Aerosol particle size distributions at a traffic exposed site and an urban background location in oporto, Portugal

Abstract

Aerosol size distributions from 6 to 700 nm were measured simultaneously at an urban background site ana a roadside station in Oporto. The particle number concentration was higher at the traffic exposea site, where up to 90% of the size spectrum was aominatea by the nucleation mode. Larger aerosol mode aiameters were observea in the urban backgrouna site possibly aue to the coagulation processes or uptake of gases during transport. Factor analysis has shown that road traffic ana the neighbour stationary sources localised upwind affect the urban area thought intra-regional pollutant transport.