Relationships of Outdoor and Indoor Ultrafine Particles at Residences Downwind of a Major International Border Crossing in Buffalo, NY

Fine and ultrafine particle removal efficiency of new residential HVAC filters

“…Google Scholar was used to search for the following terms: indoor concentration, particle size distribution, particle size characterization, SMPS, ultrafine particle emissions, and fine particle emissions. Sixteen studies reporting a total of 201 PSDs were selected for analysis through this procedure . Most of these studies (a) occurred in various European cities (with a few in the United States and Asia), (b) measured size‐resolved particle number concentrations in the range of 10 nm to 1000 nm, and (c) reported their results graphically in terms of dN/dlog D p versus the log of particle size, D p .…”

Penetration of ambient submicron particles into single-family residences and associations with building characteristics

“…Previous investigations of the penetration of outdoor airborne particulate matter have generally occurred in four forms, including: (i) modeling efforts (Liu and Nazaroff, 2001); (ii) laboratory measurements of building envelope structures (Liu and Nazaroff, 2003; Mosley et al., 2001); (iii) measurement of indoor–outdoor concentration ratios (or ‘infiltration factors’) during periods free of indoor sources (e.g., Abt et al., 2000; Bennett and Koutrakis, 2006; Bhangar et al., 2011; Fogh et al., 1997; McAuley et al., 2010), which are sometimes coupled with models to estimate penetration factors from measured data (e.g., Long et al., 2001; Lunden et al., 2003; Vette et al., 2001; Williams et al., 2003; Zhu et al., 2005); and (4) specific particle penetration methods applied in buildings (Chao et al., 2003; Rim et al., 2010; Thatcher and Layton, 1995; Thatcher et al., 2003). Chen and Zhao (2011) present an extensive review of many of these studies, but the previous studies on specific particle penetration methods provide the most relevant motivation for this work.…”

Physical processes of indoor aerosols in modern microenvironments

“…This finding is closely associated with particle dynamics, where, easier penetration and higher infiltration corresponds to particle sizes in the range 0.1 -0.5 μm (Bennett and Koutrakis 2006), whereas, infiltration of ultrafine particles is limited due to Brownian diffusion (Nazaroff 2004) and infiltration of coarse particles is likely less effective due inertial impaction and gravitational settling (Chen and Zhao 2001). Several studies that examined the contribution from outdoor sources to indoors confirm the present findings (Abt et al 2000;Long et al 2001;Matson 2005;Cao et al 2006;McAuley et al 2010;Chen and Zhao 2011;Stephens and Siegel 2012;Sangiorgi et al 2013;.…”

“…indicate a strong influence by the outdoor particulate matter indoors both in terms of number and mass concentration, when no major indoor source was present. Numerous studies have already highlighted the contribution from outdoor sources to indoor number and mass concentration (Abt et al 2000;Ferro et al 2004;Matson 2005;Cao et al 2006;McAuley et al 2010;Quang et al 2013;Sangiorgi et al 2013). In general, indoor particles both for number and for mass concentration data presented temporal fluctuations similar to the ones observed outdoors.…”