Detection and Characterization of Nanoparticles from Motor Vehicles

EPA Grant Number: R834677C173
Subproject: this is subproject number 173 , established and managed by the Center Director under grant R834677
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Health Effects Institute (2010 — 2015)
Center Director: Greenbaum, Daniel S.
Title: Detection and Characterization of Nanoparticles from Motor Vehicles
Investigators: Johnston, Murray V.
Institution: University of Delaware , Health Effects Institute (HEI)
EPA Project Officer: Hunt, Sherri
Project Period: April 1, 2010 through March 31, 2015
RFA: Health Effects Institute (2010) RFA Text |  Recipients Lists
Research Category: Health Effects , Air Quality and Air Toxics , Air


Ambient nanoparticles, particularly those ≤ 100 nm in diameter, are an important focus of research on the health effects of air pollution. Scientists have hypothesized that these particles may be more toxic than particulate matter ≤ 2.5 μm in aerodynamic diameter because of their physical characteristics and composition. To better identify human exposures and potential health effects associated with nanoparticles, a clearer understanding is needed of sources, atmospheric transport and chemical reactions, concentrations, and composition at the point of exposure.

Earlier research has identified motor vehicle traffic as an important source of nanoparticles. However, little is known about the formation, growth, and change in composition of particles within 100m of a roadway. Previously, Dr. Murray V. Johnston and colleagues developed an experimental instrument, the nano aerosol mass spectrometer (NAMS), to study individual nanoparticles (< 30nm) and analyze their major chemical components continuously. For the current investigation, they proposed to study nanoparticles near a major roadway intersection, to test and improve the instrument’s performance in a real-world setting, and to assess whether it could aid in identifying motor vehicles’ contribution to peak and ambient background nanoparticle concentrations.


Johnston and colleagues will conduct a field test of the NAMS at a major intersection in Wilmington, Delaware, through which approximately 28,000 vehicles pass daily. Monitoring will take place over two- to three-week periods during the summer and winter. The investigators will continuously measure particle number concentrations, size distributions, wind speed and direction, and sulfur dioxide concentrations and compare the results to those of two other methods that particles over longer averaging times but during the same monitoring period as the NAMS.

The investigators will use photographs from traffic cameras in conjunction with air monitoring data to differentiate heavy-duty diesel from gasoline-powered vehicles; to determine whether vehicles are  likely to be idling, accelerating, or decelerating; and to assess a vehicle’s contribution to nanoparticle levels at a particular moment in time. They will use a statistical method, “wavelet decomposition,” to differentiate short-term spikes in concentrations, thought to be caused by recent vehicle activities, from longer-term changes in background nanoparticle concentrations that may reflect regional sources, including traffic. The investigators will then apply the NAMS output to determine major source contributions to spikes and background levels, including distinguishing diesel from gasoline vehicles.

Expected Results:

The investigators believe that this study could both advance the refinement of nanoparticle speciation monitors and demonstrate their usefulness for apportioning vehicle contributions to nanoparticle concentrations in a near-roadway environment.

Supplemental Keywords:

Health Effects, Air Toxics, VOCs, urban air toxics, mobile-source air toxics, ambient nanoparticles, NAMS

Relevant Websites: Exit

Main Center Abstract and Reports:

R834677    Health Effects Institute (2010 — 2015)

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R834677C149 Development and Application of a Sensitive Method to Determine Concentrations of Acrolein and Other Carbonyls in Ambient Air
R834677C150 Mutagenicity of Stereochemical Configurations of 1,3-Butadiene Epoxy Metabolites in Human Cells
R834677C151 Biologic Effects of Inhaled Diesel Exhaust in Young and Old Mice: A Pilot Project
R834677C152 Evaluating Heterogeneity in Indoor and Outdoor Air Pollution Using Land-Use Regression and Constrained Factor Analysis
R834677C153 Improved Source Apportionment and Speciation of Low-Volume Particulate Matter Samples
R834677C155 The Impact of the Congestion Charging Scheme on Air Quality in London
R834677C156 Concentrations of Air Toxics in Motor Vehicle-Dominated Environments
R834677C158 Air Toxics Exposure from Vehicle Emissions at a U.S. Border Crossing: Buffalo Peace Bridge Study
R834677C159 Role of Neprilysin in Airway Inflammation Induced by Diesel Exhaust Emissions
R834677C160 Personal and Ambient Exposures to Air Toxics in Camden, New Jersey
R834677C162 Assessing the Impact of a Wood Stove Replacement Program on Air Quality and Children’s Health
R834677C163 The London Low Emission Zone Baseline Study
R834677C165 Effects of Controlled Exposure to Diesel Exhaust in Allergic Asthmatic Individuals
R834677C168 Evaluating the Effects of Title IV of the 1990 Clean Air Act Amendments on Air Quality
R834677C172 Potential Air Toxics Hot Spots in Truck Terminals and Cabs
R834677C173 Detection and Characterization of Nanoparticles from Motor Vehicles
R834677C174 Cardiorespiratory Biomarker Responses in Healthy Young Adults to Drastic Air Quality Changes Surrounding the 2008 Beijing Olympics