Cuando las concentraciones son más altas, la dosis diaria promedio se duplica. Se encontró que las concentraciones de PM 2.5 son muy variables en términos de hora del día y temporada del año. Los puntos críticos se identificaron como las zonas en la ruta con concentraciones de tres desviaciones estándar por encima del promedio. La dosis diaria promedio de PM 2.5 se calculó con base en el tiempo promedio de exposición y el nivel de esfuerzo al usar la bicicleta. Diseñamos una ruta dentro del sistema de bicicletas compartidas de Medellín para evaluar concentraciones y la exposición de ciclistas a PM 2.5, las mediciones se realizaron con un sensor de bajo costo validado con información local.
Los ciclistas están expuestos al tráfico y a contaminantes en sus viajes por lo tanto, el análisis de concentraciones de contaminantes y la exposición de los usuarios es importante para planificar la expansión de estos sistemas. Los sistemas de bicicletas compartidas son una alternativa para promover el transporte sostenible y la vida activa. Keywords: Air pollution, environmental monitoring, environmental health, environmental management. The present results are key for the discussion leading to the implementation of measures that will improve the welfare of cyclists in Medellin, that may span from infrastructure intervention to early warning systems. There are two types of hotspot according to the built environment configuration on the route, and the concentrations in these hotspots are reaching values considered as harmful for sensitive population groups. When the concentrations are higher, the potential average daily dose is doubled. PM 2.5 concentrations were found to be highly variable in terms of hour of the day and season of the year. Hotspots were identified as the zones on the route with concentrations three standard deviations above the average for each route. Potential average daily dose of PM 2.5 was calculated based on the average time of exposure and the level of effort made by the user while riding. Measurements were carried out with a low-cost sensor validated with local information. In order to evaluate the concentrations and exposure of cyclists to PM 2.5, we designed a route within the bicycle sharing system of Medellin and implemented a sensor-based monitoring protocol. Bicycle users are exposed to traffic and to pollutants in their trips therefore, the analysis of pollutant concentrations and user exposure is of utmost importance for planning the expansion of creation of these transportation systems. Bicycle sharing systems are an alternative to promote sustainable transportation and active living.