Objective Assessing the risk to health by inhaling particles and particle-bound PAH during daily commuting along a high traffic flow route/corridor in Bogota. Methods A van was equipped with a PAS2000 photo-electric sensor for real-time measurement of particle-bound PAH and a DustTrak for monitoring PM concentration; it drovealong typical commuting routes in the city. Exposure to particles and particle-bound PAH was assessed by using an inhalation intake model. Results A similar trend was observed for both PM and PAH concentration, indicating that traffic was the same source for both contaminants. Extreme PM and PAH inhalation concentrations were recorded every time direct bus and microbus emissions were measured by the van. Inhalation model results indicated that exposure was significantly greater when using avenues having mixed traffic use (i.e. buses, microbuses, passenger vehicles, motorcycles) compared to using roads where the Trans Milenio system (articulated buses) had been implemented. Conclusions The results may support evaluating bus drivers, commuters and bike users' exposure to toxic compounds in the city. 10 10 10