Using miniaturised scanning mobility particle sizers to observe size distribution patterns of quasi-ultrafine aerosols inhaled during city commuting.

Abstract Portable miniaturised scanning mobility particle sizer (SMPS) instruments measuring atmospheric particles within the 10-241nm size range were used to track particle number size distributions and concentrations during near-simultaneous pedestrian, bicycle, bus, car, tram and subway commuting journeys in Barcelona, Spain on 4th-6th July 2018. The majority of particles in this size range were 100nm (especially in the subway environment) and so lie outside the commonly defined range of “ultrafine” particles (UFP, or