Abstract
Fine Particulate Matter (PM₂․₅) has become a major issue in cities around the world as it adversely affects human health and the environment. This study aims to develop a deeper understanding of the impact of bicycle lanes designs on cyclist exposure to air pollution in a developing-country city. PM₂․₅ concentrations were measured along a predefined route with different bicycle lane designs in the city of Medellín, Colombia. The measurement campaign was made between October and December 2020 during peak and off-peak hours on weekdays, where a total of 29 bicycle trips were carried out. To obtain accurate measurements, we used a laser-based particle monitoring system. The study's findings reveal that the bicycle route section without dedicated bicycle lanes had the highest PM₂․₅ exposure and inhaled dose per kilometer traveled. The next highest exposure was observed in bike lanes that were separated from the road by a sidewalk, while the lowest exposure was in lanes separated by a road. Furthermore, the mean PM₂․₅ exposure for cyclists during the morning peak hours was higher (33.8 μg/m³) compared to the evening peak (16.1 μg/m³) and off-peak hours (11.1 μg/m³). The inhaled PM₂․₅ dose was three times higher during morning peak hours than during off-peak hours and twice as high during evening peak hours. These results show that segregated cycling lanes on the sidewalk can considerably lower PM₂․₅ exposure and inhaled doses for cyclists when compared to other lane designs, highlighting the significance of infrastructure development in supporting sustainable transportation and public health.