[Pedestrian exposure to air pollution on routes with heavy vehicular traffic]

Objective This pilot study aimed to characterize pedestrians' exposure to air pollution alongside three routes with high traffic in Bogota, Colombia (ninth avenue, eleventh avenue and seventh avenue). Method Black carbon (BC) was used as an air quality indicator since it is recognized as a tracer compound for emissions from mobile sources. The concentrations of BC were recorded continuously with a portable Micro Aethalometer Model AE51. The instrument was carried by the people doing the 1.5 kilometer-long routes, while they filled in an activity form that recorded the events occurring during the walk. Results A direct (observed) relationship between BC concentration peaks and documented events at each route was found. Although BC concentrations at all three studied corridors indicate an inadequate air quality, different concentration distributions were found for each route. The authors attribute this result to the difference in the volume of heavy traffic (mainly buses and minibuses). Eleventh Avenue was the route with the greatest flow of such vehicles and higher concentrations of BC. Conclusion The collected evidence reinforces the importance of involving air quality as a critical variable when designing non-motorized transport oriented infrastructure.