 2.5 samplers were collocated both outdoors and indoors to measure particulate organic (OC) and elemental (EC) carbon on quartz filters via thermal optical transmittance using a modified version of the National Institute of Occupational Safety and Health method. 26,27 The particle light absorption coefficient (b ap ) on the Teflon filters was also measured using an integrating plate method. 28 -30 It is important to note that personal quartz filter samples were collected but suffered from various analysis problems, mainly a large positive sampling artifact for OC.…”