UNMIX modeling of ambient PM2.5 near an interstate highway in Cincinnati, OH, USA

Abstract

The "Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS)" is underway to determine if infants who are exposed to diesel engine exhaust particles are at an increased risk for atopy and atopic respiratory disorders, and to determine if this effect is magnified in a genetically at risk population. In support of this study, a methodology has been developed to allocate local traffic source contributions to ambient PM 2.5 in the Cincinnati airshed. As a first step towards this allocation, UNMIX was used to generate factors for ambient PM 2.5 at two sites near at interstate highway. Procedures adopted to collect, analyze and prepare the data sets to run UNMIX are described. The factors attributed to traffic sources were similar for the two sites. These factors were also similar to locally measured truck engine-exhaust enriched ambient profiles. The temporal variation of the factors was analyzed with clear differences observed between factors attributed to traffic sources and combustion-related regional secondary sources.

A Comparison of Proximity and Land Use Regression Traffic Exposure Models and Wheezing in Infants

“…The study’s purpose is to determine whether infants who are exposed to DEP are at an increased risk for developing atopy and allergic respiratory diseases and to determine whether this effect is modified in a genetically at-risk population. The study methods, population, and sampling methodology are described in detail elsewhere (Hu et al 2006; LeMasters et al 2006; Martuzevicius et al 2004; Ryan et al 2005). Briefly, eligible infants were identified from birth records, and the addresses obtained using these records were geocoded using EZLocate software (TeleAtlas Inc., Menlo Park, CA).…”

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

“…The number and direction of the edges derived from Unmix depend on the set of species used, and the solution is sensitive to the species included in the model. It has been successfully employed in various source attribution studies and generates results that compare well with other techniques (Hu et al, 2006;Chakraborty and Gupta, 2010;Mukerjee et al, 2004;Song et al, 2006).…”

Traffic Particles in Ambient Air of a Major US Urban Area: Has Anything Changed over a Decade?

“…The characteristics of these sites are presented in Table 1. The first site, referred to as DOWNTOWN, is located in a residential area of downtown Cincinnati and was previously identified to have high levels of EC attributable to traffic and EC attributable to diesel (Martuzevicius et al, 2004;Hu et al, 2006;Sahu et al, 2011). The second and third sites, GROOMS and NEWPORT, are respectively located on a road in a northern suburb and in Newport city, Kentucky, south of Ohio River.…”

“…The selection was based on our previous ambient aerosol measurements (Martuzevicius et al, 2004(Martuzevicius et al, , 2005, modeling (Hu et al, 2006) and DEP exposure assessment (Ryan et al, 2007). The characteristics of these sites are presented in Table 1.…”

“…Due to the CCAAPS original design, the earlier campaign (2002)(2003)(2004)(2005) featured different number of samples (n) collected at each site and subjected to different types of analysis; no attempt was made to stratify by season or account for daily wind variables. A total of n = 38 carbon samples were Martuzevicius et al (2004Martuzevicius et al ( , 2005, Hu et al (2006) and Ryan et al (2007). originally collected at DOWNTOWN, n = 15 at GROOMS, n = 4 at NEWPORT, and n=16 at MONT.…”