Cyclists’ exposure to air pollution: in situ evaluation with a cargo bike platform.

Carreras H, Ehrnsperger L, Klemm O, Paas B

Zusammenfassung

Cyclists' exposure to air pollutants near roadwayshas been associated with numerous health effects.While the adverse health effects concerning aerosolshave traditionally been assessed with data of particlemass concentrations, it appears that the number concentrationis also another important indicator of toxicity.Thus, to holistically evaluate one's exposure to aerosolparticles, assessments should be based on mass concentrationsand number concentrations. In order to assessindividual cyclists' exposure as they move throughspace and time, spatiotemporal high-resolution approachesare needed. Therefore, a mobile, fastresponsemonitoring platform was developed that usesa cargo bicycle as a base. Data of particle mass concentrations(PM1, PM2.5, PM10) and particle number concentrations(PN10) were collected along two differentroutes, one characterized by high-intensity vehicle trafficand one by low-intensity vehicle traffic. While highspatiotemporal heterogeneity was observed for all measuredquantities, the PN10 concentrations fluctuated themost. High concentrations of PN10 could be clearlyassociated with vehicle traffic. For PM2.5, this relationwas less pronounced. Mean particle concentrations ofall measures were significantly higher along the hightrafficroute. Comparing route exposures, the inhalationof PM2.5 was similar between both routes, whereasalong the high-traffic route, cyclists were exposed totwice the particle number. We conclude that the cargobike, featuring high-frequency mobile measurements,was useful to characterize the spatial distribution ofmass concentrations and number concentrations acrossan urban environment. Overall, our results suggest thatthe choice of route is a key factor in reducing cyclists'exposure to air pollution.