Nanoparticle emissions on Minnesota highways

• Published in: Atmospheric environment (1994) 2004, Vol.38 (1), p.9-19
• Main Authors: Kittelson, D.B., Watts, W.F., Johnson, J.P.
• Format: Article
• Language: English
• Subjects: Aerosols; Air quality; Applied sciences; Atmospheric pollution; Emission; Exact sciences and technology; Highways; Nanoparticles; Nuclei mode; On-road measurements; Particle size; Particle size distribution; Particulate matter; Pollution; Pollution sources. Measurement results; Roads; Traffic engineering; Traffic flow; Transports; Variations; Vehicles
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2003.09.037

The objective of this project was to characterize on-road aerosol on highways surrounding the Minneapolis area. Data were collected under varying on-road traffic conditions and in residential areas to determine the impact of highway traffic on air quality. The study was focused on determining on-road nanoparticle concentrations, and estimating fuel-specific and particle emissions km −1. On-road aerosol number concentrations ranged from 10 4 to 10 6 particles cm −3. The highest nanoparticle concentrations were associated with high-speed traffic. At high vehicular speeds engine load, exhaust temperature, and exhaust flow all increase resulting in higher emissions. Less variation was observed in particle volume, a surrogate measure of particle mass. Most of the particles added by the on-road fleet were below 50 nm in diameter. Particles in this size range may dominate particle number, but contribute little to particle volume or mass. Furthermore, particle number is strongly influenced by nucleation and coagulation, which have little or no effect on particle volume. Measurements made in heavy traffic, speeds