An interdisciplinary approach was used to investigate the problem of urban particulate air pollution in a traffic corridor in Swansea, UK. Research in this area frequently focuses on one aspect of the problem, limiting the conclusions that can be drawn from the studies. In contrast, this study aimed to investigate many aspects of the problem, including particle number concentrations, the physicochemistry of these particles, and an assessment of their toxicological potentials. It was found that number concentrations of particles fluctuated in response to meteorological and vehicle conditions and that the way in which concentrations were affected varied between size fractions. Characterisation of the particles showed variability in terms of morphology and composition between the smallest (nano-sized) and largest (up to 10µm) particles; notably particle composition variability increased with increasing particle size, and relative carbon percentage decreased. The toxicological potential of the particle was identified as being a function of size, morphology and composition. Due to the interdisciplinary approach of the study, real insight could be gained into the potential impact of the particles upon local populations, and future work will focus on the spatial influence on particle number concentrations, chemistry and toxicity and bioreactivity.