Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2006;40(S2):378-395.
doi: 10.1016/j.atmosenv.2006.02.038.

UNMIX modeling of ambient PM(2.5) near an interstate highway in Cincinnati, OH, USA

Shaohua Hu  1 , Rafael McDonald, Dainius Martuzevicius, Pratim Biswas, Sergey A Grinshpun, Anna Kelley, Tiina Reponen, James Lockey, Grace Lemasters
Affiliations

UNMIX modeling of ambient PM(2.5) near an interstate highway in Cincinnati, OH, USA

Shaohua Hu et al. Atmos Environ (1994). 2006.

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.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Schematic diagram and aerial photograph of study area.
Fig. 2
Fig. 2
Box plots of EC/OC ratio at Lower Price Hill (N = 68) and Findlay (N = 39). Whiskers represent 5th and 95th percentiles with individual data points outside these thresholds denoted by open circles.
Fig. 3
Fig. 3
Plot of reconstructed PM2.5 mass concentrations based on speciated measurements against the gravimetric PM2.5 mass concentrations: (A) Findlay; and (B) LPH. The solid line is the 1:1 line. Samples deemed outliers for the purpose of UNMIX modeling are denoted by ‘×’.
Fig. 4
Fig. 4
Plot of measured EC concentration (NIOSH 5040 ECOC analysis on quartz filters) against absorption coefficients from reflectance measurements on Telfon filters for collocated samples. Solid line is the best-fit simple linear regression; dashed lines are the 95% confidence levels.
Fig. 5
Fig. 5
Scatter plots of various species concentrations (ng m-3) versus PM2.5 mass concentration (μg m-3) for the Findlay site.
Fig. 6
Fig. 6
Comparison of UNMIX-estimated traffic source profiles for various diesel engine emissions measurements. Normalized chemical profiles (sum of the identified weight = 1) of EC, OC, and sulfur.
Fig. 7
Fig. 7
(A) Daily average of PM2.5 mass contributions (μg m-3) at Findlay from the UNMIX-generated source profiles. (B) Monthly average PM2.5 mass contributions (μg m-3) at Findlay from the UNMIX-generated source profiles.
Fig. 8
Fig. 8
Monthly average PM2.5 mass contributions (μg m-3) at LPH from the UNMIX-generated source profiles.
See this image and copyright information in PMC

References

    1. Birch ME, Cary RA. Elemental carbon based method for monitoring occupational exposures to particulate diesel exhaust. Aerosol Science Technology. 1996;25:221–241. - PubMed
    1. Brunekreef B, Janssen NA, de Hartog J, Harssema H, Knape M, van Vliet P. Air pollution from truck traffic and lung function in children living near motorways. Epidemiology. 1997;8:298–303. - PubMed
    1. Cadle SH, Mulawa PA, Hunsanger EC, Nelson K, Ragazzi RA, Barrett R, Gallagher GL, Lawson DR, Knapp KT, Snow R. Composition of light-duty motor vehicle exhaust particulate matter in the Denver, Colorado area. Environmental Science and Technology. 1999;33(14):2328–2339. - PubMed
    1. Chen L-WA, Doddridge BG, Dickerson RR, Chow JC, Henry RC. Origins of fine aerosol mass in the Baltimore-Washington corridor: implications from observation, factor analysis, and ensemble air parcel back trajectories. Atmospheric Environment. 2002;36:4541–4554.
    1. Dockery DW, Pope DCA, III., Xu X, Spengler JD, Ware JH, Fay ME, Ferris BG, Speizer FE. An association between air pollution and mortality in six US cities. New England Journal of Medicine. 1993;329:1753–1759. - PubMed

LinkOut - more resources