title: PMF analysis of wide-range particle size spectra collected on a major highway.
abstract: Particle number concentration data have been collected on a very busy road in central London (Marylebone Road). Continuous size distributions from 15 nm to 10 μm diameter, collected over 21 days, were analyzed using positive matrix factorization which identified 10 factors, five of which were observed to make major contributions (greater than 8%) to either the total number or volume of particulate matter. The sources associated with each factor were identified from the size distribution, directional association, diurnal variation and their relationship to meteorological pollution and traffic volume variables. The factors related to the emissions on Marylebone Road accounted for 40.5% of particle volume and 71.9% of particle number. These comprised nucleation mode exhaust particles (3.6% of total volume and 27.4% of total number), solid mode exhaust particles (18.8% of total volume and 38.0% of total number), brake dust (13.7% of total volume and 1.7% of total number and resuspension (4.4% of total volume and 4.8% of total number). Another six factors were associated with the urban background accounting for 59.5% of total volume and 28.2% of total particle number count. The method is extremely successful at separating the components of on-road emissions including brake wear and resuspension.
authors.affiliation: National Centre for Atmospheric Science, Division of Environmental Health & Risk Management, School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
authors.forename: Roy M
authors.initials: RM
authors.lastname: Harrison
authors.forename: David C S
authors.initials: DC
authors.lastname: Beddows
authors.forename: Manuel
authors.initials: M
authors.lastname: Dall'Osto
mesh_terms: D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D008131:London; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D025341:Principal Component Analysis; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D052638:Particulate Matter; D001335:Vehicle Emissions