TY - JOUR
T1 - Emissions of organic compounds and trace metals in fine particulate matter from motor vehicles
T2 - A tunnel study in houston, Texas
AU - Chellam, Shankararaman
AU - Kulkarni, Pranav
AU - Fraser, Matthew P.
N1 - Funding Information:
This project has been funded entirely with funds from the state of Texas as part of the program of the Texas Air Research Center. The contents do not necessarily reflect the views and policies of the sponsor nor does the mention of trade names or commercial products constitute endorsement or recommendation for use. The authors also would like to thank Zhiwei Yue (Rice University); Gary McGaughey and David Allen (University of Texas); Bob Seila and Bill Lonneman (U.S. Environmental Protection Agency); and Rob Harley (University of California) for sample collection, analysis, and data interpretation during the Washburn tunnel study, which made this analysis possible. The authors also appreciate the detailed and constructive comments obtained during the peer review process.
PY - 2005/1
Y1 - 2005/1
N2 - Fine particulate matter (PM) samples collected in a highway tunnel in Houston, TX, were analyzed to quantify the concentrations of 14 n-alkanes, 12 polycyclic aromatic hydrocarbons, and nine petroleum biomarkers, as well as 21 metals, with the ultimate aim of identifying appropriate tracers for diesel engines. First, an exploratory multivariate dimensionality reduction technique called principal component analysis (PCA) was employed to identify all potential candidates for tracers. Next, emission indices were calculated to interpret PCA results physically. Emission indices of n-heneicosane, n-docosane, n-tricosane, n-tetracosane, n-pentacosane, fluoranthene, and pyrene were correlated highly and increased strongly with percentage carbon present in the tunnel emanating from diesel vehicles. This suggests that these organic compounds are useful molecular markers to separate emissions from diesel and gasoline engines. Additionally, the results are the first quantification of the metal composition of PM with aerodynamic diameters smaller than 2.5 [H9262]m (PM2.5) emissions from mobile sources in Houston. PCA of trace metal concentrations followed by emission index calculations revealed that barium in fine airborne particles can be linked quantitatively to diesel engine emissions, demonstrating its role as an elemental tracer for heavy-duty trucks.
AB - Fine particulate matter (PM) samples collected in a highway tunnel in Houston, TX, were analyzed to quantify the concentrations of 14 n-alkanes, 12 polycyclic aromatic hydrocarbons, and nine petroleum biomarkers, as well as 21 metals, with the ultimate aim of identifying appropriate tracers for diesel engines. First, an exploratory multivariate dimensionality reduction technique called principal component analysis (PCA) was employed to identify all potential candidates for tracers. Next, emission indices were calculated to interpret PCA results physically. Emission indices of n-heneicosane, n-docosane, n-tricosane, n-tetracosane, n-pentacosane, fluoranthene, and pyrene were correlated highly and increased strongly with percentage carbon present in the tunnel emanating from diesel vehicles. This suggests that these organic compounds are useful molecular markers to separate emissions from diesel and gasoline engines. Additionally, the results are the first quantification of the metal composition of PM with aerodynamic diameters smaller than 2.5 [H9262]m (PM2.5) emissions from mobile sources in Houston. PCA of trace metal concentrations followed by emission index calculations revealed that barium in fine airborne particles can be linked quantitatively to diesel engine emissions, demonstrating its role as an elemental tracer for heavy-duty trucks.
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U2 - 10.1080/10473289.2005.10464597
DO - 10.1080/10473289.2005.10464597
M3 - Article
C2 - 15704540
AN - SCOPUS:11344254688
SN - 1096-2247
VL - 55
SP - 60
EP - 72
JO - Journal of the Air and Waste Management Association
JF - Journal of the Air and Waste Management Association
IS - 1
ER -